~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP M68000 Hi-Performance Microprocessor Division M68060 Software Package Production Release P1.00 -- October 10, 1994 M68060 Software Package Copyright © 1993, 1994 Motorola Inc. All rights reserved. THE SOFTWARE is provided on an "AS IS" basis and without warranty. To the maximum extent permitted by applicable law, MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE and any warranty against infringement with regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF) and any accompanying written materials. To the maximum extent permitted by applicable law, IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE. Motorola assumes no responsibility for the maintenance and support of the SOFTWARE. You are hereby granted a copyright license to use, modify, and distribute the SOFTWARE so long as this entire notice is retained without alteration in any modified and/or redistributed versions, and that such modified versions are clearly identified as such. No licenses are granted by implication, estoppel or otherwise under any patents or trademarks of Motorola, Inc. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # freal.s: # This file is appended to the top of the 060FPSP package # and contains the entry points into the package. The user, in # effect, branches to one of the branch table entries located # after _060FPSP_TABLE. # Also, subroutine stubs exist in this file (_fpsp_done for # example) that are referenced by the FPSP package itself in order # to call a given routine. The stub routine actually performs the # callout. The FPSP code does a "bsr" to the stub routine. This # extra layer of hierarchy adds a slight performance penalty but # it makes the FPSP code easier to read and more mainatinable. # set _off_bsun, 0x00 set _off_snan, 0x04 set _off_operr, 0x08 set _off_ovfl, 0x0c set _off_unfl, 0x10 set _off_dz, 0x14 set _off_inex, 0x18 set _off_fline, 0x1c set _off_fpu_dis, 0x20 set _off_trap, 0x24 set _off_trace, 0x28 set _off_access, 0x2c set _off_done, 0x30 set _off_imr, 0x40 set _off_dmr, 0x44 set _off_dmw, 0x48 set _off_irw, 0x4c set _off_irl, 0x50 set _off_drb, 0x54 set _off_drw, 0x58 set _off_drl, 0x5c set _off_dwb, 0x60 set _off_dww, 0x64 set _off_dwl, 0x68 _060FPSP_TABLE: ############################################################### # Here's the table of ENTRY POINTS for those linking the package. bra.l _fpsp_snan short 0x0000 bra.l _fpsp_operr short 0x0000 bra.l _fpsp_ovfl short 0x0000 bra.l _fpsp_unfl short 0x0000 bra.l _fpsp_dz short 0x0000 bra.l _fpsp_inex short 0x0000 bra.l _fpsp_fline short 0x0000 bra.l _fpsp_unsupp short 0x0000 bra.l _fpsp_effadd short 0x0000 space 56 ############################################################### global _fpsp_done _fpsp_done: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_done,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_ovfl _real_ovfl: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_ovfl,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_unfl _real_unfl: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_unfl,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_inex _real_inex: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_inex,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_bsun _real_bsun: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_bsun,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_operr _real_operr: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_operr,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_snan _real_snan: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_snan,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_dz _real_dz: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_dz,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_fline _real_fline: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_fline,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_fpu_disabled _real_fpu_disabled: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_fpu_dis,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_trap _real_trap: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_trap,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_trace _real_trace: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_trace,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _real_access _real_access: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_access,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 ####################################### global _imem_read _imem_read: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_imr,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_read _dmem_read: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_dmr,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_write _dmem_write: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_dmw,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _imem_read_word _imem_read_word: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_irw,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _imem_read_long _imem_read_long: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_irl,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_read_byte _dmem_read_byte: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_drb,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_read_word _dmem_read_word: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_drw,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_read_long _dmem_read_long: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_drl,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_write_byte _dmem_write_byte: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_dwb,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_write_word _dmem_write_word: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_dww,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 global _dmem_write_long _dmem_write_long: mov.l %d0,-(%sp) mov.l (_060FPSP_TABLE-0x80+_off_dwl,%pc),%d0 pea.l (_060FPSP_TABLE-0x80,%pc,%d0) mov.l 0x4(%sp),%d0 rtd &0x4 # # This file contains a set of define statements for constants # in order to promote readability within the corecode itself. # set LOCAL_SIZE, 192 # stack frame size(bytes) set LV, -LOCAL_SIZE # stack offset set EXC_SR, 0x4 # stack status register set EXC_PC, 0x6 # stack pc set EXC_VOFF, 0xa # stacked vector offset set EXC_EA, 0xc # stacked set EXC_FP, 0x0 # frame pointer set EXC_AREGS, -68 # offset of all address regs set EXC_DREGS, -100 # offset of all data regs set EXC_FPREGS, -36 # offset of all fp regs set EXC_A7, EXC_AREGS+(7*4) # offset of saved a7 set OLD_A7, EXC_AREGS+(6*4) # extra copy of saved a7 set EXC_A6, EXC_AREGS+(6*4) # offset of saved a6 set EXC_A5, EXC_AREGS+(5*4) set EXC_A4, EXC_AREGS+(4*4) set EXC_A3, EXC_AREGS+(3*4) set EXC_A2, EXC_AREGS+(2*4) set EXC_A1, EXC_AREGS+(1*4) set EXC_A0, EXC_AREGS+(0*4) set EXC_D7, EXC_DREGS+(7*4) set EXC_D6, EXC_DREGS+(6*4) set EXC_D5, EXC_DREGS+(5*4) set EXC_D4, EXC_DREGS+(4*4) set EXC_D3, EXC_DREGS+(3*4) set EXC_D2, EXC_DREGS+(2*4) set EXC_D1, EXC_DREGS+(1*4) set EXC_D0, EXC_DREGS+(0*4) set EXC_FP0, EXC_FPREGS+(0*12) # offset of saved fp0 set EXC_FP1, EXC_FPREGS+(1*12) # offset of saved fp1 set EXC_FP2, EXC_FPREGS+(2*12) # offset of saved fp2 (not used) set FP_SCR1, LV+80 # fp scratch 1 set FP_SCR1_EX, FP_SCR1+0 set FP_SCR1_SGN, FP_SCR1+2 set FP_SCR1_HI, FP_SCR1+4 set FP_SCR1_LO, FP_SCR1+8 set FP_SCR0, LV+68 # fp scratch 0 set FP_SCR0_EX, FP_SCR0+0 set FP_SCR0_SGN, FP_SCR0+2 set FP_SCR0_HI, FP_SCR0+4 set FP_SCR0_LO, FP_SCR0+8 set FP_DST, LV+56 # fp destination operand set FP_DST_EX, FP_DST+0 set FP_DST_SGN, FP_DST+2 set FP_DST_HI, FP_DST+4 set FP_DST_LO, FP_DST+8 set FP_SRC, LV+44 # fp source operand set FP_SRC_EX, FP_SRC+0 set FP_SRC_SGN, FP_SRC+2 set FP_SRC_HI, FP_SRC+4 set FP_SRC_LO, FP_SRC+8 set USER_FPIAR, LV+40 # FP instr address register set USER_FPSR, LV+36 # FP status register set FPSR_CC, USER_FPSR+0 # FPSR condition codes set FPSR_QBYTE, USER_FPSR+1 # FPSR qoutient byte set FPSR_EXCEPT, USER_FPSR+2 # FPSR exception status byte set FPSR_AEXCEPT, USER_FPSR+3 # FPSR accrued exception byte set USER_FPCR, LV+32 # FP control register set FPCR_ENABLE, USER_FPCR+2 # FPCR exception enable set FPCR_MODE, USER_FPCR+3 # FPCR rounding mode control set L_SCR3, LV+28 # integer scratch 3 set L_SCR2, LV+24 # integer scratch 2 set L_SCR1, LV+20 # integer scratch 1 set STORE_FLG, LV+19 # flag: operand store (ie. not fcmp/ftst) set EXC_TEMP2, LV+24 # temporary space set EXC_TEMP, LV+16 # temporary space set DTAG, LV+15 # destination operand type set STAG, LV+14 # source operand type set SPCOND_FLG, LV+10 # flag: special case (see below) set EXC_CC, LV+8 # saved condition codes set EXC_EXTWPTR, LV+4 # saved current PC (active) set EXC_EXTWORD, LV+2 # saved extension word set EXC_CMDREG, LV+2 # saved extension word set EXC_OPWORD, LV+0 # saved operation word ################################ # Helpful macros set FTEMP, 0 # offsets within an set FTEMP_EX, 0 # extended precision set FTEMP_SGN, 2 # value saved in memory. set FTEMP_HI, 4 set FTEMP_LO, 8 set FTEMP_GRS, 12 set LOCAL, 0 # offsets within an set LOCAL_EX, 0 # extended precision set LOCAL_SGN, 2 # value saved in memory. set LOCAL_HI, 4 set LOCAL_LO, 8 set LOCAL_GRS, 12 set DST, 0 # offsets within an set DST_EX, 0 # extended precision set DST_HI, 4 # value saved in memory. set DST_LO, 8 set SRC, 0 # offsets within an set SRC_EX, 0 # extended precision set SRC_HI, 4 # value saved in memory. set SRC_LO, 8 set SGL_LO, 0x3f81 # min sgl prec exponent set SGL_HI, 0x407e # max sgl prec exponent set DBL_LO, 0x3c01 # min dbl prec exponent set DBL_HI, 0x43fe # max dbl prec exponent set EXT_LO, 0x0 # min ext prec exponent set EXT_HI, 0x7ffe # max ext prec exponent set EXT_BIAS, 0x3fff # extended precision bias set SGL_BIAS, 0x007f # single precision bias set DBL_BIAS, 0x03ff # double precision bias set NORM, 0x00 # operand type for STAG/DTAG set ZERO, 0x01 # operand type for STAG/DTAG set INF, 0x02 # operand type for STAG/DTAG set QNAN, 0x03 # operand type for STAG/DTAG set DENORM, 0x04 # operand type for STAG/DTAG set SNAN, 0x05 # operand type for STAG/DTAG set UNNORM, 0x06 # operand type for STAG/DTAG ################## # FPSR/FPCR bits # ################## set neg_bit, 0x3 # negative result set z_bit, 0x2 # zero result set inf_bit, 0x1 # infinite result set nan_bit, 0x0 # NAN result set q_sn_bit, 0x7 # sign bit of quotient byte set bsun_bit, 7 # branch on unordered set snan_bit, 6 # signalling NAN set operr_bit, 5 # operand error set ovfl_bit, 4 # overflow set unfl_bit, 3 # underflow set dz_bit, 2 # divide by zero set inex2_bit, 1 # inexact result 2 set inex1_bit, 0 # inexact result 1 set aiop_bit, 7 # accrued inexact operation bit set aovfl_bit, 6 # accrued overflow bit set aunfl_bit, 5 # accrued underflow bit set adz_bit, 4 # accrued dz bit set ainex_bit, 3 # accrued inexact bit ############################# # FPSR individual bit masks # ############################# set neg_mask, 0x08000000 # negative bit mask (lw) set inf_mask, 0x02000000 # infinity bit mask (lw) set z_mask, 0x04000000 # zero bit mask (lw) set nan_mask, 0x01000000 # nan bit mask (lw) set neg_bmask, 0x08 # negative bit mask (byte) set inf_bmask, 0x02 # infinity bit mask (byte) set z_bmask, 0x04 # zero bit mask (byte) set nan_bmask, 0x01 # nan bit mask (byte) set bsun_mask, 0x00008000 # bsun exception mask set snan_mask, 0x00004000 # snan exception mask set operr_mask, 0x00002000 # operr exception mask set ovfl_mask, 0x00001000 # overflow exception mask set unfl_mask, 0x00000800 # underflow exception mask set dz_mask, 0x00000400 # dz exception mask set inex2_mask, 0x00000200 # inex2 exception mask set inex1_mask, 0x00000100 # inex1 exception mask set aiop_mask, 0x00000080 # accrued illegal operation set aovfl_mask, 0x00000040 # accrued overflow set aunfl_mask, 0x00000020 # accrued underflow set adz_mask, 0x00000010 # accrued divide by zero set ainex_mask, 0x00000008 # accrued inexact ###################################### # FPSR combinations used in the FPSP # ###################################### set dzinf_mask, inf_mask+dz_mask+adz_mask set opnan_mask, nan_mask+operr_mask+aiop_mask set nzi_mask, 0x01ffffff #clears N, Z, and I set unfinx_mask, unfl_mask+inex2_mask+aunfl_mask+ainex_mask set unf2inx_mask, unfl_mask+inex2_mask+ainex_mask set ovfinx_mask, ovfl_mask+inex2_mask+aovfl_mask+ainex_mask set inx1a_mask, inex1_mask+ainex_mask set inx2a_mask, inex2_mask+ainex_mask set snaniop_mask, nan_mask+snan_mask+aiop_mask set snaniop2_mask, snan_mask+aiop_mask set naniop_mask, nan_mask+aiop_mask set neginf_mask, neg_mask+inf_mask set infaiop_mask, inf_mask+aiop_mask set negz_mask, neg_mask+z_mask set opaop_mask, operr_mask+aiop_mask set unfl_inx_mask, unfl_mask+aunfl_mask+ainex_mask set ovfl_inx_mask, ovfl_mask+aovfl_mask+ainex_mask ######### # misc. # ######### set rnd_stky_bit, 29 # stky bit pos in longword set sign_bit, 0x7 # sign bit set signan_bit, 0x6 # signalling nan bit set sgl_thresh, 0x3f81 # minimum sgl exponent set dbl_thresh, 0x3c01 # minimum dbl exponent set x_mode, 0x0 # extended precision set s_mode, 0x4 # single precision set d_mode, 0x8 # double precision set rn_mode, 0x0 # round-to-nearest set rz_mode, 0x1 # round-to-zero set rm_mode, 0x2 # round-tp-minus-infinity set rp_mode, 0x3 # round-to-plus-infinity set mantissalen, 64 # length of mantissa in bits set BYTE, 1 # len(byte) == 1 byte set WORD, 2 # len(word) == 2 bytes set LONG, 4 # len(longword) == 2 bytes set BSUN_VEC, 0xc0 # bsun vector offset set INEX_VEC, 0xc4 # inexact vector offset set DZ_VEC, 0xc8 # dz vector offset set UNFL_VEC, 0xcc # unfl vector offset set OPERR_VEC, 0xd0 # operr vector offset set OVFL_VEC, 0xd4 # ovfl vector offset set SNAN_VEC, 0xd8 # snan vector offset ########################### # SPecial CONDition FLaGs # ########################### set ftrapcc_flg, 0x01 # flag bit: ftrapcc exception set fbsun_flg, 0x02 # flag bit: bsun exception set mia7_flg, 0x04 # flag bit: (a7)+ set mda7_flg, 0x08 # flag bit: -(a7) set fmovm_flg, 0x40 # flag bit: fmovm instruction set immed_flg, 0x80 # flag bit: & set ftrapcc_bit, 0x0 set fbsun_bit, 0x1 set mia7_bit, 0x2 set mda7_bit, 0x3 set immed_bit, 0x7 ################################## # TRANSCENDENTAL "LAST-OP" FLAGS # ################################## set FMUL_OP, 0x0 # fmul instr performed last set FDIV_OP, 0x1 # fdiv performed last set FADD_OP, 0x2 # fadd performed last set FMOV_OP, 0x3 # fmov performed last ############# # CONSTANTS # ############# T1: long 0x40C62D38,0xD3D64634 # 16381 LOG2 LEAD T2: long 0x3D6F90AE,0xB1E75CC7 # 16381 LOG2 TRAIL PI: long 0x40000000,0xC90FDAA2,0x2168C235,0x00000000 PIBY2: long 0x3FFF0000,0xC90FDAA2,0x2168C235,0x00000000 TWOBYPI: long 0x3FE45F30,0x6DC9C883 ######################################################################### # XDEF **************************************************************** # # _fpsp_ovfl(): 060FPSP entry point for FP Overflow exception. # # # # This handler should be the first code executed upon taking the # # FP Overflow exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword # # fix_skewed_ops() - adjust src operand in fsave frame # # set_tag_x() - determine optype of src/dst operands # # store_fpreg() - store opclass 0 or 2 result to FP regfile # # unnorm_fix() - change UNNORM operands to NORM or ZERO # # load_fpn2() - load dst operand from FP regfile # # fout() - emulate an opclass 3 instruction # # tbl_unsupp - add of table of emulation routines for opclass 0,2 # # _fpsp_done() - "callout" for 060FPSP exit (all work done!) # # _real_ovfl() - "callout" for Overflow exception enabled code # # _real_inex() - "callout" for Inexact exception enabled code # # _real_trace() - "callout" for Trace exception code # # # # INPUT *************************************************************** # # - The system stack contains the FP Ovfl exception stack frame # # - The fsave frame contains the source operand # # # # OUTPUT ************************************************************** # # Overflow Exception enabled: # # - The system stack is unchanged # # - The fsave frame contains the adjusted src op for opclass 0,2 # # Overflow Exception disabled: # # - The system stack is unchanged # # - The "exception present" flag in the fsave frame is cleared # # # # ALGORITHM *********************************************************** # # On the 060, if an FP overflow is present as the result of any # # instruction, the 060 will take an overflow exception whether the # # exception is enabled or disabled in the FPCR. For the disabled case, # # This handler emulates the instruction to determine what the correct # # default result should be for the operation. This default result is # # then stored in either the FP regfile, data regfile, or memory. # # Finally, the handler exits through the "callout" _fpsp_done() # # denoting that no exceptional conditions exist within the machine. # # If the exception is enabled, then this handler must create the # # exceptional operand and plave it in the fsave state frame, and store # # the default result (only if the instruction is opclass 3). For # # exceptions enabled, this handler must exit through the "callout" # # _real_ovfl() so that the operating system enabled overflow handler # # can handle this case. # # Two other conditions exist. First, if overflow was disabled # # but the inexact exception was enabled, this handler must exit # # through the "callout" _real_inex() regardless of whether the result # # was inexact. # # Also, in the case of an opclass three instruction where # # overflow was disabled and the trace exception was enabled, this # # handler must exit through the "callout" _real_trace(). # # # ######################################################################### global _fpsp_ovfl _fpsp_ovfl: #$# sub.l &24,%sp # make room for src/dst link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # grab the "busy" frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # the FPIAR holds the "current PC" of the faulting instruction mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) ############################################################################## btst &0x5,EXC_CMDREG(%a6) # is instr an fmove out? bne.w fovfl_out lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l fix_skewed_ops # fix src op # since, I believe, only NORMs and DENORMs can come through here, # maybe we can avoid the subroutine call. lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l set_tag_x # tag the operand type mov.b %d0,STAG(%a6) # maybe NORM,DENORM # bit five of the fp extension word separates the monadic and dyadic operations # that can pass through fpsp_ovfl(). remember that fcmp, ftst, and fsincos # will never take this exception. btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? beq.b fovfl_extract # monadic bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg bsr.l load_fpn2 # load dst into FP_DST lea FP_DST(%a6),%a0 # pass: ptr to dst op bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b fovfl_op2_done # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO fovfl_op2_done: mov.b %d0,DTAG(%a6) # save dst optype tag fovfl_extract: #$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) #$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) #$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) #$# mov.l FP_DST_EX(%a6),TRAP_DSTOP_EX(%a6) #$# mov.l FP_DST_HI(%a6),TRAP_DSTOP_HI(%a6) #$# mov.l FP_DST_LO(%a6),TRAP_DSTOP_LO(%a6) clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode mov.b 1+EXC_CMDREG(%a6),%d1 andi.w &0x007f,%d1 # extract extension andi.l &0x00ff01ff,USER_FPSR(%a6) # zero all but accured field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr lea FP_SRC(%a6),%a0 lea FP_DST(%a6),%a1 # maybe we can make these entry points ONLY the OVFL entry points of each routine. mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr jsr (tbl_unsupp.l,%pc,%d1.l*1) # the operation has been emulated. the result is in fp0. # the EXOP, if an exception occurred, is in fp1. # we must save the default result regardless of whether # traps are enabled or disabled. bfextu EXC_CMDREG(%a6){&6:&3},%d0 bsr.l store_fpreg # the exceptional possibilities we have left ourselves with are ONLY overflow # and inexact. and, the inexact is such that overflow occurred and was disabled # but inexact was enabled. btst &ovfl_bit,FPCR_ENABLE(%a6) bne.b fovfl_ovfl_on btst &inex2_bit,FPCR_ENABLE(%a6) bne.b fovfl_inex_on fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 #$# add.l &24,%sp bra.l _fpsp_done # overflow is enabled AND overflow, of course, occurred. so, we have the EXOP # in fp1. now, simply jump to _real_ovfl()! fovfl_ovfl_on: fmovm.x &0x40,FP_SRC(%a6) # save EXOP (fp1) to stack mov.w &0xe005,2+FP_SRC(%a6) # save exc status fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # do this after fmovm,other fs! unlk %a6 bra.l _real_ovfl # overflow occurred but is disabled. meanwhile, inexact is enabled. Therefore, # we must jump to real_inex(). fovfl_inex_on: fmovm.x &0x40,FP_SRC(%a6) # save EXOP (fp1) to stack mov.b &0xc4,1+EXC_VOFF(%a6) # vector offset = 0xc4 mov.w &0xe001,2+FP_SRC(%a6) # save exc status fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # do this after fmovm,other fs! unlk %a6 bra.l _real_inex ######################################################################## fovfl_out: #$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) #$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) #$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) # the src operand is definitely a NORM(!), so tag it as such mov.b &NORM,STAG(%a6) # set src optype tag clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode and.l &0xffff00ff,USER_FPSR(%a6) # zero all but accured field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr lea FP_SRC(%a6),%a0 # pass ptr to src operand bsr.l fout btst &ovfl_bit,FPCR_ENABLE(%a6) bne.w fovfl_ovfl_on btst &inex2_bit,FPCR_ENABLE(%a6) bne.w fovfl_inex_on fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 #$# add.l &24,%sp btst &0x7,(%sp) # is trace on? beq.l _fpsp_done # no fmov.l %fpiar,0x8(%sp) # "Current PC" is in FPIAR mov.w &0x2024,0x6(%sp) # stk fmt = 0x2; voff = 0x024 bra.l _real_trace ######################################################################### # XDEF **************************************************************** # # _fpsp_unfl(): 060FPSP entry point for FP Underflow exception. # # # # This handler should be the first code executed upon taking the # # FP Underflow exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword # # fix_skewed_ops() - adjust src operand in fsave frame # # set_tag_x() - determine optype of src/dst operands # # store_fpreg() - store opclass 0 or 2 result to FP regfile # # unnorm_fix() - change UNNORM operands to NORM or ZERO # # load_fpn2() - load dst operand from FP regfile # # fout() - emulate an opclass 3 instruction # # tbl_unsupp - add of table of emulation routines for opclass 0,2 # # _fpsp_done() - "callout" for 060FPSP exit (all work done!) # # _real_ovfl() - "callout" for Overflow exception enabled code # # _real_inex() - "callout" for Inexact exception enabled code # # _real_trace() - "callout" for Trace exception code # # # # INPUT *************************************************************** # # - The system stack contains the FP Unfl exception stack frame # # - The fsave frame contains the source operand # # # # OUTPUT ************************************************************** # # Underflow Exception enabled: # # - The system stack is unchanged # # - The fsave frame contains the adjusted src op for opclass 0,2 # # Underflow Exception disabled: # # - The system stack is unchanged # # - The "exception present" flag in the fsave frame is cleared # # # # ALGORITHM *********************************************************** # # On the 060, if an FP underflow is present as the result of any # # instruction, the 060 will take an underflow exception whether the # # exception is enabled or disabled in the FPCR. For the disabled case, # # This handler emulates the instruction to determine what the correct # # default result should be for the operation. This default result is # # then stored in either the FP regfile, data regfile, or memory. # # Finally, the handler exits through the "callout" _fpsp_done() # # denoting that no exceptional conditions exist within the machine. # # If the exception is enabled, then this handler must create the # # exceptional operand and plave it in the fsave state frame, and store # # the default result (only if the instruction is opclass 3). For # # exceptions enabled, this handler must exit through the "callout" # # _real_unfl() so that the operating system enabled overflow handler # # can handle this case. # # Two other conditions exist. First, if underflow was disabled # # but the inexact exception was enabled and the result was inexact, # # this handler must exit through the "callout" _real_inex(). # # was inexact. # # Also, in the case of an opclass three instruction where # # underflow was disabled and the trace exception was enabled, this # # handler must exit through the "callout" _real_trace(). # # # ######################################################################### global _fpsp_unfl _fpsp_unfl: #$# sub.l &24,%sp # make room for src/dst link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # grab the "busy" frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # the FPIAR holds the "current PC" of the faulting instruction mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) ############################################################################## btst &0x5,EXC_CMDREG(%a6) # is instr an fmove out? bne.w funfl_out lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l fix_skewed_ops # fix src op lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l set_tag_x # tag the operand type mov.b %d0,STAG(%a6) # maybe NORM,DENORM # bit five of the fp ext word separates the monadic and dyadic operations # that can pass through fpsp_unfl(). remember that fcmp, and ftst # will never take this exception. btst &0x5,1+EXC_CMDREG(%a6) # is op monadic or dyadic? beq.b funfl_extract # monadic # now, what's left that's not dyadic is fsincos. we can distinguish it # from all dyadics by the '0110xxx pattern btst &0x4,1+EXC_CMDREG(%a6) # is op an fsincos? bne.b funfl_extract # yes bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg bsr.l load_fpn2 # load dst into FP_DST lea FP_DST(%a6),%a0 # pass: ptr to dst op bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b funfl_op2_done # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO funfl_op2_done: mov.b %d0,DTAG(%a6) # save dst optype tag funfl_extract: #$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) #$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) #$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) #$# mov.l FP_DST_EX(%a6),TRAP_DSTOP_EX(%a6) #$# mov.l FP_DST_HI(%a6),TRAP_DSTOP_HI(%a6) #$# mov.l FP_DST_LO(%a6),TRAP_DSTOP_LO(%a6) clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode mov.b 1+EXC_CMDREG(%a6),%d1 andi.w &0x007f,%d1 # extract extension andi.l &0x00ff01ff,USER_FPSR(%a6) fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr lea FP_SRC(%a6),%a0 lea FP_DST(%a6),%a1 # maybe we can make these entry points ONLY the OVFL entry points of each routine. mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr jsr (tbl_unsupp.l,%pc,%d1.l*1) bfextu EXC_CMDREG(%a6){&6:&3},%d0 bsr.l store_fpreg # The `060 FPU multiplier hardware is such that if the result of a # multiply operation is the smallest possible normalized number # (0x00000000_80000000_00000000), then the machine will take an # underflow exception. Since this is incorrect, we need to check # if our emulation, after re-doing the operation, decided that # no underflow was called for. We do these checks only in # funfl_{unfl,inex}_on() because w/ both exceptions disabled, this # special case will simply exit gracefully with the correct result. # the exceptional possibilities we have left ourselves with are ONLY overflow # and inexact. and, the inexact is such that overflow occurred and was disabled # but inexact was enabled. btst &unfl_bit,FPCR_ENABLE(%a6) bne.b funfl_unfl_on funfl_chkinex: btst &inex2_bit,FPCR_ENABLE(%a6) bne.b funfl_inex_on funfl_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 #$# add.l &24,%sp bra.l _fpsp_done # overflow is enabled AND overflow, of course, occurred. so, we have the EXOP # in fp1 (don't forget to save fp0). what to do now? # well, we simply have to get to go to _real_unfl()! funfl_unfl_on: # The `060 FPU multiplier hardware is such that if the result of a # multiply operation is the smallest possible normalized number # (0x00000000_80000000_00000000), then the machine will take an # underflow exception. Since this is incorrect, we check here to see # if our emulation, after re-doing the operation, decided that # no underflow was called for. btst &unfl_bit,FPSR_EXCEPT(%a6) beq.w funfl_chkinex funfl_unfl_on2: fmovm.x &0x40,FP_SRC(%a6) # save EXOP (fp1) to stack mov.w &0xe003,2+FP_SRC(%a6) # save exc status fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # do this after fmovm,other fs! unlk %a6 bra.l _real_unfl # underflow occurred but is disabled. meanwhile, inexact is enabled. Therefore, # we must jump to real_inex(). funfl_inex_on: # The `060 FPU multiplier hardware is such that if the result of a # multiply operation is the smallest possible normalized number # (0x00000000_80000000_00000000), then the machine will take an # underflow exception. # But, whether bogus or not, if inexact is enabled AND it occurred, # then we have to branch to real_inex. btst &inex2_bit,FPSR_EXCEPT(%a6) beq.w funfl_exit funfl_inex_on2: fmovm.x &0x40,FP_SRC(%a6) # save EXOP to stack mov.b &0xc4,1+EXC_VOFF(%a6) # vector offset = 0xc4 mov.w &0xe001,2+FP_SRC(%a6) # save exc status fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # do this after fmovm,other fs! unlk %a6 bra.l _real_inex ####################################################################### funfl_out: #$# mov.l FP_SRC_EX(%a6),TRAP_SRCOP_EX(%a6) #$# mov.l FP_SRC_HI(%a6),TRAP_SRCOP_HI(%a6) #$# mov.l FP_SRC_LO(%a6),TRAP_SRCOP_LO(%a6) # the src operand is definitely a NORM(!), so tag it as such mov.b &NORM,STAG(%a6) # set src optype tag clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode and.l &0xffff00ff,USER_FPSR(%a6) # zero all but accured field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr lea FP_SRC(%a6),%a0 # pass ptr to src operand bsr.l fout btst &unfl_bit,FPCR_ENABLE(%a6) bne.w funfl_unfl_on2 btst &inex2_bit,FPCR_ENABLE(%a6) bne.w funfl_inex_on2 fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 #$# add.l &24,%sp btst &0x7,(%sp) # is trace on? beq.l _fpsp_done # no fmov.l %fpiar,0x8(%sp) # "Current PC" is in FPIAR mov.w &0x2024,0x6(%sp) # stk fmt = 0x2; voff = 0x024 bra.l _real_trace ######################################################################### # XDEF **************************************************************** # # _fpsp_unsupp(): 060FPSP entry point for FP "Unimplemented # # Data Type" exception. # # # # This handler should be the first code executed upon taking the # # FP Unimplemented Data Type exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_{word,long}() - read instruction word/longword # # fix_skewed_ops() - adjust src operand in fsave frame # # set_tag_x() - determine optype of src/dst operands # # store_fpreg() - store opclass 0 or 2 result to FP regfile # # unnorm_fix() - change UNNORM operands to NORM or ZERO # # load_fpn2() - load dst operand from FP regfile # # load_fpn1() - load src operand from FP regfile # # fout() - emulate an opclass 3 instruction # # tbl_unsupp - add of table of emulation routines for opclass 0,2 # # _real_inex() - "callout" to operating system inexact handler # # _fpsp_done() - "callout" for exit; work all done # # _real_trace() - "callout" for Trace enabled exception # # funimp_skew() - adjust fsave src ops to "incorrect" value # # _real_snan() - "callout" for SNAN exception # # _real_operr() - "callout" for OPERR exception # # _real_ovfl() - "callout" for OVFL exception # # _real_unfl() - "callout" for UNFL exception # # get_packed() - fetch packed operand from memory # # # # INPUT *************************************************************** # # - The system stack contains the "Unimp Data Type" stk frame # # - The fsave frame contains the ssrc op (for UNNORM/DENORM) # # # # OUTPUT ************************************************************** # # If Inexact exception (opclass 3): # # - The system stack is changed to an Inexact exception stk frame # # If SNAN exception (opclass 3): # # - The system stack is changed to an SNAN exception stk frame # # If OPERR exception (opclass 3): # # - The system stack is changed to an OPERR exception stk frame # # If OVFL exception (opclass 3): # # - The system stack is changed to an OVFL exception stk frame # # If UNFL exception (opclass 3): # # - The system stack is changed to an UNFL exception stack frame # # If Trace exception enabled: # # - The system stack is changed to a Trace exception stack frame # # Else: (normal case) # # - Correct result has been stored as appropriate # # # # ALGORITHM *********************************************************** # # Two main instruction types can enter here: (1) DENORM or UNNORM # # unimplemented data types. These can be either opclass 0,2 or 3 # # instructions, and (2) PACKED unimplemented data format instructions # # also of opclasses 0,2, or 3. # # For UNNORM/DENORM opclass 0 and 2, the handler fetches the src # # operand from the fsave state frame and the dst operand (if dyadic) # # from the FP register file. The instruction is then emulated by # # choosing an emulation routine from a table of routines indexed by # # instruction type. Once the instruction has been emulated and result # # saved, then we check to see if any enabled exceptions resulted from # # instruction emulation. If none, then we exit through the "callout" # # _fpsp_done(). If there is an enabled FP exception, then we insert # # this exception into the FPU in the fsave state frame and then exit # # through _fpsp_done(). # # PACKED opclass 0 and 2 is similar in how the instruction is # # emulated and exceptions handled. The differences occur in how the # # handler loads the packed op (by calling get_packed() routine) and # # by the fact that a Trace exception could be pending for PACKED ops. # # If a Trace exception is pending, then the current exception stack # # frame is changed to a Trace exception stack frame and an exit is # # made through _real_trace(). # # For UNNORM/DENORM opclass 3, the actual move out to memory is # # performed by calling the routine fout(). If no exception should occur # # as the result of emulation, then an exit either occurs through # # _fpsp_done() or through _real_trace() if a Trace exception is pending # # (a Trace stack frame must be created here, too). If an FP exception # # should occur, then we must create an exception stack frame of that # # type and jump to either _real_snan(), _real_operr(), _real_inex(), # # _real_unfl(), or _real_ovfl() as appropriate. PACKED opclass 3 # # emulation is performed in a similar manner. # # # ######################################################################### # # (1) DENORM and UNNORM (unimplemented) data types: # # post-instruction # ***************** # * EA * # pre-instruction * * # ***************** ***************** # * 0x0 * 0x0dc * * 0x3 * 0x0dc * # ***************** ***************** # * Next * * Next * # * PC * * PC * # ***************** ***************** # * SR * * SR * # ***************** ***************** # # (2) PACKED format (unsupported) opclasses two and three: # ***************** # * EA * # * * # ***************** # * 0x2 * 0x0dc * # ***************** # * Next * # * PC * # ***************** # * SR * # ***************** # global _fpsp_unsupp _fpsp_unsupp: link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # save fp state movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack btst &0x5,EXC_SR(%a6) # user or supervisor mode? bne.b fu_s fu_u: mov.l %usp,%a0 # fetch user stack pointer mov.l %a0,EXC_A7(%a6) # save on stack bra.b fu_cont # if the exception is an opclass zero or two unimplemented data type # exception, then the a7' calculated here is wrong since it doesn't # stack an ea. however, we don't need an a7' for this case anyways. fu_s: lea 0x4+EXC_EA(%a6),%a0 # load old a7' mov.l %a0,EXC_A7(%a6) # save on stack fu_cont: # the FPIAR holds the "current PC" of the faulting instruction # the FPIAR should be set correctly for ALL exceptions passing through # this point. mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) # store OPWORD and EXTWORD ############################ clr.b SPCOND_FLG(%a6) # clear special condition flag # Separate opclass three (fpn-to-mem) ops since they have a different # stack frame and protocol. btst &0x5,EXC_CMDREG(%a6) # is it an fmove out? bne.w fu_out # yes # Separate packed opclass two instructions. bfextu EXC_CMDREG(%a6){&0:&6},%d0 cmpi.b %d0,&0x13 beq.w fu_in_pack # I'm not sure at this point what FPSR bits are valid for this instruction. # so, since the emulation routines re-create them anyways, zero exception field andi.l &0x00ff00ff,USER_FPSR(%a6) # zero exception field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr # Opclass two w/ memory-to-fpn operation will have an incorrect extended # precision format if the src format was single or double and the # source data type was an INF, NAN, DENORM, or UNNORM lea FP_SRC(%a6),%a0 # pass ptr to input bsr.l fix_skewed_ops # we don't know whether the src operand or the dst operand (or both) is the # UNNORM or DENORM. call the function that tags the operand type. if the # input is an UNNORM, then convert it to a NORM, DENORM, or ZERO. lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b fu_op2 # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO fu_op2: mov.b %d0,STAG(%a6) # save src optype tag bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg # bit five of the fp extension word separates the monadic and dyadic operations # at this point btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? beq.b fu_extract # monadic cmpi.b 1+EXC_CMDREG(%a6),&0x3a # is operation an ftst? beq.b fu_extract # yes, so it's monadic, too bsr.l load_fpn2 # load dst into FP_DST lea FP_DST(%a6),%a0 # pass: ptr to dst op bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b fu_op2_done # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO fu_op2_done: mov.b %d0,DTAG(%a6) # save dst optype tag fu_extract: clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec bfextu 1+EXC_CMDREG(%a6){&1:&7},%d1 # extract extension lea FP_SRC(%a6),%a0 lea FP_DST(%a6),%a1 mov.l (tbl_unsupp.l,%pc,%d1.l*4),%d1 # fetch routine addr jsr (tbl_unsupp.l,%pc,%d1.l*1) # # Exceptions in order of precedence: # BSUN : none # SNAN : all dyadic ops # OPERR : fsqrt(-NORM) # OVFL : all except ftst,fcmp # UNFL : all except ftst,fcmp # DZ : fdiv # INEX2 : all except ftst,fcmp # INEX1 : none (packed doesn't go through here) # # we determine the highest priority exception(if any) set by the # emulation routine that has also been enabled by the user. mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions set bne.b fu_in_ena # some are enabled fu_in_cont: # fcmp and ftst do not store any result. mov.b 1+EXC_CMDREG(%a6),%d0 # fetch extension andi.b &0x38,%d0 # extract bits 3-5 cmpi.b %d0,&0x38 # is instr fcmp or ftst? beq.b fu_in_exit # yes bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg bsr.l store_fpreg # store the result fu_in_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 bra.l _fpsp_done fu_in_ena: and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled bfffo %d0{&24:&8},%d0 # find highest priority exception bne.b fu_in_exc # there is at least one set # # No exceptions occurred that were also enabled. Now: # # if (OVFL && ovfl_disabled && inexact_enabled) { # branch to _real_inex() (even if the result was exact!); # } else { # save the result in the proper fp reg (unless the op is fcmp or ftst); # return; # } # btst &ovfl_bit,FPSR_EXCEPT(%a6) # was overflow set? beq.b fu_in_cont # no fu_in_ovflchk: btst &inex2_bit,FPCR_ENABLE(%a6) # was inexact enabled? beq.b fu_in_cont # no bra.w fu_in_exc_ovfl # go insert overflow frame # # An exception occurred and that exception was enabled: # # shift enabled exception field into lo byte of d0; # if (((INEX2 || INEX1) && inex_enabled && OVFL && ovfl_disabled) || # ((INEX2 || INEX1) && inex_enabled && UNFL && unfl_disabled)) { # /* # * this is the case where we must call _real_inex() now or else # * there will be no other way to pass it the exceptional operand # */ # call _real_inex(); # } else { # restore exc state (SNAN||OPERR||OVFL||UNFL||DZ||INEX) into the FPU; # } # fu_in_exc: subi.l &24,%d0 # fix offset to be 0-8 cmpi.b %d0,&0x6 # is exception INEX? (6) bne.b fu_in_exc_exit # no # the enabled exception was inexact btst &unfl_bit,FPSR_EXCEPT(%a6) # did disabled underflow occur? bne.w fu_in_exc_unfl # yes btst &ovfl_bit,FPSR_EXCEPT(%a6) # did disabled overflow occur? bne.w fu_in_exc_ovfl # yes # here, we insert the correct fsave status value into the fsave frame for the # corresponding exception. the operand in the fsave frame should be the original # src operand. fu_in_exc_exit: mov.l %d0,-(%sp) # save d0 bsr.l funimp_skew # skew sgl or dbl inputs mov.l (%sp)+,%d0 # restore d0 mov.w (tbl_except.b,%pc,%d0.w*2),2+FP_SRC(%a6) # create exc status fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # restore src op unlk %a6 bra.l _fpsp_done tbl_except: short 0xe000,0xe006,0xe004,0xe005 short 0xe003,0xe002,0xe001,0xe001 fu_in_exc_unfl: mov.w &0x4,%d0 bra.b fu_in_exc_exit fu_in_exc_ovfl: mov.w &0x03,%d0 bra.b fu_in_exc_exit # If the input operand to this operation was opclass two and a single # or double precision denorm, inf, or nan, the operand needs to be # "corrected" in order to have the proper equivalent extended precision # number. global fix_skewed_ops fix_skewed_ops: bfextu EXC_CMDREG(%a6){&0:&6},%d0 # extract opclass,src fmt cmpi.b %d0,&0x11 # is class = 2 & fmt = sgl? beq.b fso_sgl # yes cmpi.b %d0,&0x15 # is class = 2 & fmt = dbl? beq.b fso_dbl # yes rts # no fso_sgl: mov.w LOCAL_EX(%a0),%d0 # fetch src exponent andi.w &0x7fff,%d0 # strip sign cmpi.w %d0,&0x3f80 # is |exp| == $3f80? beq.b fso_sgl_dnrm_zero # yes cmpi.w %d0,&0x407f # no; is |exp| == $407f? beq.b fso_infnan # yes rts # no fso_sgl_dnrm_zero: andi.l &0x7fffffff,LOCAL_HI(%a0) # clear j-bit beq.b fso_zero # it's a skewed zero fso_sgl_dnrm: # here, we count on norm not to alter a0... bsr.l norm # normalize mantissa neg.w %d0 # -shft amt addi.w &0x3f81,%d0 # adjust new exponent andi.w &0x8000,LOCAL_EX(%a0) # clear old exponent or.w %d0,LOCAL_EX(%a0) # insert new exponent rts fso_zero: andi.w &0x8000,LOCAL_EX(%a0) # clear bogus exponent rts fso_infnan: andi.b &0x7f,LOCAL_HI(%a0) # clear j-bit ori.w &0x7fff,LOCAL_EX(%a0) # make exponent = $7fff rts fso_dbl: mov.w LOCAL_EX(%a0),%d0 # fetch src exponent andi.w &0x7fff,%d0 # strip sign cmpi.w %d0,&0x3c00 # is |exp| == $3c00? beq.b fso_dbl_dnrm_zero # yes cmpi.w %d0,&0x43ff # no; is |exp| == $43ff? beq.b fso_infnan # yes rts # no fso_dbl_dnrm_zero: andi.l &0x7fffffff,LOCAL_HI(%a0) # clear j-bit bne.b fso_dbl_dnrm # it's a skewed denorm tst.l LOCAL_LO(%a0) # is it a zero? beq.b fso_zero # yes fso_dbl_dnrm: # here, we count on norm not to alter a0... bsr.l norm # normalize mantissa neg.w %d0 # -shft amt addi.w &0x3c01,%d0 # adjust new exponent andi.w &0x8000,LOCAL_EX(%a0) # clear old exponent or.w %d0,LOCAL_EX(%a0) # insert new exponent rts ################################################################# # fmove out took an unimplemented data type exception. # the src operand is in FP_SRC. Call _fout() to write out the result and # to determine which exceptions, if any, to take. fu_out: # Separate packed move outs from the UNNORM and DENORM move outs. bfextu EXC_CMDREG(%a6){&3:&3},%d0 cmpi.b %d0,&0x3 beq.w fu_out_pack cmpi.b %d0,&0x7 beq.w fu_out_pack # I'm not sure at this point what FPSR bits are valid for this instruction. # so, since the emulation routines re-create them anyways, zero exception field. # fmove out doesn't affect ccodes. and.l &0xffff00ff,USER_FPSR(%a6) # zero exception field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr # the src can ONLY be a DENORM or an UNNORM! so, don't make any big subroutine # call here. just figure out what it is... mov.w FP_SRC_EX(%a6),%d0 # get exponent andi.w &0x7fff,%d0 # strip sign beq.b fu_out_denorm # it's a DENORM lea FP_SRC(%a6),%a0 bsr.l unnorm_fix # yes; fix it mov.b %d0,STAG(%a6) bra.b fu_out_cont fu_out_denorm: mov.b &DENORM,STAG(%a6) fu_out_cont: clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec lea FP_SRC(%a6),%a0 # pass ptr to src operand mov.l (%a6),EXC_A6(%a6) # in case a6 changes bsr.l fout # call fmove out routine # Exceptions in order of precedence: # BSUN : none # SNAN : none # OPERR : fmove.{b,w,l} out of large UNNORM # OVFL : fmove.{s,d} # UNFL : fmove.{s,d,x} # DZ : none # INEX2 : all # INEX1 : none (packed doesn't travel through here) # determine the highest priority exception(if any) set by the # emulation routine that has also been enabled by the user. mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled bne.w fu_out_ena # some are enabled fu_out_done: mov.l EXC_A6(%a6),(%a6) # in case a6 changed # on extended precision opclass three instructions using pre-decrement or # post-increment addressing mode, the address register is not updated. is the # address register was the stack pointer used from user mode, then let's update # it here. if it was used from supervisor mode, then we have to handle this # as a special case. btst &0x5,EXC_SR(%a6) bne.b fu_out_done_s mov.l EXC_A7(%a6),%a0 # restore a7 mov.l %a0,%usp fu_out_done_cont: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 btst &0x7,(%sp) # is trace on? bne.b fu_out_trace # yes bra.l _fpsp_done # is the ea mode pre-decrement of the stack pointer from supervisor mode? # ("fmov.x fpm,-(a7)") if so, fu_out_done_s: cmpi.b SPCOND_FLG(%a6),&mda7_flg bne.b fu_out_done_cont # the extended precision result is still in fp0. but, we need to save it # somewhere on the stack until we can copy it to its final resting place. # here, we're counting on the top of the stack to be the old place-holders # for fp0/fp1 which have already been restored. that way, we can write # over those destinations with the shifted stack frame. fmovm.x &0x80,FP_SRC(%a6) # put answer on stack fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.l (%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) # now, copy the result to the proper place on the stack mov.l LOCAL_SIZE+FP_SRC_EX(%sp),LOCAL_SIZE+EXC_SR+0x0(%sp) mov.l LOCAL_SIZE+FP_SRC_HI(%sp),LOCAL_SIZE+EXC_SR+0x4(%sp) mov.l LOCAL_SIZE+FP_SRC_LO(%sp),LOCAL_SIZE+EXC_SR+0x8(%sp) add.l &LOCAL_SIZE-0x8,%sp btst &0x7,(%sp) bne.b fu_out_trace bra.l _fpsp_done fu_out_ena: and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled bfffo %d0{&24:&8},%d0 # find highest priority exception bne.b fu_out_exc # there is at least one set # no exceptions were set. # if a disabled overflow occurred and inexact was enabled but the result # was exact, then a branch to _real_inex() is made. btst &ovfl_bit,FPSR_EXCEPT(%a6) # was overflow set? beq.w fu_out_done # no fu_out_ovflchk: btst &inex2_bit,FPCR_ENABLE(%a6) # was inexact enabled? beq.w fu_out_done # no bra.w fu_inex # yes # # The fp move out that took the "Unimplemented Data Type" exception was # being traced. Since the stack frames are similar, get the "current" PC # from FPIAR and put it in the trace stack frame then jump to _real_trace(). # # UNSUPP FRAME TRACE FRAME # ***************** ***************** # * EA * * Current * # * * * PC * # ***************** ***************** # * 0x3 * 0x0dc * * 0x2 * 0x024 * # ***************** ***************** # * Next * * Next * # * PC * * PC * # ***************** ***************** # * SR * * SR * # ***************** ***************** # fu_out_trace: mov.w &0x2024,0x6(%sp) fmov.l %fpiar,0x8(%sp) bra.l _real_trace # an exception occurred and that exception was enabled. fu_out_exc: subi.l &24,%d0 # fix offset to be 0-8 # we don't mess with the existing fsave frame. just re-insert it and # jump to the "_real_{}()" handler... mov.w (tbl_fu_out.b,%pc,%d0.w*2),%d0 jmp (tbl_fu_out.b,%pc,%d0.w*1) swbeg &0x8 tbl_fu_out: short tbl_fu_out - tbl_fu_out # BSUN can't happen short tbl_fu_out - tbl_fu_out # SNAN can't happen short fu_operr - tbl_fu_out # OPERR short fu_ovfl - tbl_fu_out # OVFL short fu_unfl - tbl_fu_out # UNFL short tbl_fu_out - tbl_fu_out # DZ can't happen short fu_inex - tbl_fu_out # INEX2 short tbl_fu_out - tbl_fu_out # INEX1 won't make it here # for snan,operr,ovfl,unfl, src op is still in FP_SRC so just # frestore it. fu_snan: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30d8,EXC_VOFF(%a6) # vector offset = 0xd8 mov.w &0xe006,2+FP_SRC(%a6) frestore FP_SRC(%a6) unlk %a6 bra.l _real_snan fu_operr: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30d0,EXC_VOFF(%a6) # vector offset = 0xd0 mov.w &0xe004,2+FP_SRC(%a6) frestore FP_SRC(%a6) unlk %a6 bra.l _real_operr fu_ovfl: fmovm.x &0x40,FP_SRC(%a6) # save EXOP to the stack fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30d4,EXC_VOFF(%a6) # vector offset = 0xd4 mov.w &0xe005,2+FP_SRC(%a6) frestore FP_SRC(%a6) # restore EXOP unlk %a6 bra.l _real_ovfl # underflow can happen for extended precision. extended precision opclass # three instruction exceptions don't update the stack pointer. so, if the # exception occurred from user mode, then simply update a7 and exit normally. # if the exception occurred from supervisor mode, check if fu_unfl: mov.l EXC_A6(%a6),(%a6) # restore a6 btst &0x5,EXC_SR(%a6) bne.w fu_unfl_s mov.l EXC_A7(%a6),%a0 # restore a7 whether we need mov.l %a0,%usp # to or not... fu_unfl_cont: fmovm.x &0x40,FP_SRC(%a6) # save EXOP to the stack fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30cc,EXC_VOFF(%a6) # vector offset = 0xcc mov.w &0xe003,2+FP_SRC(%a6) frestore FP_SRC(%a6) # restore EXOP unlk %a6 bra.l _real_unfl fu_unfl_s: cmpi.b SPCOND_FLG(%a6),&mda7_flg # was the mode -(sp)? bne.b fu_unfl_cont # the extended precision result is still in fp0. but, we need to save it # somewhere on the stack until we can copy it to its final resting place # (where the exc frame is currently). make sure it's not at the top of the # frame or it will get overwritten when the exc stack frame is shifted "down". fmovm.x &0x80,FP_SRC(%a6) # put answer on stack fmovm.x &0x40,FP_DST(%a6) # put EXOP on stack fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30cc,EXC_VOFF(%a6) # vector offset = 0xcc mov.w &0xe003,2+FP_DST(%a6) frestore FP_DST(%a6) # restore EXOP mov.l (%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) # now, copy the result to the proper place on the stack mov.l LOCAL_SIZE+FP_SRC_EX(%sp),LOCAL_SIZE+EXC_SR+0x0(%sp) mov.l LOCAL_SIZE+FP_SRC_HI(%sp),LOCAL_SIZE+EXC_SR+0x4(%sp) mov.l LOCAL_SIZE+FP_SRC_LO(%sp),LOCAL_SIZE+EXC_SR+0x8(%sp) add.l &LOCAL_SIZE-0x8,%sp bra.l _real_unfl # fmove in and out enter here. fu_inex: fmovm.x &0x40,FP_SRC(%a6) # save EXOP to the stack fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30c4,EXC_VOFF(%a6) # vector offset = 0xc4 mov.w &0xe001,2+FP_SRC(%a6) frestore FP_SRC(%a6) # restore EXOP unlk %a6 bra.l _real_inex ######################################################################### ######################################################################### fu_in_pack: # I'm not sure at this point what FPSR bits are valid for this instruction. # so, since the emulation routines re-create them anyways, zero exception field andi.l &0x0ff00ff,USER_FPSR(%a6) # zero exception field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr bsr.l get_packed # fetch packed src operand lea FP_SRC(%a6),%a0 # pass ptr to src bsr.l set_tag_x # set src optype tag mov.b %d0,STAG(%a6) # save src optype tag bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg # bit five of the fp extension word separates the monadic and dyadic operations # at this point btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? beq.b fu_extract_p # monadic cmpi.b 1+EXC_CMDREG(%a6),&0x3a # is operation an ftst? beq.b fu_extract_p # yes, so it's monadic, too bsr.l load_fpn2 # load dst into FP_DST lea FP_DST(%a6),%a0 # pass: ptr to dst op bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b fu_op2_done_p # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO fu_op2_done_p: mov.b %d0,DTAG(%a6) # save dst optype tag fu_extract_p: clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec bfextu 1+EXC_CMDREG(%a6){&1:&7},%d1 # extract extension lea FP_SRC(%a6),%a0 lea FP_DST(%a6),%a1 mov.l (tbl_unsupp.l,%pc,%d1.l*4),%d1 # fetch routine addr jsr (tbl_unsupp.l,%pc,%d1.l*1) # # Exceptions in order of precedence: # BSUN : none # SNAN : all dyadic ops # OPERR : fsqrt(-NORM) # OVFL : all except ftst,fcmp # UNFL : all except ftst,fcmp # DZ : fdiv # INEX2 : all except ftst,fcmp # INEX1 : all # # we determine the highest priority exception(if any) set by the # emulation routine that has also been enabled by the user. mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled bne.w fu_in_ena_p # some are enabled fu_in_cont_p: # fcmp and ftst do not store any result. mov.b 1+EXC_CMDREG(%a6),%d0 # fetch extension andi.b &0x38,%d0 # extract bits 3-5 cmpi.b %d0,&0x38 # is instr fcmp or ftst? beq.b fu_in_exit_p # yes bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg bsr.l store_fpreg # store the result fu_in_exit_p: btst &0x5,EXC_SR(%a6) # user or supervisor? bne.w fu_in_exit_s_p # supervisor mov.l EXC_A7(%a6),%a0 # update user a7 mov.l %a0,%usp fu_in_exit_cont_p: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 # unravel stack frame btst &0x7,(%sp) # is trace on? bne.w fu_trace_p # yes bra.l _fpsp_done # exit to os # the exception occurred in supervisor mode. check to see if the # addressing mode was (a7)+. if so, we'll need to shift the # stack frame "up". fu_in_exit_s_p: btst &mia7_bit,SPCOND_FLG(%a6) # was ea mode (a7)+ beq.b fu_in_exit_cont_p # no fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 # unravel stack frame # shift the stack frame "up". we don't really care about the field. mov.l 0x4(%sp),0x10(%sp) mov.l 0x0(%sp),0xc(%sp) add.l &0xc,%sp btst &0x7,(%sp) # is trace on? bne.w fu_trace_p # yes bra.l _fpsp_done # exit to os fu_in_ena_p: and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled & set bfffo %d0{&24:&8},%d0 # find highest priority exception bne.b fu_in_exc_p # at least one was set # # No exceptions occurred that were also enabled. Now: # # if (OVFL && ovfl_disabled && inexact_enabled) { # branch to _real_inex() (even if the result was exact!); # } else { # save the result in the proper fp reg (unless the op is fcmp or ftst); # return; # } # btst &ovfl_bit,FPSR_EXCEPT(%a6) # was overflow set? beq.w fu_in_cont_p # no fu_in_ovflchk_p: btst &inex2_bit,FPCR_ENABLE(%a6) # was inexact enabled? beq.w fu_in_cont_p # no bra.w fu_in_exc_ovfl_p # do _real_inex() now # # An exception occurred and that exception was enabled: # # shift enabled exception field into lo byte of d0; # if (((INEX2 || INEX1) && inex_enabled && OVFL && ovfl_disabled) || # ((INEX2 || INEX1) && inex_enabled && UNFL && unfl_disabled)) { # /* # * this is the case where we must call _real_inex() now or else # * there will be no other way to pass it the exceptional operand # */ # call _real_inex(); # } else { # restore exc state (SNAN||OPERR||OVFL||UNFL||DZ||INEX) into the FPU; # } # fu_in_exc_p: subi.l &24,%d0 # fix offset to be 0-8 cmpi.b %d0,&0x6 # is exception INEX? (6 or 7) blt.b fu_in_exc_exit_p # no # the enabled exception was inexact btst &unfl_bit,FPSR_EXCEPT(%a6) # did disabled underflow occur? bne.w fu_in_exc_unfl_p # yes btst &ovfl_bit,FPSR_EXCEPT(%a6) # did disabled overflow occur? bne.w fu_in_exc_ovfl_p # yes # here, we insert the correct fsave status value into the fsave frame for the # corresponding exception. the operand in the fsave frame should be the original # src operand. # as a reminder for future predicted pain and agony, we are passing in fsave the # "non-skewed" operand for cases of sgl and dbl src INFs,NANs, and DENORMs. # this is INCORRECT for enabled SNAN which would give to the user the skewed SNAN!!! fu_in_exc_exit_p: btst &0x5,EXC_SR(%a6) # user or supervisor? bne.w fu_in_exc_exit_s_p # supervisor mov.l EXC_A7(%a6),%a0 # update user a7 mov.l %a0,%usp fu_in_exc_exit_cont_p: mov.w (tbl_except_p.b,%pc,%d0.w*2),2+FP_SRC(%a6) fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # restore src op unlk %a6 btst &0x7,(%sp) # is trace enabled? bne.w fu_trace_p # yes bra.l _fpsp_done tbl_except_p: short 0xe000,0xe006,0xe004,0xe005 short 0xe003,0xe002,0xe001,0xe001 fu_in_exc_ovfl_p: mov.w &0x3,%d0 bra.w fu_in_exc_exit_p fu_in_exc_unfl_p: mov.w &0x4,%d0 bra.w fu_in_exc_exit_p fu_in_exc_exit_s_p: btst &mia7_bit,SPCOND_FLG(%a6) beq.b fu_in_exc_exit_cont_p mov.w (tbl_except_p.b,%pc,%d0.w*2),2+FP_SRC(%a6) fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # restore src op unlk %a6 # unravel stack frame # shift stack frame "up". who cares about field. mov.l 0x4(%sp),0x10(%sp) mov.l 0x0(%sp),0xc(%sp) add.l &0xc,%sp btst &0x7,(%sp) # is trace on? bne.b fu_trace_p # yes bra.l _fpsp_done # exit to os # # The opclass two PACKED instruction that took an "Unimplemented Data Type" # exception was being traced. Make the "current" PC the FPIAR and put it in the # trace stack frame then jump to _real_trace(). # # UNSUPP FRAME TRACE FRAME # ***************** ***************** # * EA * * Current * # * * * PC * # ***************** ***************** # * 0x2 * 0x0dc * * 0x2 * 0x024 * # ***************** ***************** # * Next * * Next * # * PC * * PC * # ***************** ***************** # * SR * * SR * # ***************** ***************** fu_trace_p: mov.w &0x2024,0x6(%sp) fmov.l %fpiar,0x8(%sp) bra.l _real_trace ######################################################### ######################################################### fu_out_pack: # I'm not sure at this point what FPSR bits are valid for this instruction. # so, since the emulation routines re-create them anyways, zero exception field. # fmove out doesn't affect ccodes. and.l &0xffff00ff,USER_FPSR(%a6) # zero exception field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr bfextu EXC_CMDREG(%a6){&6:&3},%d0 bsr.l load_fpn1 # unlike other opclass 3, unimplemented data type exceptions, packed must be # able to detect all operand types. lea FP_SRC(%a6),%a0 bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b fu_op2_p # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO fu_op2_p: mov.b %d0,STAG(%a6) # save src optype tag clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # fetch rnd mode/prec lea FP_SRC(%a6),%a0 # pass ptr to src operand mov.l (%a6),EXC_A6(%a6) # in case a6 changes bsr.l fout # call fmove out routine # Exceptions in order of precedence: # BSUN : no # SNAN : yes # OPERR : if ((k_factor > +17) || (dec. exp exceeds 3 digits)) # OVFL : no # UNFL : no # DZ : no # INEX2 : yes # INEX1 : no # determine the highest priority exception(if any) set by the # emulation routine that has also been enabled by the user. mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled bne.w fu_out_ena_p # some are enabled fu_out_exit_p: mov.l EXC_A6(%a6),(%a6) # restore a6 btst &0x5,EXC_SR(%a6) # user or supervisor? bne.b fu_out_exit_s_p # supervisor mov.l EXC_A7(%a6),%a0 # update user a7 mov.l %a0,%usp fu_out_exit_cont_p: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 # unravel stack frame btst &0x7,(%sp) # is trace on? bne.w fu_trace_p # yes bra.l _fpsp_done # exit to os # the exception occurred in supervisor mode. check to see if the # addressing mode was -(a7). if so, we'll need to shift the # stack frame "down". fu_out_exit_s_p: btst &mda7_bit,SPCOND_FLG(%a6) # was ea mode -(a7) beq.b fu_out_exit_cont_p # no fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.l (%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) # now, copy the result to the proper place on the stack mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+EXC_SR+0x0(%sp) mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+EXC_SR+0x4(%sp) mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+EXC_SR+0x8(%sp) add.l &LOCAL_SIZE-0x8,%sp btst &0x7,(%sp) bne.w fu_trace_p bra.l _fpsp_done fu_out_ena_p: and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enabled bfffo %d0{&24:&8},%d0 # find highest priority exception beq.w fu_out_exit_p mov.l EXC_A6(%a6),(%a6) # restore a6 # an exception occurred and that exception was enabled. # the only exception possible on packed move out are INEX, OPERR, and SNAN. fu_out_exc_p: cmpi.b %d0,&0x1a bgt.w fu_inex_p2 beq.w fu_operr_p fu_snan_p: btst &0x5,EXC_SR(%a6) bne.b fu_snan_s_p mov.l EXC_A7(%a6),%a0 mov.l %a0,%usp bra.w fu_snan fu_snan_s_p: cmpi.b SPCOND_FLG(%a6),&mda7_flg bne.w fu_snan # the instruction was "fmove.p fpn,-(a7)" from supervisor mode. # the strategy is to move the exception frame "down" 12 bytes. then, we # can store the default result where the exception frame was. fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30d8,EXC_VOFF(%a6) # vector offset = 0xd0 mov.w &0xe006,2+FP_SRC(%a6) # set fsave status frestore FP_SRC(%a6) # restore src operand mov.l (%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) # now, we copy the default result to its proper location mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+0x4(%sp) mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+0x8(%sp) mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+0xc(%sp) add.l &LOCAL_SIZE-0x8,%sp bra.l _real_snan fu_operr_p: btst &0x5,EXC_SR(%a6) bne.w fu_operr_p_s mov.l EXC_A7(%a6),%a0 mov.l %a0,%usp bra.w fu_operr fu_operr_p_s: cmpi.b SPCOND_FLG(%a6),&mda7_flg bne.w fu_operr # the instruction was "fmove.p fpn,-(a7)" from supervisor mode. # the strategy is to move the exception frame "down" 12 bytes. then, we # can store the default result where the exception frame was. fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30d0,EXC_VOFF(%a6) # vector offset = 0xd0 mov.w &0xe004,2+FP_SRC(%a6) # set fsave status frestore FP_SRC(%a6) # restore src operand mov.l (%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) # now, we copy the default result to its proper location mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+0x4(%sp) mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+0x8(%sp) mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+0xc(%sp) add.l &LOCAL_SIZE-0x8,%sp bra.l _real_operr fu_inex_p2: btst &0x5,EXC_SR(%a6) bne.w fu_inex_s_p2 mov.l EXC_A7(%a6),%a0 mov.l %a0,%usp bra.w fu_inex fu_inex_s_p2: cmpi.b SPCOND_FLG(%a6),&mda7_flg bne.w fu_inex # the instruction was "fmove.p fpn,-(a7)" from supervisor mode. # the strategy is to move the exception frame "down" 12 bytes. then, we # can store the default result where the exception frame was. fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0/fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.w &0x30c4,EXC_VOFF(%a6) # vector offset = 0xc4 mov.w &0xe001,2+FP_SRC(%a6) # set fsave status frestore FP_SRC(%a6) # restore src operand mov.l (%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+2+EXC_PC(%sp),LOCAL_SIZE+2+EXC_PC-0xc(%sp) mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) # now, we copy the default result to its proper location mov.l LOCAL_SIZE+FP_DST_EX(%sp),LOCAL_SIZE+0x4(%sp) mov.l LOCAL_SIZE+FP_DST_HI(%sp),LOCAL_SIZE+0x8(%sp) mov.l LOCAL_SIZE+FP_DST_LO(%sp),LOCAL_SIZE+0xc(%sp) add.l &LOCAL_SIZE-0x8,%sp bra.l _real_inex ######################################################################### # # if we're stuffing a source operand back into an fsave frame then we # have to make sure that for single or double source operands that the # format stuffed is as weird as the hardware usually makes it. # global funimp_skew funimp_skew: bfextu EXC_EXTWORD(%a6){&3:&3},%d0 # extract src specifier cmpi.b %d0,&0x1 # was src sgl? beq.b funimp_skew_sgl # yes cmpi.b %d0,&0x5 # was src dbl? beq.b funimp_skew_dbl # yes rts funimp_skew_sgl: mov.w FP_SRC_EX(%a6),%d0 # fetch DENORM exponent andi.w &0x7fff,%d0 # strip sign beq.b funimp_skew_sgl_not cmpi.w %d0,&0x3f80 bgt.b funimp_skew_sgl_not neg.w %d0 # make exponent negative addi.w &0x3f81,%d0 # find amt to shift mov.l FP_SRC_HI(%a6),%d1 # fetch DENORM hi(man) lsr.l %d0,%d1 # shift it bset &31,%d1 # set j-bit mov.l %d1,FP_SRC_HI(%a6) # insert new hi(man) andi.w &0x8000,FP_SRC_EX(%a6) # clear old exponent ori.w &0x3f80,FP_SRC_EX(%a6) # insert new "skewed" exponent funimp_skew_sgl_not: rts funimp_skew_dbl: mov.w FP_SRC_EX(%a6),%d0 # fetch DENORM exponent andi.w &0x7fff,%d0 # strip sign beq.b funimp_skew_dbl_not cmpi.w %d0,&0x3c00 bgt.b funimp_skew_dbl_not tst.b FP_SRC_EX(%a6) # make "internal format" smi.b 0x2+FP_SRC(%a6) mov.w %d0,FP_SRC_EX(%a6) # insert exponent with cleared sign clr.l %d0 # clear g,r,s lea FP_SRC(%a6),%a0 # pass ptr to src op mov.w &0x3c01,%d1 # pass denorm threshold bsr.l dnrm_lp # denorm it mov.w &0x3c00,%d0 # new exponent tst.b 0x2+FP_SRC(%a6) # is sign set? beq.b fss_dbl_denorm_done # no bset &15,%d0 # set sign fss_dbl_denorm_done: bset &0x7,FP_SRC_HI(%a6) # set j-bit mov.w %d0,FP_SRC_EX(%a6) # insert new exponent funimp_skew_dbl_not: rts ######################################################################### global _mem_write2 _mem_write2: btst &0x5,EXC_SR(%a6) beq.l _dmem_write mov.l 0x0(%a0),FP_DST_EX(%a6) mov.l 0x4(%a0),FP_DST_HI(%a6) mov.l 0x8(%a0),FP_DST_LO(%a6) clr.l %d1 rts ######################################################################### # XDEF **************************************************************** # # _fpsp_effadd(): 060FPSP entry point for FP "Unimplemented # # effective address" exception. # # # # This handler should be the first code executed upon taking the # # FP Unimplemented Effective Address exception in an operating # # system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword # # fix_skewed_ops() - adjust src operand in fsave frame # # set_tag_x() - determine optype of src/dst operands # # store_fpreg() - store opclass 0 or 2 result to FP regfile # # unnorm_fix() - change UNNORM operands to NORM or ZERO # # load_fpn2() - load dst operand from FP regfile # # tbl_unsupp - add of table of emulation routines for opclass 0,2 # # decbin() - convert packed data to FP binary data # # _real_fpu_disabled() - "callout" for "FPU disabled" exception # # _real_access() - "callout" for access error exception # # _mem_read() - read extended immediate operand from memory # # _fpsp_done() - "callout" for exit; work all done # # _real_trace() - "callout" for Trace enabled exception # # fmovm_dynamic() - emulate dynamic fmovm instruction # # fmovm_ctrl() - emulate fmovm control instruction # # # # INPUT *************************************************************** # # - The system stack contains the "Unimplemented " stk frame # # # # OUTPUT ************************************************************** # # If access error: # # - The system stack is changed to an access error stack frame # # If FPU disabled: # # - The system stack is changed to an FPU disabled stack frame # # If Trace exception enabled: # # - The system stack is changed to a Trace exception stack frame # # Else: (normal case) # # - None (correct result has been stored as appropriate) # # # # ALGORITHM *********************************************************** # # This exception handles 3 types of operations: # # (1) FP Instructions using extended precision or packed immediate # # addressing mode. # # (2) The "fmovm.x" instruction w/ dynamic register specification. # # (3) The "fmovm.l" instruction w/ 2 or 3 control registers. # # # # For immediate data operations, the data is read in w/ a # # _mem_read() "callout", converted to FP binary (if packed), and used # # as the source operand to the instruction specified by the instruction # # word. If no FP exception should be reported ads a result of the # # emulation, then the result is stored to the destination register and # # the handler exits through _fpsp_done(). If an enabled exc has been # # signalled as a result of emulation, then an fsave state frame # # corresponding to the FP exception type must be entered into the 060 # # FPU before exiting. In either the enabled or disabled cases, we # # must also check if a Trace exception is pending, in which case, we # # must create a Trace exception stack frame from the current exception # # stack frame. If no Trace is pending, we simply exit through # # _fpsp_done(). # # For "fmovm.x", call the routine fmovm_dynamic() which will # # decode and emulate the instruction. No FP exceptions can be pending # # as a result of this operation emulation. A Trace exception can be # # pending, though, which means the current stack frame must be changed # # to a Trace stack frame and an exit made through _real_trace(). # # For the case of "fmovm.x Dn,-(a7)", where the offending instruction # # was executed from supervisor mode, this handler must store the FP # # register file values to the system stack by itself since # # fmovm_dynamic() can't handle this. A normal exit is made through # # fpsp_done(). # # For "fmovm.l", fmovm_ctrl() is used to emulate the instruction. # # Again, a Trace exception may be pending and an exit made through # # _real_trace(). Else, a normal exit is made through _fpsp_done(). # # # # Before any of the above is attempted, it must be checked to # # see if the FPU is disabled. Since the "Unimp " exception is taken # # before the "FPU disabled" exception, but the "FPU disabled" exception # # has higher priority, we check the disabled bit in the PCR. If set, # # then we must create an 8 word "FPU disabled" exception stack frame # # from the current 4 word exception stack frame. This includes # # reproducing the effective address of the instruction to put on the # # new stack frame. # # # # In the process of all emulation work, if a _mem_read() # # "callout" returns a failing result indicating an access error, then # # we must create an access error stack frame from the current stack # # frame. This information includes a faulting address and a fault- # # status-longword. These are created within this handler. # # # ######################################################################### global _fpsp_effadd _fpsp_effadd: # This exception type takes priority over the "Line F Emulator" # exception. Therefore, the FPU could be disabled when entering here. # So, we must check to see if it's disabled and handle that case separately. mov.l %d0,-(%sp) # save d0 movc %pcr,%d0 # load proc cr btst &0x1,%d0 # is FPU disabled? bne.w iea_disabled # yes mov.l (%sp)+,%d0 # restore d0 link %a6,&-LOCAL_SIZE # init stack frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # PC of instruction that took the exception is the PC in the frame mov.l EXC_PC(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) # store OPWORD and EXTWORD ######################################################################### tst.w %d0 # is operation fmovem? bmi.w iea_fmovm # yes # # here, we will have: # fabs fdabs fsabs facos fmod # fadd fdadd fsadd fasin frem # fcmp fatan fscale # fdiv fddiv fsdiv fatanh fsin # fint fcos fsincos # fintrz fcosh fsinh # fmove fdmove fsmove fetox ftan # fmul fdmul fsmul fetoxm1 ftanh # fneg fdneg fsneg fgetexp ftentox # fsgldiv fgetman ftwotox # fsglmul flog10 # fsqrt flog2 # fsub fdsub fssub flogn # ftst flognp1 # which can all use f.{x,p} # so, now it's immediate data extended precision AND PACKED FORMAT! # iea_op: andi.l &0x00ff00ff,USER_FPSR(%a6) btst &0xa,%d0 # is src fmt x or p? bne.b iea_op_pack # packed mov.l EXC_EXTWPTR(%a6),%a0 # pass: ptr to # lea FP_SRC(%a6),%a1 # pass: ptr to super addr mov.l &0xc,%d0 # pass: 12 bytes bsr.l _imem_read # read extended immediate tst.l %d1 # did ifetch fail? bne.w iea_iacc # yes bra.b iea_op_setsrc iea_op_pack: mov.l EXC_EXTWPTR(%a6),%a0 # pass: ptr to # lea FP_SRC(%a6),%a1 # pass: ptr to super dst mov.l &0xc,%d0 # pass: 12 bytes bsr.l _imem_read # read packed operand tst.l %d1 # did ifetch fail? bne.w iea_iacc # yes # The packed operand is an INF or a NAN if the exponent field is all ones. bfextu FP_SRC(%a6){&1:&15},%d0 # get exp cmpi.w %d0,&0x7fff # INF or NAN? beq.b iea_op_setsrc # operand is an INF or NAN # The packed operand is a zero if the mantissa is all zero, else it's # a normal packed op. mov.b 3+FP_SRC(%a6),%d0 # get byte 4 andi.b &0x0f,%d0 # clear all but last nybble bne.b iea_op_gp_not_spec # not a zero tst.l FP_SRC_HI(%a6) # is lw 2 zero? bne.b iea_op_gp_not_spec # not a zero tst.l FP_SRC_LO(%a6) # is lw 3 zero? beq.b iea_op_setsrc # operand is a ZERO iea_op_gp_not_spec: lea FP_SRC(%a6),%a0 # pass: ptr to packed op bsr.l decbin # convert to extended fmovm.x &0x80,FP_SRC(%a6) # make this the srcop iea_op_setsrc: addi.l &0xc,EXC_EXTWPTR(%a6) # update extension word pointer # FP_SRC now holds the src operand. lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l set_tag_x # tag the operand type mov.b %d0,STAG(%a6) # could be ANYTHING!!! cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b iea_op_getdst # no bsr.l unnorm_fix # yes; convert to NORM/DENORM/ZERO mov.b %d0,STAG(%a6) # set new optype tag iea_op_getdst: clr.b STORE_FLG(%a6) # clear "store result" boolean btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? beq.b iea_op_extract # monadic btst &0x4,1+EXC_CMDREG(%a6) # is operation fsincos,ftst,fcmp? bne.b iea_op_spec # yes iea_op_loaddst: bfextu EXC_CMDREG(%a6){&6:&3},%d0 # fetch dst regno bsr.l load_fpn2 # load dst operand lea FP_DST(%a6),%a0 # pass: ptr to dst op bsr.l set_tag_x # tag the operand type mov.b %d0,DTAG(%a6) # could be ANYTHING!!! cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b iea_op_extract # no bsr.l unnorm_fix # yes; convert to NORM/DENORM/ZERO mov.b %d0,DTAG(%a6) # set new optype tag bra.b iea_op_extract # the operation is fsincos, ftst, or fcmp. only fcmp is dyadic iea_op_spec: btst &0x3,1+EXC_CMDREG(%a6) # is operation fsincos? beq.b iea_op_extract # yes # now, we're left with ftst and fcmp. so, first let's tag them so that they don't # store a result. then, only fcmp will branch back and pick up a dst operand. st STORE_FLG(%a6) # don't store a final result btst &0x1,1+EXC_CMDREG(%a6) # is operation fcmp? beq.b iea_op_loaddst # yes iea_op_extract: clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass: rnd mode,prec mov.b 1+EXC_CMDREG(%a6),%d1 andi.w &0x007f,%d1 # extract extension fmov.l &0x0,%fpcr fmov.l &0x0,%fpsr lea FP_SRC(%a6),%a0 lea FP_DST(%a6),%a1 mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr jsr (tbl_unsupp.l,%pc,%d1.l*1) # # Exceptions in order of precedence: # BSUN : none # SNAN : all operations # OPERR : all reg-reg or mem-reg operations that can normally operr # OVFL : same as OPERR # UNFL : same as OPERR # DZ : same as OPERR # INEX2 : same as OPERR # INEX1 : all packed immediate operations # # we determine the highest priority exception(if any) set by the # emulation routine that has also been enabled by the user. mov.b FPCR_ENABLE(%a6),%d0 # fetch exceptions enabled bne.b iea_op_ena # some are enabled # now, we save the result, unless, of course, the operation was ftst or fcmp. # these don't save results. iea_op_save: tst.b STORE_FLG(%a6) # does this op store a result? bne.b iea_op_exit1 # exit with no frestore iea_op_store: bfextu EXC_CMDREG(%a6){&6:&3},%d0 # fetch dst regno bsr.l store_fpreg # store the result iea_op_exit1: mov.l EXC_PC(%a6),USER_FPIAR(%a6) # set FPIAR to "Current PC" mov.l EXC_EXTWPTR(%a6),EXC_PC(%a6) # set "Next PC" in exc frame fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 # unravel the frame btst &0x7,(%sp) # is trace on? bne.w iea_op_trace # yes bra.l _fpsp_done # exit to os iea_op_ena: and.b FPSR_EXCEPT(%a6),%d0 # keep only ones enable and set bfffo %d0{&24:&8},%d0 # find highest priority exception bne.b iea_op_exc # at least one was set # no exception occurred. now, did a disabled, exact overflow occur with inexact # enabled? if so, then we have to stuff an overflow frame into the FPU. btst &ovfl_bit,FPSR_EXCEPT(%a6) # did overflow occur? beq.b iea_op_save iea_op_ovfl: btst &inex2_bit,FPCR_ENABLE(%a6) # is inexact enabled? beq.b iea_op_store # no bra.b iea_op_exc_ovfl # yes # an enabled exception occurred. we have to insert the exception type back into # the machine. iea_op_exc: subi.l &24,%d0 # fix offset to be 0-8 cmpi.b %d0,&0x6 # is exception INEX? bne.b iea_op_exc_force # no # the enabled exception was inexact. so, if it occurs with an overflow # or underflow that was disabled, then we have to force an overflow or # underflow frame. btst &ovfl_bit,FPSR_EXCEPT(%a6) # did overflow occur? bne.b iea_op_exc_ovfl # yes btst &unfl_bit,FPSR_EXCEPT(%a6) # did underflow occur? bne.b iea_op_exc_unfl # yes iea_op_exc_force: mov.w (tbl_iea_except.b,%pc,%d0.w*2),2+FP_SRC(%a6) bra.b iea_op_exit2 # exit with frestore tbl_iea_except: short 0xe002, 0xe006, 0xe004, 0xe005 short 0xe003, 0xe002, 0xe001, 0xe001 iea_op_exc_ovfl: mov.w &0xe005,2+FP_SRC(%a6) bra.b iea_op_exit2 iea_op_exc_unfl: mov.w &0xe003,2+FP_SRC(%a6) iea_op_exit2: mov.l EXC_PC(%a6),USER_FPIAR(%a6) # set FPIAR to "Current PC" mov.l EXC_EXTWPTR(%a6),EXC_PC(%a6) # set "Next PC" in exc frame fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) # restore exceptional state unlk %a6 # unravel the frame btst &0x7,(%sp) # is trace on? bne.b iea_op_trace # yes bra.l _fpsp_done # exit to os # # The opclass two instruction that took an "Unimplemented Effective Address" # exception was being traced. Make the "current" PC the FPIAR and put it in # the trace stack frame then jump to _real_trace(). # # UNIMP EA FRAME TRACE FRAME # ***************** ***************** # * 0x0 * 0x0f0 * * Current * # ***************** * PC * # * Current * ***************** # * PC * * 0x2 * 0x024 * # ***************** ***************** # * SR * * Next * # ***************** * PC * # ***************** # * SR * # ***************** iea_op_trace: mov.l (%sp),-(%sp) # shift stack frame "down" mov.w 0x8(%sp),0x4(%sp) mov.w &0x2024,0x6(%sp) # stk fmt = 0x2; voff = 0x024 fmov.l %fpiar,0x8(%sp) # "Current PC" is in FPIAR bra.l _real_trace ######################################################################### iea_fmovm: btst &14,%d0 # ctrl or data reg beq.w iea_fmovm_ctrl iea_fmovm_data: btst &0x5,EXC_SR(%a6) # user or supervisor mode bne.b iea_fmovm_data_s iea_fmovm_data_u: mov.l %usp,%a0 mov.l %a0,EXC_A7(%a6) # store current a7 bsr.l fmovm_dynamic # do dynamic fmovm mov.l EXC_A7(%a6),%a0 # load possibly new a7 mov.l %a0,%usp # update usp bra.w iea_fmovm_exit iea_fmovm_data_s: clr.b SPCOND_FLG(%a6) lea 0x2+EXC_VOFF(%a6),%a0 mov.l %a0,EXC_A7(%a6) bsr.l fmovm_dynamic # do dynamic fmovm cmpi.b SPCOND_FLG(%a6),&mda7_flg beq.w iea_fmovm_data_predec cmpi.b SPCOND_FLG(%a6),&mia7_flg bne.w iea_fmovm_exit # right now, d0 = the size. # the data has been fetched from the supervisor stack, but we have not # incremented the stack pointer by the appropriate number of bytes. # do it here. iea_fmovm_data_postinc: btst &0x7,EXC_SR(%a6) bne.b iea_fmovm_data_pi_trace mov.w EXC_SR(%a6),(EXC_SR,%a6,%d0) mov.l EXC_EXTWPTR(%a6),(EXC_PC,%a6,%d0) mov.w &0x00f0,(EXC_VOFF,%a6,%d0) lea (EXC_SR,%a6,%d0),%a0 mov.l %a0,EXC_SR(%a6) fmovm.x EXC_FP0(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 mov.l (%sp)+,%sp bra.l _fpsp_done iea_fmovm_data_pi_trace: mov.w EXC_SR(%a6),(EXC_SR-0x4,%a6,%d0) mov.l EXC_EXTWPTR(%a6),(EXC_PC-0x4,%a6,%d0) mov.w &0x2024,(EXC_VOFF-0x4,%a6,%d0) mov.l EXC_PC(%a6),(EXC_VOFF+0x2-0x4,%a6,%d0) lea (EXC_SR-0x4,%a6,%d0),%a0 mov.l %a0,EXC_SR(%a6) fmovm.x EXC_FP0(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 mov.l (%sp)+,%sp bra.l _real_trace # right now, d1 = size and d0 = the strg. iea_fmovm_data_predec: mov.b %d1,EXC_VOFF(%a6) # store strg mov.b %d0,0x1+EXC_VOFF(%a6) # store size fmovm.x EXC_FP0(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 mov.l (%a6),-(%sp) # make a copy of a6 mov.l %d0,-(%sp) # save d0 mov.l %d1,-(%sp) # save d1 mov.l EXC_EXTWPTR(%a6),-(%sp) # make a copy of Next PC clr.l %d0 mov.b 0x1+EXC_VOFF(%a6),%d0 # fetch size neg.l %d0 # get negative of size btst &0x7,EXC_SR(%a6) # is trace enabled? beq.b iea_fmovm_data_p2 mov.w EXC_SR(%a6),(EXC_SR-0x4,%a6,%d0) mov.l EXC_PC(%a6),(EXC_VOFF-0x2,%a6,%d0) mov.l (%sp)+,(EXC_PC-0x4,%a6,%d0) mov.w &0x2024,(EXC_VOFF-0x4,%a6,%d0) pea (%a6,%d0) # create final sp bra.b iea_fmovm_data_p3 iea_fmovm_data_p2: mov.w EXC_SR(%a6),(EXC_SR,%a6,%d0) mov.l (%sp)+,(EXC_PC,%a6,%d0) mov.w &0x00f0,(EXC_VOFF,%a6,%d0) pea (0x4,%a6,%d0) # create final sp iea_fmovm_data_p3: clr.l %d1 mov.b EXC_VOFF(%a6),%d1 # fetch strg tst.b %d1 bpl.b fm_1 fmovm.x &0x80,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_1: lsl.b &0x1,%d1 bpl.b fm_2 fmovm.x &0x40,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_2: lsl.b &0x1,%d1 bpl.b fm_3 fmovm.x &0x20,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_3: lsl.b &0x1,%d1 bpl.b fm_4 fmovm.x &0x10,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_4: lsl.b &0x1,%d1 bpl.b fm_5 fmovm.x &0x08,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_5: lsl.b &0x1,%d1 bpl.b fm_6 fmovm.x &0x04,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_6: lsl.b &0x1,%d1 bpl.b fm_7 fmovm.x &0x02,(0x4+0x8,%a6,%d0) addi.l &0xc,%d0 fm_7: lsl.b &0x1,%d1 bpl.b fm_end fmovm.x &0x01,(0x4+0x8,%a6,%d0) fm_end: mov.l 0x4(%sp),%d1 mov.l 0x8(%sp),%d0 mov.l 0xc(%sp),%a6 mov.l (%sp)+,%sp btst &0x7,(%sp) # is trace enabled? beq.l _fpsp_done bra.l _real_trace ######################################################################### iea_fmovm_ctrl: bsr.l fmovm_ctrl # load ctrl regs iea_fmovm_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 btst &0x7,EXC_SR(%a6) # is trace on? bne.b iea_fmovm_trace # yes mov.l EXC_EXTWPTR(%a6),EXC_PC(%a6) # set Next PC unlk %a6 # unravel the frame bra.l _fpsp_done # exit to os # # The control reg instruction that took an "Unimplemented Effective Address" # exception was being traced. The "Current PC" for the trace frame is the # PC stacked for Unimp EA. The "Next PC" is in EXC_EXTWPTR. # After fixing the stack frame, jump to _real_trace(). # # UNIMP EA FRAME TRACE FRAME # ***************** ***************** # * 0x0 * 0x0f0 * * Current * # ***************** * PC * # * Current * ***************** # * PC * * 0x2 * 0x024 * # ***************** ***************** # * SR * * Next * # ***************** * PC * # ***************** # * SR * # ***************** # this ain't a pretty solution, but it works: # -restore a6 (not with unlk) # -shift stack frame down over where old a6 used to be # -add LOCAL_SIZE to stack pointer iea_fmovm_trace: mov.l (%a6),%a6 # restore frame pointer mov.w EXC_SR+LOCAL_SIZE(%sp),0x0+LOCAL_SIZE(%sp) mov.l EXC_PC+LOCAL_SIZE(%sp),0x8+LOCAL_SIZE(%sp) mov.l EXC_EXTWPTR+LOCAL_SIZE(%sp),0x2+LOCAL_SIZE(%sp) mov.w &0x2024,0x6+LOCAL_SIZE(%sp) # stk fmt = 0x2; voff = 0x024 add.l &LOCAL_SIZE,%sp # clear stack frame bra.l _real_trace ######################################################################### # The FPU is disabled and so we should really have taken the "Line # F Emulator" exception. So, here we create an 8-word stack frame # from our 4-word stack frame. This means we must calculate the length # the faulting instruction to get the "next PC". This is trivial for # immediate operands but requires some extra work for fmovm dynamic # which can use most addressing modes. iea_disabled: mov.l (%sp)+,%d0 # restore d0 link %a6,&-LOCAL_SIZE # init stack frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 # PC of instruction that took the exception is the PC in the frame mov.l EXC_PC(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) # store OPWORD and EXTWORD tst.w %d0 # is instr fmovm? bmi.b iea_dis_fmovm # yes # instruction is using an extended precision immediate operand. Therefore, # the total instruction length is 16 bytes. iea_dis_immed: mov.l &0x10,%d0 # 16 bytes of instruction bra.b iea_dis_cont iea_dis_fmovm: btst &0xe,%d0 # is instr fmovm ctrl bne.b iea_dis_fmovm_data # no # the instruction is a fmovm.l with 2 or 3 registers. bfextu %d0{&19:&3},%d1 mov.l &0xc,%d0 cmpi.b %d1,&0x7 # move all regs? bne.b iea_dis_cont addq.l &0x4,%d0 bra.b iea_dis_cont # the instruction is an fmovm.x dynamic which can use many addressing # modes and thus can have several different total instruction lengths. # call fmovm_calc_ea which will go through the ea calc process and, # as a by-product, will tell us how long the instruction is. iea_dis_fmovm_data: clr.l %d0 bsr.l fmovm_calc_ea mov.l EXC_EXTWPTR(%a6),%d0 sub.l EXC_PC(%a6),%d0 iea_dis_cont: mov.w %d0,EXC_VOFF(%a6) # store stack shift value movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 # here, we actually create the 8-word frame from the 4-word frame, # with the "next PC" as additional info. # the field is let as undefined. subq.l &0x8,%sp # make room for new stack mov.l %d0,-(%sp) # save d0 mov.w 0xc(%sp),0x4(%sp) # move SR mov.l 0xe(%sp),0x6(%sp) # move Current PC clr.l %d0 mov.w 0x12(%sp),%d0 mov.l 0x6(%sp),0x10(%sp) # move Current PC add.l %d0,0x6(%sp) # make Next PC mov.w &0x402c,0xa(%sp) # insert offset,frame format mov.l (%sp)+,%d0 # restore d0 bra.l _real_fpu_disabled ########## iea_iacc: movc %pcr,%d0 btst &0x1,%d0 bne.b iea_iacc_cont fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 on stack iea_iacc_cont: movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 subq.w &0x8,%sp # make stack frame bigger mov.l 0x8(%sp),(%sp) # store SR,hi(PC) mov.w 0xc(%sp),0x4(%sp) # store lo(PC) mov.w &0x4008,0x6(%sp) # store voff mov.l 0x2(%sp),0x8(%sp) # store ea mov.l &0x09428001,0xc(%sp) # store fslw iea_acc_done: btst &0x5,(%sp) # user or supervisor mode? beq.b iea_acc_done2 # user bset &0x2,0xd(%sp) # set supervisor TM bit iea_acc_done2: bra.l _real_access iea_dacc: lea -LOCAL_SIZE(%a6),%sp movc %pcr,%d1 btst &0x1,%d1 bne.b iea_dacc_cont fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 on stack fmovm.l LOCAL_SIZE+USER_FPCR(%sp),%fpcr,%fpsr,%fpiar # restore ctrl regs iea_dacc_cont: mov.l (%a6),%a6 mov.l 0x4+LOCAL_SIZE(%sp),-0x8+0x4+LOCAL_SIZE(%sp) mov.w 0x8+LOCAL_SIZE(%sp),-0x8+0x8+LOCAL_SIZE(%sp) mov.w &0x4008,-0x8+0xa+LOCAL_SIZE(%sp) mov.l %a0,-0x8+0xc+LOCAL_SIZE(%sp) mov.w %d0,-0x8+0x10+LOCAL_SIZE(%sp) mov.w &0x0001,-0x8+0x12+LOCAL_SIZE(%sp) movm.l LOCAL_SIZE+EXC_DREGS(%sp),&0x0303 # restore d0-d1/a0-a1 add.w &LOCAL_SIZE-0x4,%sp bra.b iea_acc_done ######################################################################### # XDEF **************************************************************** # # _fpsp_operr(): 060FPSP entry point for FP Operr exception. # # # # This handler should be the first code executed upon taking the # # FP Operand Error exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword # # fix_skewed_ops() - adjust src operand in fsave frame # # _real_operr() - "callout" to operating system operr handler # # _dmem_write_{byte,word,long}() - store data to mem (opclass 3) # # store_dreg_{b,w,l}() - store data to data regfile (opclass 3) # # facc_out_{b,w,l}() - store to memory took access error (opcl 3) # # # # INPUT *************************************************************** # # - The system stack contains the FP Operr exception frame # # - The fsave frame contains the source operand # # # # OUTPUT ************************************************************** # # No access error: # # - The system stack is unchanged # # - The fsave frame contains the adjusted src op for opclass 0,2 # # # # ALGORITHM *********************************************************** # # In a system where the FP Operr exception is enabled, the goal # # is to get to the handler specified at _real_operr(). But, on the 060, # # for opclass zero and two instruction taking this exception, the # # input operand in the fsave frame may be incorrect for some cases # # and needs to be corrected. This handler calls fix_skewed_ops() to # # do just this and then exits through _real_operr(). # # For opclass 3 instructions, the 060 doesn't store the default # # operr result out to memory or data register file as it should. # # This code must emulate the move out before finally exiting through # # _real_inex(). The move out, if to memory, is performed using # # _mem_write() "callout" routines that may return a failing result. # # In this special case, the handler must exit through facc_out() # # which creates an access error stack frame from the current operr # # stack frame. # # # ######################################################################### global _fpsp_operr _fpsp_operr: link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # grab the "busy" frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # the FPIAR holds the "current PC" of the faulting instruction mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) ############################################################################## btst &13,%d0 # is instr an fmove out? bne.b foperr_out # fmove out # here, we simply see if the operand in the fsave frame needs to be "unskewed". # this would be the case for opclass two operations with a source infinity or # denorm operand in the sgl or dbl format. NANs also become skewed, but can't # cause an operr so we don't need to check for them here. lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l fix_skewed_ops # fix src op foperr_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) unlk %a6 bra.l _real_operr ######################################################################## # # the hardware does not save the default result to memory on enabled # operand error exceptions. we do this here before passing control to # the user operand error handler. # # byte, word, and long destination format operations can pass # through here. we simply need to test the sign of the src # operand and save the appropriate minimum or maximum integer value # to the effective address as pointed to by the stacked effective address. # # although packed opclass three operations can take operand error # exceptions, they won't pass through here since they are caught # first by the unsupported data format exception handler. that handler # sends them directly to _real_operr() if necessary. # foperr_out: mov.w FP_SRC_EX(%a6),%d1 # fetch exponent andi.w &0x7fff,%d1 cmpi.w %d1,&0x7fff bne.b foperr_out_not_qnan # the operand is either an infinity or a QNAN. tst.l FP_SRC_LO(%a6) bne.b foperr_out_qnan mov.l FP_SRC_HI(%a6),%d1 andi.l &0x7fffffff,%d1 beq.b foperr_out_not_qnan foperr_out_qnan: mov.l FP_SRC_HI(%a6),L_SCR1(%a6) bra.b foperr_out_jmp foperr_out_not_qnan: mov.l &0x7fffffff,%d1 tst.b FP_SRC_EX(%a6) bpl.b foperr_out_not_qnan2 addq.l &0x1,%d1 foperr_out_not_qnan2: mov.l %d1,L_SCR1(%a6) foperr_out_jmp: bfextu %d0{&19:&3},%d0 # extract dst format field mov.b 1+EXC_OPWORD(%a6),%d1 # extract mode,reg mov.w (tbl_operr.b,%pc,%d0.w*2),%a0 jmp (tbl_operr.b,%pc,%a0) tbl_operr: short foperr_out_l - tbl_operr # long word integer short tbl_operr - tbl_operr # sgl prec shouldn't happen short tbl_operr - tbl_operr # ext prec shouldn't happen short foperr_exit - tbl_operr # packed won't enter here short foperr_out_w - tbl_operr # word integer short tbl_operr - tbl_operr # dbl prec shouldn't happen short foperr_out_b - tbl_operr # byte integer short tbl_operr - tbl_operr # packed won't enter here foperr_out_b: mov.b L_SCR1(%a6),%d0 # load positive default result cmpi.b %d1,&0x7 # is mode a data reg? ble.b foperr_out_b_save_dn # yes mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_byte # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_b # yes bra.w foperr_exit foperr_out_b_save_dn: andi.w &0x0007,%d1 bsr.l store_dreg_b # store result to regfile bra.w foperr_exit foperr_out_w: mov.w L_SCR1(%a6),%d0 # load positive default result cmpi.b %d1,&0x7 # is mode a data reg? ble.b foperr_out_w_save_dn # yes mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_word # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_w # yes bra.w foperr_exit foperr_out_w_save_dn: andi.w &0x0007,%d1 bsr.l store_dreg_w # store result to regfile bra.w foperr_exit foperr_out_l: mov.l L_SCR1(%a6),%d0 # load positive default result cmpi.b %d1,&0x7 # is mode a data reg? ble.b foperr_out_l_save_dn # yes mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_long # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_l # yes bra.w foperr_exit foperr_out_l_save_dn: andi.w &0x0007,%d1 bsr.l store_dreg_l # store result to regfile bra.w foperr_exit ######################################################################### # XDEF **************************************************************** # # _fpsp_snan(): 060FPSP entry point for FP SNAN exception. # # # # This handler should be the first code executed upon taking the # # FP Signalling NAN exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword # # fix_skewed_ops() - adjust src operand in fsave frame # # _real_snan() - "callout" to operating system SNAN handler # # _dmem_write_{byte,word,long}() - store data to mem (opclass 3) # # store_dreg_{b,w,l}() - store data to data regfile (opclass 3) # # facc_out_{b,w,l,d,x}() - store to mem took acc error (opcl 3) # # _calc_ea_fout() - fix An if is -() or ()+; also get # # # # INPUT *************************************************************** # # - The system stack contains the FP SNAN exception frame # # - The fsave frame contains the source operand # # # # OUTPUT ************************************************************** # # No access error: # # - The system stack is unchanged # # - The fsave frame contains the adjusted src op for opclass 0,2 # # # # ALGORITHM *********************************************************** # # In a system where the FP SNAN exception is enabled, the goal # # is to get to the handler specified at _real_snan(). But, on the 060, # # for opclass zero and two instructions taking this exception, the # # input operand in the fsave frame may be incorrect for some cases # # and needs to be corrected. This handler calls fix_skewed_ops() to # # do just this and then exits through _real_snan(). # # For opclass 3 instructions, the 060 doesn't store the default # # SNAN result out to memory or data register file as it should. # # This code must emulate the move out before finally exiting through # # _real_snan(). The move out, if to memory, is performed using # # _mem_write() "callout" routines that may return a failing result. # # In this special case, the handler must exit through facc_out() # # which creates an access error stack frame from the current SNAN # # stack frame. # # For the case of an extended precision opclass 3 instruction, # # if the effective addressing mode was -() or ()+, then the address # # register must get updated by calling _calc_ea_fout(). If the # # was -(a7) from supervisor mode, then the exception frame currently # # on the system stack must be carefully moved "down" to make room # # for the operand being moved. # # # ######################################################################### global _fpsp_snan _fpsp_snan: link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # grab the "busy" frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # the FPIAR holds the "current PC" of the faulting instruction mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) ############################################################################## btst &13,%d0 # is instr an fmove out? bne.w fsnan_out # fmove out # here, we simply see if the operand in the fsave frame needs to be "unskewed". # this would be the case for opclass two operations with a source infinity or # denorm operand in the sgl or dbl format. NANs also become skewed and must be # fixed here. lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l fix_skewed_ops # fix src op fsnan_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) unlk %a6 bra.l _real_snan ######################################################################## # # the hardware does not save the default result to memory on enabled # snan exceptions. we do this here before passing control to # the user snan handler. # # byte, word, long, and packed destination format operations can pass # through here. since packed format operations already were handled by # fpsp_unsupp(), then we need to do nothing else for them here. # for byte, word, and long, we simply need to test the sign of the src # operand and save the appropriate minimum or maximum integer value # to the effective address as pointed to by the stacked effective address. # fsnan_out: bfextu %d0{&19:&3},%d0 # extract dst format field mov.b 1+EXC_OPWORD(%a6),%d1 # extract mode,reg mov.w (tbl_snan.b,%pc,%d0.w*2),%a0 jmp (tbl_snan.b,%pc,%a0) tbl_snan: short fsnan_out_l - tbl_snan # long word integer short fsnan_out_s - tbl_snan # sgl prec shouldn't happen short fsnan_out_x - tbl_snan # ext prec shouldn't happen short tbl_snan - tbl_snan # packed needs no help short fsnan_out_w - tbl_snan # word integer short fsnan_out_d - tbl_snan # dbl prec shouldn't happen short fsnan_out_b - tbl_snan # byte integer short tbl_snan - tbl_snan # packed needs no help fsnan_out_b: mov.b FP_SRC_HI(%a6),%d0 # load upper byte of SNAN bset &6,%d0 # set SNAN bit cmpi.b %d1,&0x7 # is mode a data reg? ble.b fsnan_out_b_dn # yes mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_byte # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_b # yes bra.w fsnan_exit fsnan_out_b_dn: andi.w &0x0007,%d1 bsr.l store_dreg_b # store result to regfile bra.w fsnan_exit fsnan_out_w: mov.w FP_SRC_HI(%a6),%d0 # load upper word of SNAN bset &14,%d0 # set SNAN bit cmpi.b %d1,&0x7 # is mode a data reg? ble.b fsnan_out_w_dn # yes mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_word # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_w # yes bra.w fsnan_exit fsnan_out_w_dn: andi.w &0x0007,%d1 bsr.l store_dreg_w # store result to regfile bra.w fsnan_exit fsnan_out_l: mov.l FP_SRC_HI(%a6),%d0 # load upper longword of SNAN bset &30,%d0 # set SNAN bit cmpi.b %d1,&0x7 # is mode a data reg? ble.b fsnan_out_l_dn # yes mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_long # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_l # yes bra.w fsnan_exit fsnan_out_l_dn: andi.w &0x0007,%d1 bsr.l store_dreg_l # store result to regfile bra.w fsnan_exit fsnan_out_s: cmpi.b %d1,&0x7 # is mode a data reg? ble.b fsnan_out_d_dn # yes mov.l FP_SRC_EX(%a6),%d0 # fetch SNAN sign andi.l &0x80000000,%d0 # keep sign ori.l &0x7fc00000,%d0 # insert new exponent,SNAN bit mov.l FP_SRC_HI(%a6),%d1 # load mantissa lsr.l &0x8,%d1 # shift mantissa for sgl or.l %d1,%d0 # create sgl SNAN mov.l EXC_EA(%a6),%a0 # pass: of default result bsr.l _dmem_write_long # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_l # yes bra.w fsnan_exit fsnan_out_d_dn: mov.l FP_SRC_EX(%a6),%d0 # fetch SNAN sign andi.l &0x80000000,%d0 # keep sign ori.l &0x7fc00000,%d0 # insert new exponent,SNAN bit mov.l %d1,-(%sp) mov.l FP_SRC_HI(%a6),%d1 # load mantissa lsr.l &0x8,%d1 # shift mantissa for sgl or.l %d1,%d0 # create sgl SNAN mov.l (%sp)+,%d1 andi.w &0x0007,%d1 bsr.l store_dreg_l # store result to regfile bra.w fsnan_exit fsnan_out_d: mov.l FP_SRC_EX(%a6),%d0 # fetch SNAN sign andi.l &0x80000000,%d0 # keep sign ori.l &0x7ff80000,%d0 # insert new exponent,SNAN bit mov.l FP_SRC_HI(%a6),%d1 # load hi mantissa mov.l %d0,FP_SCR0_EX(%a6) # store to temp space mov.l &11,%d0 # load shift amt lsr.l %d0,%d1 or.l %d1,FP_SCR0_EX(%a6) # create dbl hi mov.l FP_SRC_HI(%a6),%d1 # load hi mantissa andi.l &0x000007ff,%d1 ror.l %d0,%d1 mov.l %d1,FP_SCR0_HI(%a6) # store to temp space mov.l FP_SRC_LO(%a6),%d1 # load lo mantissa lsr.l %d0,%d1 or.l %d1,FP_SCR0_HI(%a6) # create dbl lo lea FP_SCR0(%a6),%a0 # pass: ptr to operand mov.l EXC_EA(%a6),%a1 # pass: dst addr movq.l &0x8,%d0 # pass: size of 8 bytes bsr.l _dmem_write # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_d # yes bra.w fsnan_exit # for extended precision, if the addressing mode is pre-decrement or # post-increment, then the address register did not get updated. # in addition, for pre-decrement, the stacked is incorrect. fsnan_out_x: clr.b SPCOND_FLG(%a6) # clear special case flag mov.w FP_SRC_EX(%a6),FP_SCR0_EX(%a6) clr.w 2+FP_SCR0(%a6) mov.l FP_SRC_HI(%a6),%d0 bset &30,%d0 mov.l %d0,FP_SCR0_HI(%a6) mov.l FP_SRC_LO(%a6),FP_SCR0_LO(%a6) btst &0x5,EXC_SR(%a6) # supervisor mode exception? bne.b fsnan_out_x_s # yes mov.l %usp,%a0 # fetch user stack pointer mov.l %a0,EXC_A7(%a6) # save on stack for calc_ea() mov.l (%a6),EXC_A6(%a6) bsr.l _calc_ea_fout # find the correct ea,update An mov.l %a0,%a1 mov.l %a0,EXC_EA(%a6) # stack correct mov.l EXC_A7(%a6),%a0 mov.l %a0,%usp # restore user stack pointer mov.l EXC_A6(%a6),(%a6) fsnan_out_x_save: lea FP_SCR0(%a6),%a0 # pass: ptr to operand movq.l &0xc,%d0 # pass: size of extended bsr.l _dmem_write # write the default result tst.l %d1 # did dstore fail? bne.l facc_out_x # yes bra.w fsnan_exit fsnan_out_x_s: mov.l (%a6),EXC_A6(%a6) bsr.l _calc_ea_fout # find the correct ea,update An mov.l %a0,%a1 mov.l %a0,EXC_EA(%a6) # stack correct mov.l EXC_A6(%a6),(%a6) cmpi.b SPCOND_FLG(%a6),&mda7_flg # is mode -(a7)? bne.b fsnan_out_x_save # no # the operation was "fmove.x SNAN,-(a7)" from supervisor mode. fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) mov.l EXC_A6(%a6),%a6 # restore frame pointer mov.l LOCAL_SIZE+EXC_SR(%sp),LOCAL_SIZE+EXC_SR-0xc(%sp) mov.l LOCAL_SIZE+EXC_PC+0x2(%sp),LOCAL_SIZE+EXC_PC+0x2-0xc(%sp) mov.l LOCAL_SIZE+EXC_EA(%sp),LOCAL_SIZE+EXC_EA-0xc(%sp) mov.l LOCAL_SIZE+FP_SCR0_EX(%sp),LOCAL_SIZE+EXC_SR(%sp) mov.l LOCAL_SIZE+FP_SCR0_HI(%sp),LOCAL_SIZE+EXC_PC+0x2(%sp) mov.l LOCAL_SIZE+FP_SCR0_LO(%sp),LOCAL_SIZE+EXC_EA(%sp) add.l &LOCAL_SIZE-0x8,%sp bra.l _real_snan ######################################################################### # XDEF **************************************************************** # # _fpsp_inex(): 060FPSP entry point for FP Inexact exception. # # # # This handler should be the first code executed upon taking the # # FP Inexact exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword # # fix_skewed_ops() - adjust src operand in fsave frame # # set_tag_x() - determine optype of src/dst operands # # store_fpreg() - store opclass 0 or 2 result to FP regfile # # unnorm_fix() - change UNNORM operands to NORM or ZERO # # load_fpn2() - load dst operand from FP regfile # # smovcr() - emulate an "fmovcr" instruction # # fout() - emulate an opclass 3 instruction # # tbl_unsupp - add of table of emulation routines for opclass 0,2 # # _real_inex() - "callout" to operating system inexact handler # # # # INPUT *************************************************************** # # - The system stack contains the FP Inexact exception frame # # - The fsave frame contains the source operand # # # # OUTPUT ************************************************************** # # - The system stack is unchanged # # - The fsave frame contains the adjusted src op for opclass 0,2 # # # # ALGORITHM *********************************************************** # # In a system where the FP Inexact exception is enabled, the goal # # is to get to the handler specified at _real_inex(). But, on the 060, # # for opclass zero and two instruction taking this exception, the # # hardware doesn't store the correct result to the destination FP # # register as did the '040 and '881/2. This handler must emulate the # # instruction in order to get this value and then store it to the # # correct register before calling _real_inex(). # # For opclass 3 instructions, the 060 doesn't store the default # # inexact result out to memory or data register file as it should. # # This code must emulate the move out by calling fout() before finally # # exiting through _real_inex(). # # # ######################################################################### global _fpsp_inex _fpsp_inex: link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # grab the "busy" frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # the FPIAR holds the "current PC" of the faulting instruction mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) ############################################################################## btst &13,%d0 # is instr an fmove out? bne.w finex_out # fmove out # the hardware, for "fabs" and "fneg" w/ a long source format, puts the # longword integer directly into the upper longword of the mantissa along # w/ an exponent value of 0x401e. we convert this to extended precision here. bfextu %d0{&19:&3},%d0 # fetch instr size bne.b finex_cont # instr size is not long cmpi.w FP_SRC_EX(%a6),&0x401e # is exponent 0x401e? bne.b finex_cont # no fmov.l &0x0,%fpcr fmov.l FP_SRC_HI(%a6),%fp0 # load integer src fmov.x %fp0,FP_SRC(%a6) # store integer as extended precision mov.w &0xe001,0x2+FP_SRC(%a6) finex_cont: lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l fix_skewed_ops # fix src op # Here, we zero the ccode and exception byte field since we're going to # emulate the whole instruction. Notice, though, that we don't kill the # INEX1 bit. This is because a packed op has long since been converted # to extended before arriving here. Therefore, we need to retain the # INEX1 bit from when the operand was first converted. andi.l &0x00ff01ff,USER_FPSR(%a6) # zero all but accured field fmov.l &0x0,%fpcr # zero current control regs fmov.l &0x0,%fpsr bfextu EXC_EXTWORD(%a6){&0:&6},%d1 # extract upper 6 of cmdreg cmpi.b %d1,&0x17 # is op an fmovecr? beq.w finex_fmovcr # yes lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l set_tag_x # tag the operand type mov.b %d0,STAG(%a6) # maybe NORM,DENORM # bits four and five of the fp extension word separate the monadic and dyadic # operations that can pass through fpsp_inex(). remember that fcmp and ftst # will never take this exception, but fsincos will. btst &0x5,1+EXC_CMDREG(%a6) # is operation monadic or dyadic? beq.b finex_extract # monadic btst &0x4,1+EXC_CMDREG(%a6) # is operation an fsincos? bne.b finex_extract # yes bfextu EXC_CMDREG(%a6){&6:&3},%d0 # dyadic; load dst reg bsr.l load_fpn2 # load dst into FP_DST lea FP_DST(%a6),%a0 # pass: ptr to dst op bsr.l set_tag_x # tag the operand type cmpi.b %d0,&UNNORM # is operand an UNNORM? bne.b finex_op2_done # no bsr.l unnorm_fix # yes; convert to NORM,DENORM,or ZERO finex_op2_done: mov.b %d0,DTAG(%a6) # save dst optype tag finex_extract: clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec/mode mov.b 1+EXC_CMDREG(%a6),%d1 andi.w &0x007f,%d1 # extract extension lea FP_SRC(%a6),%a0 lea FP_DST(%a6),%a1 mov.l (tbl_unsupp.l,%pc,%d1.w*4),%d1 # fetch routine addr jsr (tbl_unsupp.l,%pc,%d1.l*1) # the operation has been emulated. the result is in fp0. finex_save: bfextu EXC_CMDREG(%a6){&6:&3},%d0 bsr.l store_fpreg finex_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) unlk %a6 bra.l _real_inex finex_fmovcr: clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec,mode mov.b 1+EXC_CMDREG(%a6),%d1 andi.l &0x0000007f,%d1 # pass rom offset bsr.l smovcr bra.b finex_save ######################################################################## # # the hardware does not save the default result to memory on enabled # inexact exceptions. we do this here before passing control to # the user inexact handler. # # byte, word, and long destination format operations can pass # through here. so can double and single precision. # although packed opclass three operations can take inexact # exceptions, they won't pass through here since they are caught # first by the unsupported data format exception handler. that handler # sends them directly to _real_inex() if necessary. # finex_out: mov.b &NORM,STAG(%a6) # src is a NORM clr.l %d0 mov.b FPCR_MODE(%a6),%d0 # pass rnd prec,mode andi.l &0xffff00ff,USER_FPSR(%a6) # zero exception field lea FP_SRC(%a6),%a0 # pass ptr to src operand bsr.l fout # store the default result bra.b finex_exit ######################################################################### # XDEF **************************************************************** # # _fpsp_dz(): 060FPSP entry point for FP DZ exception. # # # # This handler should be the first code executed upon taking # # the FP DZ exception in an operating system. # # # # XREF **************************************************************** # # _imem_read_long() - read instruction longword from memory # # fix_skewed_ops() - adjust fsave operand # # _real_dz() - "callout" exit point from FP DZ handler # # # # INPUT *************************************************************** # # - The system stack contains the FP DZ exception stack. # # - The fsave frame contains the source operand. # # # # OUTPUT ************************************************************** # # - The system stack contains the FP DZ exception stack. # # - The fsave frame contains the adjusted source operand. # # # # ALGORITHM *********************************************************** # # In a system where the DZ exception is enabled, the goal is to # # get to the handler specified at _real_dz(). But, on the 060, when the # # exception is taken, the input operand in the fsave state frame may # # be incorrect for some cases and need to be adjusted. So, this package # # adjusts the operand using fix_skewed_ops() and then branches to # # _real_dz(). # # # ######################################################################### global _fpsp_dz _fpsp_dz: link.w %a6,&-LOCAL_SIZE # init stack frame fsave FP_SRC(%a6) # grab the "busy" frame movm.l &0x0303,EXC_DREGS(%a6) # save d0-d1/a0-a1 fmovm.l %fpcr,%fpsr,%fpiar,USER_FPCR(%a6) # save ctrl regs fmovm.x &0xc0,EXC_FPREGS(%a6) # save fp0-fp1 on stack # the FPIAR holds the "current PC" of the faulting instruction mov.l USER_FPIAR(%a6),EXC_EXTWPTR(%a6) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch the instruction words mov.l %d0,EXC_OPWORD(%a6) ############################################################################## # here, we simply see if the operand in the fsave frame needs to be "unskewed". # this would be the case for opclass two operations with a source zero # in the sgl or dbl format. lea FP_SRC(%a6),%a0 # pass: ptr to src op bsr.l fix_skewed_ops # fix src op fdz_exit: fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 frestore FP_SRC(%a6) unlk %a6 bra.l _real_dz ######################################################################### # XDEF **************************************************************** # # _fpsp_fline(): 060FPSP entry point for "Line F emulator" # # exception when the "reduced" version of the # # FPSP is implemented that does not emulate # # FP unimplemented instructions. # # # # This handler should be the first code executed upon taking a # # "Line F Emulator" exception in an operating system integrating # # the reduced version of 060FPSP. # # # # XREF **************************************************************** # # _real_fpu_disabled() - Handle "FPU disabled" exceptions # # _real_fline() - Handle all other cases (treated equally) # # # # INPUT *************************************************************** # # - The system stack contains a "Line F Emulator" exception # # stack frame. # # # # OUTPUT ************************************************************** # # - The system stack is unchanged. # # # # ALGORITHM *********************************************************** # # When a "Line F Emulator" exception occurs in a system where # # "FPU Unimplemented" instructions will not be emulated, the exception # # can occur because then FPU is disabled or the instruction is to be # # classifed as "Line F". This module determines which case exists and # # calls the appropriate "callout". # # # ######################################################################### global _fpsp_fline _fpsp_fline: # check to see if the FPU is disabled. if so, jump to the OS entry # point for that condition. cmpi.w 0x6(%sp),&0x402c beq.l _real_fpu_disabled bra.l _real_fline ######################################################################### # XDEF **************************************************************** # # _dcalc_ea(): calc correct from stacked on exception # # # # XREF **************************************************************** # # inc_areg() - increment an address register # # dec_areg() - decrement an address register # # # # INPUT *************************************************************** # # d0 = number of bytes to adjust by # # # # OUTPUT ************************************************************** # # None # # # # ALGORITHM *********************************************************** # # "Dummy" CALCulate Effective Address: # # The stacked for FP unimplemented instructions and opclass # # two packed instructions is correct with the exception of... # # # # 1) -(An) : The register is not updated regardless of size. # # Also, for extended precision and packed, the # # stacked value is 8 bytes too big # # 2) (An)+ : The register is not updated. # # 3) # : The upper longword of the immediate operand is # # stacked b,w,l and s sizes are completely stacked. # # d,x, and p are not. # # # ######################################################################### global _dcalc_ea _dcalc_ea: mov.l %d0, %a0 # move # bytes to %a0 mov.b 1+EXC_OPWORD(%a6), %d0 # fetch opcode word mov.l %d0, %d1 # make a copy andi.w &0x38, %d0 # extract mode field andi.l &0x7, %d1 # extract reg field cmpi.b %d0,&0x18 # is mode (An)+ ? beq.b dcea_pi # yes cmpi.b %d0,&0x20 # is mode -(An) ? beq.b dcea_pd # yes or.w %d1,%d0 # concat mode,reg cmpi.b %d0,&0x3c # is mode #? beq.b dcea_imm # yes mov.l EXC_EA(%a6),%a0 # return rts # need to set immediate data flag here since we'll need to do # an imem_read to fetch this later. dcea_imm: mov.b &immed_flg,SPCOND_FLG(%a6) lea ([USER_FPIAR,%a6],0x4),%a0 # no; return rts # here, the is stacked correctly. however, we must update the # address register... dcea_pi: mov.l %a0,%d0 # pass amt to inc by bsr.l inc_areg # inc addr register mov.l EXC_EA(%a6),%a0 # stacked is correct rts # the is stacked correctly for all but extended and packed which # the s are 8 bytes too large. # it would make no sense to have a pre-decrement to a7 in supervisor # mode so we don't even worry about this tricky case here : ) dcea_pd: mov.l %a0,%d0 # pass amt to dec by bsr.l dec_areg # dec addr register mov.l EXC_EA(%a6),%a0 # stacked is correct cmpi.b %d0,&0xc # is opsize ext or packed? beq.b dcea_pd2 # yes rts dcea_pd2: sub.l &0x8,%a0 # correct mov.l %a0,EXC_EA(%a6) # put correct on stack rts ######################################################################### # XDEF **************************************************************** # # _calc_ea_fout(): calculate correct stacked for extended # # and packed data opclass 3 operations. # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # None # # # # OUTPUT ************************************************************** # # a0 = return correct effective address # # # # ALGORITHM *********************************************************** # # For opclass 3 extended and packed data operations, the # # stacked for the exception is incorrect for -(an) and (an)+ addressing # # modes. Also, while we're at it, the index register itself must get # # updated. # # So, for -(an), we must subtract 8 off of the stacked value # # and return that value as the correct and store that value in An. # # For (an)+, the stacked is correct but we must adjust An by +12. # # # ######################################################################### # This calc_ea is currently used to retrieve the correct # for fmove outs of type extended and packed. global _calc_ea_fout _calc_ea_fout: mov.b 1+EXC_OPWORD(%a6),%d0 # fetch opcode word mov.l %d0,%d1 # make a copy andi.w &0x38,%d0 # extract mode field andi.l &0x7,%d1 # extract reg field cmpi.b %d0,&0x18 # is mode (An)+ ? beq.b ceaf_pi # yes cmpi.b %d0,&0x20 # is mode -(An) ? beq.w ceaf_pd # yes mov.l EXC_EA(%a6),%a0 # stacked is correct rts # (An)+ : extended and packed fmove out # : stacked is correct # : "An" not updated ceaf_pi: mov.w (tbl_ceaf_pi.b,%pc,%d1.w*2),%d1 mov.l EXC_EA(%a6),%a0 jmp (tbl_ceaf_pi.b,%pc,%d1.w*1) swbeg &0x8 tbl_ceaf_pi: short ceaf_pi0 - tbl_ceaf_pi short ceaf_pi1 - tbl_ceaf_pi short ceaf_pi2 - tbl_ceaf_pi short ceaf_pi3 - tbl_ceaf_pi short ceaf_pi4 - tbl_ceaf_pi short ceaf_pi5 - tbl_ceaf_pi short ceaf_pi6 - tbl_ceaf_pi short ceaf_pi7 - tbl_ceaf_pi ceaf_pi0: addi.l &0xc,EXC_DREGS+0x8(%a6) rts ceaf_pi1: addi.l &0xc,EXC_DREGS+0xc(%a6) rts ceaf_pi2: add.l &0xc,%a2 rts ceaf_pi3: add.l &0xc,%a3 rts ceaf_pi4: add.l &0xc,%a4 rts ceaf_pi5: add.l &0xc,%a5 rts ceaf_pi6: addi.l &0xc,EXC_A6(%a6) rts ceaf_pi7: mov.b &mia7_flg,SPCOND_FLG(%a6) addi.l &0xc,EXC_A7(%a6) rts # -(An) : extended and packed fmove out # : stacked = actual + 8 # : "An" not updated ceaf_pd: mov.w (tbl_ceaf_pd.b,%pc,%d1.w*2),%d1 mov.l EXC_EA(%a6),%a0 sub.l &0x8,%a0 sub.l &0x8,EXC_EA(%a6) jmp (tbl_ceaf_pd.b,%pc,%d1.w*1) swbeg &0x8 tbl_ceaf_pd: short ceaf_pd0 - tbl_ceaf_pd short ceaf_pd1 - tbl_ceaf_pd short ceaf_pd2 - tbl_ceaf_pd short ceaf_pd3 - tbl_ceaf_pd short ceaf_pd4 - tbl_ceaf_pd short ceaf_pd5 - tbl_ceaf_pd short ceaf_pd6 - tbl_ceaf_pd short ceaf_pd7 - tbl_ceaf_pd ceaf_pd0: mov.l %a0,EXC_DREGS+0x8(%a6) rts ceaf_pd1: mov.l %a0,EXC_DREGS+0xc(%a6) rts ceaf_pd2: mov.l %a0,%a2 rts ceaf_pd3: mov.l %a0,%a3 rts ceaf_pd4: mov.l %a0,%a4 rts ceaf_pd5: mov.l %a0,%a5 rts ceaf_pd6: mov.l %a0,EXC_A6(%a6) rts ceaf_pd7: mov.l %a0,EXC_A7(%a6) mov.b &mda7_flg,SPCOND_FLG(%a6) rts # # This table holds the offsets of the emulation routines for each individual # math operation relative to the address of this table. Included are # routines like fadd/fmul/fabs. The transcendentals ARE NOT. This is because # this table is for the version if the 060FPSP without transcendentals. # The location within the table is determined by the extension bits of the # operation longword. # swbeg &109 tbl_unsupp: long fin - tbl_unsupp # 00: fmove long fint - tbl_unsupp # 01: fint long tbl_unsupp - tbl_unsupp # 02: fsinh long fintrz - tbl_unsupp # 03: fintrz long fsqrt - tbl_unsupp # 04: fsqrt long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp # 06: flognp1 long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp # 08: fetoxm1 long tbl_unsupp - tbl_unsupp # 09: ftanh long tbl_unsupp - tbl_unsupp # 0a: fatan long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp # 0c: fasin long tbl_unsupp - tbl_unsupp # 0d: fatanh long tbl_unsupp - tbl_unsupp # 0e: fsin long tbl_unsupp - tbl_unsupp # 0f: ftan long tbl_unsupp - tbl_unsupp # 10: fetox long tbl_unsupp - tbl_unsupp # 11: ftwotox long tbl_unsupp - tbl_unsupp # 12: ftentox long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp # 14: flogn long tbl_unsupp - tbl_unsupp # 15: flog10 long tbl_unsupp - tbl_unsupp # 16: flog2 long tbl_unsupp - tbl_unsupp long fabs - tbl_unsupp # 18: fabs long tbl_unsupp - tbl_unsupp # 19: fcosh long fneg - tbl_unsupp # 1a: fneg long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp # 1c: facos long tbl_unsupp - tbl_unsupp # 1d: fcos long tbl_unsupp - tbl_unsupp # 1e: fgetexp long tbl_unsupp - tbl_unsupp # 1f: fgetman long fdiv - tbl_unsupp # 20: fdiv long tbl_unsupp - tbl_unsupp # 21: fmod long fadd - tbl_unsupp # 22: fadd long fmul - tbl_unsupp # 23: fmul long fsgldiv - tbl_unsupp # 24: fsgldiv long tbl_unsupp - tbl_unsupp # 25: frem long tbl_unsupp - tbl_unsupp # 26: fscale long fsglmul - tbl_unsupp # 27: fsglmul long fsub - tbl_unsupp # 28: fsub long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp # 30: fsincos long tbl_unsupp - tbl_unsupp # 31: fsincos long tbl_unsupp - tbl_unsupp # 32: fsincos long tbl_unsupp - tbl_unsupp # 33: fsincos long tbl_unsupp - tbl_unsupp # 34: fsincos long tbl_unsupp - tbl_unsupp # 35: fsincos long tbl_unsupp - tbl_unsupp # 36: fsincos long tbl_unsupp - tbl_unsupp # 37: fsincos long fcmp - tbl_unsupp # 38: fcmp long tbl_unsupp - tbl_unsupp long ftst - tbl_unsupp # 3a: ftst long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long fsin - tbl_unsupp # 40: fsmove long fssqrt - tbl_unsupp # 41: fssqrt long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long fdin - tbl_unsupp # 44: fdmove long fdsqrt - tbl_unsupp # 45: fdsqrt long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long fsabs - tbl_unsupp # 58: fsabs long tbl_unsupp - tbl_unsupp long fsneg - tbl_unsupp # 5a: fsneg long tbl_unsupp - tbl_unsupp long fdabs - tbl_unsupp # 5c: fdabs long tbl_unsupp - tbl_unsupp long fdneg - tbl_unsupp # 5e: fdneg long tbl_unsupp - tbl_unsupp long fsdiv - tbl_unsupp # 60: fsdiv long tbl_unsupp - tbl_unsupp long fsadd - tbl_unsupp # 62: fsadd long fsmul - tbl_unsupp # 63: fsmul long fddiv - tbl_unsupp # 64: fddiv long tbl_unsupp - tbl_unsupp long fdadd - tbl_unsupp # 66: fdadd long fdmul - tbl_unsupp # 67: fdmul long fssub - tbl_unsupp # 68: fssub long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long tbl_unsupp - tbl_unsupp long fdsub - tbl_unsupp # 6c: fdsub ################################################# # Add this here so non-fp modules can compile. # (smovcr is called from fpsp_inex.) global smovcr smovcr: bra.b smovcr ######################################################################### # XDEF **************************************************************** # # fmovm_dynamic(): emulate "fmovm" dynamic instruction # # # # XREF **************************************************************** # # fetch_dreg() - fetch data register # # {i,d,}mem_read() - fetch data from memory # # _mem_write() - write data to memory # # iea_iacc() - instruction memory access error occurred # # iea_dacc() - data memory access error occurred # # restore() - restore An index regs if access error occurred # # # # INPUT *************************************************************** # # None # # # # OUTPUT ************************************************************** # # If instr is "fmovm Dn,-(A7)" from supervisor mode, # # d0 = size of dump # # d1 = Dn # # Else if instruction access error, # # d0 = FSLW # # Else if data access error, # # d0 = FSLW # # a0 = address of fault # # Else # # none. # # # # ALGORITHM *********************************************************** # # The effective address must be calculated since this is entered # # from an "Unimplemented Effective Address" exception handler. So, we # # have our own fcalc_ea() routine here. If an access error is flagged # # by a _{i,d,}mem_read() call, we must exit through the special # # handler. # # The data register is determined and its value loaded to get the # # string of FP registers affected. This value is used as an index into # # a lookup table such that we can determine the number of bytes # # involved. # # If the instruction is "fmovm.x ,Dn", a _mem_read() is used # # to read in all FP values. Again, _mem_read() may fail and require a # # special exit. # # If the instruction is "fmovm.x DN,", a _mem_write() is used # # to write all FP values. _mem_write() may also fail. # # If the instruction is "fmovm.x DN,-(a7)" from supervisor mode, # # then we return the size of the dump and the string to the caller # # so that the move can occur outside of this routine. This special # # case is required so that moves to the system stack are handled # # correctly. # # # # DYNAMIC: # # fmovm.x dn, # # fmovm.x , dn # # # # # # 1111 0010 00 || 11@& 1000 0$$$ 0000 # # # # & = (0): predecrement addressing mode # # (1): postincrement or control addressing mode # # @ = (0): move listed regs from memory to the FPU # # (1): move listed regs from the FPU to memory # # $$$ : index of data register holding reg select mask # # # # NOTES: # # If the data register holds a zero, then the # # instruction is a nop. # # # ######################################################################### global fmovm_dynamic fmovm_dynamic: # extract the data register in which the bit string resides... mov.b 1+EXC_EXTWORD(%a6),%d1 # fetch extword andi.w &0x70,%d1 # extract reg bits lsr.b &0x4,%d1 # shift into lo bits # fetch the bit string into d0... bsr.l fetch_dreg # fetch reg string andi.l &0x000000ff,%d0 # keep only lo byte mov.l %d0,-(%sp) # save strg mov.b (tbl_fmovm_size.w,%pc,%d0),%d0 mov.l %d0,-(%sp) # save size bsr.l fmovm_calc_ea # calculate mov.l (%sp)+,%d0 # restore size mov.l (%sp)+,%d1 # restore strg # if the bit string is a zero, then the operation is a no-op # but, make sure that we've calculated ea and advanced the opword pointer beq.w fmovm_data_done # separate move ins from move outs... btst &0x5,EXC_EXTWORD(%a6) # is it a move in or out? beq.w fmovm_data_in # it's a move out ############# # MOVE OUT: # ############# fmovm_data_out: btst &0x4,EXC_EXTWORD(%a6) # control or predecrement? bne.w fmovm_out_ctrl # control ############################ fmovm_out_predec: # for predecrement mode, the bit string is the opposite of both control # operations and postincrement mode. (bit7 = FP7 ... bit0 = FP0) # here, we convert it to be just like the others... mov.b (tbl_fmovm_convert.w,%pc,%d1.w*1),%d1 btst &0x5,EXC_SR(%a6) # user or supervisor mode? beq.b fmovm_out_ctrl # user fmovm_out_predec_s: cmpi.b SPCOND_FLG(%a6),&mda7_flg # is mode -(a7)? bne.b fmovm_out_ctrl # the operation was unfortunately an: fmovm.x dn,-(sp) # called from supervisor mode. # we're also passing "size" and "strg" back to the calling routine rts ############################ fmovm_out_ctrl: mov.l %a0,%a1 # move to a1 sub.l %d0,%sp # subtract size of dump lea (%sp),%a0 tst.b %d1 # should FP0 be moved? bpl.b fmovm_out_ctrl_fp1 # no mov.l 0x0+EXC_FP0(%a6),(%a0)+ # yes mov.l 0x4+EXC_FP0(%a6),(%a0)+ mov.l 0x8+EXC_FP0(%a6),(%a0)+ fmovm_out_ctrl_fp1: lsl.b &0x1,%d1 # should FP1 be moved? bpl.b fmovm_out_ctrl_fp2 # no mov.l 0x0+EXC_FP1(%a6),(%a0)+ # yes mov.l 0x4+EXC_FP1(%a6),(%a0)+ mov.l 0x8+EXC_FP1(%a6),(%a0)+ fmovm_out_ctrl_fp2: lsl.b &0x1,%d1 # should FP2 be moved? bpl.b fmovm_out_ctrl_fp3 # no fmovm.x &0x20,(%a0) # yes add.l &0xc,%a0 fmovm_out_ctrl_fp3: lsl.b &0x1,%d1 # should FP3 be moved? bpl.b fmovm_out_ctrl_fp4 # no fmovm.x &0x10,(%a0) # yes add.l &0xc,%a0 fmovm_out_ctrl_fp4: lsl.b &0x1,%d1 # should FP4 be moved? bpl.b fmovm_out_ctrl_fp5 # no fmovm.x &0x08,(%a0) # yes add.l &0xc,%a0 fmovm_out_ctrl_fp5: lsl.b &0x1,%d1 # should FP5 be moved? bpl.b fmovm_out_ctrl_fp6 # no fmovm.x &0x04,(%a0) # yes add.l &0xc,%a0 fmovm_out_ctrl_fp6: lsl.b &0x1,%d1 # should FP6 be moved? bpl.b fmovm_out_ctrl_fp7 # no fmovm.x &0x02,(%a0) # yes add.l &0xc,%a0 fmovm_out_ctrl_fp7: lsl.b &0x1,%d1 # should FP7 be moved? bpl.b fmovm_out_ctrl_done # no fmovm.x &0x01,(%a0) # yes add.l &0xc,%a0 fmovm_out_ctrl_done: mov.l %a1,L_SCR1(%a6) lea (%sp),%a0 # pass: supervisor src mov.l %d0,-(%sp) # save size bsr.l _dmem_write # copy data to user mem mov.l (%sp)+,%d0 add.l %d0,%sp # clear fpreg data from stack tst.l %d1 # did dstore err? bne.w fmovm_out_err # yes rts ############ # MOVE IN: # ############ fmovm_data_in: mov.l %a0,L_SCR1(%a6) sub.l %d0,%sp # make room for fpregs lea (%sp),%a1 mov.l %d1,-(%sp) # save bit string for later mov.l %d0,-(%sp) # save # of bytes bsr.l _dmem_read # copy data from user mem mov.l (%sp)+,%d0 # retrieve # of bytes tst.l %d1 # did dfetch fail? bne.w fmovm_in_err # yes mov.l (%sp)+,%d1 # load bit string lea (%sp),%a0 # addr of stack tst.b %d1 # should FP0 be moved? bpl.b fmovm_data_in_fp1 # no mov.l (%a0)+,0x0+EXC_FP0(%a6) # yes mov.l (%a0)+,0x4+EXC_FP0(%a6) mov.l (%a0)+,0x8+EXC_FP0(%a6) fmovm_data_in_fp1: lsl.b &0x1,%d1 # should FP1 be moved? bpl.b fmovm_data_in_fp2 # no mov.l (%a0)+,0x0+EXC_FP1(%a6) # yes mov.l (%a0)+,0x4+EXC_FP1(%a6) mov.l (%a0)+,0x8+EXC_FP1(%a6) fmovm_data_in_fp2: lsl.b &0x1,%d1 # should FP2 be moved? bpl.b fmovm_data_in_fp3 # no fmovm.x (%a0)+,&0x20 # yes fmovm_data_in_fp3: lsl.b &0x1,%d1 # should FP3 be moved? bpl.b fmovm_data_in_fp4 # no fmovm.x (%a0)+,&0x10 # yes fmovm_data_in_fp4: lsl.b &0x1,%d1 # should FP4 be moved? bpl.b fmovm_data_in_fp5 # no fmovm.x (%a0)+,&0x08 # yes fmovm_data_in_fp5: lsl.b &0x1,%d1 # should FP5 be moved? bpl.b fmovm_data_in_fp6 # no fmovm.x (%a0)+,&0x04 # yes fmovm_data_in_fp6: lsl.b &0x1,%d1 # should FP6 be moved? bpl.b fmovm_data_in_fp7 # no fmovm.x (%a0)+,&0x02 # yes fmovm_data_in_fp7: lsl.b &0x1,%d1 # should FP7 be moved? bpl.b fmovm_data_in_done # no fmovm.x (%a0)+,&0x01 # yes fmovm_data_in_done: add.l %d0,%sp # remove fpregs from stack rts ##################################### fmovm_data_done: rts ############################################################################## # # table indexed by the operation's bit string that gives the number # of bytes that will be moved. # # number of bytes = (# of 1's in bit string) * 12(bytes/fpreg) # tbl_fmovm_size: byte 0x00,0x0c,0x0c,0x18,0x0c,0x18,0x18,0x24 byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 byte 0x0c,0x18,0x18,0x24,0x18,0x24,0x24,0x30 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 byte 0x18,0x24,0x24,0x30,0x24,0x30,0x30,0x3c byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 byte 0x24,0x30,0x30,0x3c,0x30,0x3c,0x3c,0x48 byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 byte 0x30,0x3c,0x3c,0x48,0x3c,0x48,0x48,0x54 byte 0x3c,0x48,0x48,0x54,0x48,0x54,0x54,0x60 # # table to convert a pre-decrement bit string into a post-increment # or control bit string. # ex: 0x00 ==> 0x00 # 0x01 ==> 0x80 # 0x02 ==> 0x40 # . # . # 0xfd ==> 0xbf # 0xfe ==> 0x7f # 0xff ==> 0xff # tbl_fmovm_convert: byte 0x00,0x80,0x40,0xc0,0x20,0xa0,0x60,0xe0 byte 0x10,0x90,0x50,0xd0,0x30,0xb0,0x70,0xf0 byte 0x08,0x88,0x48,0xc8,0x28,0xa8,0x68,0xe8 byte 0x18,0x98,0x58,0xd8,0x38,0xb8,0x78,0xf8 byte 0x04,0x84,0x44,0xc4,0x24,0xa4,0x64,0xe4 byte 0x14,0x94,0x54,0xd4,0x34,0xb4,0x74,0xf4 byte 0x0c,0x8c,0x4c,0xcc,0x2c,0xac,0x6c,0xec byte 0x1c,0x9c,0x5c,0xdc,0x3c,0xbc,0x7c,0xfc byte 0x02,0x82,0x42,0xc2,0x22,0xa2,0x62,0xe2 byte 0x12,0x92,0x52,0xd2,0x32,0xb2,0x72,0xf2 byte 0x0a,0x8a,0x4a,0xca,0x2a,0xaa,0x6a,0xea byte 0x1a,0x9a,0x5a,0xda,0x3a,0xba,0x7a,0xfa byte 0x06,0x86,0x46,0xc6,0x26,0xa6,0x66,0xe6 byte 0x16,0x96,0x56,0xd6,0x36,0xb6,0x76,0xf6 byte 0x0e,0x8e,0x4e,0xce,0x2e,0xae,0x6e,0xee byte 0x1e,0x9e,0x5e,0xde,0x3e,0xbe,0x7e,0xfe byte 0x01,0x81,0x41,0xc1,0x21,0xa1,0x61,0xe1 byte 0x11,0x91,0x51,0xd1,0x31,0xb1,0x71,0xf1 byte 0x09,0x89,0x49,0xc9,0x29,0xa9,0x69,0xe9 byte 0x19,0x99,0x59,0xd9,0x39,0xb9,0x79,0xf9 byte 0x05,0x85,0x45,0xc5,0x25,0xa5,0x65,0xe5 byte 0x15,0x95,0x55,0xd5,0x35,0xb5,0x75,0xf5 byte 0x0d,0x8d,0x4d,0xcd,0x2d,0xad,0x6d,0xed byte 0x1d,0x9d,0x5d,0xdd,0x3d,0xbd,0x7d,0xfd byte 0x03,0x83,0x43,0xc3,0x23,0xa3,0x63,0xe3 byte 0x13,0x93,0x53,0xd3,0x33,0xb3,0x73,0xf3 byte 0x0b,0x8b,0x4b,0xcb,0x2b,0xab,0x6b,0xeb byte 0x1b,0x9b,0x5b,0xdb,0x3b,0xbb,0x7b,0xfb byte 0x07,0x87,0x47,0xc7,0x27,0xa7,0x67,0xe7 byte 0x17,0x97,0x57,0xd7,0x37,0xb7,0x77,0xf7 byte 0x0f,0x8f,0x4f,0xcf,0x2f,0xaf,0x6f,0xef byte 0x1f,0x9f,0x5f,0xdf,0x3f,0xbf,0x7f,0xff global fmovm_calc_ea ############################################### # _fmovm_calc_ea: calculate effective address # ############################################### fmovm_calc_ea: mov.l %d0,%a0 # move # bytes to a0 # currently, MODE and REG are taken from the EXC_OPWORD. this could be # easily changed if they were inputs passed in registers. mov.w EXC_OPWORD(%a6),%d0 # fetch opcode word mov.w %d0,%d1 # make a copy andi.w &0x3f,%d0 # extract mode field andi.l &0x7,%d1 # extract reg field # jump to the corresponding function for each {MODE,REG} pair. mov.w (tbl_fea_mode.b,%pc,%d0.w*2),%d0 # fetch jmp distance jmp (tbl_fea_mode.b,%pc,%d0.w*1) # jmp to correct ea mode swbeg &64 tbl_fea_mode: short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short faddr_ind_a0 - tbl_fea_mode short faddr_ind_a1 - tbl_fea_mode short faddr_ind_a2 - tbl_fea_mode short faddr_ind_a3 - tbl_fea_mode short faddr_ind_a4 - tbl_fea_mode short faddr_ind_a5 - tbl_fea_mode short faddr_ind_a6 - tbl_fea_mode short faddr_ind_a7 - tbl_fea_mode short faddr_ind_p_a0 - tbl_fea_mode short faddr_ind_p_a1 - tbl_fea_mode short faddr_ind_p_a2 - tbl_fea_mode short faddr_ind_p_a3 - tbl_fea_mode short faddr_ind_p_a4 - tbl_fea_mode short faddr_ind_p_a5 - tbl_fea_mode short faddr_ind_p_a6 - tbl_fea_mode short faddr_ind_p_a7 - tbl_fea_mode short faddr_ind_m_a0 - tbl_fea_mode short faddr_ind_m_a1 - tbl_fea_mode short faddr_ind_m_a2 - tbl_fea_mode short faddr_ind_m_a3 - tbl_fea_mode short faddr_ind_m_a4 - tbl_fea_mode short faddr_ind_m_a5 - tbl_fea_mode short faddr_ind_m_a6 - tbl_fea_mode short faddr_ind_m_a7 - tbl_fea_mode short faddr_ind_disp_a0 - tbl_fea_mode short faddr_ind_disp_a1 - tbl_fea_mode short faddr_ind_disp_a2 - tbl_fea_mode short faddr_ind_disp_a3 - tbl_fea_mode short faddr_ind_disp_a4 - tbl_fea_mode short faddr_ind_disp_a5 - tbl_fea_mode short faddr_ind_disp_a6 - tbl_fea_mode short faddr_ind_disp_a7 - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short faddr_ind_ext - tbl_fea_mode short fabs_short - tbl_fea_mode short fabs_long - tbl_fea_mode short fpc_ind - tbl_fea_mode short fpc_ind_ext - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode short tbl_fea_mode - tbl_fea_mode ################################### # Address register indirect: (An) # ################################### faddr_ind_a0: mov.l EXC_DREGS+0x8(%a6),%a0 # Get current a0 rts faddr_ind_a1: mov.l EXC_DREGS+0xc(%a6),%a0 # Get current a1 rts faddr_ind_a2: mov.l %a2,%a0 # Get current a2 rts faddr_ind_a3: mov.l %a3,%a0 # Get current a3 rts faddr_ind_a4: mov.l %a4,%a0 # Get current a4 rts faddr_ind_a5: mov.l %a5,%a0 # Get current a5 rts faddr_ind_a6: mov.l (%a6),%a0 # Get current a6 rts faddr_ind_a7: mov.l EXC_A7(%a6),%a0 # Get current a7 rts ##################################################### # Address register indirect w/ postincrement: (An)+ # ##################################################### faddr_ind_p_a0: mov.l EXC_DREGS+0x8(%a6),%d0 # Get current a0 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,EXC_DREGS+0x8(%a6) # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a1: mov.l EXC_DREGS+0xc(%a6),%d0 # Get current a1 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,EXC_DREGS+0xc(%a6) # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a2: mov.l %a2,%d0 # Get current a2 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,%a2 # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a3: mov.l %a3,%d0 # Get current a3 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,%a3 # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a4: mov.l %a4,%d0 # Get current a4 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,%a4 # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a5: mov.l %a5,%d0 # Get current a5 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,%a5 # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a6: mov.l (%a6),%d0 # Get current a6 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,(%a6) # Save incr value mov.l %d0,%a0 rts faddr_ind_p_a7: mov.b &mia7_flg,SPCOND_FLG(%a6) # set "special case" flag mov.l EXC_A7(%a6),%d0 # Get current a7 mov.l %d0,%d1 add.l %a0,%d1 # Increment mov.l %d1,EXC_A7(%a6) # Save incr value mov.l %d0,%a0 rts #################################################### # Address register indirect w/ predecrement: -(An) # #################################################### faddr_ind_m_a0: mov.l EXC_DREGS+0x8(%a6),%d0 # Get current a0 sub.l %a0,%d0 # Decrement mov.l %d0,EXC_DREGS+0x8(%a6) # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a1: mov.l EXC_DREGS+0xc(%a6),%d0 # Get current a1 sub.l %a0,%d0 # Decrement mov.l %d0,EXC_DREGS+0xc(%a6) # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a2: mov.l %a2,%d0 # Get current a2 sub.l %a0,%d0 # Decrement mov.l %d0,%a2 # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a3: mov.l %a3,%d0 # Get current a3 sub.l %a0,%d0 # Decrement mov.l %d0,%a3 # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a4: mov.l %a4,%d0 # Get current a4 sub.l %a0,%d0 # Decrement mov.l %d0,%a4 # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a5: mov.l %a5,%d0 # Get current a5 sub.l %a0,%d0 # Decrement mov.l %d0,%a5 # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a6: mov.l (%a6),%d0 # Get current a6 sub.l %a0,%d0 # Decrement mov.l %d0,(%a6) # Save decr value mov.l %d0,%a0 rts faddr_ind_m_a7: mov.b &mda7_flg,SPCOND_FLG(%a6) # set "special case" flag mov.l EXC_A7(%a6),%d0 # Get current a7 sub.l %a0,%d0 # Decrement mov.l %d0,EXC_A7(%a6) # Save decr value mov.l %d0,%a0 rts ######################################################## # Address register indirect w/ displacement: (d16, An) # ######################################################## faddr_ind_disp_a0: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l EXC_DREGS+0x8(%a6),%a0 # a0 + d16 rts faddr_ind_disp_a1: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l EXC_DREGS+0xc(%a6),%a0 # a1 + d16 rts faddr_ind_disp_a2: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l %a2,%a0 # a2 + d16 rts faddr_ind_disp_a3: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l %a3,%a0 # a3 + d16 rts faddr_ind_disp_a4: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l %a4,%a0 # a4 + d16 rts faddr_ind_disp_a5: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l %a5,%a0 # a5 + d16 rts faddr_ind_disp_a6: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l (%a6),%a0 # a6 + d16 rts faddr_ind_disp_a7: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l EXC_A7(%a6),%a0 # a7 + d16 rts ######################################################################## # Address register indirect w/ index(8-bit displacement): (d8, An, Xn) # # " " " w/ " (base displacement): (bd, An, Xn) # # Memory indirect postindexed: ([bd, An], Xn, od) # # Memory indirect preindexed: ([bd, An, Xn], od) # ######################################################################## faddr_ind_ext: addq.l &0x8,%d1 bsr.l fetch_dreg # fetch base areg mov.l %d0,-(%sp) mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word # fetch extword in d0 tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l (%sp)+,%a0 btst &0x8,%d0 bne.w fcalc_mem_ind mov.l %d0,L_SCR1(%a6) # hold opword mov.l %d0,%d1 rol.w &0x4,%d1 andi.w &0xf,%d1 # extract index regno # count on fetch_dreg() not to alter a0... bsr.l fetch_dreg # fetch index mov.l %d2,-(%sp) # save d2 mov.l L_SCR1(%a6),%d2 # fetch opword btst &0xb,%d2 # is it word or long? bne.b faii8_long ext.l %d0 # sign extend word index faii8_long: mov.l %d2,%d1 rol.w &0x7,%d1 andi.l &0x3,%d1 # extract scale value lsl.l %d1,%d0 # shift index by scale extb.l %d2 # sign extend displacement add.l %d2,%d0 # index + disp add.l %d0,%a0 # An + (index + disp) mov.l (%sp)+,%d2 # restore old d2 rts ########################### # Absolute short: (XXX).W # ########################### fabs_short: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word # fetch short address tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # return in a0 rts ########################## # Absolute long: (XXX).L # ########################## fabs_long: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch long address tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,%a0 # return in a0 rts ####################################################### # Program counter indirect w/ displacement: (d16, PC) # ####################################################### fpc_ind: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word # fetch word displacement tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.w %d0,%a0 # sign extend displacement add.l EXC_EXTWPTR(%a6),%a0 # pc + d16 # _imem_read_word() increased the extwptr by 2. need to adjust here. subq.l &0x2,%a0 # adjust rts ########################################################## # PC indirect w/ index(8-bit displacement): (d8, PC, An) # # " " w/ " (base displacement): (bd, PC, An) # # PC memory indirect postindexed: ([bd, PC], Xn, od) # # PC memory indirect preindexed: ([bd, PC, Xn], od) # ########################################################## fpc_ind_ext: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word # fetch ext word tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l EXC_EXTWPTR(%a6),%a0 # put base in a0 subq.l &0x2,%a0 # adjust base btst &0x8,%d0 # is disp only 8 bits? bne.w fcalc_mem_ind # calc memory indirect mov.l %d0,L_SCR1(%a6) # store opword mov.l %d0,%d1 # make extword copy rol.w &0x4,%d1 # rotate reg num into place andi.w &0xf,%d1 # extract register number # count on fetch_dreg() not to alter a0... bsr.l fetch_dreg # fetch index mov.l %d2,-(%sp) # save d2 mov.l L_SCR1(%a6),%d2 # fetch opword btst &0xb,%d2 # is index word or long? bne.b fpii8_long # long ext.l %d0 # sign extend word index fpii8_long: mov.l %d2,%d1 rol.w &0x7,%d1 # rotate scale value into place andi.l &0x3,%d1 # extract scale value lsl.l %d1,%d0 # shift index by scale extb.l %d2 # sign extend displacement add.l %d2,%d0 # disp + index add.l %d0,%a0 # An + (index + disp) mov.l (%sp)+,%d2 # restore temp register rts # d2 = index # d3 = base # d4 = od # d5 = extword fcalc_mem_ind: btst &0x6,%d0 # is the index suppressed? beq.b fcalc_index movm.l &0x3c00,-(%sp) # save d2-d5 mov.l %d0,%d5 # put extword in d5 mov.l %a0,%d3 # put base in d3 clr.l %d2 # yes, so index = 0 bra.b fbase_supp_ck # index: fcalc_index: mov.l %d0,L_SCR1(%a6) # save d0 (opword) bfextu %d0{&16:&4},%d1 # fetch dreg index bsr.l fetch_dreg movm.l &0x3c00,-(%sp) # save d2-d5 mov.l %d0,%d2 # put index in d2 mov.l L_SCR1(%a6),%d5 mov.l %a0,%d3 btst &0xb,%d5 # is index word or long? bne.b fno_ext ext.l %d2 fno_ext: bfextu %d5{&21:&2},%d0 lsl.l %d0,%d2 # base address (passed as parameter in d3): # we clear the value here if it should actually be suppressed. fbase_supp_ck: btst &0x7,%d5 # is the bd suppressed? beq.b fno_base_sup clr.l %d3 # base displacement: fno_base_sup: bfextu %d5{&26:&2},%d0 # get bd size # beq.l fmovm_error # if (size == 0) it's reserved cmpi.b %d0,&0x2 blt.b fno_bd beq.b fget_word_bd mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long tst.l %d1 # did ifetch fail? bne.l fcea_iacc # yes bra.b fchk_ind fget_word_bd: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l fcea_iacc # yes ext.l %d0 # sign extend bd fchk_ind: add.l %d0,%d3 # base += bd # outer displacement: fno_bd: bfextu %d5{&30:&2},%d0 # is od suppressed? beq.w faii_bd cmpi.b %d0,&0x2 blt.b fnull_od beq.b fword_od mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long tst.l %d1 # did ifetch fail? bne.l fcea_iacc # yes bra.b fadd_them fword_od: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_word tst.l %d1 # did ifetch fail? bne.l fcea_iacc # yes ext.l %d0 # sign extend od bra.b fadd_them fnull_od: clr.l %d0 fadd_them: mov.l %d0,%d4 btst &0x2,%d5 # pre or post indexing? beq.b fpre_indexed mov.l %d3,%a0 bsr.l _dmem_read_long tst.l %d1 # did dfetch fail? bne.w fcea_err # yes add.l %d2,%d0 # += index add.l %d4,%d0 # += od bra.b fdone_ea fpre_indexed: add.l %d2,%d3 # preindexing mov.l %d3,%a0 bsr.l _dmem_read_long tst.l %d1 # did dfetch fail? bne.w fcea_err # yes add.l %d4,%d0 # ea += od bra.b fdone_ea faii_bd: add.l %d2,%d3 # ea = (base + bd) + index mov.l %d3,%d0 fdone_ea: mov.l %d0,%a0 movm.l (%sp)+,&0x003c # restore d2-d5 rts ######################################################### fcea_err: mov.l %d3,%a0 movm.l (%sp)+,&0x003c # restore d2-d5 mov.w &0x0101,%d0 bra.l iea_dacc fcea_iacc: movm.l (%sp)+,&0x003c # restore d2-d5 bra.l iea_iacc fmovm_out_err: bsr.l restore mov.w &0x00e1,%d0 bra.b fmovm_err fmovm_in_err: bsr.l restore mov.w &0x0161,%d0 fmovm_err: mov.l L_SCR1(%a6),%a0 bra.l iea_dacc ######################################################################### # XDEF **************************************************************** # # fmovm_ctrl(): emulate fmovm.l of control registers instr # # # # XREF **************************************************************** # # _imem_read_long() - read longword from memory # # iea_iacc() - _imem_read_long() failed; error recovery # # # # INPUT *************************************************************** # # None # # # # OUTPUT ************************************************************** # # If _imem_read_long() doesn't fail: # # USER_FPCR(a6) = new FPCR value # # USER_FPSR(a6) = new FPSR value # # USER_FPIAR(a6) = new FPIAR value # # # # ALGORITHM *********************************************************** # # Decode the instruction type by looking at the extension word # # in order to see how many control registers to fetch from memory. # # Fetch them using _imem_read_long(). If this fetch fails, exit through # # the special access error exit handler iea_iacc(). # # # # Instruction word decoding: # # # # fmovem.l #, {FPIAR&|FPCR&|FPSR} # # # # WORD1 WORD2 # # 1111 0010 00 111100 100$ $$00 0000 0000 # # # # $$$ (100): FPCR # # (010): FPSR # # (001): FPIAR # # (000): FPIAR # # # ######################################################################### global fmovm_ctrl fmovm_ctrl: mov.b EXC_EXTWORD(%a6),%d0 # fetch reg select bits cmpi.b %d0,&0x9c # fpcr & fpsr & fpiar ? beq.w fctrl_in_7 # yes cmpi.b %d0,&0x98 # fpcr & fpsr ? beq.w fctrl_in_6 # yes cmpi.b %d0,&0x94 # fpcr & fpiar ? beq.b fctrl_in_5 # yes # fmovem.l #, fpsr/fpiar fctrl_in_3: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPSR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPSR(%a6) # store new FPSR to stack mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPIAR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPIAR(%a6) # store new FPIAR to stack rts # fmovem.l #, fpcr/fpiar fctrl_in_5: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPCR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPCR(%a6) # store new FPCR to stack mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPIAR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPIAR(%a6) # store new FPIAR to stack rts # fmovem.l #, fpcr/fpsr fctrl_in_6: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPCR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPCR(%a6) # store new FPCR to mem mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPSR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPSR(%a6) # store new FPSR to mem rts # fmovem.l #, fpcr/fpsr/fpiar fctrl_in_7: mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPCR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPCR(%a6) # store new FPCR to mem mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPSR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPSR(%a6) # store new FPSR to mem mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr bsr.l _imem_read_long # fetch FPIAR from mem tst.l %d1 # did ifetch fail? bne.l iea_iacc # yes mov.l %d0,USER_FPIAR(%a6) # store new FPIAR to mem rts ########################################################################## ######################################################################### # XDEF **************************************************************** # # addsub_scaler2(): scale inputs to fadd/fsub such that no # # OVFL/UNFL exceptions will result # # # # XREF **************************************************************** # # norm() - normalize mantissa after adjusting exponent # # # # INPUT *************************************************************** # # FP_SRC(a6) = fp op1(src) # # FP_DST(a6) = fp op2(dst) # # # # OUTPUT ************************************************************** # # FP_SRC(a6) = fp op1 scaled(src) # # FP_DST(a6) = fp op2 scaled(dst) # # d0 = scale amount # # # # ALGORITHM *********************************************************** # # If the DST exponent is > the SRC exponent, set the DST exponent # # equal to 0x3fff and scale the SRC exponent by the value that the # # DST exponent was scaled by. If the SRC exponent is greater or equal, # # do the opposite. Return this scale factor in d0. # # If the two exponents differ by > the number of mantissa bits # # plus two, then set the smallest exponent to a very small value as a # # quick shortcut. # # # ######################################################################### global addsub_scaler2 addsub_scaler2: mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) mov.w SRC_EX(%a0),%d0 mov.w DST_EX(%a1),%d1 mov.w %d0,FP_SCR0_EX(%a6) mov.w %d1,FP_SCR1_EX(%a6) andi.w &0x7fff,%d0 andi.w &0x7fff,%d1 mov.w %d0,L_SCR1(%a6) # store src exponent mov.w %d1,2+L_SCR1(%a6) # store dst exponent cmp.w %d0, %d1 # is src exp >= dst exp? bge.l src_exp_ge2 # dst exp is > src exp; scale dst to exp = 0x3fff dst_exp_gt2: bsr.l scale_to_zero_dst mov.l %d0,-(%sp) # save scale factor cmpi.b STAG(%a6),&DENORM # is dst denormalized? bne.b cmpexp12 lea FP_SCR0(%a6),%a0 bsr.l norm # normalize the denorm; result is new exp neg.w %d0 # new exp = -(shft val) mov.w %d0,L_SCR1(%a6) # inset new exp cmpexp12: mov.w 2+L_SCR1(%a6),%d0 subi.w &mantissalen+2,%d0 # subtract mantissalen+2 from larger exp cmp.w %d0,L_SCR1(%a6) # is difference >= len(mantissa)+2? bge.b quick_scale12 mov.w L_SCR1(%a6),%d0 add.w 0x2(%sp),%d0 # scale src exponent by scale factor mov.w FP_SCR0_EX(%a6),%d1 and.w &0x8000,%d1 or.w %d1,%d0 # concat {sgn,new exp} mov.w %d0,FP_SCR0_EX(%a6) # insert new dst exponent mov.l (%sp)+,%d0 # return SCALE factor rts quick_scale12: andi.w &0x8000,FP_SCR0_EX(%a6) # zero src exponent bset &0x0,1+FP_SCR0_EX(%a6) # set exp = 1 mov.l (%sp)+,%d0 # return SCALE factor rts # src exp is >= dst exp; scale src to exp = 0x3fff src_exp_ge2: bsr.l scale_to_zero_src mov.l %d0,-(%sp) # save scale factor cmpi.b DTAG(%a6),&DENORM # is dst denormalized? bne.b cmpexp22 lea FP_SCR1(%a6),%a0 bsr.l norm # normalize the denorm; result is new exp neg.w %d0 # new exp = -(shft val) mov.w %d0,2+L_SCR1(%a6) # inset new exp cmpexp22: mov.w L_SCR1(%a6),%d0 subi.w &mantissalen+2,%d0 # subtract mantissalen+2 from larger exp cmp.w %d0,2+L_SCR1(%a6) # is difference >= len(mantissa)+2? bge.b quick_scale22 mov.w 2+L_SCR1(%a6),%d0 add.w 0x2(%sp),%d0 # scale dst exponent by scale factor mov.w FP_SCR1_EX(%a6),%d1 andi.w &0x8000,%d1 or.w %d1,%d0 # concat {sgn,new exp} mov.w %d0,FP_SCR1_EX(%a6) # insert new dst exponent mov.l (%sp)+,%d0 # return SCALE factor rts quick_scale22: andi.w &0x8000,FP_SCR1_EX(%a6) # zero dst exponent bset &0x0,1+FP_SCR1_EX(%a6) # set exp = 1 mov.l (%sp)+,%d0 # return SCALE factor rts ########################################################################## ######################################################################### # XDEF **************************************************************** # # scale_to_zero_src(): scale the exponent of extended precision # # value at FP_SCR0(a6). # # # # XREF **************************************************************** # # norm() - normalize the mantissa if the operand was a DENORM # # # # INPUT *************************************************************** # # FP_SCR0(a6) = extended precision operand to be scaled # # # # OUTPUT ************************************************************** # # FP_SCR0(a6) = scaled extended precision operand # # d0 = scale value # # # # ALGORITHM *********************************************************** # # Set the exponent of the input operand to 0x3fff. Save the value # # of the difference between the original and new exponent. Then, # # normalize the operand if it was a DENORM. Add this normalization # # value to the previous value. Return the result. # # # ######################################################################### global scale_to_zero_src scale_to_zero_src: mov.w FP_SCR0_EX(%a6),%d1 # extract operand's {sgn,exp} mov.w %d1,%d0 # make a copy andi.l &0x7fff,%d1 # extract operand's exponent andi.w &0x8000,%d0 # extract operand's sgn or.w &0x3fff,%d0 # insert new operand's exponent(=0) mov.w %d0,FP_SCR0_EX(%a6) # insert biased exponent cmpi.b STAG(%a6),&DENORM # is operand normalized? beq.b stzs_denorm # normalize the DENORM stzs_norm: mov.l &0x3fff,%d0 sub.l %d1,%d0 # scale = BIAS + (-exp) rts stzs_denorm: lea FP_SCR0(%a6),%a0 # pass ptr to src op bsr.l norm # normalize denorm neg.l %d0 # new exponent = -(shft val) mov.l %d0,%d1 # prepare for op_norm call bra.b stzs_norm # finish scaling ### ######################################################################### # XDEF **************************************************************** # # scale_sqrt(): scale the input operand exponent so a subsequent # # fsqrt operation won't take an exception. # # # # XREF **************************************************************** # # norm() - normalize the mantissa if the operand was a DENORM # # # # INPUT *************************************************************** # # FP_SCR0(a6) = extended precision operand to be scaled # # # # OUTPUT ************************************************************** # # FP_SCR0(a6) = scaled extended precision operand # # d0 = scale value # # # # ALGORITHM *********************************************************** # # If the input operand is a DENORM, normalize it. # # If the exponent of the input operand is even, set the exponent # # to 0x3ffe and return a scale factor of "(exp-0x3ffe)/2". If the # # exponent of the input operand is off, set the exponent to ox3fff and # # return a scale factor of "(exp-0x3fff)/2". # # # ######################################################################### global scale_sqrt scale_sqrt: cmpi.b STAG(%a6),&DENORM # is operand normalized? beq.b ss_denorm # normalize the DENORM mov.w FP_SCR0_EX(%a6),%d1 # extract operand's {sgn,exp} andi.l &0x7fff,%d1 # extract operand's exponent andi.w &0x8000,FP_SCR0_EX(%a6) # extract operand's sgn btst &0x0,%d1 # is exp even or odd? beq.b ss_norm_even ori.w &0x3fff,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) mov.l &0x3fff,%d0 sub.l %d1,%d0 # scale = BIAS + (-exp) asr.l &0x1,%d0 # divide scale factor by 2 rts ss_norm_even: ori.w &0x3ffe,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) mov.l &0x3ffe,%d0 sub.l %d1,%d0 # scale = BIAS + (-exp) asr.l &0x1,%d0 # divide scale factor by 2 rts ss_denorm: lea FP_SCR0(%a6),%a0 # pass ptr to src op bsr.l norm # normalize denorm btst &0x0,%d0 # is exp even or odd? beq.b ss_denorm_even ori.w &0x3fff,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) add.l &0x3fff,%d0 asr.l &0x1,%d0 # divide scale factor by 2 rts ss_denorm_even: ori.w &0x3ffe,FP_SCR0_EX(%a6) # insert new operand's exponent(=0) add.l &0x3ffe,%d0 asr.l &0x1,%d0 # divide scale factor by 2 rts ### ######################################################################### # XDEF **************************************************************** # # scale_to_zero_dst(): scale the exponent of extended precision # # value at FP_SCR1(a6). # # # # XREF **************************************************************** # # norm() - normalize the mantissa if the operand was a DENORM # # # # INPUT *************************************************************** # # FP_SCR1(a6) = extended precision operand to be scaled # # # # OUTPUT ************************************************************** # # FP_SCR1(a6) = scaled extended precision operand # # d0 = scale value # # # # ALGORITHM *********************************************************** # # Set the exponent of the input operand to 0x3fff. Save the value # # of the difference between the original and new exponent. Then, # # normalize the operand if it was a DENORM. Add this normalization # # value to the previous value. Return the result. # # # ######################################################################### global scale_to_zero_dst scale_to_zero_dst: mov.w FP_SCR1_EX(%a6),%d1 # extract operand's {sgn,exp} mov.w %d1,%d0 # make a copy andi.l &0x7fff,%d1 # extract operand's exponent andi.w &0x8000,%d0 # extract operand's sgn or.w &0x3fff,%d0 # insert new operand's exponent(=0) mov.w %d0,FP_SCR1_EX(%a6) # insert biased exponent cmpi.b DTAG(%a6),&DENORM # is operand normalized? beq.b stzd_denorm # normalize the DENORM stzd_norm: mov.l &0x3fff,%d0 sub.l %d1,%d0 # scale = BIAS + (-exp) rts stzd_denorm: lea FP_SCR1(%a6),%a0 # pass ptr to dst op bsr.l norm # normalize denorm neg.l %d0 # new exponent = -(shft val) mov.l %d0,%d1 # prepare for op_norm call bra.b stzd_norm # finish scaling ########################################################################## ######################################################################### # XDEF **************************************************************** # # res_qnan(): return default result w/ QNAN operand for dyadic # # res_snan(): return default result w/ SNAN operand for dyadic # # res_qnan_1op(): return dflt result w/ QNAN operand for monadic # # res_snan_1op(): return dflt result w/ SNAN operand for monadic # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # FP_SRC(a6) = pointer to extended precision src operand # # FP_DST(a6) = pointer to extended precision dst operand # # # # OUTPUT ************************************************************** # # fp0 = default result # # # # ALGORITHM *********************************************************** # # If either operand (but not both operands) of an operation is a # # nonsignalling NAN, then that NAN is returned as the result. If both # # operands are nonsignalling NANs, then the destination operand # # nonsignalling NAN is returned as the result. # # If either operand to an operation is a signalling NAN (SNAN), # # then, the SNAN bit is set in the FPSR EXC byte. If the SNAN trap # # enable bit is set in the FPCR, then the trap is taken and the # # destination is not modified. If the SNAN trap enable bit is not set, # # then the SNAN is converted to a nonsignalling NAN (by setting the # # SNAN bit in the operand to one), and the operation continues as # # described in the preceding paragraph, for nonsignalling NANs. # # Make sure the appropriate FPSR bits are set before exiting. # # # ######################################################################### global res_qnan global res_snan res_qnan: res_snan: cmp.b DTAG(%a6), &SNAN # is the dst an SNAN? beq.b dst_snan2 cmp.b DTAG(%a6), &QNAN # is the dst a QNAN? beq.b dst_qnan2 src_nan: cmp.b STAG(%a6), &QNAN beq.b src_qnan2 global res_snan_1op res_snan_1op: src_snan2: bset &0x6, FP_SRC_HI(%a6) # set SNAN bit or.l &nan_mask+aiop_mask+snan_mask, USER_FPSR(%a6) lea FP_SRC(%a6), %a0 bra.b nan_comp global res_qnan_1op res_qnan_1op: src_qnan2: or.l &nan_mask, USER_FPSR(%a6) lea FP_SRC(%a6), %a0 bra.b nan_comp dst_snan2: or.l &nan_mask+aiop_mask+snan_mask, USER_FPSR(%a6) bset &0x6, FP_DST_HI(%a6) # set SNAN bit lea FP_DST(%a6), %a0 bra.b nan_comp dst_qnan2: lea FP_DST(%a6), %a0 cmp.b STAG(%a6), &SNAN bne nan_done or.l &aiop_mask+snan_mask, USER_FPSR(%a6) nan_done: or.l &nan_mask, USER_FPSR(%a6) nan_comp: btst &0x7, FTEMP_EX(%a0) # is NAN neg? beq.b nan_not_neg or.l &neg_mask, USER_FPSR(%a6) nan_not_neg: fmovm.x (%a0), &0x80 rts ######################################################################### # XDEF **************************************************************** # # res_operr(): return default result during operand error # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # None # # # # OUTPUT ************************************************************** # # fp0 = default operand error result # # # # ALGORITHM *********************************************************** # # An nonsignalling NAN is returned as the default result when # # an operand error occurs for the following cases: # # # # Multiply: (Infinity x Zero) # # Divide : (Zero / Zero) || (Infinity / Infinity) # # # ######################################################################### global res_operr res_operr: or.l &nan_mask+operr_mask+aiop_mask, USER_FPSR(%a6) fmovm.x nan_return(%pc), &0x80 rts nan_return: long 0x7fff0000, 0xffffffff, 0xffffffff ######################################################################### # XDEF **************************************************************** # # _denorm(): denormalize an intermediate result # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # a0 = points to the operand to be denormalized # # (in the internal extended format) # # # # d0 = rounding precision # # # # OUTPUT ************************************************************** # # a0 = pointer to the denormalized result # # (in the internal extended format) # # # # d0 = guard,round,sticky # # # # ALGORITHM *********************************************************** # # According to the exponent underflow threshold for the given # # precision, shift the mantissa bits to the right in order raise the # # exponent of the operand to the threshold value. While shifting the # # mantissa bits right, maintain the value of the guard, round, and # # sticky bits. # # other notes: # # (1) _denorm() is called by the underflow routines # # (2) _denorm() does NOT affect the status register # # # ######################################################################### # # table of exponent threshold values for each precision # tbl_thresh: short 0x0 short sgl_thresh short dbl_thresh global _denorm _denorm: # # Load the exponent threshold for the precision selected and check # to see if (threshold - exponent) is > 65 in which case we can # simply calculate the sticky bit and zero the mantissa. otherwise # we have to call the denormalization routine. # lsr.b &0x2, %d0 # shift prec to lo bits mov.w (tbl_thresh.b,%pc,%d0.w*2), %d1 # load prec threshold mov.w %d1, %d0 # copy d1 into d0 sub.w FTEMP_EX(%a0), %d0 # diff = threshold - exp cmpi.w %d0, &66 # is diff > 65? (mant + g,r bits) bpl.b denorm_set_stky # yes; just calc sticky clr.l %d0 # clear g,r,s btst &inex2_bit, FPSR_EXCEPT(%a6) # yes; was INEX2 set? beq.b denorm_call # no; don't change anything bset &29, %d0 # yes; set sticky bit denorm_call: bsr.l dnrm_lp # denormalize the number rts # # all bit would have been shifted off during the denorm so simply # calculate if the sticky should be set and clear the entire mantissa. # denorm_set_stky: mov.l &0x20000000, %d0 # set sticky bit in return value mov.w %d1, FTEMP_EX(%a0) # load exp with threshold clr.l FTEMP_HI(%a0) # set d1 = 0 (ms mantissa) clr.l FTEMP_LO(%a0) # set d2 = 0 (ms mantissa) rts # # # dnrm_lp(): normalize exponent/mantissa to specified threshold # # # # INPUT: # # %a0 : points to the operand to be denormalized # # %d0{31:29} : initial guard,round,sticky # # %d1{15:0} : denormalization threshold # # OUTPUT: # # %a0 : points to the denormalized operand # # %d0{31:29} : final guard,round,sticky # # # # *** Local Equates *** # set GRS, L_SCR2 # g,r,s temp storage set FTEMP_LO2, L_SCR1 # FTEMP_LO copy global dnrm_lp dnrm_lp: # # make a copy of FTEMP_LO and place the g,r,s bits directly after it # in memory so as to make the bitfield extraction for denormalization easier. # mov.l FTEMP_LO(%a0), FTEMP_LO2(%a6) # make FTEMP_LO copy mov.l %d0, GRS(%a6) # place g,r,s after it # # check to see how much less than the underflow threshold the operand # exponent is. # mov.l %d1, %d0 # copy the denorm threshold sub.w FTEMP_EX(%a0), %d1 # d1 = threshold - uns exponent ble.b dnrm_no_lp # d1 <= 0 cmpi.w %d1, &0x20 # is ( 0 <= d1 < 32) ? blt.b case_1 # yes cmpi.w %d1, &0x40 # is (32 <= d1 < 64) ? blt.b case_2 # yes bra.w case_3 # (d1 >= 64) # # No normalization necessary # dnrm_no_lp: mov.l GRS(%a6), %d0 # restore original g,r,s rts # # case (0<-(n)-><-(32 - n)-><-(n)-><-(32 - n)-><-(n)-> # \ \ \ \ # \ \ \ \ # \ \ \ \ # \ \ \ \ # \ \ \ \ # \ \ \ \ # \ \ \ \ # \ \ \ \ # <-(n)-><-(32 - n)-><------(32)-------><------(32)-------> # --------------------------------------------------------- # |0.....0| NEW_HI | NEW_FTEMP_LO |grs | # --------------------------------------------------------- # case_1: mov.l %d2, -(%sp) # create temp storage mov.w %d0, FTEMP_EX(%a0) # exponent = denorm threshold mov.l &32, %d0 sub.w %d1, %d0 # %d0 = 32 - %d1 cmpi.w %d1, &29 # is shft amt >= 29 blt.b case1_extract # no; no fix needed mov.b GRS(%a6), %d2 or.b %d2, 3+FTEMP_LO2(%a6) case1_extract: bfextu FTEMP_HI(%a0){&0:%d0}, %d2 # %d2 = new FTEMP_HI bfextu FTEMP_HI(%a0){%d0:&32}, %d1 # %d1 = new FTEMP_LO bfextu FTEMP_LO2(%a6){%d0:&32}, %d0 # %d0 = new G,R,S mov.l %d2, FTEMP_HI(%a0) # store new FTEMP_HI mov.l %d1, FTEMP_LO(%a0) # store new FTEMP_LO bftst %d0{&2:&30} # were bits shifted off? beq.b case1_sticky_clear # no; go finish bset &rnd_stky_bit, %d0 # yes; set sticky bit case1_sticky_clear: and.l &0xe0000000, %d0 # clear all but G,R,S mov.l (%sp)+, %d2 # restore temp register rts # # case (32<=d1<64) # # %d0 = denorm threshold # %d1 = "n" = amt to shift # # --------------------------------------------------------- # | FTEMP_HI | FTEMP_LO |grs000.........000| # --------------------------------------------------------- # <-(32 - n)-><-(n)-><-(32 - n)-><-(n)-><-(32 - n)-><-(n)-> # \ \ \ # \ \ \ # \ \ ------------------- # \ -------------------- \ # ------------------- \ \ # \ \ \ # \ \ \ # \ \ \ # <-------(32)------><-(n)-><-(32 - n)-><------(32)-------> # --------------------------------------------------------- # |0...............0|0....0| NEW_LO |grs | # --------------------------------------------------------- # case_2: mov.l %d2, -(%sp) # create temp storage mov.w %d0, FTEMP_EX(%a0) # exponent = denorm threshold subi.w &0x20, %d1 # %d1 now between 0 and 32 mov.l &0x20, %d0 sub.w %d1, %d0 # %d0 = 32 - %d1 # subtle step here; or in the g,r,s at the bottom of FTEMP_LO to minimize # the number of bits to check for the sticky detect. # it only plays a role in shift amounts of 61-63. mov.b GRS(%a6), %d2 or.b %d2, 3+FTEMP_LO2(%a6) bfextu FTEMP_HI(%a0){&0:%d0}, %d2 # %d2 = new FTEMP_LO bfextu FTEMP_HI(%a0){%d0:&32}, %d1 # %d1 = new G,R,S bftst %d1{&2:&30} # were any bits shifted off? bne.b case2_set_sticky # yes; set sticky bit bftst FTEMP_LO2(%a6){%d0:&31} # were any bits shifted off? bne.b case2_set_sticky # yes; set sticky bit mov.l %d1, %d0 # move new G,R,S to %d0 bra.b case2_end case2_set_sticky: mov.l %d1, %d0 # move new G,R,S to %d0 bset &rnd_stky_bit, %d0 # set sticky bit case2_end: clr.l FTEMP_HI(%a0) # store FTEMP_HI = 0 mov.l %d2, FTEMP_LO(%a0) # store FTEMP_LO and.l &0xe0000000, %d0 # clear all but G,R,S mov.l (%sp)+,%d2 # restore temp register rts # # case (d1>=64) # # %d0 = denorm threshold # %d1 = amt to shift # case_3: mov.w %d0, FTEMP_EX(%a0) # insert denorm threshold cmpi.w %d1, &65 # is shift amt > 65? blt.b case3_64 # no; it's == 64 beq.b case3_65 # no; it's == 65 # # case (d1>65) # # Shift value is > 65 and out of range. All bits are shifted off. # Return a zero mantissa with the sticky bit set # clr.l FTEMP_HI(%a0) # clear hi(mantissa) clr.l FTEMP_LO(%a0) # clear lo(mantissa) mov.l &0x20000000, %d0 # set sticky bit rts # # case (d1 == 64) # # --------------------------------------------------------- # | FTEMP_HI | FTEMP_LO |grs000.........000| # --------------------------------------------------------- # <-------(32)------> # \ \ # \ \ # \ \ # \ ------------------------------ # ------------------------------- \ # \ \ # \ \ # \ \ # <-------(32)------> # --------------------------------------------------------- # |0...............0|0................0|grs | # --------------------------------------------------------- # case3_64: mov.l FTEMP_HI(%a0), %d0 # fetch hi(mantissa) mov.l %d0, %d1 # make a copy and.l &0xc0000000, %d0 # extract G,R and.l &0x3fffffff, %d1 # extract other bits bra.b case3_complete # # case (d1 == 65) # # --------------------------------------------------------- # | FTEMP_HI | FTEMP_LO |grs000.........000| # --------------------------------------------------------- # <-------(32)------> # \ \ # \ \ # \ \ # \ ------------------------------ # -------------------------------- \ # \ \ # \ \ # \ \ # <-------(31)-----> # --------------------------------------------------------- # |0...............0|0................0|0rs | # --------------------------------------------------------- # case3_65: mov.l FTEMP_HI(%a0), %d0 # fetch hi(mantissa) and.l &0x80000000, %d0 # extract R bit lsr.l &0x1, %d0 # shift high bit into R bit and.l &0x7fffffff, %d1 # extract other bits case3_complete: # last operation done was an "and" of the bits shifted off so the condition # codes are already set so branch accordingly. bne.b case3_set_sticky # yes; go set new sticky tst.l FTEMP_LO(%a0) # were any bits shifted off? bne.b case3_set_sticky # yes; go set new sticky tst.b GRS(%a6) # were any bits shifted off? bne.b case3_set_sticky # yes; go set new sticky # # no bits were shifted off so don't set the sticky bit. # the guard and # the entire mantissa is zero. # clr.l FTEMP_HI(%a0) # clear hi(mantissa) clr.l FTEMP_LO(%a0) # clear lo(mantissa) rts # # some bits were shifted off so set the sticky bit. # the entire mantissa is zero. # case3_set_sticky: bset &rnd_stky_bit,%d0 # set new sticky bit clr.l FTEMP_HI(%a0) # clear hi(mantissa) clr.l FTEMP_LO(%a0) # clear lo(mantissa) rts ######################################################################### # XDEF **************************************************************** # # _round(): round result according to precision/mode # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # a0 = ptr to input operand in internal extended format # # d1(hi) = contains rounding precision: # # ext = $0000xxxx # # sgl = $0004xxxx # # dbl = $0008xxxx # # d1(lo) = contains rounding mode: # # RN = $xxxx0000 # # RZ = $xxxx0001 # # RM = $xxxx0002 # # RP = $xxxx0003 # # d0{31:29} = contains the g,r,s bits (extended) # # # # OUTPUT ************************************************************** # # a0 = pointer to rounded result # # # # ALGORITHM *********************************************************** # # On return the value pointed to by a0 is correctly rounded, # # a0 is preserved and the g-r-s bits in d0 are cleared. # # The result is not typed - the tag field is invalid. The # # result is still in the internal extended format. # # # # The INEX bit of USER_FPSR will be set if the rounded result was # # inexact (i.e. if any of the g-r-s bits were set). # # # ######################################################################### global _round _round: # # ext_grs() looks at the rounding precision and sets the appropriate # G,R,S bits. # If (G,R,S == 0) then result is exact and round is done, else set # the inex flag in status reg and continue. # bsr.l ext_grs # extract G,R,S tst.l %d0 # are G,R,S zero? beq.w truncate # yes; round is complete or.w &inx2a_mask, 2+USER_FPSR(%a6) # set inex2/ainex # # Use rounding mode as an index into a jump table for these modes. # All of the following assumes grs != 0. # mov.w (tbl_mode.b,%pc,%d1.w*2), %a1 # load jump offset jmp (tbl_mode.b,%pc,%a1) # jmp to rnd mode handler tbl_mode: short rnd_near - tbl_mode short truncate - tbl_mode # RZ always truncates short rnd_mnus - tbl_mode short rnd_plus - tbl_mode ################################################################# # ROUND PLUS INFINITY # # # # If sign of fp number = 0 (positive), then add 1 to l. # ################################################################# rnd_plus: tst.b FTEMP_SGN(%a0) # check for sign bmi.w truncate # if positive then truncate mov.l &0xffffffff, %d0 # force g,r,s to be all f's swap %d1 # set up d1 for round prec. cmpi.b %d1, &s_mode # is prec = sgl? beq.w add_sgl # yes bgt.w add_dbl # no; it's dbl bra.w add_ext # no; it's ext ################################################################# # ROUND MINUS INFINITY # # # # If sign of fp number = 1 (negative), then add 1 to l. # ################################################################# rnd_mnus: tst.b FTEMP_SGN(%a0) # check for sign bpl.w truncate # if negative then truncate mov.l &0xffffffff, %d0 # force g,r,s to be all f's swap %d1 # set up d1 for round prec. cmpi.b %d1, &s_mode # is prec = sgl? beq.w add_sgl # yes bgt.w add_dbl # no; it's dbl bra.w add_ext # no; it's ext ################################################################# # ROUND NEAREST # # # # If (g=1), then add 1 to l and if (r=s=0), then clear l # # Note that this will round to even in case of a tie. # ################################################################# rnd_near: asl.l &0x1, %d0 # shift g-bit to c-bit bcc.w truncate # if (g=1) then swap %d1 # set up d1 for round prec. cmpi.b %d1, &s_mode # is prec = sgl? beq.w add_sgl # yes bgt.w add_dbl # no; it's dbl bra.w add_ext # no; it's ext # *** LOCAL EQUATES *** set ad_1_sgl, 0x00000100 # constant to add 1 to l-bit in sgl prec set ad_1_dbl, 0x00000800 # constant to add 1 to l-bit in dbl prec ######################### # ADD SINGLE # ######################### add_sgl: add.l &ad_1_sgl, FTEMP_HI(%a0) bcc.b scc_clr # no mantissa overflow roxr.w FTEMP_HI(%a0) # shift v-bit back in roxr.w FTEMP_HI+2(%a0) # shift v-bit back in add.w &0x1, FTEMP_EX(%a0) # and incr exponent scc_clr: tst.l %d0 # test for rs = 0 bne.b sgl_done and.w &0xfe00, FTEMP_HI+2(%a0) # clear the l-bit sgl_done: and.l &0xffffff00, FTEMP_HI(%a0) # truncate bits beyond sgl limit clr.l FTEMP_LO(%a0) # clear d2 rts ######################### # ADD EXTENDED # ######################### add_ext: addq.l &1,FTEMP_LO(%a0) # add 1 to l-bit bcc.b xcc_clr # test for carry out addq.l &1,FTEMP_HI(%a0) # propagate carry bcc.b xcc_clr roxr.w FTEMP_HI(%a0) # mant is 0 so restore v-bit roxr.w FTEMP_HI+2(%a0) # mant is 0 so restore v-bit roxr.w FTEMP_LO(%a0) roxr.w FTEMP_LO+2(%a0) add.w &0x1,FTEMP_EX(%a0) # and inc exp xcc_clr: tst.l %d0 # test rs = 0 bne.b add_ext_done and.b &0xfe,FTEMP_LO+3(%a0) # clear the l bit add_ext_done: rts ######################### # ADD DOUBLE # ######################### add_dbl: add.l &ad_1_dbl, FTEMP_LO(%a0) # add 1 to lsb bcc.b dcc_clr # no carry addq.l &0x1, FTEMP_HI(%a0) # propagate carry bcc.b dcc_clr # no carry roxr.w FTEMP_HI(%a0) # mant is 0 so restore v-bit roxr.w FTEMP_HI+2(%a0) # mant is 0 so restore v-bit roxr.w FTEMP_LO(%a0) roxr.w FTEMP_LO+2(%a0) addq.w &0x1, FTEMP_EX(%a0) # incr exponent dcc_clr: tst.l %d0 # test for rs = 0 bne.b dbl_done and.w &0xf000, FTEMP_LO+2(%a0) # clear the l-bit dbl_done: and.l &0xfffff800,FTEMP_LO(%a0) # truncate bits beyond dbl limit rts ########################### # Truncate all other bits # ########################### truncate: swap %d1 # select rnd prec cmpi.b %d1, &s_mode # is prec sgl? beq.w sgl_done # yes bgt.b dbl_done # no; it's dbl rts # no; it's ext # # ext_grs(): extract guard, round and sticky bits according to # rounding precision. # # INPUT # d0 = extended precision g,r,s (in d0{31:29}) # d1 = {PREC,ROUND} # OUTPUT # d0{31:29} = guard, round, sticky # # The ext_grs extract the guard/round/sticky bits according to the # selected rounding precision. It is called by the round subroutine # only. All registers except d0 are kept intact. d0 becomes an # updated guard,round,sticky in d0{31:29} # # Notes: the ext_grs uses the round PREC, and therefore has to swap d1 # prior to usage, and needs to restore d1 to original. this # routine is tightly tied to the round routine and not meant to # uphold standard subroutine calling practices. # ext_grs: swap %d1 # have d1.w point to round precision tst.b %d1 # is rnd prec = extended? bne.b ext_grs_not_ext # no; go handle sgl or dbl # # %d0 actually already hold g,r,s since _round() had it before calling # this function. so, as long as we don't disturb it, we are "returning" it. # ext_grs_ext: swap %d1 # yes; return to correct positions rts ext_grs_not_ext: movm.l &0x3000, -(%sp) # make some temp registers {d2/d3} cmpi.b %d1, &s_mode # is rnd prec = sgl? bne.b ext_grs_dbl # no; go handle dbl # # sgl: # 96 64 40 32 0 # ----------------------------------------------------- # | EXP |XXXXXXX| |xx | |grs| # ----------------------------------------------------- # <--(24)--->nn\ / # ee --------------------- # ww | # v # gr new sticky # ext_grs_sgl: bfextu FTEMP_HI(%a0){&24:&2}, %d3 # sgl prec. g-r are 2 bits right mov.l &30, %d2 # of the sgl prec. limits lsl.l %d2, %d3 # shift g-r bits to MSB of d3 mov.l FTEMP_HI(%a0), %d2 # get word 2 for s-bit test and.l &0x0000003f, %d2 # s bit is the or of all other bne.b ext_grs_st_stky # bits to the right of g-r tst.l FTEMP_LO(%a0) # test lower mantissa bne.b ext_grs_st_stky # if any are set, set sticky tst.l %d0 # test original g,r,s bne.b ext_grs_st_stky # if any are set, set sticky bra.b ext_grs_end_sd # if words 3 and 4 are clr, exit # # dbl: # 96 64 32 11 0 # ----------------------------------------------------- # | EXP |XXXXXXX| | |xx |grs| # ----------------------------------------------------- # nn\ / # ee ------- # ww | # v # gr new sticky # ext_grs_dbl: bfextu FTEMP_LO(%a0){&21:&2}, %d3 # dbl-prec. g-r are 2 bits right mov.l &30, %d2 # of the dbl prec. limits lsl.l %d2, %d3 # shift g-r bits to the MSB of d3 mov.l FTEMP_LO(%a0), %d2 # get lower mantissa for s-bit test and.l &0x000001ff, %d2 # s bit is the or-ing of all bne.b ext_grs_st_stky # other bits to the right of g-r tst.l %d0 # test word original g,r,s bne.b ext_grs_st_stky # if any are set, set sticky bra.b ext_grs_end_sd # if clear, exit ext_grs_st_stky: bset &rnd_stky_bit, %d3 # set sticky bit ext_grs_end_sd: mov.l %d3, %d0 # return grs to d0 movm.l (%sp)+, &0xc # restore scratch registers {d2/d3} swap %d1 # restore d1 to original rts ######################################################################### # norm(): normalize the mantissa of an extended precision input. the # # input operand should not be normalized already. # # # # XDEF **************************************************************** # # norm() # # # # XREF **************************************************************** # # none # # # # INPUT *************************************************************** # # a0 = pointer fp extended precision operand to normalize # # # # OUTPUT ************************************************************** # # d0 = number of bit positions the mantissa was shifted # # a0 = the input operand's mantissa is normalized; the exponent # # is unchanged. # # # ######################################################################### global norm norm: mov.l %d2, -(%sp) # create some temp regs mov.l %d3, -(%sp) mov.l FTEMP_HI(%a0), %d0 # load hi(mantissa) mov.l FTEMP_LO(%a0), %d1 # load lo(mantissa) bfffo %d0{&0:&32}, %d2 # how many places to shift? beq.b norm_lo # hi(man) is all zeroes! norm_hi: lsl.l %d2, %d0 # left shift hi(man) bfextu %d1{&0:%d2}, %d3 # extract lo bits or.l %d3, %d0 # create hi(man) lsl.l %d2, %d1 # create lo(man) mov.l %d0, FTEMP_HI(%a0) # store new hi(man) mov.l %d1, FTEMP_LO(%a0) # store new lo(man) mov.l %d2, %d0 # return shift amount mov.l (%sp)+, %d3 # restore temp regs mov.l (%sp)+, %d2 rts norm_lo: bfffo %d1{&0:&32}, %d2 # how many places to shift? lsl.l %d2, %d1 # shift lo(man) add.l &32, %d2 # add 32 to shft amount mov.l %d1, FTEMP_HI(%a0) # store hi(man) clr.l FTEMP_LO(%a0) # lo(man) is now zero mov.l %d2, %d0 # return shift amount mov.l (%sp)+, %d3 # restore temp regs mov.l (%sp)+, %d2 rts ######################################################################### # unnorm_fix(): - changes an UNNORM to one of NORM, DENORM, or ZERO # # - returns corresponding optype tag # # # # XDEF **************************************************************** # # unnorm_fix() # # # # XREF **************************************************************** # # norm() - normalize the mantissa # # # # INPUT *************************************************************** # # a0 = pointer to unnormalized extended precision number # # # # OUTPUT ************************************************************** # # d0 = optype tag - is corrected to one of NORM, DENORM, or ZERO # # a0 = input operand has been converted to a norm, denorm, or # # zero; both the exponent and mantissa are changed. # # # ######################################################################### global unnorm_fix unnorm_fix: bfffo FTEMP_HI(%a0){&0:&32}, %d0 # how many shifts are needed? bne.b unnorm_shift # hi(man) is not all zeroes # # hi(man) is all zeroes so see if any bits in lo(man) are set # unnorm_chk_lo: bfffo FTEMP_LO(%a0){&0:&32}, %d0 # is operand really a zero? beq.w unnorm_zero # yes add.w &32, %d0 # no; fix shift distance # # d0 = # shifts needed for complete normalization # unnorm_shift: clr.l %d1 # clear top word mov.w FTEMP_EX(%a0), %d1 # extract exponent and.w &0x7fff, %d1 # strip off sgn cmp.w %d0, %d1 # will denorm push exp < 0? bgt.b unnorm_nrm_zero # yes; denorm only until exp = 0 # # exponent would not go < 0. Therefore, number stays normalized # sub.w %d0, %d1 # shift exponent value mov.w FTEMP_EX(%a0), %d0 # load old exponent and.w &0x8000, %d0 # save old sign or.w %d0, %d1 # {sgn,new exp} mov.w %d1, FTEMP_EX(%a0) # insert new exponent bsr.l norm # normalize UNNORM mov.b &NORM, %d0 # return new optype tag rts # # exponent would go < 0, so only denormalize until exp = 0 # unnorm_nrm_zero: cmp.b %d1, &32 # is exp <= 32? bgt.b unnorm_nrm_zero_lrg # no; go handle large exponent bfextu FTEMP_HI(%a0){%d1:&32}, %d0 # extract new hi(man) mov.l %d0, FTEMP_HI(%a0) # save new hi(man) mov.l FTEMP_LO(%a0), %d0 # fetch old lo(man) lsl.l %d1, %d0 # extract new lo(man) mov.l %d0, FTEMP_LO(%a0) # save new lo(man) and.w &0x8000, FTEMP_EX(%a0) # set exp = 0 mov.b &DENORM, %d0 # return new optype tag rts # # only mantissa bits set are in lo(man) # unnorm_nrm_zero_lrg: sub.w &32, %d1 # adjust shft amt by 32 mov.l FTEMP_LO(%a0), %d0 # fetch old lo(man) lsl.l %d1, %d0 # left shift lo(man) mov.l %d0, FTEMP_HI(%a0) # store new hi(man) clr.l FTEMP_LO(%a0) # lo(man) = 0 and.w &0x8000, FTEMP_EX(%a0) # set exp = 0 mov.b &DENORM, %d0 # return new optype tag rts # # whole mantissa is zero so this UNNORM is actually a zero # unnorm_zero: and.w &0x8000, FTEMP_EX(%a0) # force exponent to zero mov.b &ZERO, %d0 # fix optype tag rts ######################################################################### # XDEF **************************************************************** # # set_tag_x(): return the optype of the input ext fp number # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # a0 = pointer to extended precision operand # # # # OUTPUT ************************************************************** # # d0 = value of type tag # # one of: NORM, INF, QNAN, SNAN, DENORM, UNNORM, ZERO # # # # ALGORITHM *********************************************************** # # Simply test the exponent, j-bit, and mantissa values to # # determine the type of operand. # # If it's an unnormalized zero, alter the operand and force it # # to be a normal zero. # # # ######################################################################### global set_tag_x set_tag_x: mov.w FTEMP_EX(%a0), %d0 # extract exponent andi.w &0x7fff, %d0 # strip off sign cmpi.w %d0, &0x7fff # is (EXP == MAX)? beq.b inf_or_nan_x not_inf_or_nan_x: btst &0x7,FTEMP_HI(%a0) beq.b not_norm_x is_norm_x: mov.b &NORM, %d0 rts not_norm_x: tst.w %d0 # is exponent = 0? bne.b is_unnorm_x not_unnorm_x: tst.l FTEMP_HI(%a0) bne.b is_denorm_x tst.l FTEMP_LO(%a0) bne.b is_denorm_x is_zero_x: mov.b &ZERO, %d0 rts is_denorm_x: mov.b &DENORM, %d0 rts # must distinguish now "Unnormalized zeroes" which we # must convert to zero. is_unnorm_x: tst.l FTEMP_HI(%a0) bne.b is_unnorm_reg_x tst.l FTEMP_LO(%a0) bne.b is_unnorm_reg_x # it's an "unnormalized zero". let's convert it to an actual zero... andi.w &0x8000,FTEMP_EX(%a0) # clear exponent mov.b &ZERO, %d0 rts is_unnorm_reg_x: mov.b &UNNORM, %d0 rts inf_or_nan_x: tst.l FTEMP_LO(%a0) bne.b is_nan_x mov.l FTEMP_HI(%a0), %d0 and.l &0x7fffffff, %d0 # msb is a don't care! bne.b is_nan_x is_inf_x: mov.b &INF, %d0 rts is_nan_x: btst &0x6, FTEMP_HI(%a0) beq.b is_snan_x mov.b &QNAN, %d0 rts is_snan_x: mov.b &SNAN, %d0 rts ######################################################################### # XDEF **************************************************************** # # set_tag_d(): return the optype of the input dbl fp number # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # a0 = points to double precision operand # # # # OUTPUT ************************************************************** # # d0 = value of type tag # # one of: NORM, INF, QNAN, SNAN, DENORM, ZERO # # # # ALGORITHM *********************************************************** # # Simply test the exponent, j-bit, and mantissa values to # # determine the type of operand. # # # ######################################################################### global set_tag_d set_tag_d: mov.l FTEMP(%a0), %d0 mov.l %d0, %d1 andi.l &0x7ff00000, %d0 beq.b zero_or_denorm_d cmpi.l %d0, &0x7ff00000 beq.b inf_or_nan_d is_norm_d: mov.b &NORM, %d0 rts zero_or_denorm_d: and.l &0x000fffff, %d1 bne is_denorm_d tst.l 4+FTEMP(%a0) bne is_denorm_d is_zero_d: mov.b &ZERO, %d0 rts is_denorm_d: mov.b &DENORM, %d0 rts inf_or_nan_d: and.l &0x000fffff, %d1 bne is_nan_d tst.l 4+FTEMP(%a0) bne is_nan_d is_inf_d: mov.b &INF, %d0 rts is_nan_d: btst &19, %d1 bne is_qnan_d is_snan_d: mov.b &SNAN, %d0 rts is_qnan_d: mov.b &QNAN, %d0 rts ######################################################################### # XDEF **************************************************************** # # set_tag_s(): return the optype of the input sgl fp number # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # a0 = pointer to single precision operand # # # # OUTPUT ************************************************************** # # d0 = value of type tag # # one of: NORM, INF, QNAN, SNAN, DENORM, ZERO # # # # ALGORITHM *********************************************************** # # Simply test the exponent, j-bit, and mantissa values to # # determine the type of operand. # # # ######################################################################### global set_tag_s set_tag_s: mov.l FTEMP(%a0), %d0 mov.l %d0, %d1 andi.l &0x7f800000, %d0 beq.b zero_or_denorm_s cmpi.l %d0, &0x7f800000 beq.b inf_or_nan_s is_norm_s: mov.b &NORM, %d0 rts zero_or_denorm_s: and.l &0x007fffff, %d1 bne is_denorm_s is_zero_s: mov.b &ZERO, %d0 rts is_denorm_s: mov.b &DENORM, %d0 rts inf_or_nan_s: and.l &0x007fffff, %d1 bne is_nan_s is_inf_s: mov.b &INF, %d0 rts is_nan_s: btst &22, %d1 bne is_qnan_s is_snan_s: mov.b &SNAN, %d0 rts is_qnan_s: mov.b &QNAN, %d0 rts ######################################################################### # XDEF **************************************************************** # # unf_res(): routine to produce default underflow result of a # # scaled extended precision number; this is used by # # fadd/fdiv/fmul/etc. emulation routines. # # unf_res4(): same as above but for fsglmul/fsgldiv which use # # single round prec and extended prec mode. # # # # XREF **************************************************************** # # _denorm() - denormalize according to scale factor # # _round() - round denormalized number according to rnd prec # # # # INPUT *************************************************************** # # a0 = pointer to extended precison operand # # d0 = scale factor # # d1 = rounding precision/mode # # # # OUTPUT ************************************************************** # # a0 = pointer to default underflow result in extended precision # # d0.b = result FPSR_cc which caller may or may not want to save # # # # ALGORITHM *********************************************************** # # Convert the input operand to "internal format" which means the # # exponent is extended to 16 bits and the sign is stored in the unused # # portion of the extended precison operand. Denormalize the number # # according to the scale factor passed in d0. Then, round the # # denormalized result. # # Set the FPSR_exc bits as appropriate but return the cc bits in # # d0 in case the caller doesn't want to save them (as is the case for # # fmove out). # # unf_res4() for fsglmul/fsgldiv forces the denorm to extended # # precision and the rounding mode to single. # # # ######################################################################### global unf_res unf_res: mov.l %d1, -(%sp) # save rnd prec,mode on stack btst &0x7, FTEMP_EX(%a0) # make "internal" format sne FTEMP_SGN(%a0) mov.w FTEMP_EX(%a0), %d1 # extract exponent and.w &0x7fff, %d1 sub.w %d0, %d1 mov.w %d1, FTEMP_EX(%a0) # insert 16 bit exponent mov.l %a0, -(%sp) # save operand ptr during calls mov.l 0x4(%sp),%d0 # pass rnd prec. andi.w &0x00c0,%d0 lsr.w &0x4,%d0 bsr.l _denorm # denorm result mov.l (%sp),%a0 mov.w 0x6(%sp),%d1 # load prec:mode into %d1 andi.w &0xc0,%d1 # extract rnd prec lsr.w &0x4,%d1 swap %d1 mov.w 0x6(%sp),%d1 andi.w &0x30,%d1 lsr.w &0x4,%d1 bsr.l _round # round the denorm mov.l (%sp)+, %a0 # result is now rounded properly. convert back to normal format bclr &0x7, FTEMP_EX(%a0) # clear sgn first; may have residue tst.b FTEMP_SGN(%a0) # is "internal result" sign set? beq.b unf_res_chkifzero # no; result is positive bset &0x7, FTEMP_EX(%a0) # set result sgn clr.b FTEMP_SGN(%a0) # clear temp sign # the number may have become zero after rounding. set ccodes accordingly. unf_res_chkifzero: clr.l %d0 tst.l FTEMP_HI(%a0) # is value now a zero? bne.b unf_res_cont # no tst.l FTEMP_LO(%a0) bne.b unf_res_cont # no # bset &z_bit, FPSR_CC(%a6) # yes; set zero ccode bit bset &z_bit, %d0 # yes; set zero ccode bit unf_res_cont: # # can inex1 also be set along with unfl and inex2??? # # we know that underflow has occurred. aunfl should be set if INEX2 is also set. # btst &inex2_bit, FPSR_EXCEPT(%a6) # is INEX2 set? beq.b unf_res_end # no bset &aunfl_bit, FPSR_AEXCEPT(%a6) # yes; set aunfl unf_res_end: add.l &0x4, %sp # clear stack rts # unf_res() for fsglmul() and fsgldiv(). global unf_res4 unf_res4: mov.l %d1,-(%sp) # save rnd prec,mode on stack btst &0x7,FTEMP_EX(%a0) # make "internal" format sne FTEMP_SGN(%a0) mov.w FTEMP_EX(%a0),%d1 # extract exponent and.w &0x7fff,%d1 sub.w %d0,%d1 mov.w %d1,FTEMP_EX(%a0) # insert 16 bit exponent mov.l %a0,-(%sp) # save operand ptr during calls clr.l %d0 # force rnd prec = ext bsr.l _denorm # denorm result mov.l (%sp),%a0 mov.w &s_mode,%d1 # force rnd prec = sgl swap %d1 mov.w 0x6(%sp),%d1 # load rnd mode andi.w &0x30,%d1 # extract rnd prec lsr.w &0x4,%d1 bsr.l _round # round the denorm mov.l (%sp)+,%a0 # result is now rounded properly. convert back to normal format bclr &0x7,FTEMP_EX(%a0) # clear sgn first; may have residue tst.b FTEMP_SGN(%a0) # is "internal result" sign set? beq.b unf_res4_chkifzero # no; result is positive bset &0x7,FTEMP_EX(%a0) # set result sgn clr.b FTEMP_SGN(%a0) # clear temp sign # the number may have become zero after rounding. set ccodes accordingly. unf_res4_chkifzero: clr.l %d0 tst.l FTEMP_HI(%a0) # is value now a zero? bne.b unf_res4_cont # no tst.l FTEMP_LO(%a0) bne.b unf_res4_cont # no # bset &z_bit,FPSR_CC(%a6) # yes; set zero ccode bit bset &z_bit,%d0 # yes; set zero ccode bit unf_res4_cont: # # can inex1 also be set along with unfl and inex2??? # # we know that underflow has occurred. aunfl should be set if INEX2 is also set. # btst &inex2_bit,FPSR_EXCEPT(%a6) # is INEX2 set? beq.b unf_res4_end # no bset &aunfl_bit,FPSR_AEXCEPT(%a6) # yes; set aunfl unf_res4_end: add.l &0x4,%sp # clear stack rts ######################################################################### # XDEF **************************************************************** # # ovf_res(): routine to produce the default overflow result of # # an overflowing number. # # ovf_res2(): same as above but the rnd mode/prec are passed # # differently. # # # # XREF **************************************************************** # # none # # # # INPUT *************************************************************** # # d1.b = '-1' => (-); '0' => (+) # # ovf_res(): # # d0 = rnd mode/prec # # ovf_res2(): # # hi(d0) = rnd prec # # lo(d0) = rnd mode # # # # OUTPUT ************************************************************** # # a0 = points to extended precision result # # d0.b = condition code bits # # # # ALGORITHM *********************************************************** # # The default overflow result can be determined by the sign of # # the result and the rounding mode/prec in effect. These bits are # # concatenated together to create an index into the default result # # table. A pointer to the correct result is returned in a0. The # # resulting condition codes are returned in d0 in case the caller # # doesn't want FPSR_cc altered (as is the case for fmove out). # # # ######################################################################### global ovf_res ovf_res: andi.w &0x10,%d1 # keep result sign lsr.b &0x4,%d0 # shift prec/mode or.b %d0,%d1 # concat the two mov.w %d1,%d0 # make a copy lsl.b &0x1,%d1 # multiply d1 by 2 bra.b ovf_res_load global ovf_res2 ovf_res2: and.w &0x10, %d1 # keep result sign or.b %d0, %d1 # insert rnd mode swap %d0 or.b %d0, %d1 # insert rnd prec mov.w %d1, %d0 # make a copy lsl.b &0x1, %d1 # shift left by 1 # # use the rounding mode, precision, and result sign as in index into the # two tables below to fetch the default result and the result ccodes. # ovf_res_load: mov.b (tbl_ovfl_cc.b,%pc,%d0.w*1), %d0 # fetch result ccodes lea (tbl_ovfl_result.b,%pc,%d1.w*8), %a0 # return result ptr rts tbl_ovfl_cc: byte 0x2, 0x0, 0x0, 0x2 byte 0x2, 0x0, 0x0, 0x2 byte 0x2, 0x0, 0x0, 0x2 byte 0x0, 0x0, 0x0, 0x0 byte 0x2+0x8, 0x8, 0x2+0x8, 0x8 byte 0x2+0x8, 0x8, 0x2+0x8, 0x8 byte 0x2+0x8, 0x8, 0x2+0x8, 0x8 tbl_ovfl_result: long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RN long 0x7ffe0000,0xffffffff,0xffffffff,0x00000000 # +EXT; RZ long 0x7ffe0000,0xffffffff,0xffffffff,0x00000000 # +EXT; RM long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RP long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RN long 0x407e0000,0xffffff00,0x00000000,0x00000000 # +SGL; RZ long 0x407e0000,0xffffff00,0x00000000,0x00000000 # +SGL; RM long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RP long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RN long 0x43fe0000,0xffffffff,0xfffff800,0x00000000 # +DBL; RZ long 0x43fe0000,0xffffffff,0xfffff800,0x00000000 # +DBL; RM long 0x7fff0000,0x00000000,0x00000000,0x00000000 # +INF; RP long 0x00000000,0x00000000,0x00000000,0x00000000 long 0x00000000,0x00000000,0x00000000,0x00000000 long 0x00000000,0x00000000,0x00000000,0x00000000 long 0x00000000,0x00000000,0x00000000,0x00000000 long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RN long 0xfffe0000,0xffffffff,0xffffffff,0x00000000 # -EXT; RZ long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RM long 0xfffe0000,0xffffffff,0xffffffff,0x00000000 # -EXT; RP long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RN long 0xc07e0000,0xffffff00,0x00000000,0x00000000 # -SGL; RZ long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RM long 0xc07e0000,0xffffff00,0x00000000,0x00000000 # -SGL; RP long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RN long 0xc3fe0000,0xffffffff,0xfffff800,0x00000000 # -DBL; RZ long 0xffff0000,0x00000000,0x00000000,0x00000000 # -INF; RM long 0xc3fe0000,0xffffffff,0xfffff800,0x00000000 # -DBL; RP ######################################################################### # XDEF **************************************************************** # # fout(): move from fp register to memory or data register # # # # XREF **************************************************************** # # _round() - needed to create EXOP for sgl/dbl precision # # norm() - needed to create EXOP for extended precision # # ovf_res() - create default overflow result for sgl/dbl precision# # unf_res() - create default underflow result for sgl/dbl prec. # # dst_dbl() - create rounded dbl precision result. # # dst_sgl() - create rounded sgl precision result. # # fetch_dreg() - fetch dynamic k-factor reg for packed. # # bindec() - convert FP binary number to packed number. # # _mem_write() - write data to memory. # # _mem_write2() - write data to memory unless supv mode -(a7) exc.# # _dmem_write_{byte,word,long}() - write data to memory. # # store_dreg_{b,w,l}() - store data to data register file. # # facc_out_{b,w,l,d,x}() - data access error occurred. # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 = round prec,mode # # # # OUTPUT ************************************************************** # # fp0 : intermediate underflow or overflow result if # # OVFL/UNFL occurred for a sgl or dbl operand # # # # ALGORITHM *********************************************************** # # This routine is accessed by many handlers that need to do an # # opclass three move of an operand out to memory. # # Decode an fmove out (opclass 3) instruction to determine if # # it's b,w,l,s,d,x, or p in size. b,w,l can be stored to either a data # # register or memory. The algorithm uses a standard "fmove" to create # # the rounded result. Also, since exceptions are disabled, this also # # create the correct OPERR default result if appropriate. # # For sgl or dbl precision, overflow or underflow can occur. If # # either occurs and is enabled, the EXOP. # # For extended precision, the stacked must be fixed along # # w/ the address index register as appropriate w/ _calc_ea_fout(). If # # the source is a denorm and if underflow is enabled, an EXOP must be # # created. # # For packed, the k-factor must be fetched from the instruction # # word or a data register. The must be fixed as w/ extended # # precision. Then, bindec() is called to create the appropriate # # packed result. # # If at any time an access error is flagged by one of the move- # # to-memory routines, then a special exit must be made so that the # # access error can be handled properly. # # # ######################################################################### global fout fout: bfextu EXC_CMDREG(%a6){&3:&3},%d1 # extract dst fmt mov.w (tbl_fout.b,%pc,%d1.w*2),%a1 # use as index jmp (tbl_fout.b,%pc,%a1) # jump to routine swbeg &0x8 tbl_fout: short fout_long - tbl_fout short fout_sgl - tbl_fout short fout_ext - tbl_fout short fout_pack - tbl_fout short fout_word - tbl_fout short fout_dbl - tbl_fout short fout_byte - tbl_fout short fout_pack - tbl_fout ################################################################# # fmove.b out ################################################### ################################################################# # Only "Unimplemented Data Type" exceptions enter here. The operand # is either a DENORM or a NORM. fout_byte: tst.b STAG(%a6) # is operand normalized? bne.b fout_byte_denorm # no fmovm.x SRC(%a0),&0x80 # load value fout_byte_norm: fmov.l %d0,%fpcr # insert rnd prec,mode fmov.b %fp0,%d0 # exec move out w/ correct rnd mode fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # fetch FPSR or.w %d1,2+USER_FPSR(%a6) # save new exc,accrued bits mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode andi.b &0x38,%d1 # is mode == 0? (Dreg dst) beq.b fout_byte_dn # must save to integer regfile mov.l EXC_EA(%a6),%a0 # stacked is correct bsr.l _dmem_write_byte # write byte tst.l %d1 # did dstore fail? bne.l facc_out_b # yes rts fout_byte_dn: mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn andi.w &0x7,%d1 bsr.l store_dreg_b rts fout_byte_denorm: mov.l SRC_EX(%a0),%d1 andi.l &0x80000000,%d1 # keep DENORM sign ori.l &0x00800000,%d1 # make smallest sgl fmov.s %d1,%fp0 bra.b fout_byte_norm ################################################################# # fmove.w out ################################################### ################################################################# # Only "Unimplemented Data Type" exceptions enter here. The operand # is either a DENORM or a NORM. fout_word: tst.b STAG(%a6) # is operand normalized? bne.b fout_word_denorm # no fmovm.x SRC(%a0),&0x80 # load value fout_word_norm: fmov.l %d0,%fpcr # insert rnd prec:mode fmov.w %fp0,%d0 # exec move out w/ correct rnd mode fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # fetch FPSR or.w %d1,2+USER_FPSR(%a6) # save new exc,accrued bits mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode andi.b &0x38,%d1 # is mode == 0? (Dreg dst) beq.b fout_word_dn # must save to integer regfile mov.l EXC_EA(%a6),%a0 # stacked is correct bsr.l _dmem_write_word # write word tst.l %d1 # did dstore fail? bne.l facc_out_w # yes rts fout_word_dn: mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn andi.w &0x7,%d1 bsr.l store_dreg_w rts fout_word_denorm: mov.l SRC_EX(%a0),%d1 andi.l &0x80000000,%d1 # keep DENORM sign ori.l &0x00800000,%d1 # make smallest sgl fmov.s %d1,%fp0 bra.b fout_word_norm ################################################################# # fmove.l out ################################################### ################################################################# # Only "Unimplemented Data Type" exceptions enter here. The operand # is either a DENORM or a NORM. fout_long: tst.b STAG(%a6) # is operand normalized? bne.b fout_long_denorm # no fmovm.x SRC(%a0),&0x80 # load value fout_long_norm: fmov.l %d0,%fpcr # insert rnd prec:mode fmov.l %fp0,%d0 # exec move out w/ correct rnd mode fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # fetch FPSR or.w %d1,2+USER_FPSR(%a6) # save new exc,accrued bits fout_long_write: mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode andi.b &0x38,%d1 # is mode == 0? (Dreg dst) beq.b fout_long_dn # must save to integer regfile mov.l EXC_EA(%a6),%a0 # stacked is correct bsr.l _dmem_write_long # write long tst.l %d1 # did dstore fail? bne.l facc_out_l # yes rts fout_long_dn: mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn andi.w &0x7,%d1 bsr.l store_dreg_l rts fout_long_denorm: mov.l SRC_EX(%a0),%d1 andi.l &0x80000000,%d1 # keep DENORM sign ori.l &0x00800000,%d1 # make smallest sgl fmov.s %d1,%fp0 bra.b fout_long_norm ################################################################# # fmove.x out ################################################### ################################################################# # Only "Unimplemented Data Type" exceptions enter here. The operand # is either a DENORM or a NORM. # The DENORM causes an Underflow exception. fout_ext: # we copy the extended precision result to FP_SCR0 so that the reserved # 16-bit field gets zeroed. we do this since we promise not to disturb # what's at SRC(a0). mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) clr.w 2+FP_SCR0_EX(%a6) # clear reserved field mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) fmovm.x SRC(%a0),&0x80 # return result bsr.l _calc_ea_fout # fix stacked mov.l %a0,%a1 # pass: dst addr lea FP_SCR0(%a6),%a0 # pass: src addr mov.l &0xc,%d0 # pass: opsize is 12 bytes # we must not yet write the extended precision data to the stack # in the pre-decrement case from supervisor mode or else we'll corrupt # the stack frame. so, leave it in FP_SRC for now and deal with it later... cmpi.b SPCOND_FLG(%a6),&mda7_flg beq.b fout_ext_a7 bsr.l _dmem_write # write ext prec number to memory tst.l %d1 # did dstore fail? bne.w fout_ext_err # yes tst.b STAG(%a6) # is operand normalized? bne.b fout_ext_denorm # no rts # the number is a DENORM. must set the underflow exception bit fout_ext_denorm: bset &unfl_bit,FPSR_EXCEPT(%a6) # set underflow exc bit mov.b FPCR_ENABLE(%a6),%d0 andi.b &0x0a,%d0 # is UNFL or INEX enabled? bne.b fout_ext_exc # yes rts # we don't want to do the write if the exception occurred in supervisor mode # so _mem_write2() handles this for us. fout_ext_a7: bsr.l _mem_write2 # write ext prec number to memory tst.l %d1 # did dstore fail? bne.w fout_ext_err # yes tst.b STAG(%a6) # is operand normalized? bne.b fout_ext_denorm # no rts fout_ext_exc: lea FP_SCR0(%a6),%a0 bsr.l norm # normalize the mantissa neg.w %d0 # new exp = -(shft amt) andi.w &0x7fff,%d0 andi.w &0x8000,FP_SCR0_EX(%a6) # keep only old sign or.w %d0,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 rts fout_ext_err: mov.l EXC_A6(%a6),(%a6) # fix stacked a6 bra.l facc_out_x ######################################################################### # fmove.s out ########################################################### ######################################################################### fout_sgl: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl prec mov.l %d0,L_SCR3(%a6) # save rnd prec,mode on stack # # operand is a normalized number. first, we check to see if the move out # would cause either an underflow or overflow. these cases are handled # separately. otherwise, set the FPCR to the proper rounding mode and # execute the move. # mov.w SRC_EX(%a0),%d0 # extract exponent andi.w &0x7fff,%d0 # strip sign cmpi.w %d0,&SGL_HI # will operand overflow? bgt.w fout_sgl_ovfl # yes; go handle OVFL beq.w fout_sgl_may_ovfl # maybe; go handle possible OVFL cmpi.w %d0,&SGL_LO # will operand underflow? blt.w fout_sgl_unfl # yes; go handle underflow # # NORMs(in range) can be stored out by a simple "fmov.s" # Unnormalized inputs can come through this point. # fout_sgl_exg: fmovm.x SRC(%a0),&0x80 # fetch fop from stack fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmov.s %fp0,%d0 # store does convert and round fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save FPSR or.w %d1,2+USER_FPSR(%a6) # set possible inex2/ainex fout_sgl_exg_write: mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode andi.b &0x38,%d1 # is mode == 0? (Dreg dst) beq.b fout_sgl_exg_write_dn # must save to integer regfile mov.l EXC_EA(%a6),%a0 # stacked is correct bsr.l _dmem_write_long # write long tst.l %d1 # did dstore fail? bne.l facc_out_l # yes rts fout_sgl_exg_write_dn: mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn andi.w &0x7,%d1 bsr.l store_dreg_l rts # # here, we know that the operand would UNFL if moved out to single prec, # so, denorm and round and then use generic store single routine to # write the value to memory. # fout_sgl_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set UNFL mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.l %a0,-(%sp) clr.l %d0 # pass: S.F. = 0 cmpi.b STAG(%a6),&DENORM # fetch src optype tag bne.b fout_sgl_unfl_cont # let DENORMs fall through lea FP_SCR0(%a6),%a0 bsr.l norm # normalize the DENORM fout_sgl_unfl_cont: lea FP_SCR0(%a6),%a0 # pass: ptr to operand mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calc default underflow result lea FP_SCR0(%a6),%a0 # pass: ptr to fop bsr.l dst_sgl # convert to single prec mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode andi.b &0x38,%d1 # is mode == 0? (Dreg dst) beq.b fout_sgl_unfl_dn # must save to integer regfile mov.l EXC_EA(%a6),%a0 # stacked is correct bsr.l _dmem_write_long # write long tst.l %d1 # did dstore fail? bne.l facc_out_l # yes bra.b fout_sgl_unfl_chkexc fout_sgl_unfl_dn: mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn andi.w &0x7,%d1 bsr.l store_dreg_l fout_sgl_unfl_chkexc: mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0a,%d1 # is UNFL or INEX enabled? bne.w fout_sd_exc_unfl # yes addq.l &0x4,%sp rts # # it's definitely an overflow so call ovf_res to get the correct answer # fout_sgl_ovfl: tst.b 3+SRC_HI(%a0) # is result inexact? bne.b fout_sgl_ovfl_inex2 tst.l SRC_LO(%a0) # is result inexact? bne.b fout_sgl_ovfl_inex2 ori.w &ovfl_inx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex bra.b fout_sgl_ovfl_cont fout_sgl_ovfl_inex2: ori.w &ovfinx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex/inex2 fout_sgl_ovfl_cont: mov.l %a0,-(%sp) # call ovf_res() w/ sgl prec and the correct rnd mode to create the default # overflow result. DON'T save the returned ccodes from ovf_res() since # fmove out doesn't alter them. tst.b SRC_EX(%a0) # is operand negative? smi %d1 # set if so mov.l L_SCR3(%a6),%d0 # pass: sgl prec,rnd mode bsr.l ovf_res # calc OVFL result fmovm.x (%a0),&0x80 # load default overflow result fmov.s %fp0,%d0 # store to single mov.b 1+EXC_OPWORD(%a6),%d1 # extract dst mode andi.b &0x38,%d1 # is mode == 0? (Dreg dst) beq.b fout_sgl_ovfl_dn # must save to integer regfile mov.l EXC_EA(%a6),%a0 # stacked is correct bsr.l _dmem_write_long # write long tst.l %d1 # did dstore fail? bne.l facc_out_l # yes bra.b fout_sgl_ovfl_chkexc fout_sgl_ovfl_dn: mov.b 1+EXC_OPWORD(%a6),%d1 # extract Dn andi.w &0x7,%d1 bsr.l store_dreg_l fout_sgl_ovfl_chkexc: mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0a,%d1 # is UNFL or INEX enabled? bne.w fout_sd_exc_ovfl # yes addq.l &0x4,%sp rts # # move out MAY overflow: # (1) force the exp to 0x3fff # (2) do a move w/ appropriate rnd mode # (3) if exp still equals zero, then insert original exponent # for the correct result. # if exp now equals one, then it overflowed so call ovf_res. # fout_sgl_may_ovfl: mov.w SRC_EX(%a0),%d1 # fetch current sign andi.w &0x8000,%d1 # keep it,clear exp ori.w &0x3fff,%d1 # insert exp = 0 mov.w %d1,FP_SCR0_EX(%a6) # insert scaled exp mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) # copy hi(man) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) # copy lo(man) fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.x FP_SCR0(%a6),%fp0 # force fop to be rounded fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp0 # need absolute value fcmp.b %fp0,&0x2 # did exponent increase? fblt.w fout_sgl_exg # no; go finish NORM bra.w fout_sgl_ovfl # yes; go handle overflow ################ fout_sd_exc_unfl: mov.l (%sp)+,%a0 mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) cmpi.b STAG(%a6),&DENORM # was src a DENORM? bne.b fout_sd_exc_cont # no lea FP_SCR0(%a6),%a0 bsr.l norm neg.l %d0 andi.w &0x7fff,%d0 bfins %d0,FP_SCR0_EX(%a6){&1:&15} bra.b fout_sd_exc_cont fout_sd_exc: fout_sd_exc_ovfl: mov.l (%sp)+,%a0 # restore a0 mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) fout_sd_exc_cont: bclr &0x7,FP_SCR0_EX(%a6) # clear sign bit sne.b 2+FP_SCR0_EX(%a6) # set internal sign bit lea FP_SCR0(%a6),%a0 # pass: ptr to DENORM mov.b 3+L_SCR3(%a6),%d1 lsr.b &0x4,%d1 andi.w &0x0c,%d1 swap %d1 mov.b 3+L_SCR3(%a6),%d1 lsr.b &0x4,%d1 andi.w &0x03,%d1 clr.l %d0 # pass: zero g,r,s bsr.l _round # round the DENORM tst.b 2+FP_SCR0_EX(%a6) # is EXOP negative? beq.b fout_sd_exc_done # no bset &0x7,FP_SCR0_EX(%a6) # yes fout_sd_exc_done: fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 rts ################################################################# # fmove.d out ################################################### ################################################################# fout_dbl: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl prec mov.l %d0,L_SCR3(%a6) # save rnd prec,mode on stack # # operand is a normalized number. first, we check to see if the move out # would cause either an underflow or overflow. these cases are handled # separately. otherwise, set the FPCR to the proper rounding mode and # execute the move. # mov.w SRC_EX(%a0),%d0 # extract exponent andi.w &0x7fff,%d0 # strip sign cmpi.w %d0,&DBL_HI # will operand overflow? bgt.w fout_dbl_ovfl # yes; go handle OVFL beq.w fout_dbl_may_ovfl # maybe; go handle possible OVFL cmpi.w %d0,&DBL_LO # will operand underflow? blt.w fout_dbl_unfl # yes; go handle underflow # # NORMs(in range) can be stored out by a simple "fmov.d" # Unnormalized inputs can come through this point. # fout_dbl_exg: fmovm.x SRC(%a0),&0x80 # fetch fop from stack fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmov.d %fp0,L_SCR1(%a6) # store does convert and round fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d0 # save FPSR or.w %d0,2+USER_FPSR(%a6) # set possible inex2/ainex mov.l EXC_EA(%a6),%a1 # pass: dst addr lea L_SCR1(%a6),%a0 # pass: src addr movq.l &0x8,%d0 # pass: opsize is 8 bytes bsr.l _dmem_write # store dbl fop to memory tst.l %d1 # did dstore fail? bne.l facc_out_d # yes rts # no; so we're finished # # here, we know that the operand would UNFL if moved out to double prec, # so, denorm and round and then use generic store double routine to # write the value to memory. # fout_dbl_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set UNFL mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.l %a0,-(%sp) clr.l %d0 # pass: S.F. = 0 cmpi.b STAG(%a6),&DENORM # fetch src optype tag bne.b fout_dbl_unfl_cont # let DENORMs fall through lea FP_SCR0(%a6),%a0 bsr.l norm # normalize the DENORM fout_dbl_unfl_cont: lea FP_SCR0(%a6),%a0 # pass: ptr to operand mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calc default underflow result lea FP_SCR0(%a6),%a0 # pass: ptr to fop bsr.l dst_dbl # convert to single prec mov.l %d0,L_SCR1(%a6) mov.l %d1,L_SCR2(%a6) mov.l EXC_EA(%a6),%a1 # pass: dst addr lea L_SCR1(%a6),%a0 # pass: src addr movq.l &0x8,%d0 # pass: opsize is 8 bytes bsr.l _dmem_write # store dbl fop to memory tst.l %d1 # did dstore fail? bne.l facc_out_d # yes mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0a,%d1 # is UNFL or INEX enabled? bne.w fout_sd_exc_unfl # yes addq.l &0x4,%sp rts # # it's definitely an overflow so call ovf_res to get the correct answer # fout_dbl_ovfl: mov.w 2+SRC_LO(%a0),%d0 andi.w &0x7ff,%d0 bne.b fout_dbl_ovfl_inex2 ori.w &ovfl_inx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex bra.b fout_dbl_ovfl_cont fout_dbl_ovfl_inex2: ori.w &ovfinx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex/inex2 fout_dbl_ovfl_cont: mov.l %a0,-(%sp) # call ovf_res() w/ dbl prec and the correct rnd mode to create the default # overflow result. DON'T save the returned ccodes from ovf_res() since # fmove out doesn't alter them. tst.b SRC_EX(%a0) # is operand negative? smi %d1 # set if so mov.l L_SCR3(%a6),%d0 # pass: dbl prec,rnd mode bsr.l ovf_res # calc OVFL result fmovm.x (%a0),&0x80 # load default overflow result fmov.d %fp0,L_SCR1(%a6) # store to double mov.l EXC_EA(%a6),%a1 # pass: dst addr lea L_SCR1(%a6),%a0 # pass: src addr movq.l &0x8,%d0 # pass: opsize is 8 bytes bsr.l _dmem_write # store dbl fop to memory tst.l %d1 # did dstore fail? bne.l facc_out_d # yes mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0a,%d1 # is UNFL or INEX enabled? bne.w fout_sd_exc_ovfl # yes addq.l &0x4,%sp rts # # move out MAY overflow: # (1) force the exp to 0x3fff # (2) do a move w/ appropriate rnd mode # (3) if exp still equals zero, then insert original exponent # for the correct result. # if exp now equals one, then it overflowed so call ovf_res. # fout_dbl_may_ovfl: mov.w SRC_EX(%a0),%d1 # fetch current sign andi.w &0x8000,%d1 # keep it,clear exp ori.w &0x3fff,%d1 # insert exp = 0 mov.w %d1,FP_SCR0_EX(%a6) # insert scaled exp mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) # copy hi(man) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) # copy lo(man) fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.x FP_SCR0(%a6),%fp0 # force fop to be rounded fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp0 # need absolute value fcmp.b %fp0,&0x2 # did exponent increase? fblt.w fout_dbl_exg # no; go finish NORM bra.w fout_dbl_ovfl # yes; go handle overflow ######################################################################### # XDEF **************************************************************** # # dst_dbl(): create double precision value from extended prec. # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # a0 = pointer to source operand in extended precision # # # # OUTPUT ************************************************************** # # d0 = hi(double precision result) # # d1 = lo(double precision result) # # # # ALGORITHM *********************************************************** # # # # Changes extended precision to double precision. # # Note: no attempt is made to round the extended value to double. # # dbl_sign = ext_sign # # dbl_exp = ext_exp - $3fff(ext bias) + $7ff(dbl bias) # # get rid of ext integer bit # # dbl_mant = ext_mant{62:12} # # # # --------------- --------------- --------------- # # extended -> |s| exp | |1| ms mant | | ls mant | # # --------------- --------------- --------------- # # 95 64 63 62 32 31 11 0 # # | | # # | | # # | | # # v v # # --------------- --------------- # # double -> |s|exp| mant | | mant | # # --------------- --------------- # # 63 51 32 31 0 # # # ######################################################################### dst_dbl: clr.l %d0 # clear d0 mov.w FTEMP_EX(%a0),%d0 # get exponent subi.w &EXT_BIAS,%d0 # subtract extended precision bias addi.w &DBL_BIAS,%d0 # add double precision bias tst.b FTEMP_HI(%a0) # is number a denorm? bmi.b dst_get_dupper # no subq.w &0x1,%d0 # yes; denorm bias = DBL_BIAS - 1 dst_get_dupper: swap %d0 # d0 now in upper word lsl.l &0x4,%d0 # d0 in proper place for dbl prec exp tst.b FTEMP_EX(%a0) # test sign bpl.b dst_get_dman # if positive, go process mantissa bset &0x1f,%d0 # if negative, set sign dst_get_dman: mov.l FTEMP_HI(%a0),%d1 # get ms mantissa bfextu %d1{&1:&20},%d1 # get upper 20 bits of ms or.l %d1,%d0 # put these bits in ms word of double mov.l %d0,L_SCR1(%a6) # put the new exp back on the stack mov.l FTEMP_HI(%a0),%d1 # get ms mantissa mov.l &21,%d0 # load shift count lsl.l %d0,%d1 # put lower 11 bits in upper bits mov.l %d1,L_SCR2(%a6) # build lower lword in memory mov.l FTEMP_LO(%a0),%d1 # get ls mantissa bfextu %d1{&0:&21},%d0 # get ls 21 bits of double mov.l L_SCR2(%a6),%d1 or.l %d0,%d1 # put them in double result mov.l L_SCR1(%a6),%d0 rts ######################################################################### # XDEF **************************************************************** # # dst_sgl(): create single precision value from extended prec # # # # XREF **************************************************************** # # # # INPUT *************************************************************** # # a0 = pointer to source operand in extended precision # # # # OUTPUT ************************************************************** # # d0 = single precision result # # # # ALGORITHM *********************************************************** # # # # Changes extended precision to single precision. # # sgl_sign = ext_sign # # sgl_exp = ext_exp - $3fff(ext bias) + $7f(sgl bias) # # get rid of ext integer bit # # sgl_mant = ext_mant{62:12} # # # # --------------- --------------- --------------- # # extended -> |s| exp | |1| ms mant | | ls mant | # # --------------- --------------- --------------- # # 95 64 63 62 40 32 31 12 0 # # | | # # | | # # | | # # v v # # --------------- # # single -> |s|exp| mant | # # --------------- # # 31 22 0 # # # ######################################################################### dst_sgl: clr.l %d0 mov.w FTEMP_EX(%a0),%d0 # get exponent subi.w &EXT_BIAS,%d0 # subtract extended precision bias addi.w &SGL_BIAS,%d0 # add single precision bias tst.b FTEMP_HI(%a0) # is number a denorm? bmi.b dst_get_supper # no subq.w &0x1,%d0 # yes; denorm bias = SGL_BIAS - 1 dst_get_supper: swap %d0 # put exp in upper word of d0 lsl.l &0x7,%d0 # shift it into single exp bits tst.b FTEMP_EX(%a0) # test sign bpl.b dst_get_sman # if positive, continue bset &0x1f,%d0 # if negative, put in sign first dst_get_sman: mov.l FTEMP_HI(%a0),%d1 # get ms mantissa andi.l &0x7fffff00,%d1 # get upper 23 bits of ms lsr.l &0x8,%d1 # and put them flush right or.l %d1,%d0 # put these bits in ms word of single rts ############################################################################## fout_pack: bsr.l _calc_ea_fout # fetch the mov.l %a0,-(%sp) mov.b STAG(%a6),%d0 # fetch input type bne.w fout_pack_not_norm # input is not NORM fout_pack_norm: btst &0x4,EXC_CMDREG(%a6) # static or dynamic? beq.b fout_pack_s # static fout_pack_d: mov.b 1+EXC_CMDREG(%a6),%d1 # fetch dynamic reg lsr.b &0x4,%d1 andi.w &0x7,%d1 bsr.l fetch_dreg # fetch Dn w/ k-factor bra.b fout_pack_type fout_pack_s: mov.b 1+EXC_CMDREG(%a6),%d0 # fetch static field fout_pack_type: bfexts %d0{&25:&7},%d0 # extract k-factor mov.l %d0,-(%sp) lea FP_SRC(%a6),%a0 # pass: ptr to input # bindec is currently scrambling FP_SRC for denorm inputs. # we'll have to change this, but for now, tough luck!!! bsr.l bindec # convert xprec to packed # andi.l &0xcfff000f,FP_SCR0(%a6) # clear unused fields andi.l &0xcffff00f,FP_SCR0(%a6) # clear unused fields mov.l (%sp)+,%d0 tst.b 3+FP_SCR0_EX(%a6) bne.b fout_pack_set tst.l FP_SCR0_HI(%a6) bne.b fout_pack_set tst.l FP_SCR0_LO(%a6) bne.b fout_pack_set # add the extra condition that only if the k-factor was zero, too, should # we zero the exponent tst.l %d0 bne.b fout_pack_set # "mantissa" is all zero which means that the answer is zero. but, the '040 # algorithm allows the exponent to be non-zero. the 881/2 do not. Therefore, # if the mantissa is zero, I will zero the exponent, too. # the question now is whether the exponents sign bit is allowed to be non-zero # for a zero, also... andi.w &0xf000,FP_SCR0(%a6) fout_pack_set: lea FP_SCR0(%a6),%a0 # pass: src addr fout_pack_write: mov.l (%sp)+,%a1 # pass: dst addr mov.l &0xc,%d0 # pass: opsize is 12 bytes cmpi.b SPCOND_FLG(%a6),&mda7_flg beq.b fout_pack_a7 bsr.l _dmem_write # write ext prec number to memory tst.l %d1 # did dstore fail? bne.w fout_ext_err # yes rts # we don't want to do the write if the exception occurred in supervisor mode # so _mem_write2() handles this for us. fout_pack_a7: bsr.l _mem_write2 # write ext prec number to memory tst.l %d1 # did dstore fail? bne.w fout_ext_err # yes rts fout_pack_not_norm: cmpi.b %d0,&DENORM # is it a DENORM? beq.w fout_pack_norm # yes lea FP_SRC(%a6),%a0 clr.w 2+FP_SRC_EX(%a6) cmpi.b %d0,&SNAN # is it an SNAN? beq.b fout_pack_snan # yes bra.b fout_pack_write # no fout_pack_snan: ori.w &snaniop2_mask,FPSR_EXCEPT(%a6) # set SNAN/AIOP bset &0x6,FP_SRC_HI(%a6) # set snan bit bra.b fout_pack_write ######################################################################### # XDEF **************************************************************** # # fmul(): emulates the fmul instruction # # fsmul(): emulates the fsmul instruction # # fdmul(): emulates the fdmul instruction # # # # XREF **************************************************************** # # scale_to_zero_src() - scale src exponent to zero # # scale_to_zero_dst() - scale dst exponent to zero # # unf_res() - return default underflow result # # ovf_res() - return default overflow result # # res_qnan() - return QNAN result # # res_snan() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # d0 rnd prec,mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms/denorms into ext/sgl/dbl precision. # # For norms/denorms, scale the exponents such that a multiply # # instruction won't cause an exception. Use the regular fmul to # # compute a result. Check if the regular operands would have taken # # an exception. If so, return the default overflow/underflow result # # and return the EXOP if exceptions are enabled. Else, scale the # # result operand to the proper exponent. # # # ######################################################################### align 0x10 tbl_fmul_ovfl: long 0x3fff - 0x7ffe # ext_max long 0x3fff - 0x407e # sgl_max long 0x3fff - 0x43fe # dbl_max tbl_fmul_unfl: long 0x3fff + 0x0001 # ext_unfl long 0x3fff - 0x3f80 # sgl_unfl long 0x3fff - 0x3c00 # dbl_unfl global fsmul fsmul: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl prec bra.b fmul global fdmul fdmul: andi.b &0x30,%d0 ori.b &d_mode*0x10,%d0 # insert dbl prec global fmul fmul: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 # combine src tags bne.w fmul_not_norm # optimize on non-norm input fmul_norm: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # scale src exponent mov.l %d0,-(%sp) # save scale factor 1 bsr.l scale_to_zero_dst # scale dst exponent add.l %d0,(%sp) # SCALE_FACTOR = scale1 + scale2 mov.w 2+L_SCR3(%a6),%d1 # fetch precision lsr.b &0x6,%d1 # shift to lo bits mov.l (%sp)+,%d0 # load S.F. cmp.l %d0,(tbl_fmul_ovfl.w,%pc,%d1.w*4) # would result ovfl? beq.w fmul_may_ovfl # result may rnd to overflow blt.w fmul_ovfl # result will overflow cmp.l %d0,(tbl_fmul_unfl.w,%pc,%d1.w*4) # would result unfl? beq.w fmul_may_unfl # result may rnd to no unfl bgt.w fmul_unfl # result will underflow # # NORMAL: # - the result of the multiply operation will neither overflow nor underflow. # - do the multiply to the proper precision and rounding mode. # - scale the result exponent using the scale factor. if both operands were # normalized then we really don't need to go through this scaling. but for now, # this will do. # fmul_normal: fmovm.x FP_SCR1(%a6),&0x80 # load dst operand fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp0 # execute multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fmul_normal_exit: fmovm.x &0x80,FP_SCR0(%a6) # store out result mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # OVERFLOW: # - the result of the multiply operation is an overflow. # - do the multiply to the proper precision and rounding mode in order to # set the inexact bits. # - calculate the default result and return it in fp0. # - if overflow or inexact is enabled, we need a multiply result rounded to # extended precision. if the original operation was extended, then we have this # result. if the original operation was single or double, we have to do another # multiply using extended precision and the correct rounding mode. the result # of this operation then has its exponent scaled by -0x6000 to create the # exceptional operand. # fmul_ovfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst operand fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp0 # execute multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N # save setting this until now because this is where fmul_may_ovfl may jump in fmul_ovfl_tst: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fmul_ovfl_ena # yes # calculate the default result fmul_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass rnd prec,mode bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts # # OVFL is enabled; Create EXOP: # - if precision is extended, then we have the EXOP. simply bias the exponent # with an extra -0x6000. if the precision is single or double, we need to # calculate a result rounded to extended precision. # fmul_ovfl_ena: mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # test the rnd prec bne.b fmul_ovfl_ena_sd # it's sgl or dbl fmul_ovfl_ena_cont: fmovm.x &0x80,FP_SCR0(%a6) # move result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.w %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 # clear sign bit andi.w &0x8000,%d2 # keep old sign or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.b fmul_ovfl_dis fmul_ovfl_ena_sd: fmovm.x FP_SCR1(%a6),&0x80 # load dst operand mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # keep rnd mode only fmov.l %d1,%fpcr # set FPCR fmul.x FP_SCR0(%a6),%fp0 # execute multiply fmov.l &0x0,%fpcr # clear FPCR bra.b fmul_ovfl_ena_cont # # may OVERFLOW: # - the result of the multiply operation MAY overflow. # - do the multiply to the proper precision and rounding mode in order to # set the inexact bits. # - calculate the default result and return it in fp0. # fmul_may_ovfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp0 # execute multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| >= 2.b? fbge.w fmul_ovfl_tst # yes; overflow has occurred # no, it didn't overflow; we have correct result bra.w fmul_normal_exit # # UNDERFLOW: # - the result of the multiply operation is an underflow. # - do the multiply to the proper precision and rounding mode in order to # set the inexact bits. # - calculate the default result and return it in fp0. # - if overflow or inexact is enabled, we need a multiply result rounded to # extended precision. if the original operation was extended, then we have this # result. if the original operation was single or double, we have to do another # multiply using extended precision and the correct rounding mode. the result # of this operation then has its exponent scaled by -0x6000 to create the # exceptional operand. # fmul_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit # for fun, let's use only extended precision, round to zero. then, let # the unf_res() routine figure out all the rest. # will we get the correct answer. fmovm.x FP_SCR1(%a6),&0x80 # load dst operand fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp0 # execute multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fmul_unfl_ena # yes fmul_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # unf_res2 may have set 'Z' fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # UNFL is enabled. # fmul_unfl_ena: fmovm.x FP_SCR1(%a6),&0x40 # load dst op mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fmul_unfl_ena_sd # no, sgl or dbl # if the rnd mode is anything but RZ, then we have to re-do the above # multiplication because we used RZ for all. fmov.l L_SCR3(%a6),%fpcr # set FPCR fmul_unfl_ena_cont: fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp1 # execute multiply fmov.l &0x0,%fpcr # clear FPCR fmovm.x &0x40,FP_SCR0(%a6) # save result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor addi.l &0x6000,%d1 # add bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.w fmul_unfl_dis fmul_unfl_ena_sd: mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # use only rnd mode fmov.l %d1,%fpcr # set FPCR bra.b fmul_unfl_ena_cont # MAY UNDERFLOW: # -use the correct rounding mode and precision. this code favors operations # that do not underflow. fmul_may_unfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst operand fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp0 # execute multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| > 2.b? fbgt.w fmul_normal_exit # no; no underflow occurred fblt.w fmul_unfl # yes; underflow occurred # # we still don't know if underflow occurred. result is ~ equal to 2. but, # we don't know if the result was an underflow that rounded up to a 2 or # a normalized number that rounded down to a 2. so, redo the entire operation # using RZ as the rounding mode to see what the pre-rounded result is. # this case should be relatively rare. # fmovm.x FP_SCR1(%a6),&0x40 # load dst operand mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # keep rnd prec ori.b &rz_mode*0x10,%d1 # insert RZ fmov.l %d1,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fmul.x FP_SCR0(%a6),%fp1 # execute multiply fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp1 # make absolute value fcmp.b %fp1,&0x2 # is |result| < 2.b? fbge.w fmul_normal_exit # no; no underflow occurred bra.w fmul_unfl # yes, underflow occurred ################################################################################ # # Multiply: inputs are not both normalized; what are they? # fmul_not_norm: mov.w (tbl_fmul_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fmul_op.b,%pc,%d1.w) swbeg &48 tbl_fmul_op: short fmul_norm - tbl_fmul_op # NORM x NORM short fmul_zero - tbl_fmul_op # NORM x ZERO short fmul_inf_src - tbl_fmul_op # NORM x INF short fmul_res_qnan - tbl_fmul_op # NORM x QNAN short fmul_norm - tbl_fmul_op # NORM x DENORM short fmul_res_snan - tbl_fmul_op # NORM x SNAN short tbl_fmul_op - tbl_fmul_op # short tbl_fmul_op - tbl_fmul_op # short fmul_zero - tbl_fmul_op # ZERO x NORM short fmul_zero - tbl_fmul_op # ZERO x ZERO short fmul_res_operr - tbl_fmul_op # ZERO x INF short fmul_res_qnan - tbl_fmul_op # ZERO x QNAN short fmul_zero - tbl_fmul_op # ZERO x DENORM short fmul_res_snan - tbl_fmul_op # ZERO x SNAN short tbl_fmul_op - tbl_fmul_op # short tbl_fmul_op - tbl_fmul_op # short fmul_inf_dst - tbl_fmul_op # INF x NORM short fmul_res_operr - tbl_fmul_op # INF x ZERO short fmul_inf_dst - tbl_fmul_op # INF x INF short fmul_res_qnan - tbl_fmul_op # INF x QNAN short fmul_inf_dst - tbl_fmul_op # INF x DENORM short fmul_res_snan - tbl_fmul_op # INF x SNAN short tbl_fmul_op - tbl_fmul_op # short tbl_fmul_op - tbl_fmul_op # short fmul_res_qnan - tbl_fmul_op # QNAN x NORM short fmul_res_qnan - tbl_fmul_op # QNAN x ZERO short fmul_res_qnan - tbl_fmul_op # QNAN x INF short fmul_res_qnan - tbl_fmul_op # QNAN x QNAN short fmul_res_qnan - tbl_fmul_op # QNAN x DENORM short fmul_res_snan - tbl_fmul_op # QNAN x SNAN short tbl_fmul_op - tbl_fmul_op # short tbl_fmul_op - tbl_fmul_op # short fmul_norm - tbl_fmul_op # NORM x NORM short fmul_zero - tbl_fmul_op # NORM x ZERO short fmul_inf_src - tbl_fmul_op # NORM x INF short fmul_res_qnan - tbl_fmul_op # NORM x QNAN short fmul_norm - tbl_fmul_op # NORM x DENORM short fmul_res_snan - tbl_fmul_op # NORM x SNAN short tbl_fmul_op - tbl_fmul_op # short tbl_fmul_op - tbl_fmul_op # short fmul_res_snan - tbl_fmul_op # SNAN x NORM short fmul_res_snan - tbl_fmul_op # SNAN x ZERO short fmul_res_snan - tbl_fmul_op # SNAN x INF short fmul_res_snan - tbl_fmul_op # SNAN x QNAN short fmul_res_snan - tbl_fmul_op # SNAN x DENORM short fmul_res_snan - tbl_fmul_op # SNAN x SNAN short tbl_fmul_op - tbl_fmul_op # short tbl_fmul_op - tbl_fmul_op # fmul_res_operr: bra.l res_operr fmul_res_snan: bra.l res_snan fmul_res_qnan: bra.l res_qnan # # Multiply: (Zero x Zero) || (Zero x norm) || (Zero x denorm) # global fmul_zero # global for fsglmul fmul_zero: mov.b SRC_EX(%a0),%d0 # exclusive or the signs mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bpl.b fmul_zero_p # result ZERO is pos. fmul_zero_n: fmov.s &0x80000000,%fp0 # load -ZERO mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set Z/N rts fmul_zero_p: fmov.s &0x00000000,%fp0 # load +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set Z rts # # Multiply: (inf x inf) || (inf x norm) || (inf x denorm) # # Note: The j-bit for an infinity is a don't-care. However, to be # strictly compatible w/ the 68881/882, we make sure to return an # INF w/ the j-bit set if the input INF j-bit was set. Destination # INFs take priority. # global fmul_inf_dst # global for fsglmul fmul_inf_dst: fmovm.x DST(%a1),&0x80 # return INF result in fp0 mov.b SRC_EX(%a0),%d0 # exclusive or the signs mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bpl.b fmul_inf_dst_p # result INF is pos. fmul_inf_dst_n: fabs.x %fp0 # clear result sign fneg.x %fp0 # set result sign mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set INF/N rts fmul_inf_dst_p: fabs.x %fp0 # clear result sign mov.b &inf_bmask,FPSR_CC(%a6) # set INF rts global fmul_inf_src # global for fsglmul fmul_inf_src: fmovm.x SRC(%a0),&0x80 # return INF result in fp0 mov.b SRC_EX(%a0),%d0 # exclusive or the signs mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bpl.b fmul_inf_dst_p # result INF is pos. bra.b fmul_inf_dst_n ######################################################################### # XDEF **************************************************************** # # fin(): emulates the fmove instruction # # fsin(): emulates the fsmove instruction # # fdin(): emulates the fdmove instruction # # # # XREF **************************************************************** # # norm() - normalize mantissa for EXOP on denorm # # scale_to_zero_src() - scale src exponent to zero # # ovf_res() - return default overflow result # # unf_res() - return default underflow result # # res_qnan_1op() - return QNAN result # # res_snan_1op() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 = round prec/mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms into extended, single, and double precision. # # Norms can be emulated w/ a regular fmove instruction. For # # sgl/dbl, must scale exponent and perform an "fmove". Check to see # # if the result would have overflowed/underflowed. If so, use unf_res() # # or ovf_res() to return the default result. Also return EXOP if # # exception is enabled. If no exception, return the default result. # # Unnorms don't pass through here. # # # ######################################################################### global fsin fsin: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl precision bra.b fin global fdin fdin: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl precision global fin fin: mov.l %d0,L_SCR3(%a6) # store rnd info mov.b STAG(%a6),%d1 # fetch src optype tag bne.w fin_not_norm # optimize on non-norm input # # FP MOVE IN: NORMs and DENORMs ONLY! # fin_norm: andi.b &0xc0,%d0 # is precision extended? bne.w fin_not_ext # no, so go handle dbl or sgl # # precision selected is extended. so...we cannot get an underflow # or overflow because of rounding to the correct precision. so... # skip the scaling and unscaling... # tst.b SRC_EX(%a0) # is the operand negative? bpl.b fin_norm_done # no bset &neg_bit,FPSR_CC(%a6) # yes, so set 'N' ccode bit fin_norm_done: fmovm.x SRC(%a0),&0x80 # return result in fp0 rts # # for an extended precision DENORM, the UNFL exception bit is set # the accrued bit is NOT set in this instance(no inexactness!) # fin_denorm: andi.b &0xc0,%d0 # is precision extended? bne.w fin_not_ext # no, so go handle dbl or sgl bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit tst.b SRC_EX(%a0) # is the operand negative? bpl.b fin_denorm_done # no bset &neg_bit,FPSR_CC(%a6) # yes, so set 'N' ccode bit fin_denorm_done: fmovm.x SRC(%a0),&0x80 # return result in fp0 btst &unfl_bit,FPCR_ENABLE(%a6) # is UNFL enabled? bne.b fin_denorm_unfl_ena # yes rts # # the input is an extended DENORM and underflow is enabled in the FPCR. # normalize the mantissa and add the bias of 0x6000 to the resulting negative # exponent and insert back into the operand. # fin_denorm_unfl_ena: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) lea FP_SCR0(%a6),%a0 # pass: ptr to operand bsr.l norm # normalize result neg.w %d0 # new exponent = -(shft val) addi.w &0x6000,%d0 # add new bias to exponent mov.w FP_SCR0_EX(%a6),%d1 # fetch old sign,exp andi.w &0x8000,%d1 # keep old sign andi.w &0x7fff,%d0 # clear sign position or.w %d1,%d0 # concat new exo,old sign mov.w %d0,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 rts # # operand is to be rounded to single or double precision # fin_not_ext: cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec bne.b fin_dbl # # operand is to be rounded to single precision # fin_sgl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor cmpi.l %d0,&0x3fff-0x3f80 # will move in underflow? bge.w fin_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x407e # will move in overflow? beq.w fin_sd_may_ovfl # maybe; go check blt.w fin_sd_ovfl # yes; go handle overflow # # operand will NOT overflow or underflow when moved into the fp reg file # fin_sd_normal: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.x FP_SCR0(%a6),%fp0 # perform move fmov.l %fpsr,%d1 # save FPSR fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fin_sd_normal_exit: mov.l %d2,-(%sp) # save d2 fmovm.x &0x80,FP_SCR0(%a6) # store out result mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} mov.w %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor andi.w &0x8000,%d2 # keep old sign or.w %d1,%d2 # concat old sign,new exponent mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts # # operand is to be rounded to double precision # fin_dbl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor cmpi.l %d0,&0x3fff-0x3c00 # will move in underflow? bge.w fin_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x43fe # will move in overflow? beq.w fin_sd_may_ovfl # maybe; go check blt.w fin_sd_ovfl # yes; go handle overflow bra.w fin_sd_normal # no; ho handle normalized op # # operand WILL underflow when moved in to the fp register file # fin_sd_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit tst.b FP_SCR0_EX(%a6) # is operand negative? bpl.b fin_sd_unfl_tst bset &neg_bit,FPSR_CC(%a6) # set 'N' ccode bit # if underflow or inexact is enabled, then go calculate the EXOP first. fin_sd_unfl_tst: mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fin_sd_unfl_ena # yes fin_sd_unfl_dis: lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # unf_res may have set 'Z' fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # operand will underflow AND underflow or inexact is enabled. # Therefore, we must return the result rounded to extended precision. # fin_sd_unfl_ena: mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) mov.w FP_SCR0_EX(%a6),%d1 # load current exponent mov.l %d2,-(%sp) # save d2 mov.w %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # subtract scale factor andi.w &0x8000,%d2 # extract old sign addi.l &0x6000,%d1 # add new bias andi.w &0x7fff,%d1 or.w %d1,%d2 # concat old sign,new exp mov.w %d2,FP_SCR1_EX(%a6) # insert new exponent fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fin_sd_unfl_dis # # operand WILL overflow. # fin_sd_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.x FP_SCR0(%a6),%fp0 # perform move fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save FPSR or.l %d1,USER_FPSR(%a6) # save INEX2,N fin_sd_ovfl_tst: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fin_sd_ovfl_ena # yes # # OVFL is not enabled; therefore, we must create the default result by # calling ovf_res(). # fin_sd_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass: prec,mode bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts # # OVFL is enabled. # the INEX2 bit has already been updated by the round to the correct precision. # now, round to extended(and don't alter the FPSR). # fin_sd_ovfl_ena: mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor sub.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 or.w %d2,%d1 mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.b fin_sd_ovfl_dis # # the move in MAY overflow. so... # fin_sd_may_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.x FP_SCR0(%a6),%fp0 # perform the move fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| >= 2.b? fbge.w fin_sd_ovfl_tst # yes; overflow has occurred # no, it didn't overflow; we have correct result bra.w fin_sd_normal_exit ########################################################################## # # operand is not a NORM: check its optype and branch accordingly # fin_not_norm: cmpi.b %d1,&DENORM # weed out DENORM beq.w fin_denorm cmpi.b %d1,&SNAN # weed out SNANs beq.l res_snan_1op cmpi.b %d1,&QNAN # weed out QNANs beq.l res_qnan_1op # # do the fmove in; at this point, only possible ops are ZERO and INF. # use fmov to determine ccodes. # prec:mode should be zero at this point but it won't affect answer anyways. # fmov.x SRC(%a0),%fp0 # do fmove in fmov.l %fpsr,%d0 # no exceptions possible rol.l &0x8,%d0 # put ccodes in lo byte mov.b %d0,FPSR_CC(%a6) # insert correct ccodes rts ######################################################################### # XDEF **************************************************************** # # fdiv(): emulates the fdiv instruction # # fsdiv(): emulates the fsdiv instruction # # fddiv(): emulates the fddiv instruction # # # # XREF **************************************************************** # # scale_to_zero_src() - scale src exponent to zero # # scale_to_zero_dst() - scale dst exponent to zero # # unf_res() - return default underflow result # # ovf_res() - return default overflow result # # res_qnan() - return QNAN result # # res_snan() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # d0 rnd prec,mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms/denorms into ext/sgl/dbl precision. # # For norms/denorms, scale the exponents such that a divide # # instruction won't cause an exception. Use the regular fdiv to # # compute a result. Check if the regular operands would have taken # # an exception. If so, return the default overflow/underflow result # # and return the EXOP if exceptions are enabled. Else, scale the # # result operand to the proper exponent. # # # ######################################################################### align 0x10 tbl_fdiv_unfl: long 0x3fff - 0x0000 # ext_unfl long 0x3fff - 0x3f81 # sgl_unfl long 0x3fff - 0x3c01 # dbl_unfl tbl_fdiv_ovfl: long 0x3fff - 0x7ffe # ext overflow exponent long 0x3fff - 0x407e # sgl overflow exponent long 0x3fff - 0x43fe # dbl overflow exponent global fsdiv fsdiv: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl prec bra.b fdiv global fddiv fddiv: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl prec global fdiv fdiv: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 # combine src tags bne.w fdiv_not_norm # optimize on non-norm input # # DIVIDE: NORMs and DENORMs ONLY! # fdiv_norm: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # scale src exponent mov.l %d0,-(%sp) # save scale factor 1 bsr.l scale_to_zero_dst # scale dst exponent neg.l (%sp) # SCALE FACTOR = scale1 - scale2 add.l %d0,(%sp) mov.w 2+L_SCR3(%a6),%d1 # fetch precision lsr.b &0x6,%d1 # shift to lo bits mov.l (%sp)+,%d0 # load S.F. cmp.l %d0,(tbl_fdiv_ovfl.b,%pc,%d1.w*4) # will result overflow? ble.w fdiv_may_ovfl # result will overflow cmp.l %d0,(tbl_fdiv_unfl.w,%pc,%d1.w*4) # will result underflow? beq.w fdiv_may_unfl # maybe bgt.w fdiv_unfl # yes; go handle underflow fdiv_normal: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # save FPCR fmov.l &0x0,%fpsr # clear FPSR fdiv.x FP_SCR0(%a6),%fp0 # perform divide fmov.l %fpsr,%d1 # save FPSR fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fdiv_normal_exit: fmovm.x &0x80,FP_SCR0(%a6) # store result on stack mov.l %d2,-(%sp) # store d2 mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts tbl_fdiv_ovfl2: long 0x7fff long 0x407f long 0x43ff fdiv_no_ovfl: mov.l (%sp)+,%d0 # restore scale factor bra.b fdiv_normal_exit fdiv_may_ovfl: mov.l %d0,-(%sp) # save scale factor fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # set FPSR fdiv.x FP_SCR0(%a6),%fp0 # execute divide fmov.l %fpsr,%d0 fmov.l &0x0,%fpcr or.l %d0,USER_FPSR(%a6) # save INEX,N fmovm.x &0x01,-(%sp) # save result to stack mov.w (%sp),%d0 # fetch new exponent add.l &0xc,%sp # clear result from stack andi.l &0x7fff,%d0 # strip sign sub.l (%sp),%d0 # add scale factor cmp.l %d0,(tbl_fdiv_ovfl2.b,%pc,%d1.w*4) blt.b fdiv_no_ovfl mov.l (%sp)+,%d0 fdiv_ovfl_tst: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fdiv_ovfl_ena # yes fdiv_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass prec:rnd bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts fdiv_ovfl_ena: mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fdiv_ovfl_ena_sd # no, do sgl or dbl fdiv_ovfl_ena_cont: fmovm.x &0x80,FP_SCR0(%a6) # move result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.w %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 # clear sign bit andi.w &0x8000,%d2 # keep old sign or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.b fdiv_ovfl_dis fdiv_ovfl_ena_sd: fmovm.x FP_SCR1(%a6),&0x80 # load dst operand mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # keep rnd mode fmov.l %d1,%fpcr # set FPCR fdiv.x FP_SCR0(%a6),%fp0 # execute divide fmov.l &0x0,%fpcr # clear FPCR bra.b fdiv_ovfl_ena_cont fdiv_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fdiv.x FP_SCR0(%a6),%fp0 # execute divide fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fdiv_unfl_ena # yes fdiv_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # 'Z' may have been set fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # UNFL is enabled. # fdiv_unfl_ena: fmovm.x FP_SCR1(%a6),&0x40 # load dst op mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fdiv_unfl_ena_sd # no, sgl or dbl fmov.l L_SCR3(%a6),%fpcr # set FPCR fdiv_unfl_ena_cont: fmov.l &0x0,%fpsr # clear FPSR fdiv.x FP_SCR0(%a6),%fp1 # execute divide fmov.l &0x0,%fpcr # clear FPCR fmovm.x &0x40,FP_SCR0(%a6) # save result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factoer addi.l &0x6000,%d1 # add bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exp mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.w fdiv_unfl_dis fdiv_unfl_ena_sd: mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # use only rnd mode fmov.l %d1,%fpcr # set FPCR bra.b fdiv_unfl_ena_cont # # the divide operation MAY underflow: # fdiv_may_unfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fdiv.x FP_SCR0(%a6),%fp0 # execute divide fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x1 # is |result| > 1.b? fbgt.w fdiv_normal_exit # no; no underflow occurred fblt.w fdiv_unfl # yes; underflow occurred # # we still don't know if underflow occurred. result is ~ equal to 1. but, # we don't know if the result was an underflow that rounded up to a 1 # or a normalized number that rounded down to a 1. so, redo the entire # operation using RZ as the rounding mode to see what the pre-rounded # result is. this case should be relatively rare. # fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # keep rnd prec ori.b &rz_mode*0x10,%d1 # insert RZ fmov.l %d1,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fdiv.x FP_SCR0(%a6),%fp1 # execute divide fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp1 # make absolute value fcmp.b %fp1,&0x1 # is |result| < 1.b? fbge.w fdiv_normal_exit # no; no underflow occurred bra.w fdiv_unfl # yes; underflow occurred ############################################################################ # # Divide: inputs are not both normalized; what are they? # fdiv_not_norm: mov.w (tbl_fdiv_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fdiv_op.b,%pc,%d1.w*1) swbeg &48 tbl_fdiv_op: short fdiv_norm - tbl_fdiv_op # NORM / NORM short fdiv_inf_load - tbl_fdiv_op # NORM / ZERO short fdiv_zero_load - tbl_fdiv_op # NORM / INF short fdiv_res_qnan - tbl_fdiv_op # NORM / QNAN short fdiv_norm - tbl_fdiv_op # NORM / DENORM short fdiv_res_snan - tbl_fdiv_op # NORM / SNAN short tbl_fdiv_op - tbl_fdiv_op # short tbl_fdiv_op - tbl_fdiv_op # short fdiv_zero_load - tbl_fdiv_op # ZERO / NORM short fdiv_res_operr - tbl_fdiv_op # ZERO / ZERO short fdiv_zero_load - tbl_fdiv_op # ZERO / INF short fdiv_res_qnan - tbl_fdiv_op # ZERO / QNAN short fdiv_zero_load - tbl_fdiv_op # ZERO / DENORM short fdiv_res_snan - tbl_fdiv_op # ZERO / SNAN short tbl_fdiv_op - tbl_fdiv_op # short tbl_fdiv_op - tbl_fdiv_op # short fdiv_inf_dst - tbl_fdiv_op # INF / NORM short fdiv_inf_dst - tbl_fdiv_op # INF / ZERO short fdiv_res_operr - tbl_fdiv_op # INF / INF short fdiv_res_qnan - tbl_fdiv_op # INF / QNAN short fdiv_inf_dst - tbl_fdiv_op # INF / DENORM short fdiv_res_snan - tbl_fdiv_op # INF / SNAN short tbl_fdiv_op - tbl_fdiv_op # short tbl_fdiv_op - tbl_fdiv_op # short fdiv_res_qnan - tbl_fdiv_op # QNAN / NORM short fdiv_res_qnan - tbl_fdiv_op # QNAN / ZERO short fdiv_res_qnan - tbl_fdiv_op # QNAN / INF short fdiv_res_qnan - tbl_fdiv_op # QNAN / QNAN short fdiv_res_qnan - tbl_fdiv_op # QNAN / DENORM short fdiv_res_snan - tbl_fdiv_op # QNAN / SNAN short tbl_fdiv_op - tbl_fdiv_op # short tbl_fdiv_op - tbl_fdiv_op # short fdiv_norm - tbl_fdiv_op # DENORM / NORM short fdiv_inf_load - tbl_fdiv_op # DENORM / ZERO short fdiv_zero_load - tbl_fdiv_op # DENORM / INF short fdiv_res_qnan - tbl_fdiv_op # DENORM / QNAN short fdiv_norm - tbl_fdiv_op # DENORM / DENORM short fdiv_res_snan - tbl_fdiv_op # DENORM / SNAN short tbl_fdiv_op - tbl_fdiv_op # short tbl_fdiv_op - tbl_fdiv_op # short fdiv_res_snan - tbl_fdiv_op # SNAN / NORM short fdiv_res_snan - tbl_fdiv_op # SNAN / ZERO short fdiv_res_snan - tbl_fdiv_op # SNAN / INF short fdiv_res_snan - tbl_fdiv_op # SNAN / QNAN short fdiv_res_snan - tbl_fdiv_op # SNAN / DENORM short fdiv_res_snan - tbl_fdiv_op # SNAN / SNAN short tbl_fdiv_op - tbl_fdiv_op # short tbl_fdiv_op - tbl_fdiv_op # fdiv_res_qnan: bra.l res_qnan fdiv_res_snan: bra.l res_snan fdiv_res_operr: bra.l res_operr global fdiv_zero_load # global for fsgldiv fdiv_zero_load: mov.b SRC_EX(%a0),%d0 # result sign is exclusive mov.b DST_EX(%a1),%d1 # or of input signs. eor.b %d0,%d1 bpl.b fdiv_zero_load_p # result is positive fmov.s &0x80000000,%fp0 # load a -ZERO mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set Z/N rts fdiv_zero_load_p: fmov.s &0x00000000,%fp0 # load a +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set Z rts # # The destination was In Range and the source was a ZERO. The result, # Therefore, is an INF w/ the proper sign. # So, determine the sign and return a new INF (w/ the j-bit cleared). # global fdiv_inf_load # global for fsgldiv fdiv_inf_load: ori.w &dz_mask+adz_mask,2+USER_FPSR(%a6) # no; set DZ/ADZ mov.b SRC_EX(%a0),%d0 # load both signs mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bpl.b fdiv_inf_load_p # result is positive fmov.s &0xff800000,%fp0 # make result -INF mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set INF/N rts fdiv_inf_load_p: fmov.s &0x7f800000,%fp0 # make result +INF mov.b &inf_bmask,FPSR_CC(%a6) # set INF rts # # The destination was an INF w/ an In Range or ZERO source, the result is # an INF w/ the proper sign. # The 68881/882 returns the destination INF w/ the new sign(if the j-bit of the # dst INF is set, then then j-bit of the result INF is also set). # global fdiv_inf_dst # global for fsgldiv fdiv_inf_dst: mov.b DST_EX(%a1),%d0 # load both signs mov.b SRC_EX(%a0),%d1 eor.b %d0,%d1 bpl.b fdiv_inf_dst_p # result is positive fmovm.x DST(%a1),&0x80 # return result in fp0 fabs.x %fp0 # clear sign bit fneg.x %fp0 # set sign bit mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set INF/NEG rts fdiv_inf_dst_p: fmovm.x DST(%a1),&0x80 # return result in fp0 fabs.x %fp0 # return positive INF mov.b &inf_bmask,FPSR_CC(%a6) # set INF rts ######################################################################### # XDEF **************************************************************** # # fneg(): emulates the fneg instruction # # fsneg(): emulates the fsneg instruction # # fdneg(): emulates the fdneg instruction # # # # XREF **************************************************************** # # norm() - normalize a denorm to provide EXOP # # scale_to_zero_src() - scale sgl/dbl source exponent # # ovf_res() - return default overflow result # # unf_res() - return default underflow result # # res_qnan_1op() - return QNAN result # # res_snan_1op() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 = rnd prec,mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, zeroes, and infinities as special cases. Separate # # norms/denorms into ext/sgl/dbl precisions. Extended precision can be # # emulated by simply setting sign bit. Sgl/dbl operands must be scaled # # and an actual fneg performed to see if overflow/underflow would have # # occurred. If so, return default underflow/overflow result. Else, # # scale the result exponent and return result. FPSR gets set based on # # the result value. # # # ######################################################################### global fsneg fsneg: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl precision bra.b fneg global fdneg fdneg: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl prec global fneg fneg: mov.l %d0,L_SCR3(%a6) # store rnd info mov.b STAG(%a6),%d1 bne.w fneg_not_norm # optimize on non-norm input # # NEGATE SIGN : norms and denorms ONLY! # fneg_norm: andi.b &0xc0,%d0 # is precision extended? bne.w fneg_not_ext # no; go handle sgl or dbl # # precision selected is extended. so...we can not get an underflow # or overflow because of rounding to the correct precision. so... # skip the scaling and unscaling... # mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.w SRC_EX(%a0),%d0 eori.w &0x8000,%d0 # negate sign bpl.b fneg_norm_load # sign is positive mov.b &neg_bmask,FPSR_CC(%a6) # set 'N' ccode bit fneg_norm_load: mov.w %d0,FP_SCR0_EX(%a6) fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts # # for an extended precision DENORM, the UNFL exception bit is set # the accrued bit is NOT set in this instance(no inexactness!) # fneg_denorm: andi.b &0xc0,%d0 # is precision extended? bne.b fneg_not_ext # no; go handle sgl or dbl bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.w SRC_EX(%a0),%d0 eori.w &0x8000,%d0 # negate sign bpl.b fneg_denorm_done # no mov.b &neg_bmask,FPSR_CC(%a6) # yes, set 'N' ccode bit fneg_denorm_done: mov.w %d0,FP_SCR0_EX(%a6) fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 btst &unfl_bit,FPCR_ENABLE(%a6) # is UNFL enabled? bne.b fneg_ext_unfl_ena # yes rts # # the input is an extended DENORM and underflow is enabled in the FPCR. # normalize the mantissa and add the bias of 0x6000 to the resulting negative # exponent and insert back into the operand. # fneg_ext_unfl_ena: lea FP_SCR0(%a6),%a0 # pass: ptr to operand bsr.l norm # normalize result neg.w %d0 # new exponent = -(shft val) addi.w &0x6000,%d0 # add new bias to exponent mov.w FP_SCR0_EX(%a6),%d1 # fetch old sign,exp andi.w &0x8000,%d1 # keep old sign andi.w &0x7fff,%d0 # clear sign position or.w %d1,%d0 # concat old sign, new exponent mov.w %d0,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 rts # # operand is either single or double # fneg_not_ext: cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec bne.b fneg_dbl # # operand is to be rounded to single precision # fneg_sgl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor cmpi.l %d0,&0x3fff-0x3f80 # will move in underflow? bge.w fneg_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x407e # will move in overflow? beq.w fneg_sd_may_ovfl # maybe; go check blt.w fneg_sd_ovfl # yes; go handle overflow # # operand will NOT overflow or underflow when moved in to the fp reg file # fneg_sd_normal: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fneg.x FP_SCR0(%a6),%fp0 # perform negation fmov.l %fpsr,%d1 # save FPSR fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fneg_sd_normal_exit: mov.l %d2,-(%sp) # save d2 fmovm.x &0x80,FP_SCR0(%a6) # store out result mov.w FP_SCR0_EX(%a6),%d1 # load sgn,exp mov.w %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor andi.w &0x8000,%d2 # keep old sign or.w %d1,%d2 # concat old sign,new exp mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts # # operand is to be rounded to double precision # fneg_dbl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor cmpi.l %d0,&0x3fff-0x3c00 # will move in underflow? bge.b fneg_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x43fe # will move in overflow? beq.w fneg_sd_may_ovfl # maybe; go check blt.w fneg_sd_ovfl # yes; go handle overflow bra.w fneg_sd_normal # no; ho handle normalized op # # operand WILL underflow when moved in to the fp register file # fneg_sd_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit eori.b &0x80,FP_SCR0_EX(%a6) # negate sign bpl.b fneg_sd_unfl_tst bset &neg_bit,FPSR_CC(%a6) # set 'N' ccode bit # if underflow or inexact is enabled, go calculate EXOP first. fneg_sd_unfl_tst: mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fneg_sd_unfl_ena # yes fneg_sd_unfl_dis: lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # unf_res may have set 'Z' fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # operand will underflow AND underflow is enabled. # Therefore, we must return the result rounded to extended precision. # fneg_sd_unfl_ena: mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) mov.w FP_SCR0_EX(%a6),%d1 # load current exponent mov.l %d2,-(%sp) # save d2 mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # subtract scale factor addi.l &0x6000,%d1 # add new bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat new sign,new exp mov.w %d1,FP_SCR1_EX(%a6) # insert new exp fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fneg_sd_unfl_dis # # operand WILL overflow. # fneg_sd_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fneg.x FP_SCR0(%a6),%fp0 # perform negation fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save FPSR or.l %d1,USER_FPSR(%a6) # save INEX2,N fneg_sd_ovfl_tst: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fneg_sd_ovfl_ena # yes # # OVFL is not enabled; therefore, we must create the default result by # calling ovf_res(). # fneg_sd_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass: prec,mode bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts # # OVFL is enabled. # the INEX2 bit has already been updated by the round to the correct precision. # now, round to extended(and don't alter the FPSR). # fneg_sd_ovfl_ena: mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat sign,exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fneg_sd_ovfl_dis # # the move in MAY underflow. so... # fneg_sd_may_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fneg.x FP_SCR0(%a6),%fp0 # perform negation fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| >= 2.b? fbge.w fneg_sd_ovfl_tst # yes; overflow has occurred # no, it didn't overflow; we have correct result bra.w fneg_sd_normal_exit ########################################################################## # # input is not normalized; what is it? # fneg_not_norm: cmpi.b %d1,&DENORM # weed out DENORM beq.w fneg_denorm cmpi.b %d1,&SNAN # weed out SNAN beq.l res_snan_1op cmpi.b %d1,&QNAN # weed out QNAN beq.l res_qnan_1op # # do the fneg; at this point, only possible ops are ZERO and INF. # use fneg to determine ccodes. # prec:mode should be zero at this point but it won't affect answer anyways. # fneg.x SRC_EX(%a0),%fp0 # do fneg fmov.l %fpsr,%d0 rol.l &0x8,%d0 # put ccodes in lo byte mov.b %d0,FPSR_CC(%a6) # insert correct ccodes rts ######################################################################### # XDEF **************************************************************** # # ftst(): emulates the ftest instruction # # # # XREF **************************************************************** # # res{s,q}nan_1op() - set NAN result for monadic instruction # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # # # OUTPUT ************************************************************** # # none # # # # ALGORITHM *********************************************************** # # Check the source operand tag (STAG) and set the FPCR according # # to the operand type and sign. # # # ######################################################################### global ftst ftst: mov.b STAG(%a6),%d1 bne.b ftst_not_norm # optimize on non-norm input # # Norm: # ftst_norm: tst.b SRC_EX(%a0) # is operand negative? bmi.b ftst_norm_m # yes rts ftst_norm_m: mov.b &neg_bmask,FPSR_CC(%a6) # set 'N' ccode bit rts # # input is not normalized; what is it? # ftst_not_norm: cmpi.b %d1,&ZERO # weed out ZERO beq.b ftst_zero cmpi.b %d1,&INF # weed out INF beq.b ftst_inf cmpi.b %d1,&SNAN # weed out SNAN beq.l res_snan_1op cmpi.b %d1,&QNAN # weed out QNAN beq.l res_qnan_1op # # Denorm: # ftst_denorm: tst.b SRC_EX(%a0) # is operand negative? bmi.b ftst_denorm_m # yes rts ftst_denorm_m: mov.b &neg_bmask,FPSR_CC(%a6) # set 'N' ccode bit rts # # Infinity: # ftst_inf: tst.b SRC_EX(%a0) # is operand negative? bmi.b ftst_inf_m # yes ftst_inf_p: mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit rts ftst_inf_m: mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set 'I','N' ccode bits rts # # Zero: # ftst_zero: tst.b SRC_EX(%a0) # is operand negative? bmi.b ftst_zero_m # yes ftst_zero_p: mov.b &z_bmask,FPSR_CC(%a6) # set 'N' ccode bit rts ftst_zero_m: mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits rts ######################################################################### # XDEF **************************************************************** # # fint(): emulates the fint instruction # # # # XREF **************************************************************** # # res_{s,q}nan_1op() - set NAN result for monadic operation # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 = round precision/mode # # # # OUTPUT ************************************************************** # # fp0 = result # # # # ALGORITHM *********************************************************** # # Separate according to operand type. Unnorms don't pass through # # here. For norms, load the rounding mode/prec, execute a "fint", then # # store the resulting FPSR bits. # # For denorms, force the j-bit to a one and do the same as for # # norms. Denorms are so low that the answer will either be a zero or a # # one. # # For zeroes/infs/NANs, return the same while setting the FPSR # # as appropriate. # # # ######################################################################### global fint fint: mov.b STAG(%a6),%d1 bne.b fint_not_norm # optimize on non-norm input # # Norm: # fint_norm: andi.b &0x30,%d0 # set prec = ext fmov.l %d0,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fint.x SRC(%a0),%fp0 # execute fint fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d0 # save FPSR or.l %d0,USER_FPSR(%a6) # set exception bits rts # # input is not normalized; what is it? # fint_not_norm: cmpi.b %d1,&ZERO # weed out ZERO beq.b fint_zero cmpi.b %d1,&INF # weed out INF beq.b fint_inf cmpi.b %d1,&DENORM # weed out DENORM beq.b fint_denorm cmpi.b %d1,&SNAN # weed out SNAN beq.l res_snan_1op bra.l res_qnan_1op # weed out QNAN # # Denorm: # # for DENORMs, the result will be either (+/-)ZERO or (+/-)1. # also, the INEX2 and AINEX exception bits will be set. # so, we could either set these manually or force the DENORM # to a very small NORM and ship it to the NORM routine. # I do the latter. # fint_denorm: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) # copy sign, zero exp mov.b &0x80,FP_SCR0_HI(%a6) # force DENORM ==> small NORM lea FP_SCR0(%a6),%a0 bra.b fint_norm # # Zero: # fint_zero: tst.b SRC_EX(%a0) # is ZERO negative? bmi.b fint_zero_m # yes fint_zero_p: fmov.s &0x00000000,%fp0 # return +ZERO in fp0 mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit rts fint_zero_m: fmov.s &0x80000000,%fp0 # return -ZERO in fp0 mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits rts # # Infinity: # fint_inf: fmovm.x SRC(%a0),&0x80 # return result in fp0 tst.b SRC_EX(%a0) # is INF negative? bmi.b fint_inf_m # yes fint_inf_p: mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit rts fint_inf_m: mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set 'N','I' ccode bits rts ######################################################################### # XDEF **************************************************************** # # fintrz(): emulates the fintrz instruction # # # # XREF **************************************************************** # # res_{s,q}nan_1op() - set NAN result for monadic operation # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 = round precision/mode # # # # OUTPUT ************************************************************** # # fp0 = result # # # # ALGORITHM *********************************************************** # # Separate according to operand type. Unnorms don't pass through # # here. For norms, load the rounding mode/prec, execute a "fintrz", # # then store the resulting FPSR bits. # # For denorms, force the j-bit to a one and do the same as for # # norms. Denorms are so low that the answer will either be a zero or a # # one. # # For zeroes/infs/NANs, return the same while setting the FPSR # # as appropriate. # # # ######################################################################### global fintrz fintrz: mov.b STAG(%a6),%d1 bne.b fintrz_not_norm # optimize on non-norm input # # Norm: # fintrz_norm: fmov.l &0x0,%fpsr # clear FPSR fintrz.x SRC(%a0),%fp0 # execute fintrz fmov.l %fpsr,%d0 # save FPSR or.l %d0,USER_FPSR(%a6) # set exception bits rts # # input is not normalized; what is it? # fintrz_not_norm: cmpi.b %d1,&ZERO # weed out ZERO beq.b fintrz_zero cmpi.b %d1,&INF # weed out INF beq.b fintrz_inf cmpi.b %d1,&DENORM # weed out DENORM beq.b fintrz_denorm cmpi.b %d1,&SNAN # weed out SNAN beq.l res_snan_1op bra.l res_qnan_1op # weed out QNAN # # Denorm: # # for DENORMs, the result will be (+/-)ZERO. # also, the INEX2 and AINEX exception bits will be set. # so, we could either set these manually or force the DENORM # to a very small NORM and ship it to the NORM routine. # I do the latter. # fintrz_denorm: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) # copy sign, zero exp mov.b &0x80,FP_SCR0_HI(%a6) # force DENORM ==> small NORM lea FP_SCR0(%a6),%a0 bra.b fintrz_norm # # Zero: # fintrz_zero: tst.b SRC_EX(%a0) # is ZERO negative? bmi.b fintrz_zero_m # yes fintrz_zero_p: fmov.s &0x00000000,%fp0 # return +ZERO in fp0 mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit rts fintrz_zero_m: fmov.s &0x80000000,%fp0 # return -ZERO in fp0 mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits rts # # Infinity: # fintrz_inf: fmovm.x SRC(%a0),&0x80 # return result in fp0 tst.b SRC_EX(%a0) # is INF negative? bmi.b fintrz_inf_m # yes fintrz_inf_p: mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit rts fintrz_inf_m: mov.b &inf_bmask+neg_bmask,FPSR_CC(%a6) # set 'N','I' ccode bits rts ######################################################################### # XDEF **************************************************************** # # fabs(): emulates the fabs instruction # # fsabs(): emulates the fsabs instruction # # fdabs(): emulates the fdabs instruction # # # # XREF **************************************************************** # # norm() - normalize denorm mantissa to provide EXOP # # scale_to_zero_src() - make exponent. = 0; get scale factor # # unf_res() - calculate underflow result # # ovf_res() - calculate overflow result # # res_{s,q}nan_1op() - set NAN result for monadic operation # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 = rnd precision/mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms into extended, single, and double precision. # # Simply clear sign for extended precision norm. Ext prec denorm # # gets an EXOP created for it since it's an underflow. # # Double and single precision can overflow and underflow. First, # # scale the operand such that the exponent is zero. Perform an "fabs" # # using the correct rnd mode/prec. Check to see if the original # # exponent would take an exception. If so, use unf_res() or ovf_res() # # to calculate the default result. Also, create the EXOP for the # # exceptional case. If no exception should occur, insert the correct # # result exponent and return. # # Unnorms don't pass through here. # # # ######################################################################### global fsabs fsabs: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl precision bra.b fabs global fdabs fdabs: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl precision global fabs fabs: mov.l %d0,L_SCR3(%a6) # store rnd info mov.b STAG(%a6),%d1 bne.w fabs_not_norm # optimize on non-norm input # # ABSOLUTE VALUE: norms and denorms ONLY! # fabs_norm: andi.b &0xc0,%d0 # is precision extended? bne.b fabs_not_ext # no; go handle sgl or dbl # # precision selected is extended. so...we can not get an underflow # or overflow because of rounding to the correct precision. so... # skip the scaling and unscaling... # mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.w SRC_EX(%a0),%d1 bclr &15,%d1 # force absolute value mov.w %d1,FP_SCR0_EX(%a6) # insert exponent fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts # # for an extended precision DENORM, the UNFL exception bit is set # the accrued bit is NOT set in this instance(no inexactness!) # fabs_denorm: andi.b &0xc0,%d0 # is precision extended? bne.b fabs_not_ext # no bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) mov.w SRC_EX(%a0),%d0 bclr &15,%d0 # clear sign mov.w %d0,FP_SCR0_EX(%a6) # insert exponent fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 btst &unfl_bit,FPCR_ENABLE(%a6) # is UNFL enabled? bne.b fabs_ext_unfl_ena rts # # the input is an extended DENORM and underflow is enabled in the FPCR. # normalize the mantissa and add the bias of 0x6000 to the resulting negative # exponent and insert back into the operand. # fabs_ext_unfl_ena: lea FP_SCR0(%a6),%a0 # pass: ptr to operand bsr.l norm # normalize result neg.w %d0 # new exponent = -(shft val) addi.w &0x6000,%d0 # add new bias to exponent mov.w FP_SCR0_EX(%a6),%d1 # fetch old sign,exp andi.w &0x8000,%d1 # keep old sign andi.w &0x7fff,%d0 # clear sign position or.w %d1,%d0 # concat old sign, new exponent mov.w %d0,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 rts # # operand is either single or double # fabs_not_ext: cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec bne.b fabs_dbl # # operand is to be rounded to single precision # fabs_sgl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor cmpi.l %d0,&0x3fff-0x3f80 # will move in underflow? bge.w fabs_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x407e # will move in overflow? beq.w fabs_sd_may_ovfl # maybe; go check blt.w fabs_sd_ovfl # yes; go handle overflow # # operand will NOT overflow or underflow when moved in to the fp reg file # fabs_sd_normal: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fabs.x FP_SCR0(%a6),%fp0 # perform absolute fmov.l %fpsr,%d1 # save FPSR fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs_sd_normal_exit: mov.l %d2,-(%sp) # save d2 fmovm.x &0x80,FP_SCR0(%a6) # store out result mov.w FP_SCR0_EX(%a6),%d1 # load sgn,exp mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor andi.w &0x8000,%d2 # keep old sign or.w %d1,%d2 # concat old sign,new exp mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts # # operand is to be rounded to double precision # fabs_dbl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor cmpi.l %d0,&0x3fff-0x3c00 # will move in underflow? bge.b fabs_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x43fe # will move in overflow? beq.w fabs_sd_may_ovfl # maybe; go check blt.w fabs_sd_ovfl # yes; go handle overflow bra.w fabs_sd_normal # no; ho handle normalized op # # operand WILL underflow when moved in to the fp register file # fabs_sd_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit bclr &0x7,FP_SCR0_EX(%a6) # force absolute value # if underflow or inexact is enabled, go calculate EXOP first. mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fabs_sd_unfl_ena # yes fabs_sd_unfl_dis: lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set possible 'Z' ccode fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # operand will underflow AND underflow is enabled. # Therefore, we must return the result rounded to extended precision. # fabs_sd_unfl_ena: mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) mov.w FP_SCR0_EX(%a6),%d1 # load current exponent mov.l %d2,-(%sp) # save d2 mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # subtract scale factor addi.l &0x6000,%d1 # add new bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat new sign,new exp mov.w %d1,FP_SCR1_EX(%a6) # insert new exp fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fabs_sd_unfl_dis # # operand WILL overflow. # fabs_sd_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fabs.x FP_SCR0(%a6),%fp0 # perform absolute fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save FPSR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs_sd_ovfl_tst: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fabs_sd_ovfl_ena # yes # # OVFL is not enabled; therefore, we must create the default result by # calling ovf_res(). # fabs_sd_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass: prec,mode bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts # # OVFL is enabled. # the INEX2 bit has already been updated by the round to the correct precision. # now, round to extended(and don't alter the FPSR). # fabs_sd_ovfl_ena: mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat sign,exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fabs_sd_ovfl_dis # # the move in MAY underflow. so... # fabs_sd_may_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fabs.x FP_SCR0(%a6),%fp0 # perform absolute fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| >= 2.b? fbge.w fabs_sd_ovfl_tst # yes; overflow has occurred # no, it didn't overflow; we have correct result bra.w fabs_sd_normal_exit ########################################################################## # # input is not normalized; what is it? # fabs_not_norm: cmpi.b %d1,&DENORM # weed out DENORM beq.w fabs_denorm cmpi.b %d1,&SNAN # weed out SNAN beq.l res_snan_1op cmpi.b %d1,&QNAN # weed out QNAN beq.l res_qnan_1op fabs.x SRC(%a0),%fp0 # force absolute value cmpi.b %d1,&INF # weed out INF beq.b fabs_inf fabs_zero: mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit rts fabs_inf: mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit rts ######################################################################### # XDEF **************************************************************** # # fcmp(): fp compare op routine # # # # XREF **************************************************************** # # res_qnan() - return QNAN result # # res_snan() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # d0 = round prec/mode # # # # OUTPUT ************************************************************** # # None # # # # ALGORITHM *********************************************************** # # Handle NANs and denorms as special cases. For everything else, # # just use the actual fcmp instruction to produce the correct condition # # codes. # # # ######################################################################### global fcmp fcmp: clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 bne.b fcmp_not_norm # optimize on non-norm input # # COMPARE FP OPs : NORMs, ZEROs, INFs, and "corrected" DENORMs # fcmp_norm: fmovm.x DST(%a1),&0x80 # load dst op fcmp.x %fp0,SRC(%a0) # do compare fmov.l %fpsr,%d0 # save FPSR rol.l &0x8,%d0 # extract ccode bits mov.b %d0,FPSR_CC(%a6) # set ccode bits(no exc bits are set) rts # # fcmp: inputs are not both normalized; what are they? # fcmp_not_norm: mov.w (tbl_fcmp_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fcmp_op.b,%pc,%d1.w*1) swbeg &48 tbl_fcmp_op: short fcmp_norm - tbl_fcmp_op # NORM - NORM short fcmp_norm - tbl_fcmp_op # NORM - ZERO short fcmp_norm - tbl_fcmp_op # NORM - INF short fcmp_res_qnan - tbl_fcmp_op # NORM - QNAN short fcmp_nrm_dnrm - tbl_fcmp_op # NORM - DENORM short fcmp_res_snan - tbl_fcmp_op # NORM - SNAN short tbl_fcmp_op - tbl_fcmp_op # short tbl_fcmp_op - tbl_fcmp_op # short fcmp_norm - tbl_fcmp_op # ZERO - NORM short fcmp_norm - tbl_fcmp_op # ZERO - ZERO short fcmp_norm - tbl_fcmp_op # ZERO - INF short fcmp_res_qnan - tbl_fcmp_op # ZERO - QNAN short fcmp_dnrm_s - tbl_fcmp_op # ZERO - DENORM short fcmp_res_snan - tbl_fcmp_op # ZERO - SNAN short tbl_fcmp_op - tbl_fcmp_op # short tbl_fcmp_op - tbl_fcmp_op # short fcmp_norm - tbl_fcmp_op # INF - NORM short fcmp_norm - tbl_fcmp_op # INF - ZERO short fcmp_norm - tbl_fcmp_op # INF - INF short fcmp_res_qnan - tbl_fcmp_op # INF - QNAN short fcmp_dnrm_s - tbl_fcmp_op # INF - DENORM short fcmp_res_snan - tbl_fcmp_op # INF - SNAN short tbl_fcmp_op - tbl_fcmp_op # short tbl_fcmp_op - tbl_fcmp_op # short fcmp_res_qnan - tbl_fcmp_op # QNAN - NORM short fcmp_res_qnan - tbl_fcmp_op # QNAN - ZERO short fcmp_res_qnan - tbl_fcmp_op # QNAN - INF short fcmp_res_qnan - tbl_fcmp_op # QNAN - QNAN short fcmp_res_qnan - tbl_fcmp_op # QNAN - DENORM short fcmp_res_snan - tbl_fcmp_op # QNAN - SNAN short tbl_fcmp_op - tbl_fcmp_op # short tbl_fcmp_op - tbl_fcmp_op # short fcmp_dnrm_nrm - tbl_fcmp_op # DENORM - NORM short fcmp_dnrm_d - tbl_fcmp_op # DENORM - ZERO short fcmp_dnrm_d - tbl_fcmp_op # DENORM - INF short fcmp_res_qnan - tbl_fcmp_op # DENORM - QNAN short fcmp_dnrm_sd - tbl_fcmp_op # DENORM - DENORM short fcmp_res_snan - tbl_fcmp_op # DENORM - SNAN short tbl_fcmp_op - tbl_fcmp_op # short tbl_fcmp_op - tbl_fcmp_op # short fcmp_res_snan - tbl_fcmp_op # SNAN - NORM short fcmp_res_snan - tbl_fcmp_op # SNAN - ZERO short fcmp_res_snan - tbl_fcmp_op # SNAN - INF short fcmp_res_snan - tbl_fcmp_op # SNAN - QNAN short fcmp_res_snan - tbl_fcmp_op # SNAN - DENORM short fcmp_res_snan - tbl_fcmp_op # SNAN - SNAN short tbl_fcmp_op - tbl_fcmp_op # short tbl_fcmp_op - tbl_fcmp_op # # unlike all other functions for QNAN and SNAN, fcmp does NOT set the # 'N' bit for a negative QNAN or SNAN input so we must squelch it here. fcmp_res_qnan: bsr.l res_qnan andi.b &0xf7,FPSR_CC(%a6) rts fcmp_res_snan: bsr.l res_snan andi.b &0xf7,FPSR_CC(%a6) rts # # DENORMs are a little more difficult. # If you have a 2 DENORMs, then you can just force the j-bit to a one # and use the fcmp_norm routine. # If you have a DENORM and an INF or ZERO, just force the DENORM's j-bit to a one # and use the fcmp_norm routine. # If you have a DENORM and a NORM with opposite signs, then use fcmp_norm, also. # But with a DENORM and a NORM of the same sign, the neg bit is set if the # (1) signs are (+) and the DENORM is the dst or # (2) signs are (-) and the DENORM is the src # fcmp_dnrm_s: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),%d0 bset &31,%d0 # DENORM src; make into small norm mov.l %d0,FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) lea FP_SCR0(%a6),%a0 bra.w fcmp_norm fcmp_dnrm_d: mov.l DST_EX(%a1),FP_SCR0_EX(%a6) mov.l DST_HI(%a1),%d0 bset &31,%d0 # DENORM src; make into small norm mov.l %d0,FP_SCR0_HI(%a6) mov.l DST_LO(%a1),FP_SCR0_LO(%a6) lea FP_SCR0(%a6),%a1 bra.w fcmp_norm fcmp_dnrm_sd: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l DST_HI(%a1),%d0 bset &31,%d0 # DENORM dst; make into small norm mov.l %d0,FP_SCR1_HI(%a6) mov.l SRC_HI(%a0),%d0 bset &31,%d0 # DENORM dst; make into small norm mov.l %d0,FP_SCR0_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) lea FP_SCR1(%a6),%a1 lea FP_SCR0(%a6),%a0 bra.w fcmp_norm fcmp_nrm_dnrm: mov.b SRC_EX(%a0),%d0 # determine if like signs mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bmi.w fcmp_dnrm_s # signs are the same, so must determine the answer ourselves. tst.b %d0 # is src op negative? bmi.b fcmp_nrm_dnrm_m # yes rts fcmp_nrm_dnrm_m: mov.b &neg_bmask,FPSR_CC(%a6) # set 'Z' ccode bit rts fcmp_dnrm_nrm: mov.b SRC_EX(%a0),%d0 # determine if like signs mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bmi.w fcmp_dnrm_d # signs are the same, so must determine the answer ourselves. tst.b %d0 # is src op negative? bpl.b fcmp_dnrm_nrm_m # no rts fcmp_dnrm_nrm_m: mov.b &neg_bmask,FPSR_CC(%a6) # set 'Z' ccode bit rts ######################################################################### # XDEF **************************************************************** # # fsglmul(): emulates the fsglmul instruction # # # # XREF **************************************************************** # # scale_to_zero_src() - scale src exponent to zero # # scale_to_zero_dst() - scale dst exponent to zero # # unf_res4() - return default underflow result for sglop # # ovf_res() - return default overflow result # # res_qnan() - return QNAN result # # res_snan() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # d0 rnd prec,mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms/denorms into ext/sgl/dbl precision. # # For norms/denorms, scale the exponents such that a multiply # # instruction won't cause an exception. Use the regular fsglmul to # # compute a result. Check if the regular operands would have taken # # an exception. If so, return the default overflow/underflow result # # and return the EXOP if exceptions are enabled. Else, scale the # # result operand to the proper exponent. # # # ######################################################################### global fsglmul fsglmul: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 bne.w fsglmul_not_norm # optimize on non-norm input fsglmul_norm: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # scale exponent mov.l %d0,-(%sp) # save scale factor 1 bsr.l scale_to_zero_dst # scale dst exponent add.l (%sp)+,%d0 # SCALE_FACTOR = scale1 + scale2 cmpi.l %d0,&0x3fff-0x7ffe # would result ovfl? beq.w fsglmul_may_ovfl # result may rnd to overflow blt.w fsglmul_ovfl # result will overflow cmpi.l %d0,&0x3fff+0x0001 # would result unfl? beq.w fsglmul_may_unfl # result may rnd to no unfl bgt.w fsglmul_unfl # result will underflow fsglmul_normal: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fsglmul_normal_exit: fmovm.x &0x80,FP_SCR0(%a6) # store out result mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts fsglmul_ovfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fsglmul_ovfl_tst: # save setting this until now because this is where fsglmul_may_ovfl may jump in or.l &ovfl_inx_mask, USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fsglmul_ovfl_ena # yes fsglmul_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass prec:rnd andi.b &0x30,%d0 # force prec = ext bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts fsglmul_ovfl_ena: fmovm.x &0x80,FP_SCR0(%a6) # move result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 andi.w &0x8000,%d2 # keep old sign or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.b fsglmul_ovfl_dis fsglmul_may_ovfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| >= 2.b? fbge.w fsglmul_ovfl_tst # yes; overflow has occurred # no, it didn't overflow; we have correct result bra.w fsglmul_normal_exit fsglmul_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fsglmul_unfl_ena # yes fsglmul_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res4 # calculate default result or.b %d0,FPSR_CC(%a6) # 'Z' bit may have been set fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # UNFL is enabled. # fsglmul_unfl_ena: fmovm.x FP_SCR1(%a6),&0x40 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp1 # execute sgl multiply fmov.l &0x0,%fpcr # clear FPCR fmovm.x &0x40,FP_SCR0(%a6) # save result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor addi.l &0x6000,%d1 # add bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.w fsglmul_unfl_dis fsglmul_may_unfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp0 # execute sgl multiply fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x2 # is |result| > 2.b? fbgt.w fsglmul_normal_exit # no; no underflow occurred fblt.w fsglmul_unfl # yes; underflow occurred # # we still don't know if underflow occurred. result is ~ equal to 2. but, # we don't know if the result was an underflow that rounded up to a 2 or # a normalized number that rounded down to a 2. so, redo the entire operation # using RZ as the rounding mode to see what the pre-rounded result is. # this case should be relatively rare. # fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # keep rnd prec ori.b &rz_mode*0x10,%d1 # insert RZ fmov.l %d1,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsglmul.x FP_SCR0(%a6),%fp1 # execute sgl multiply fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp1 # make absolute value fcmp.b %fp1,&0x2 # is |result| < 2.b? fbge.w fsglmul_normal_exit # no; no underflow occurred bra.w fsglmul_unfl # yes, underflow occurred ############################################################################## # # Single Precision Multiply: inputs are not both normalized; what are they? # fsglmul_not_norm: mov.w (tbl_fsglmul_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fsglmul_op.b,%pc,%d1.w*1) swbeg &48 tbl_fsglmul_op: short fsglmul_norm - tbl_fsglmul_op # NORM x NORM short fsglmul_zero - tbl_fsglmul_op # NORM x ZERO short fsglmul_inf_src - tbl_fsglmul_op # NORM x INF short fsglmul_res_qnan - tbl_fsglmul_op # NORM x QNAN short fsglmul_norm - tbl_fsglmul_op # NORM x DENORM short fsglmul_res_snan - tbl_fsglmul_op # NORM x SNAN short tbl_fsglmul_op - tbl_fsglmul_op # short tbl_fsglmul_op - tbl_fsglmul_op # short fsglmul_zero - tbl_fsglmul_op # ZERO x NORM short fsglmul_zero - tbl_fsglmul_op # ZERO x ZERO short fsglmul_res_operr - tbl_fsglmul_op # ZERO x INF short fsglmul_res_qnan - tbl_fsglmul_op # ZERO x QNAN short fsglmul_zero - tbl_fsglmul_op # ZERO x DENORM short fsglmul_res_snan - tbl_fsglmul_op # ZERO x SNAN short tbl_fsglmul_op - tbl_fsglmul_op # short tbl_fsglmul_op - tbl_fsglmul_op # short fsglmul_inf_dst - tbl_fsglmul_op # INF x NORM short fsglmul_res_operr - tbl_fsglmul_op # INF x ZERO short fsglmul_inf_dst - tbl_fsglmul_op # INF x INF short fsglmul_res_qnan - tbl_fsglmul_op # INF x QNAN short fsglmul_inf_dst - tbl_fsglmul_op # INF x DENORM short fsglmul_res_snan - tbl_fsglmul_op # INF x SNAN short tbl_fsglmul_op - tbl_fsglmul_op # short tbl_fsglmul_op - tbl_fsglmul_op # short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x NORM short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x ZERO short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x INF short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x QNAN short fsglmul_res_qnan - tbl_fsglmul_op # QNAN x DENORM short fsglmul_res_snan - tbl_fsglmul_op # QNAN x SNAN short tbl_fsglmul_op - tbl_fsglmul_op # short tbl_fsglmul_op - tbl_fsglmul_op # short fsglmul_norm - tbl_fsglmul_op # NORM x NORM short fsglmul_zero - tbl_fsglmul_op # NORM x ZERO short fsglmul_inf_src - tbl_fsglmul_op # NORM x INF short fsglmul_res_qnan - tbl_fsglmul_op # NORM x QNAN short fsglmul_norm - tbl_fsglmul_op # NORM x DENORM short fsglmul_res_snan - tbl_fsglmul_op # NORM x SNAN short tbl_fsglmul_op - tbl_fsglmul_op # short tbl_fsglmul_op - tbl_fsglmul_op # short fsglmul_res_snan - tbl_fsglmul_op # SNAN x NORM short fsglmul_res_snan - tbl_fsglmul_op # SNAN x ZERO short fsglmul_res_snan - tbl_fsglmul_op # SNAN x INF short fsglmul_res_snan - tbl_fsglmul_op # SNAN x QNAN short fsglmul_res_snan - tbl_fsglmul_op # SNAN x DENORM short fsglmul_res_snan - tbl_fsglmul_op # SNAN x SNAN short tbl_fsglmul_op - tbl_fsglmul_op # short tbl_fsglmul_op - tbl_fsglmul_op # fsglmul_res_operr: bra.l res_operr fsglmul_res_snan: bra.l res_snan fsglmul_res_qnan: bra.l res_qnan fsglmul_zero: bra.l fmul_zero fsglmul_inf_src: bra.l fmul_inf_src fsglmul_inf_dst: bra.l fmul_inf_dst ######################################################################### # XDEF **************************************************************** # # fsgldiv(): emulates the fsgldiv instruction # # # # XREF **************************************************************** # # scale_to_zero_src() - scale src exponent to zero # # scale_to_zero_dst() - scale dst exponent to zero # # unf_res4() - return default underflow result for sglop # # ovf_res() - return default overflow result # # res_qnan() - return QNAN result # # res_snan() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # d0 rnd prec,mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms/denorms into ext/sgl/dbl precision. # # For norms/denorms, scale the exponents such that a divide # # instruction won't cause an exception. Use the regular fsgldiv to # # compute a result. Check if the regular operands would have taken # # an exception. If so, return the default overflow/underflow result # # and return the EXOP if exceptions are enabled. Else, scale the # # result operand to the proper exponent. # # # ######################################################################### global fsgldiv fsgldiv: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 # combine src tags bne.w fsgldiv_not_norm # optimize on non-norm input # # DIVIDE: NORMs and DENORMs ONLY! # fsgldiv_norm: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # calculate scale factor 1 mov.l %d0,-(%sp) # save scale factor 1 bsr.l scale_to_zero_dst # calculate scale factor 2 neg.l (%sp) # S.F. = scale1 - scale2 add.l %d0,(%sp) mov.w 2+L_SCR3(%a6),%d1 # fetch precision,mode lsr.b &0x6,%d1 mov.l (%sp)+,%d0 cmpi.l %d0,&0x3fff-0x7ffe ble.w fsgldiv_may_ovfl cmpi.l %d0,&0x3fff-0x0000 # will result underflow? beq.w fsgldiv_may_unfl # maybe bgt.w fsgldiv_unfl # yes; go handle underflow fsgldiv_normal: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # save FPCR fmov.l &0x0,%fpsr # clear FPSR fsgldiv.x FP_SCR0(%a6),%fp0 # perform sgl divide fmov.l %fpsr,%d1 # save FPSR fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fsgldiv_normal_exit: fmovm.x &0x80,FP_SCR0(%a6) # store result on stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # load {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts fsgldiv_may_ovfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # set FPSR fsgldiv.x FP_SCR0(%a6),%fp0 # execute divide fmov.l %fpsr,%d1 fmov.l &0x0,%fpcr or.l %d1,USER_FPSR(%a6) # save INEX,N fmovm.x &0x01,-(%sp) # save result to stack mov.w (%sp),%d1 # fetch new exponent add.l &0xc,%sp # clear result andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor cmp.l %d1,&0x7fff # did divide overflow? blt.b fsgldiv_normal_exit fsgldiv_ovfl_tst: or.w &ovfl_inx_mask,2+USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fsgldiv_ovfl_ena # yes fsgldiv_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass prec:rnd andi.b &0x30,%d0 # kill precision bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts fsgldiv_ovfl_ena: fmovm.x &0x80,FP_SCR0(%a6) # move result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract new bias andi.w &0x7fff,%d1 # clear ms bit or.w %d2,%d1 # concat old sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.b fsgldiv_ovfl_dis fsgldiv_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsgldiv.x FP_SCR0(%a6),%fp0 # execute sgl divide fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fsgldiv_unfl_ena # yes fsgldiv_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res4 # calculate default result or.b %d0,FPSR_CC(%a6) # 'Z' bit may have been set fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # UNFL is enabled. # fsgldiv_unfl_ena: fmovm.x FP_SCR1(%a6),&0x40 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsgldiv.x FP_SCR0(%a6),%fp1 # execute sgl divide fmov.l &0x0,%fpcr # clear FPCR fmovm.x &0x40,FP_SCR0(%a6) # save result to stack mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor addi.l &0x6000,%d1 # add bias andi.w &0x7fff,%d1 # clear top bit or.w %d2,%d1 # concat old sign, new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.b fsgldiv_unfl_dis # # the divide operation MAY underflow: # fsgldiv_may_unfl: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsgldiv.x FP_SCR0(%a6),%fp0 # execute sgl divide fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fabs.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x1 # is |result| > 1.b? fbgt.w fsgldiv_normal_exit # no; no underflow occurred fblt.w fsgldiv_unfl # yes; underflow occurred # # we still don't know if underflow occurred. result is ~ equal to 1. but, # we don't know if the result was an underflow that rounded up to a 1 # or a normalized number that rounded down to a 1. so, redo the entire # operation using RZ as the rounding mode to see what the pre-rounded # result is. this case should be relatively rare. # fmovm.x FP_SCR1(%a6),&0x40 # load dst op into %fp1 clr.l %d1 # clear scratch register ori.b &rz_mode*0x10,%d1 # force RZ rnd mode fmov.l %d1,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsgldiv.x FP_SCR0(%a6),%fp1 # execute sgl divide fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp1 # make absolute value fcmp.b %fp1,&0x1 # is |result| < 1.b? fbge.w fsgldiv_normal_exit # no; no underflow occurred bra.w fsgldiv_unfl # yes; underflow occurred ############################################################################ # # Divide: inputs are not both normalized; what are they? # fsgldiv_not_norm: mov.w (tbl_fsgldiv_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fsgldiv_op.b,%pc,%d1.w*1) swbeg &48 tbl_fsgldiv_op: short fsgldiv_norm - tbl_fsgldiv_op # NORM / NORM short fsgldiv_inf_load - tbl_fsgldiv_op # NORM / ZERO short fsgldiv_zero_load - tbl_fsgldiv_op # NORM / INF short fsgldiv_res_qnan - tbl_fsgldiv_op # NORM / QNAN short fsgldiv_norm - tbl_fsgldiv_op # NORM / DENORM short fsgldiv_res_snan - tbl_fsgldiv_op # NORM / SNAN short tbl_fsgldiv_op - tbl_fsgldiv_op # short tbl_fsgldiv_op - tbl_fsgldiv_op # short fsgldiv_zero_load - tbl_fsgldiv_op # ZERO / NORM short fsgldiv_res_operr - tbl_fsgldiv_op # ZERO / ZERO short fsgldiv_zero_load - tbl_fsgldiv_op # ZERO / INF short fsgldiv_res_qnan - tbl_fsgldiv_op # ZERO / QNAN short fsgldiv_zero_load - tbl_fsgldiv_op # ZERO / DENORM short fsgldiv_res_snan - tbl_fsgldiv_op # ZERO / SNAN short tbl_fsgldiv_op - tbl_fsgldiv_op # short tbl_fsgldiv_op - tbl_fsgldiv_op # short fsgldiv_inf_dst - tbl_fsgldiv_op # INF / NORM short fsgldiv_inf_dst - tbl_fsgldiv_op # INF / ZERO short fsgldiv_res_operr - tbl_fsgldiv_op # INF / INF short fsgldiv_res_qnan - tbl_fsgldiv_op # INF / QNAN short fsgldiv_inf_dst - tbl_fsgldiv_op # INF / DENORM short fsgldiv_res_snan - tbl_fsgldiv_op # INF / SNAN short tbl_fsgldiv_op - tbl_fsgldiv_op # short tbl_fsgldiv_op - tbl_fsgldiv_op # short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / NORM short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / ZERO short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / INF short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / QNAN short fsgldiv_res_qnan - tbl_fsgldiv_op # QNAN / DENORM short fsgldiv_res_snan - tbl_fsgldiv_op # QNAN / SNAN short tbl_fsgldiv_op - tbl_fsgldiv_op # short tbl_fsgldiv_op - tbl_fsgldiv_op # short fsgldiv_norm - tbl_fsgldiv_op # DENORM / NORM short fsgldiv_inf_load - tbl_fsgldiv_op # DENORM / ZERO short fsgldiv_zero_load - tbl_fsgldiv_op # DENORM / INF short fsgldiv_res_qnan - tbl_fsgldiv_op # DENORM / QNAN short fsgldiv_norm - tbl_fsgldiv_op # DENORM / DENORM short fsgldiv_res_snan - tbl_fsgldiv_op # DENORM / SNAN short tbl_fsgldiv_op - tbl_fsgldiv_op # short tbl_fsgldiv_op - tbl_fsgldiv_op # short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / NORM short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / ZERO short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / INF short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / QNAN short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / DENORM short fsgldiv_res_snan - tbl_fsgldiv_op # SNAN / SNAN short tbl_fsgldiv_op - tbl_fsgldiv_op # short tbl_fsgldiv_op - tbl_fsgldiv_op # fsgldiv_res_qnan: bra.l res_qnan fsgldiv_res_snan: bra.l res_snan fsgldiv_res_operr: bra.l res_operr fsgldiv_inf_load: bra.l fdiv_inf_load fsgldiv_zero_load: bra.l fdiv_zero_load fsgldiv_inf_dst: bra.l fdiv_inf_dst ######################################################################### # XDEF **************************************************************** # # fadd(): emulates the fadd instruction # # fsadd(): emulates the fadd instruction # # fdadd(): emulates the fdadd instruction # # # # XREF **************************************************************** # # addsub_scaler2() - scale the operands so they won't take exc # # ovf_res() - return default overflow result # # unf_res() - return default underflow result # # res_qnan() - set QNAN result # # res_snan() - set SNAN result # # res_operr() - set OPERR result # # scale_to_zero_src() - set src operand exponent equal to zero # # scale_to_zero_dst() - set dst operand exponent equal to zero # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms into extended, single, and double precision. # # Do addition after scaling exponents such that exception won't # # occur. Then, check result exponent to see if exception would have # # occurred. If so, return default result and maybe EXOP. Else, insert # # the correct result exponent and return. Set FPSR bits as appropriate. # # # ######################################################################### global fsadd fsadd: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl prec bra.b fadd global fdadd fdadd: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl prec global fadd fadd: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 # combine src tags bne.w fadd_not_norm # optimize on non-norm input # # ADD: norms and denorms # fadd_norm: bsr.l addsub_scaler2 # scale exponents fadd_zero_entry: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fadd.x FP_SCR0(%a6),%fp0 # execute add fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # fetch INEX2,N,Z or.l %d1,USER_FPSR(%a6) # save exc and ccode bits fbeq.w fadd_zero_exit # if result is zero, end now mov.l %d2,-(%sp) # save d2 fmovm.x &0x01,-(%sp) # save result to stack mov.w 2+L_SCR3(%a6),%d1 lsr.b &0x6,%d1 mov.w (%sp),%d2 # fetch new sign, exp andi.l &0x7fff,%d2 # strip sign sub.l %d0,%d2 # add scale factor cmp.l %d2,(tbl_fadd_ovfl.b,%pc,%d1.w*4) # is it an overflow? bge.b fadd_ovfl # yes cmp.l %d2,(tbl_fadd_unfl.b,%pc,%d1.w*4) # is it an underflow? blt.w fadd_unfl # yes beq.w fadd_may_unfl # maybe; go find out fadd_normal: mov.w (%sp),%d1 andi.w &0x8000,%d1 # keep sign or.w %d2,%d1 # concat sign,new exp mov.w %d1,(%sp) # insert new exponent fmovm.x (%sp)+,&0x80 # return result in fp0 mov.l (%sp)+,%d2 # restore d2 rts fadd_zero_exit: # fmov.s &0x00000000,%fp0 # return zero in fp0 rts tbl_fadd_ovfl: long 0x7fff # ext ovfl long 0x407f # sgl ovfl long 0x43ff # dbl ovfl tbl_fadd_unfl: long 0x0000 # ext unfl long 0x3f81 # sgl unfl long 0x3c01 # dbl unfl fadd_ovfl: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fadd_ovfl_ena # yes add.l &0xc,%sp fadd_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass prec:rnd bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 mov.l (%sp)+,%d2 # restore d2 rts fadd_ovfl_ena: mov.b L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fadd_ovfl_ena_sd # no; prec = sgl or dbl fadd_ovfl_ena_cont: mov.w (%sp),%d1 andi.w &0x8000,%d1 # keep sign subi.l &0x6000,%d2 # add extra bias andi.w &0x7fff,%d2 or.w %d2,%d1 # concat sign,new exp mov.w %d1,(%sp) # insert new exponent fmovm.x (%sp)+,&0x40 # return EXOP in fp1 bra.b fadd_ovfl_dis fadd_ovfl_ena_sd: fmovm.x FP_SCR1(%a6),&0x80 # load dst op mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # keep rnd mode fmov.l %d1,%fpcr # set FPCR fadd.x FP_SCR0(%a6),%fp0 # execute add fmov.l &0x0,%fpcr # clear FPCR add.l &0xc,%sp fmovm.x &0x01,-(%sp) bra.b fadd_ovfl_ena_cont fadd_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit add.l &0xc,%sp fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fadd.x FP_SCR0(%a6),%fp0 # execute add fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save status or.l %d1,USER_FPSR(%a6) # save INEX,N mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fadd_unfl_ena # yes fadd_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # 'Z' bit may have been set fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 mov.l (%sp)+,%d2 # restore d2 rts fadd_unfl_ena: fmovm.x FP_SCR1(%a6),&0x40 # load dst op mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fadd_unfl_ena_sd # no; sgl or dbl fmov.l L_SCR3(%a6),%fpcr # set FPCR fadd_unfl_ena_cont: fmov.l &0x0,%fpsr # clear FPSR fadd.x FP_SCR0(%a6),%fp1 # execute multiply fmov.l &0x0,%fpcr # clear FPCR fmovm.x &0x40,FP_SCR0(%a6) # save result to stack mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor addi.l &0x6000,%d1 # add new bias andi.w &0x7fff,%d1 # clear top bit or.w %d2,%d1 # concat sign,new exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.w fadd_unfl_dis fadd_unfl_ena_sd: mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # use only rnd mode fmov.l %d1,%fpcr # set FPCR bra.b fadd_unfl_ena_cont # # result is equal to the smallest normalized number in the selected precision # if the precision is extended, this result could not have come from an # underflow that rounded up. # fadd_may_unfl: mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 beq.w fadd_normal # yes; no underflow occurred mov.l 0x4(%sp),%d1 # extract hi(man) cmpi.l %d1,&0x80000000 # is hi(man) = 0x80000000? bne.w fadd_normal # no; no underflow occurred tst.l 0x8(%sp) # is lo(man) = 0x0? bne.w fadd_normal # no; no underflow occurred btst &inex2_bit,FPSR_EXCEPT(%a6) # is INEX2 set? beq.w fadd_normal # no; no underflow occurred # # ok, so now the result has a exponent equal to the smallest normalized # exponent for the selected precision. also, the mantissa is equal to # 0x8000000000000000 and this mantissa is the result of rounding non-zero # g,r,s. # now, we must determine whether the pre-rounded result was an underflow # rounded "up" or a normalized number rounded "down". # so, we do this be re-executing the add using RZ as the rounding mode and # seeing if the new result is smaller or equal to the current result. # fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # keep rnd prec ori.b &rz_mode*0x10,%d1 # insert rnd mode fmov.l %d1,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fadd.x FP_SCR0(%a6),%fp1 # execute add fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp0 # compare absolute values fabs.x %fp1 fcmp.x %fp0,%fp1 # is first result > second? fbgt.w fadd_unfl # yes; it's an underflow bra.w fadd_normal # no; it's not an underflow ########################################################################## # # Add: inputs are not both normalized; what are they? # fadd_not_norm: mov.w (tbl_fadd_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fadd_op.b,%pc,%d1.w*1) swbeg &48 tbl_fadd_op: short fadd_norm - tbl_fadd_op # NORM + NORM short fadd_zero_src - tbl_fadd_op # NORM + ZERO short fadd_inf_src - tbl_fadd_op # NORM + INF short fadd_res_qnan - tbl_fadd_op # NORM + QNAN short fadd_norm - tbl_fadd_op # NORM + DENORM short fadd_res_snan - tbl_fadd_op # NORM + SNAN short tbl_fadd_op - tbl_fadd_op # short tbl_fadd_op - tbl_fadd_op # short fadd_zero_dst - tbl_fadd_op # ZERO + NORM short fadd_zero_2 - tbl_fadd_op # ZERO + ZERO short fadd_inf_src - tbl_fadd_op # ZERO + INF short fadd_res_qnan - tbl_fadd_op # NORM + QNAN short fadd_zero_dst - tbl_fadd_op # ZERO + DENORM short fadd_res_snan - tbl_fadd_op # NORM + SNAN short tbl_fadd_op - tbl_fadd_op # short tbl_fadd_op - tbl_fadd_op # short fadd_inf_dst - tbl_fadd_op # INF + NORM short fadd_inf_dst - tbl_fadd_op # INF + ZERO short fadd_inf_2 - tbl_fadd_op # INF + INF short fadd_res_qnan - tbl_fadd_op # NORM + QNAN short fadd_inf_dst - tbl_fadd_op # INF + DENORM short fadd_res_snan - tbl_fadd_op # NORM + SNAN short tbl_fadd_op - tbl_fadd_op # short tbl_fadd_op - tbl_fadd_op # short fadd_res_qnan - tbl_fadd_op # QNAN + NORM short fadd_res_qnan - tbl_fadd_op # QNAN + ZERO short fadd_res_qnan - tbl_fadd_op # QNAN + INF short fadd_res_qnan - tbl_fadd_op # QNAN + QNAN short fadd_res_qnan - tbl_fadd_op # QNAN + DENORM short fadd_res_snan - tbl_fadd_op # QNAN + SNAN short tbl_fadd_op - tbl_fadd_op # short tbl_fadd_op - tbl_fadd_op # short fadd_norm - tbl_fadd_op # DENORM + NORM short fadd_zero_src - tbl_fadd_op # DENORM + ZERO short fadd_inf_src - tbl_fadd_op # DENORM + INF short fadd_res_qnan - tbl_fadd_op # NORM + QNAN short fadd_norm - tbl_fadd_op # DENORM + DENORM short fadd_res_snan - tbl_fadd_op # NORM + SNAN short tbl_fadd_op - tbl_fadd_op # short tbl_fadd_op - tbl_fadd_op # short fadd_res_snan - tbl_fadd_op # SNAN + NORM short fadd_res_snan - tbl_fadd_op # SNAN + ZERO short fadd_res_snan - tbl_fadd_op # SNAN + INF short fadd_res_snan - tbl_fadd_op # SNAN + QNAN short fadd_res_snan - tbl_fadd_op # SNAN + DENORM short fadd_res_snan - tbl_fadd_op # SNAN + SNAN short tbl_fadd_op - tbl_fadd_op # short tbl_fadd_op - tbl_fadd_op # fadd_res_qnan: bra.l res_qnan fadd_res_snan: bra.l res_snan # # both operands are ZEROes # fadd_zero_2: mov.b SRC_EX(%a0),%d0 # are the signs opposite mov.b DST_EX(%a1),%d1 eor.b %d0,%d1 bmi.w fadd_zero_2_chk_rm # weed out (-ZERO)+(+ZERO) # the signs are the same. so determine whether they are positive or negative # and return the appropriately signed zero. tst.b %d0 # are ZEROes positive or negative? bmi.b fadd_zero_rm # negative fmov.s &0x00000000,%fp0 # return +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set Z rts # # the ZEROes have opposite signs: # - Therefore, we return +ZERO if the rounding modes are RN,RZ, or RP. # - -ZERO is returned in the case of RM. # fadd_zero_2_chk_rm: mov.b 3+L_SCR3(%a6),%d1 andi.b &0x30,%d1 # extract rnd mode cmpi.b %d1,&rm_mode*0x10 # is rnd mode == RM? beq.b fadd_zero_rm # yes fmov.s &0x00000000,%fp0 # return +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set Z rts fadd_zero_rm: fmov.s &0x80000000,%fp0 # return -ZERO mov.b &neg_bmask+z_bmask,FPSR_CC(%a6) # set NEG/Z rts # # one operand is a ZERO and the other is a DENORM or NORM. scale # the DENORM or NORM and jump to the regular fadd routine. # fadd_zero_dst: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # scale the operand clr.w FP_SCR1_EX(%a6) clr.l FP_SCR1_HI(%a6) clr.l FP_SCR1_LO(%a6) bra.w fadd_zero_entry # go execute fadd fadd_zero_src: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) bsr.l scale_to_zero_dst # scale the operand clr.w FP_SCR0_EX(%a6) clr.l FP_SCR0_HI(%a6) clr.l FP_SCR0_LO(%a6) bra.w fadd_zero_entry # go execute fadd # # both operands are INFs. an OPERR will result if the INFs have # different signs. else, an INF of the same sign is returned # fadd_inf_2: mov.b SRC_EX(%a0),%d0 # exclusive or the signs mov.b DST_EX(%a1),%d1 eor.b %d1,%d0 bmi.l res_operr # weed out (-INF)+(+INF) # ok, so it's not an OPERR. but, we do have to remember to return the # src INF since that's where the 881/882 gets the j-bit from... # # operands are INF and one of {ZERO, INF, DENORM, NORM} # fadd_inf_src: fmovm.x SRC(%a0),&0x80 # return src INF tst.b SRC_EX(%a0) # is INF positive? bpl.b fadd_inf_done # yes; we're done mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG rts # # operands are INF and one of {ZERO, INF, DENORM, NORM} # fadd_inf_dst: fmovm.x DST(%a1),&0x80 # return dst INF tst.b DST_EX(%a1) # is INF positive? bpl.b fadd_inf_done # yes; we're done mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG rts fadd_inf_done: mov.b &inf_bmask,FPSR_CC(%a6) # set INF rts ######################################################################### # XDEF **************************************************************** # # fsub(): emulates the fsub instruction # # fssub(): emulates the fssub instruction # # fdsub(): emulates the fdsub instruction # # # # XREF **************************************************************** # # addsub_scaler2() - scale the operands so they won't take exc # # ovf_res() - return default overflow result # # unf_res() - return default underflow result # # res_qnan() - set QNAN result # # res_snan() - set SNAN result # # res_operr() - set OPERR result # # scale_to_zero_src() - set src operand exponent equal to zero # # scale_to_zero_dst() - set dst operand exponent equal to zero # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # a1 = pointer to extended precision destination operand # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms into extended, single, and double precision. # # Do subtraction after scaling exponents such that exception won't# # occur. Then, check result exponent to see if exception would have # # occurred. If so, return default result and maybe EXOP. Else, insert # # the correct result exponent and return. Set FPSR bits as appropriate. # # # ######################################################################### global fssub fssub: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl prec bra.b fsub global fdsub fdsub: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl prec global fsub fsub: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b DTAG(%a6),%d1 lsl.b &0x3,%d1 or.b STAG(%a6),%d1 # combine src tags bne.w fsub_not_norm # optimize on non-norm input # # SUB: norms and denorms # fsub_norm: bsr.l addsub_scaler2 # scale exponents fsub_zero_entry: fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fsub.x FP_SCR0(%a6),%fp0 # execute subtract fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # fetch INEX2, N, Z or.l %d1,USER_FPSR(%a6) # save exc and ccode bits fbeq.w fsub_zero_exit # if result zero, end now mov.l %d2,-(%sp) # save d2 fmovm.x &0x01,-(%sp) # save result to stack mov.w 2+L_SCR3(%a6),%d1 lsr.b &0x6,%d1 mov.w (%sp),%d2 # fetch new exponent andi.l &0x7fff,%d2 # strip sign sub.l %d0,%d2 # add scale factor cmp.l %d2,(tbl_fsub_ovfl.b,%pc,%d1.w*4) # is it an overflow? bge.b fsub_ovfl # yes cmp.l %d2,(tbl_fsub_unfl.b,%pc,%d1.w*4) # is it an underflow? blt.w fsub_unfl # yes beq.w fsub_may_unfl # maybe; go find out fsub_normal: mov.w (%sp),%d1 andi.w &0x8000,%d1 # keep sign or.w %d2,%d1 # insert new exponent mov.w %d1,(%sp) # insert new exponent fmovm.x (%sp)+,&0x80 # return result in fp0 mov.l (%sp)+,%d2 # restore d2 rts fsub_zero_exit: # fmov.s &0x00000000,%fp0 # return zero in fp0 rts tbl_fsub_ovfl: long 0x7fff # ext ovfl long 0x407f # sgl ovfl long 0x43ff # dbl ovfl tbl_fsub_unfl: long 0x0000 # ext unfl long 0x3f81 # sgl unfl long 0x3c01 # dbl unfl fsub_ovfl: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fsub_ovfl_ena # yes add.l &0xc,%sp fsub_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass prec:rnd bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 mov.l (%sp)+,%d2 # restore d2 rts fsub_ovfl_ena: mov.b L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fsub_ovfl_ena_sd # no fsub_ovfl_ena_cont: mov.w (%sp),%d1 # fetch {sgn,exp} andi.w &0x8000,%d1 # keep sign subi.l &0x6000,%d2 # subtract new bias andi.w &0x7fff,%d2 # clear top bit or.w %d2,%d1 # concat sign,exp mov.w %d1,(%sp) # insert new exponent fmovm.x (%sp)+,&0x40 # return EXOP in fp1 bra.b fsub_ovfl_dis fsub_ovfl_ena_sd: fmovm.x FP_SCR1(%a6),&0x80 # load dst op mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # clear rnd prec fmov.l %d1,%fpcr # set FPCR fsub.x FP_SCR0(%a6),%fp0 # execute subtract fmov.l &0x0,%fpcr # clear FPCR add.l &0xc,%sp fmovm.x &0x01,-(%sp) bra.b fsub_ovfl_ena_cont fsub_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit add.l &0xc,%sp fmovm.x FP_SCR1(%a6),&0x80 # load dst op fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsub.x FP_SCR0(%a6),%fp0 # execute subtract fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save status or.l %d1,USER_FPSR(%a6) mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fsub_unfl_ena # yes fsub_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # 'Z' may have been set fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 mov.l (%sp)+,%d2 # restore d2 rts fsub_unfl_ena: fmovm.x FP_SCR1(%a6),&0x40 mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # is precision extended? bne.b fsub_unfl_ena_sd # no fmov.l L_SCR3(%a6),%fpcr # set FPCR fsub_unfl_ena_cont: fmov.l &0x0,%fpsr # clear FPSR fsub.x FP_SCR0(%a6),%fp1 # execute subtract fmov.l &0x0,%fpcr # clear FPCR fmovm.x &0x40,FP_SCR0(%a6) # store result to stack mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor addi.l &0x6000,%d1 # subtract new bias andi.w &0x7fff,%d1 # clear top bit or.w %d2,%d1 # concat sgn,exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 bra.w fsub_unfl_dis fsub_unfl_ena_sd: mov.l L_SCR3(%a6),%d1 andi.b &0x30,%d1 # clear rnd prec fmov.l %d1,%fpcr # set FPCR bra.b fsub_unfl_ena_cont # # result is equal to the smallest normalized number in the selected precision # if the precision is extended, this result could not have come from an # underflow that rounded up. # fsub_may_unfl: mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # fetch rnd prec beq.w fsub_normal # yes; no underflow occurred mov.l 0x4(%sp),%d1 cmpi.l %d1,&0x80000000 # is hi(man) = 0x80000000? bne.w fsub_normal # no; no underflow occurred tst.l 0x8(%sp) # is lo(man) = 0x0? bne.w fsub_normal # no; no underflow occurred btst &inex2_bit,FPSR_EXCEPT(%a6) # is INEX2 set? beq.w fsub_normal # no; no underflow occurred # # ok, so now the result has a exponent equal to the smallest normalized # exponent for the selected precision. also, the mantissa is equal to # 0x8000000000000000 and this mantissa is the result of rounding non-zero # g,r,s. # now, we must determine whether the pre-rounded result was an underflow # rounded "up" or a normalized number rounded "down". # so, we do this be re-executing the add using RZ as the rounding mode and # seeing if the new result is smaller or equal to the current result. # fmovm.x FP_SCR1(%a6),&0x40 # load dst op into fp1 mov.l L_SCR3(%a6),%d1 andi.b &0xc0,%d1 # keep rnd prec ori.b &rz_mode*0x10,%d1 # insert rnd mode fmov.l %d1,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsub.x FP_SCR0(%a6),%fp1 # execute subtract fmov.l &0x0,%fpcr # clear FPCR fabs.x %fp0 # compare absolute values fabs.x %fp1 fcmp.x %fp0,%fp1 # is first result > second? fbgt.w fsub_unfl # yes; it's an underflow bra.w fsub_normal # no; it's not an underflow ########################################################################## # # Sub: inputs are not both normalized; what are they? # fsub_not_norm: mov.w (tbl_fsub_op.b,%pc,%d1.w*2),%d1 jmp (tbl_fsub_op.b,%pc,%d1.w*1) swbeg &48 tbl_fsub_op: short fsub_norm - tbl_fsub_op # NORM - NORM short fsub_zero_src - tbl_fsub_op # NORM - ZERO short fsub_inf_src - tbl_fsub_op # NORM - INF short fsub_res_qnan - tbl_fsub_op # NORM - QNAN short fsub_norm - tbl_fsub_op # NORM - DENORM short fsub_res_snan - tbl_fsub_op # NORM - SNAN short tbl_fsub_op - tbl_fsub_op # short tbl_fsub_op - tbl_fsub_op # short fsub_zero_dst - tbl_fsub_op # ZERO - NORM short fsub_zero_2 - tbl_fsub_op # ZERO - ZERO short fsub_inf_src - tbl_fsub_op # ZERO - INF short fsub_res_qnan - tbl_fsub_op # NORM - QNAN short fsub_zero_dst - tbl_fsub_op # ZERO - DENORM short fsub_res_snan - tbl_fsub_op # NORM - SNAN short tbl_fsub_op - tbl_fsub_op # short tbl_fsub_op - tbl_fsub_op # short fsub_inf_dst - tbl_fsub_op # INF - NORM short fsub_inf_dst - tbl_fsub_op # INF - ZERO short fsub_inf_2 - tbl_fsub_op # INF - INF short fsub_res_qnan - tbl_fsub_op # NORM - QNAN short fsub_inf_dst - tbl_fsub_op # INF - DENORM short fsub_res_snan - tbl_fsub_op # NORM - SNAN short tbl_fsub_op - tbl_fsub_op # short tbl_fsub_op - tbl_fsub_op # short fsub_res_qnan - tbl_fsub_op # QNAN - NORM short fsub_res_qnan - tbl_fsub_op # QNAN - ZERO short fsub_res_qnan - tbl_fsub_op # QNAN - INF short fsub_res_qnan - tbl_fsub_op # QNAN - QNAN short fsub_res_qnan - tbl_fsub_op # QNAN - DENORM short fsub_res_snan - tbl_fsub_op # QNAN - SNAN short tbl_fsub_op - tbl_fsub_op # short tbl_fsub_op - tbl_fsub_op # short fsub_norm - tbl_fsub_op # DENORM - NORM short fsub_zero_src - tbl_fsub_op # DENORM - ZERO short fsub_inf_src - tbl_fsub_op # DENORM - INF short fsub_res_qnan - tbl_fsub_op # NORM - QNAN short fsub_norm - tbl_fsub_op # DENORM - DENORM short fsub_res_snan - tbl_fsub_op # NORM - SNAN short tbl_fsub_op - tbl_fsub_op # short tbl_fsub_op - tbl_fsub_op # short fsub_res_snan - tbl_fsub_op # SNAN - NORM short fsub_res_snan - tbl_fsub_op # SNAN - ZERO short fsub_res_snan - tbl_fsub_op # SNAN - INF short fsub_res_snan - tbl_fsub_op # SNAN - QNAN short fsub_res_snan - tbl_fsub_op # SNAN - DENORM short fsub_res_snan - tbl_fsub_op # SNAN - SNAN short tbl_fsub_op - tbl_fsub_op # short tbl_fsub_op - tbl_fsub_op # fsub_res_qnan: bra.l res_qnan fsub_res_snan: bra.l res_snan # # both operands are ZEROes # fsub_zero_2: mov.b SRC_EX(%a0),%d0 mov.b DST_EX(%a1),%d1 eor.b %d1,%d0 bpl.b fsub_zero_2_chk_rm # the signs are opposite, so, return a ZERO w/ the sign of the dst ZERO tst.b %d0 # is dst negative? bmi.b fsub_zero_2_rm # yes fmov.s &0x00000000,%fp0 # no; return +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set Z rts # # the ZEROes have the same signs: # - Therefore, we return +ZERO if the rounding mode is RN,RZ, or RP # - -ZERO is returned in the case of RM. # fsub_zero_2_chk_rm: mov.b 3+L_SCR3(%a6),%d1 andi.b &0x30,%d1 # extract rnd mode cmpi.b %d1,&rm_mode*0x10 # is rnd mode = RM? beq.b fsub_zero_2_rm # yes fmov.s &0x00000000,%fp0 # no; return +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set Z rts fsub_zero_2_rm: fmov.s &0x80000000,%fp0 # return -ZERO mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set Z/NEG rts # # one operand is a ZERO and the other is a DENORM or a NORM. # scale the DENORM or NORM and jump to the regular fsub routine. # fsub_zero_dst: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_to_zero_src # scale the operand clr.w FP_SCR1_EX(%a6) clr.l FP_SCR1_HI(%a6) clr.l FP_SCR1_LO(%a6) bra.w fsub_zero_entry # go execute fsub fsub_zero_src: mov.w DST_EX(%a1),FP_SCR1_EX(%a6) mov.l DST_HI(%a1),FP_SCR1_HI(%a6) mov.l DST_LO(%a1),FP_SCR1_LO(%a6) bsr.l scale_to_zero_dst # scale the operand clr.w FP_SCR0_EX(%a6) clr.l FP_SCR0_HI(%a6) clr.l FP_SCR0_LO(%a6) bra.w fsub_zero_entry # go execute fsub # # both operands are INFs. an OPERR will result if the INFs have the # same signs. else, # fsub_inf_2: mov.b SRC_EX(%a0),%d0 # exclusive or the signs mov.b DST_EX(%a1),%d1 eor.b %d1,%d0 bpl.l res_operr # weed out (-INF)+(+INF) # ok, so it's not an OPERR. but we do have to remember to return # the src INF since that's where the 881/882 gets the j-bit. fsub_inf_src: fmovm.x SRC(%a0),&0x80 # return src INF fneg.x %fp0 # invert sign fbge.w fsub_inf_done # sign is now positive mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG rts fsub_inf_dst: fmovm.x DST(%a1),&0x80 # return dst INF tst.b DST_EX(%a1) # is INF negative? bpl.b fsub_inf_done # no mov.b &neg_bmask+inf_bmask,FPSR_CC(%a6) # set INF/NEG rts fsub_inf_done: mov.b &inf_bmask,FPSR_CC(%a6) # set INF rts ######################################################################### # XDEF **************************************************************** # # fsqrt(): emulates the fsqrt instruction # # fssqrt(): emulates the fssqrt instruction # # fdsqrt(): emulates the fdsqrt instruction # # # # XREF **************************************************************** # # scale_sqrt() - scale the source operand # # unf_res() - return default underflow result # # ovf_res() - return default overflow result # # res_qnan_1op() - return QNAN result # # res_snan_1op() - return SNAN result # # # # INPUT *************************************************************** # # a0 = pointer to extended precision source operand # # d0 rnd prec,mode # # # # OUTPUT ************************************************************** # # fp0 = result # # fp1 = EXOP (if exception occurred) # # # # ALGORITHM *********************************************************** # # Handle NANs, infinities, and zeroes as special cases. Divide # # norms/denorms into ext/sgl/dbl precision. # # For norms/denorms, scale the exponents such that a sqrt # # instruction won't cause an exception. Use the regular fsqrt to # # compute a result. Check if the regular operands would have taken # # an exception. If so, return the default overflow/underflow result # # and return the EXOP if exceptions are enabled. Else, scale the # # result operand to the proper exponent. # # # ######################################################################### global fssqrt fssqrt: andi.b &0x30,%d0 # clear rnd prec ori.b &s_mode*0x10,%d0 # insert sgl precision bra.b fsqrt global fdsqrt fdsqrt: andi.b &0x30,%d0 # clear rnd prec ori.b &d_mode*0x10,%d0 # insert dbl precision global fsqrt fsqrt: mov.l %d0,L_SCR3(%a6) # store rnd info clr.w %d1 mov.b STAG(%a6),%d1 bne.w fsqrt_not_norm # optimize on non-norm input # # SQUARE ROOT: norms and denorms ONLY! # fsqrt_norm: tst.b SRC_EX(%a0) # is operand negative? bmi.l res_operr # yes andi.b &0xc0,%d0 # is precision extended? bne.b fsqrt_not_ext # no; go handle sgl or dbl fmov.l L_SCR3(%a6),%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsqrt.x (%a0),%fp0 # execute square root fmov.l %fpsr,%d1 or.l %d1,USER_FPSR(%a6) # set N,INEX rts fsqrt_denorm: tst.b SRC_EX(%a0) # is operand negative? bmi.l res_operr # yes andi.b &0xc0,%d0 # is precision extended? bne.b fsqrt_not_ext # no; go handle sgl or dbl mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_sqrt # calculate scale factor bra.w fsqrt_sd_normal # # operand is either single or double # fsqrt_not_ext: cmpi.b %d0,&s_mode*0x10 # separate sgl/dbl prec bne.w fsqrt_dbl # # operand is to be rounded to single precision # fsqrt_sgl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_sqrt # calculate scale factor cmpi.l %d0,&0x3fff-0x3f81 # will move in underflow? beq.w fsqrt_sd_may_unfl bgt.w fsqrt_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x407f # will move in overflow? beq.w fsqrt_sd_may_ovfl # maybe; go check blt.w fsqrt_sd_ovfl # yes; go handle overflow # # operand will NOT overflow or underflow when moved in to the fp reg file # fsqrt_sd_normal: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fsqrt.x FP_SCR0(%a6),%fp0 # perform absolute fmov.l %fpsr,%d1 # save FPSR fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fsqrt_sd_normal_exit: mov.l %d2,-(%sp) # save d2 fmovm.x &0x80,FP_SCR0(%a6) # store out result mov.w FP_SCR0_EX(%a6),%d1 # load sgn,exp mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign sub.l %d0,%d1 # add scale factor andi.w &0x8000,%d2 # keep old sign or.w %d1,%d2 # concat old sign,new exp mov.w %d2,FP_SCR0_EX(%a6) # insert new exponent mov.l (%sp)+,%d2 # restore d2 fmovm.x FP_SCR0(%a6),&0x80 # return result in fp0 rts # # operand is to be rounded to double precision # fsqrt_dbl: mov.w SRC_EX(%a0),FP_SCR0_EX(%a6) mov.l SRC_HI(%a0),FP_SCR0_HI(%a6) mov.l SRC_LO(%a0),FP_SCR0_LO(%a6) bsr.l scale_sqrt # calculate scale factor cmpi.l %d0,&0x3fff-0x3c01 # will move in underflow? beq.w fsqrt_sd_may_unfl bgt.b fsqrt_sd_unfl # yes; go handle underflow cmpi.l %d0,&0x3fff-0x43ff # will move in overflow? beq.w fsqrt_sd_may_ovfl # maybe; go check blt.w fsqrt_sd_ovfl # yes; go handle overflow bra.w fsqrt_sd_normal # no; ho handle normalized op # we're on the line here and the distinguising characteristic is whether # the exponent is 3fff or 3ffe. if it's 3ffe, then it's a safe number # elsewise fall through to underflow. fsqrt_sd_may_unfl: btst &0x0,1+FP_SCR0_EX(%a6) # is exponent 0x3fff? bne.w fsqrt_sd_normal # yes, so no underflow # # operand WILL underflow when moved in to the fp register file # fsqrt_sd_unfl: bset &unfl_bit,FPSR_EXCEPT(%a6) # set unfl exc bit fmov.l &rz_mode*0x10,%fpcr # set FPCR fmov.l &0x0,%fpsr # clear FPSR fsqrt.x FP_SCR0(%a6),%fp0 # execute square root fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N # if underflow or inexact is enabled, go calculate EXOP first. mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x0b,%d1 # is UNFL or INEX enabled? bne.b fsqrt_sd_unfl_ena # yes fsqrt_sd_unfl_dis: fmovm.x &0x80,FP_SCR0(%a6) # store out result lea FP_SCR0(%a6),%a0 # pass: result addr mov.l L_SCR3(%a6),%d1 # pass: rnd prec,mode bsr.l unf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set possible 'Z' ccode fmovm.x FP_SCR0(%a6),&0x80 # return default result in fp0 rts # # operand will underflow AND underflow is enabled. # Therefore, we must return the result rounded to extended precision. # fsqrt_sd_unfl_ena: mov.l FP_SCR0_HI(%a6),FP_SCR1_HI(%a6) mov.l FP_SCR0_LO(%a6),FP_SCR1_LO(%a6) mov.w FP_SCR0_EX(%a6),%d1 # load current exponent mov.l %d2,-(%sp) # save d2 mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # subtract scale factor addi.l &0x6000,%d1 # add new bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat new sign,new exp mov.w %d1,FP_SCR1_EX(%a6) # insert new exp fmovm.x FP_SCR1(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fsqrt_sd_unfl_dis # # operand WILL overflow. # fsqrt_sd_ovfl: fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fsqrt.x FP_SCR0(%a6),%fp0 # perform square root fmov.l &0x0,%fpcr # clear FPCR fmov.l %fpsr,%d1 # save FPSR or.l %d1,USER_FPSR(%a6) # save INEX2,N fsqrt_sd_ovfl_tst: or.l &ovfl_inx_mask,USER_FPSR(%a6) # set ovfl/aovfl/ainex mov.b FPCR_ENABLE(%a6),%d1 andi.b &0x13,%d1 # is OVFL or INEX enabled? bne.b fsqrt_sd_ovfl_ena # yes # # OVFL is not enabled; therefore, we must create the default result by # calling ovf_res(). # fsqrt_sd_ovfl_dis: btst &neg_bit,FPSR_CC(%a6) # is result negative? sne %d1 # set sign param accordingly mov.l L_SCR3(%a6),%d0 # pass: prec,mode bsr.l ovf_res # calculate default result or.b %d0,FPSR_CC(%a6) # set INF,N if applicable fmovm.x (%a0),&0x80 # return default result in fp0 rts # # OVFL is enabled. # the INEX2 bit has already been updated by the round to the correct precision. # now, round to extended(and don't alter the FPSR). # fsqrt_sd_ovfl_ena: mov.l %d2,-(%sp) # save d2 mov.w FP_SCR0_EX(%a6),%d1 # fetch {sgn,exp} mov.l %d1,%d2 # make a copy andi.l &0x7fff,%d1 # strip sign andi.w &0x8000,%d2 # keep old sign sub.l %d0,%d1 # add scale factor subi.l &0x6000,%d1 # subtract bias andi.w &0x7fff,%d1 or.w %d2,%d1 # concat sign,exp mov.w %d1,FP_SCR0_EX(%a6) # insert new exponent fmovm.x FP_SCR0(%a6),&0x40 # return EXOP in fp1 mov.l (%sp)+,%d2 # restore d2 bra.b fsqrt_sd_ovfl_dis # # the move in MAY underflow. so... # fsqrt_sd_may_ovfl: btst &0x0,1+FP_SCR0_EX(%a6) # is exponent 0x3fff? bne.w fsqrt_sd_ovfl # yes, so overflow fmov.l &0x0,%fpsr # clear FPSR fmov.l L_SCR3(%a6),%fpcr # set FPCR fsqrt.x FP_SCR0(%a6),%fp0 # perform absolute fmov.l %fpsr,%d1 # save status fmov.l &0x0,%fpcr # clear FPCR or.l %d1,USER_FPSR(%a6) # save INEX2,N fmov.x %fp0,%fp1 # make a copy of result fcmp.b %fp1,&0x1 # is |result| >= 1.b? fbge.w fsqrt_sd_ovfl_tst # yes; overflow has occurred # no, it didn't overflow; we have correct result bra.w fsqrt_sd_normal_exit ########################################################################## # # input is not normalized; what is it? # fsqrt_not_norm: cmpi.b %d1,&DENORM # weed out DENORM beq.w fsqrt_denorm cmpi.b %d1,&ZERO # weed out ZERO beq.b fsqrt_zero cmpi.b %d1,&INF # weed out INF beq.b fsqrt_inf cmpi.b %d1,&SNAN # weed out SNAN beq.l res_snan_1op bra.l res_qnan_1op # # fsqrt(+0) = +0 # fsqrt(-0) = -0 # fsqrt(+INF) = +INF # fsqrt(-INF) = OPERR # fsqrt_zero: tst.b SRC_EX(%a0) # is ZERO positive or negative? bmi.b fsqrt_zero_m # negative fsqrt_zero_p: fmov.s &0x00000000,%fp0 # return +ZERO mov.b &z_bmask,FPSR_CC(%a6) # set 'Z' ccode bit rts fsqrt_zero_m: fmov.s &0x80000000,%fp0 # return -ZERO mov.b &z_bmask+neg_bmask,FPSR_CC(%a6) # set 'Z','N' ccode bits rts fsqrt_inf: tst.b SRC_EX(%a0) # is INF positive or negative? bmi.l res_operr # negative fsqrt_inf_p: fmovm.x SRC(%a0),&0x80 # return +INF in fp0 mov.b &inf_bmask,FPSR_CC(%a6) # set 'I' ccode bit rts ######################################################################### # XDEF **************************************************************** # # fetch_dreg(): fetch register according to index in d1 # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d1 = index of register to fetch from # # # # OUTPUT ************************************************************** # # d0 = value of register fetched # # # # ALGORITHM *********************************************************** # # According to the index value in d1 which can range from zero # # to fifteen, load the corresponding register file value (where # # address register indexes start at 8). D0/D1/A0/A1/A6/A7 are on the # # stack. The rest should still be in their original places. # # # ######################################################################### # this routine leaves d1 intact for subsequent store_dreg calls. global fetch_dreg fetch_dreg: mov.w (tbl_fdreg.b,%pc,%d1.w*2),%d0 jmp (tbl_fdreg.b,%pc,%d0.w*1) tbl_fdreg: short fdreg0 - tbl_fdreg short fdreg1 - tbl_fdreg short fdreg2 - tbl_fdreg short fdreg3 - tbl_fdreg short fdreg4 - tbl_fdreg short fdreg5 - tbl_fdreg short fdreg6 - tbl_fdreg short fdreg7 - tbl_fdreg short fdreg8 - tbl_fdreg short fdreg9 - tbl_fdreg short fdrega - tbl_fdreg short fdregb - tbl_fdreg short fdregc - tbl_fdreg short fdregd - tbl_fdreg short fdrege - tbl_fdreg short fdregf - tbl_fdreg fdreg0: mov.l EXC_DREGS+0x0(%a6),%d0 rts fdreg1: mov.l EXC_DREGS+0x4(%a6),%d0 rts fdreg2: mov.l %d2,%d0 rts fdreg3: mov.l %d3,%d0 rts fdreg4: mov.l %d4,%d0 rts fdreg5: mov.l %d5,%d0 rts fdreg6: mov.l %d6,%d0 rts fdreg7: mov.l %d7,%d0 rts fdreg8: mov.l EXC_DREGS+0x8(%a6),%d0 rts fdreg9: mov.l EXC_DREGS+0xc(%a6),%d0 rts fdrega: mov.l %a2,%d0 rts fdregb: mov.l %a3,%d0 rts fdregc: mov.l %a4,%d0 rts fdregd: mov.l %a5,%d0 rts fdrege: mov.l (%a6),%d0 rts fdregf: mov.l EXC_A7(%a6),%d0 rts ######################################################################### # XDEF **************************************************************** # # store_dreg_l(): store longword to data register specified by d1 # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = longowrd value to store # # d1 = index of register to fetch from # # # # OUTPUT ************************************************************** # # (data register is updated) # # # # ALGORITHM *********************************************************** # # According to the index value in d1, store the longword value # # in d0 to the corresponding data register. D0/D1 are on the stack # # while the rest are in their initial places. # # # ######################################################################### global store_dreg_l store_dreg_l: mov.w (tbl_sdregl.b,%pc,%d1.w*2),%d1 jmp (tbl_sdregl.b,%pc,%d1.w*1) tbl_sdregl: short sdregl0 - tbl_sdregl short sdregl1 - tbl_sdregl short sdregl2 - tbl_sdregl short sdregl3 - tbl_sdregl short sdregl4 - tbl_sdregl short sdregl5 - tbl_sdregl short sdregl6 - tbl_sdregl short sdregl7 - tbl_sdregl sdregl0: mov.l %d0,EXC_DREGS+0x0(%a6) rts sdregl1: mov.l %d0,EXC_DREGS+0x4(%a6) rts sdregl2: mov.l %d0,%d2 rts sdregl3: mov.l %d0,%d3 rts sdregl4: mov.l %d0,%d4 rts sdregl5: mov.l %d0,%d5 rts sdregl6: mov.l %d0,%d6 rts sdregl7: mov.l %d0,%d7 rts ######################################################################### # XDEF **************************************************************** # # store_dreg_w(): store word to data register specified by d1 # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = word value to store # # d1 = index of register to fetch from # # # # OUTPUT ************************************************************** # # (data register is updated) # # # # ALGORITHM *********************************************************** # # According to the index value in d1, store the word value # # in d0 to the corresponding data register. D0/D1 are on the stack # # while the rest are in their initial places. # # # ######################################################################### global store_dreg_w store_dreg_w: mov.w (tbl_sdregw.b,%pc,%d1.w*2),%d1 jmp (tbl_sdregw.b,%pc,%d1.w*1) tbl_sdregw: short sdregw0 - tbl_sdregw short sdregw1 - tbl_sdregw short sdregw2 - tbl_sdregw short sdregw3 - tbl_sdregw short sdregw4 - tbl_sdregw short sdregw5 - tbl_sdregw short sdregw6 - tbl_sdregw short sdregw7 - tbl_sdregw sdregw0: mov.w %d0,2+EXC_DREGS+0x0(%a6) rts sdregw1: mov.w %d0,2+EXC_DREGS+0x4(%a6) rts sdregw2: mov.w %d0,%d2 rts sdregw3: mov.w %d0,%d3 rts sdregw4: mov.w %d0,%d4 rts sdregw5: mov.w %d0,%d5 rts sdregw6: mov.w %d0,%d6 rts sdregw7: mov.w %d0,%d7 rts ######################################################################### # XDEF **************************************************************** # # store_dreg_b(): store byte to data register specified by d1 # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = byte value to store # # d1 = index of register to fetch from # # # # OUTPUT ************************************************************** # # (data register is updated) # # # # ALGORITHM *********************************************************** # # According to the index value in d1, store the byte value # # in d0 to the corresponding data register. D0/D1 are on the stack # # while the rest are in their initial places. # # # ######################################################################### global store_dreg_b store_dreg_b: mov.w (tbl_sdregb.b,%pc,%d1.w*2),%d1 jmp (tbl_sdregb.b,%pc,%d1.w*1) tbl_sdregb: short sdregb0 - tbl_sdregb short sdregb1 - tbl_sdregb short sdregb2 - tbl_sdregb short sdregb3 - tbl_sdregb short sdregb4 - tbl_sdregb short sdregb5 - tbl_sdregb short sdregb6 - tbl_sdregb short sdregb7 - tbl_sdregb sdregb0: mov.b %d0,3+EXC_DREGS+0x0(%a6) rts sdregb1: mov.b %d0,3+EXC_DREGS+0x4(%a6) rts sdregb2: mov.b %d0,%d2 rts sdregb3: mov.b %d0,%d3 rts sdregb4: mov.b %d0,%d4 rts sdregb5: mov.b %d0,%d5 rts sdregb6: mov.b %d0,%d6 rts sdregb7: mov.b %d0,%d7 rts ######################################################################### # XDEF **************************************************************** # # inc_areg(): increment an address register by the value in d0 # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = amount to increment by # # d1 = index of address register to increment # # # # OUTPUT ************************************************************** # # (address register is updated) # # # # ALGORITHM *********************************************************** # # Typically used for an instruction w/ a post-increment , # # this routine adds the increment value in d0 to the address register # # specified by d1. A0/A1/A6/A7 reside on the stack. The rest reside # # in their original places. # # For a7, if the increment amount is one, then we have to # # increment by two. For any a7 update, set the mia7_flag so that if # # an access error exception occurs later in emulation, this address # # register update can be undone. # # # ######################################################################### global inc_areg inc_areg: mov.w (tbl_iareg.b,%pc,%d1.w*2),%d1 jmp (tbl_iareg.b,%pc,%d1.w*1) tbl_iareg: short iareg0 - tbl_iareg short iareg1 - tbl_iareg short iareg2 - tbl_iareg short iareg3 - tbl_iareg short iareg4 - tbl_iareg short iareg5 - tbl_iareg short iareg6 - tbl_iareg short iareg7 - tbl_iareg iareg0: add.l %d0,EXC_DREGS+0x8(%a6) rts iareg1: add.l %d0,EXC_DREGS+0xc(%a6) rts iareg2: add.l %d0,%a2 rts iareg3: add.l %d0,%a3 rts iareg4: add.l %d0,%a4 rts iareg5: add.l %d0,%a5 rts iareg6: add.l %d0,(%a6) rts iareg7: mov.b &mia7_flg,SPCOND_FLG(%a6) cmpi.b %d0,&0x1 beq.b iareg7b add.l %d0,EXC_A7(%a6) rts iareg7b: addq.l &0x2,EXC_A7(%a6) rts ######################################################################### # XDEF **************************************************************** # # dec_areg(): decrement an address register by the value in d0 # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = amount to decrement by # # d1 = index of address register to decrement # # # # OUTPUT ************************************************************** # # (address register is updated) # # # # ALGORITHM *********************************************************** # # Typically used for an instruction w/ a pre-decrement , # # this routine adds the decrement value in d0 to the address register # # specified by d1. A0/A1/A6/A7 reside on the stack. The rest reside # # in their original places. # # For a7, if the decrement amount is one, then we have to # # decrement by two. For any a7 update, set the mda7_flag so that if # # an access error exception occurs later in emulation, this address # # register update can be undone. # # # ######################################################################### global dec_areg dec_areg: mov.w (tbl_dareg.b,%pc,%d1.w*2),%d1 jmp (tbl_dareg.b,%pc,%d1.w*1) tbl_dareg: short dareg0 - tbl_dareg short dareg1 - tbl_dareg short dareg2 - tbl_dareg short dareg3 - tbl_dareg short dareg4 - tbl_dareg short dareg5 - tbl_dareg short dareg6 - tbl_dareg short dareg7 - tbl_dareg dareg0: sub.l %d0,EXC_DREGS+0x8(%a6) rts dareg1: sub.l %d0,EXC_DREGS+0xc(%a6) rts dareg2: sub.l %d0,%a2 rts dareg3: sub.l %d0,%a3 rts dareg4: sub.l %d0,%a4 rts dareg5: sub.l %d0,%a5 rts dareg6: sub.l %d0,(%a6) rts dareg7: mov.b &mda7_flg,SPCOND_FLG(%a6) cmpi.b %d0,&0x1 beq.b dareg7b sub.l %d0,EXC_A7(%a6) rts dareg7b: subq.l &0x2,EXC_A7(%a6) rts ############################################################################## ######################################################################### # XDEF **************************************************************** # # load_fpn1(): load FP register value into FP_SRC(a6). # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = index of FP register to load # # # # OUTPUT ************************************************************** # # FP_SRC(a6) = value loaded from FP register file # # # # ALGORITHM *********************************************************** # # Using the index in d0, load FP_SRC(a6) with a number from the # # FP register file. # # # ######################################################################### global load_fpn1 load_fpn1: mov.w (tbl_load_fpn1.b,%pc,%d0.w*2), %d0 jmp (tbl_load_fpn1.b,%pc,%d0.w*1) tbl_load_fpn1: short load_fpn1_0 - tbl_load_fpn1 short load_fpn1_1 - tbl_load_fpn1 short load_fpn1_2 - tbl_load_fpn1 short load_fpn1_3 - tbl_load_fpn1 short load_fpn1_4 - tbl_load_fpn1 short load_fpn1_5 - tbl_load_fpn1 short load_fpn1_6 - tbl_load_fpn1 short load_fpn1_7 - tbl_load_fpn1 load_fpn1_0: mov.l 0+EXC_FP0(%a6), 0+FP_SRC(%a6) mov.l 4+EXC_FP0(%a6), 4+FP_SRC(%a6) mov.l 8+EXC_FP0(%a6), 8+FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_1: mov.l 0+EXC_FP1(%a6), 0+FP_SRC(%a6) mov.l 4+EXC_FP1(%a6), 4+FP_SRC(%a6) mov.l 8+EXC_FP1(%a6), 8+FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_2: fmovm.x &0x20, FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_3: fmovm.x &0x10, FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_4: fmovm.x &0x08, FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_5: fmovm.x &0x04, FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_6: fmovm.x &0x02, FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts load_fpn1_7: fmovm.x &0x01, FP_SRC(%a6) lea FP_SRC(%a6), %a0 rts ############################################################################# ######################################################################### # XDEF **************************************************************** # # load_fpn2(): load FP register value into FP_DST(a6). # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # d0 = index of FP register to load # # # # OUTPUT ************************************************************** # # FP_DST(a6) = value loaded from FP register file # # # # ALGORITHM *********************************************************** # # Using the index in d0, load FP_DST(a6) with a number from the # # FP register file. # # # ######################################################################### global load_fpn2 load_fpn2: mov.w (tbl_load_fpn2.b,%pc,%d0.w*2), %d0 jmp (tbl_load_fpn2.b,%pc,%d0.w*1) tbl_load_fpn2: short load_fpn2_0 - tbl_load_fpn2 short load_fpn2_1 - tbl_load_fpn2 short load_fpn2_2 - tbl_load_fpn2 short load_fpn2_3 - tbl_load_fpn2 short load_fpn2_4 - tbl_load_fpn2 short load_fpn2_5 - tbl_load_fpn2 short load_fpn2_6 - tbl_load_fpn2 short load_fpn2_7 - tbl_load_fpn2 load_fpn2_0: mov.l 0+EXC_FP0(%a6), 0+FP_DST(%a6) mov.l 4+EXC_FP0(%a6), 4+FP_DST(%a6) mov.l 8+EXC_FP0(%a6), 8+FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_1: mov.l 0+EXC_FP1(%a6), 0+FP_DST(%a6) mov.l 4+EXC_FP1(%a6), 4+FP_DST(%a6) mov.l 8+EXC_FP1(%a6), 8+FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_2: fmovm.x &0x20, FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_3: fmovm.x &0x10, FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_4: fmovm.x &0x08, FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_5: fmovm.x &0x04, FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_6: fmovm.x &0x02, FP_DST(%a6) lea FP_DST(%a6), %a0 rts load_fpn2_7: fmovm.x &0x01, FP_DST(%a6) lea FP_DST(%a6), %a0 rts ############################################################################# ######################################################################### # XDEF **************************************************************** # # store_fpreg(): store an fp value to the fpreg designated d0. # # # # XREF **************************************************************** # # None # # # # INPUT *************************************************************** # # fp0 = extended precision value to store # # d0 = index of floating-point register # # # # OUTPUT ************************************************************** # # None # # # # ALGORITHM *********************************************************** # # Store the value in fp0 to the FP register designated by the # # value in d0. The FP number can be DENORM or SNAN so we have to be # # careful that we don't take an exception here. # # # ######################################################################### global store_fpreg store_fpreg: mov.w (tbl_store_fpreg.b,%pc,%d0.w*2), %d0 jmp (tbl_store_fpreg.b,%pc,%d0.w*1) tbl_store_fpreg: short store_fpreg_0 - tbl_store_fpreg short store_fpreg_1 - tbl_store_fpreg short store_fpreg_2 - tbl_store_fpreg short store_fpreg_3 - tbl_store_fpreg short store_fpreg_4 - tbl_store_fpreg short store_fpreg_5 - tbl_store_fpreg short store_fpreg_6 - tbl_store_fpreg short store_fpreg_7 - tbl_store_fpreg store_fpreg_0: fmovm.x &0x80, EXC_FP0(%a6) rts store_fpreg_1: fmovm.x &0x80, EXC_FP1(%a6) rts store_fpreg_2: fmovm.x &0x01, -(%sp) fmovm.x (%sp)+, &0x20 rts store_fpreg_3: fmovm.x &0x01, -(%sp) fmovm.x (%sp)+, &0x10 rts store_fpreg_4: fmovm.x &0x01, -(%sp) fmovm.x (%sp)+, &0x08 rts store_fpreg_5: fmovm.x &0x01, -(%sp) fmovm.x (%sp)+, &0x04 rts store_fpreg_6: fmovm.x &0x01, -(%sp) fmovm.x (%sp)+, &0x02 rts store_fpreg_7: fmovm.x &0x01, -(%sp) fmovm.x (%sp)+, &0x01 rts ######################################################################### # XDEF **************************************************************** # # get_packed(): fetch a packed operand from memory and then # # convert it to a floating-point binary number. # # # # XREF **************************************************************** # # _dcalc_ea() - calculate the correct # # _mem_read() - fetch the packed operand from memory # # facc_in_x() - the fetch failed so jump to special exit code # # decbin() - convert packed to binary extended precision # # # # INPUT *************************************************************** # # None # # # # OUTPUT ************************************************************** # # If no failure on _mem_read(): # # FP_SRC(a6) = packed operand now as a binary FP number # # # # ALGORITHM *********************************************************** # # Get the correct which is the value on the exception stack # # frame w/ maybe a correction factor if the is -(an) or (an)+. # # Then, fetch the operand from memory. If the fetch fails, exit # # through facc_in_x(). # # If the packed operand is a ZERO,NAN, or INF, convert it to # # its binary representation here. Else, call decbin() which will # # convert the packed value to an extended precision binary value. # # # ######################################################################### # the stacked for packed is correct except for -(An). # the base reg must be updated for both -(An) and (An)+. global get_packed get_packed: mov.l &0xc,%d0 # packed is 12 bytes bsr.l _dcalc_ea # fetch ; correct An lea FP_SRC(%a6),%a1 # pass: ptr to super dst mov.l &0xc,%d0 # pass: 12 bytes bsr.l _dmem_read # read packed operand tst.l %d1 # did dfetch fail? bne.l facc_in_x # yes # The packed operand is an INF or a NAN if the exponent field is all ones. bfextu FP_SRC(%a6){&1:&15},%d0 # get exp cmpi.w %d0,&0x7fff # INF or NAN? bne.b gp_try_zero # no rts # operand is an INF or NAN # The packed operand is a zero if the mantissa is all zero, else it's # a normal packed op. gp_try_zero: mov.b 3+FP_SRC(%a6),%d0 # get byte 4 andi.b &0x0f,%d0 # clear all but last nybble bne.b gp_not_spec # not a zero tst.l FP_SRC_HI(%a6) # is lw 2 zero? bne.b gp_not_spec # not a zero tst.l FP_SRC_LO(%a6) # is lw 3 zero? bne.b gp_not_spec # not a zero rts # operand is a ZERO gp_not_spec: lea FP_SRC(%a6),%a0 # pass: ptr to packed op bsr.l decbin # convert to extended fmovm.x &0x80,FP_SRC(%a6) # make this the srcop rts ######################################################################### # decbin(): Converts normalized packed bcd value pointed to by register # # a0 to extended-precision value in fp0. # # # # INPUT *************************************************************** # # a0 = pointer to normalized packed bcd value # # # # OUTPUT ************************************************************** # # fp0 = exact fp representation of the packed bcd value. # # # # ALGORITHM *********************************************************** # # Expected is a normal bcd (i.e. non-exceptional; all inf, zero, # # and NaN operands are dispatched without entering this routine) # # value in 68881/882 format at location (a0). # # # # A1. Convert the bcd exponent to binary by successive adds and # # muls. Set the sign according to SE. Subtract 16 to compensate # # for the mantissa which is to be interpreted as 17 integer # # digits, rather than 1 integer and 16 fraction digits. # # Note: this operation can never overflow. # # # # A2. Convert the bcd mantissa to binary by successive # # adds and muls in FP0. Set the sign according to SM. # # The mantissa digits will be converted with the decimal point # # assumed following the least-significant digit. # # Note: this operation can never overflow. # # # # A3. Count the number of leading/trailing zeros in the # # bcd string. If SE is positive, count the leading zeros; # # if negative, count the trailing zeros. Set the adjusted # # exponent equal to the exponent from A1 and the zero count # # added if SM = 1 and subtracted if SM = 0. Scale the # # mantissa the equivalent of forcing in the bcd value: # # # # SM = 0 a non-zero digit in the integer position # # SM = 1 a non-zero digit in Mant0, lsd of the fraction # # # # this will insure that any value, regardless of its # # representation (ex. 0.1E2, 1E1, 10E0, 100E-1), is converted # # consistently. # # # # A4. Calculate the factor 10^exp in FP1 using a table of # # 10^(2^n) values. To reduce the error in forming factors # # greater than 10^27, a directed rounding scheme is used with # # tables rounded to RN, RM, and RP, according to the table # # in the comments of the pwrten section. # # # # A5. Form the final binary number by scaling the mantissa by # # the exponent factor. This is done by multiplying the # # mantissa in FP0 by the factor in FP1 if the adjusted # # exponent sign is positive, and dividing FP0 by FP1 if # # it is negative. # # # # Clean up and return. Check if the final mul or div was inexact. # # If so, set INEX1 in USER_FPSR. # # # ######################################################################### # # PTENRN, PTENRM, and PTENRP are arrays of powers of 10 rounded # to nearest, minus, and plus, respectively. The tables include # 10**{1,2,4,8,16,32,64,128,256,512,1024,2048,4096}. No rounding # is required until the power is greater than 27, however, all # tables include the first 5 for ease of indexing. # RTABLE: byte 0,0,0,0 byte 2,3,2,3 byte 2,3,3,2 byte 3,2,2,3 set FNIBS,7 set FSTRT,0 set ESTRT,4 set EDIGITS,2 global decbin decbin: mov.l 0x0(%a0),FP_SCR0_EX(%a6) # make a copy of input mov.l 0x4(%a0),FP_SCR0_HI(%a6) # so we don't alter it mov.l 0x8(%a0),FP_SCR0_LO(%a6) lea FP_SCR0(%a6),%a0 movm.l &0x3c00,-(%sp) # save d2-d5 fmovm.x &0x1,-(%sp) # save fp1 # # Calculate exponent: # 1. Copy bcd value in memory for use as a working copy. # 2. Calculate absolute value of exponent in d1 by mul and add. # 3. Correct for exponent sign. # 4. Subtract 16 to compensate for interpreting the mant as all integer digits. # (i.e., all digits assumed left of the decimal point.) # # Register usage: # # calc_e: # (*) d0: temp digit storage # (*) d1: accumulator for binary exponent # (*) d2: digit count # (*) d3: offset pointer # ( ) d4: first word of bcd # ( ) a0: pointer to working bcd value # ( ) a6: pointer to original bcd value # (*) FP_SCR1: working copy of original bcd value # (*) L_SCR1: copy of original exponent word # calc_e: mov.l &EDIGITS,%d2 # # of nibbles (digits) in fraction part mov.l &ESTRT,%d3 # counter to pick up digits mov.l (%a0),%d4 # get first word of bcd clr.l %d1 # zero d1 for accumulator e_gd: mulu.l &0xa,%d1 # mul partial product by one digit place bfextu %d4{%d3:&4},%d0 # get the digit and zero extend into d0 add.l %d0,%d1 # d1 = d1 + d0 addq.b &4,%d3 # advance d3 to the next digit dbf.w %d2,e_gd # if we have used all 3 digits, exit loop btst &30,%d4 # get SE beq.b e_pos # don't negate if pos neg.l %d1 # negate before subtracting e_pos: sub.l &16,%d1 # sub to compensate for shift of mant bge.b e_save # if still pos, do not neg neg.l %d1 # now negative, make pos and set SE or.l &0x40000000,%d4 # set SE in d4, or.l &0x40000000,(%a0) # and in working bcd e_save: mov.l %d1,-(%sp) # save exp on stack # # # Calculate mantissa: # 1. Calculate absolute value of mantissa in fp0 by mul and add. # 2. Correct for mantissa sign. # (i.e., all digits assumed left of the decimal point.) # # Register usage: # # calc_m: # (*) d0: temp digit storage # (*) d1: lword counter # (*) d2: digit count # (*) d3: offset pointer # ( ) d4: words 2 and 3 of bcd # ( ) a0: pointer to working bcd value # ( ) a6: pointer to original bcd value # (*) fp0: mantissa accumulator # ( ) FP_SCR1: working copy of original bcd value # ( ) L_SCR1: copy of original exponent word # calc_m: mov.l &1,%d1 # word counter, init to 1 fmov.s &0x00000000,%fp0 # accumulator # # # Since the packed number has a long word between the first & second parts, # get the integer digit then skip down & get the rest of the # mantissa. We will unroll the loop once. # bfextu (%a0){&28:&4},%d0 # integer part is ls digit in long word fadd.b %d0,%fp0 # add digit to sum in fp0 # # # Get the rest of the mantissa. # loadlw: mov.l (%a0,%d1.L*4),%d4 # load mantissa lonqword into d4 mov.l &FSTRT,%d3 # counter to pick up digits mov.l &FNIBS,%d2 # reset number of digits per a0 ptr md2b: fmul.s &0x41200000,%fp0 # fp0 = fp0 * 10 bfextu %d4{%d3:&4},%d0 # get the digit and zero extend fadd.b %d0,%fp0 # fp0 = fp0 + digit # # # If all the digits (8) in that long word have been converted (d2=0), # then inc d1 (=2) to point to the next long word and reset d3 to 0 # to initialize the digit offset, and set d2 to 7 for the digit count; # else continue with this long word. # addq.b &4,%d3 # advance d3 to the next digit dbf.w %d2,md2b # check for last digit in this lw nextlw: addq.l &1,%d1 # inc lw pointer in mantissa cmp.l %d1,&2 # test for last lw ble.b loadlw # if not, get last one # # Check the sign of the mant and make the value in fp0 the same sign. # m_sign: btst &31,(%a0) # test sign of the mantissa beq.b ap_st_z # if clear, go to append/strip zeros fneg.x %fp0 # if set, negate fp0 # # Append/strip zeros: # # For adjusted exponents which have an absolute value greater than 27*, # this routine calculates the amount needed to normalize the mantissa # for the adjusted exponent. That number is subtracted from the exp # if the exp was positive, and added if it was negative. The purpose # of this is to reduce the value of the exponent and the possibility # of error in calculation of pwrten. # # 1. Branch on the sign of the adjusted exponent. # 2p.(positive exp) # 2. Check M16 and the digits in lwords 2 and 3 in descending order. # 3. Add one for each zero encountered until a non-zero digit. # 4. Subtract the count from the exp. # 5. Check if the exp has crossed zero in #3 above; make the exp abs # and set SE. # 6. Multiply the mantissa by 10**count. # 2n.(negative exp) # 2. Check the digits in lwords 3 and 2 in descending order. # 3. Add one for each zero encountered until a non-zero digit. # 4. Add the count to the exp. # 5. Check if the exp has crossed zero in #3 above; clear SE. # 6. Divide the mantissa by 10**count. # # *Why 27? If the adjusted exponent is within -28 < expA < 28, than # any adjustment due to append/strip zeros will drive the resultane # exponent towards zero. Since all pwrten constants with a power # of 27 or less are exact, there is no need to use this routine to # attempt to lessen the resultant exponent. # # Register usage: # # ap_st_z: # (*) d0: temp digit storage # (*) d1: zero count # (*) d2: digit count # (*) d3: offset pointer # ( ) d4: first word of bcd # (*) d5: lword counter # ( ) a0: pointer to working bcd value # ( ) FP_SCR1: working copy of original bcd value # ( ) L_SCR1: copy of original exponent word # # # First check the absolute value of the exponent to see if this # routine is necessary. If so, then check the sign of the exponent # and do append (+) or strip (-) zeros accordingly. # This section handles a positive adjusted exponent. # ap_st_z: mov.l (%sp),%d1 # load expA for range test cmp.l %d1,&27 # test is with 27 ble.w pwrten # if abs(expA) <28, skip ap/st zeros btst &30,(%a0) # check sign of exp bne.b ap_st_n # if neg, go to neg side clr.l %d1 # zero count reg mov.l (%a0),%d4 # load lword 1 to d4 bfextu %d4{&28:&4},%d0 # get M16 in d0 bne.b ap_p_fx # if M16 is non-zero, go fix exp addq.l &1,%d1 # inc zero count mov.l &1,%d5 # init lword counter mov.l (%a0,%d5.L*4),%d4 # get lword 2 to d4 bne.b ap_p_cl # if lw 2 is zero, skip it addq.l &8,%d1 # and inc count by 8 addq.l &1,%d5 # inc lword counter mov.l (%a0,%d5.L*4),%d4 # get lword 3 to d4 ap_p_cl: clr.l %d3 # init offset reg mov.l &7,%d2 # init digit counter ap_p_gd: bfextu %d4{%d3:&4},%d0 # get digit bne.b ap_p_fx # if non-zero, go to fix exp addq.l &4,%d3 # point to next digit addq.l &1,%d1 # inc digit counter dbf.w %d2,ap_p_gd # get next digit ap_p_fx: mov.l %d1,%d0 # copy counter to d2 mov.l (%sp),%d1 # get adjusted exp from memory sub.l %d0,%d1 # subtract count from exp bge.b ap_p_fm # if still pos, go to pwrten neg.l %d1 # now its neg; get abs mov.l (%a0),%d4 # load lword 1 to d4 or.l &0x40000000,%d4 # and set SE in d4 or.l &0x40000000,(%a0) # and in memory # # Calculate the mantissa multiplier to compensate for the striping of # zeros from the mantissa. # ap_p_fm: lea.l PTENRN(%pc),%a1 # get address of power-of-ten table clr.l %d3 # init table index fmov.s &0x3f800000,%fp1 # init fp1 to 1 mov.l &3,%d2 # init d2 to count bits in counter ap_p_el: asr.l &1,%d0 # shift lsb into carry bcc.b ap_p_en # if 1, mul fp1 by pwrten factor fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) ap_p_en: add.l &12,%d3 # inc d3 to next rtable entry tst.l %d0 # check if d0 is zero bne.b ap_p_el # if not, get next bit fmul.x %fp1,%fp0 # mul mantissa by 10**(no_bits_shifted) bra.b pwrten # go calc pwrten # # This section handles a negative adjusted exponent. # ap_st_n: clr.l %d1 # clr counter mov.l &2,%d5 # set up d5 to point to lword 3 mov.l (%a0,%d5.L*4),%d4 # get lword 3 bne.b ap_n_cl # if not zero, check digits sub.l &1,%d5 # dec d5 to point to lword 2 addq.l &8,%d1 # inc counter by 8 mov.l (%a0,%d5.L*4),%d4 # get lword 2 ap_n_cl: mov.l &28,%d3 # point to last digit mov.l &7,%d2 # init digit counter ap_n_gd: bfextu %d4{%d3:&4},%d0 # get digit bne.b ap_n_fx # if non-zero, go to exp fix subq.l &4,%d3 # point to previous digit addq.l &1,%d1 # inc digit counter dbf.w %d2,ap_n_gd # get next digit ap_n_fx: mov.l %d1,%d0 # copy counter to d0 mov.l (%sp),%d1 # get adjusted exp from memory sub.l %d0,%d1 # subtract count from exp bgt.b ap_n_fm # if still pos, go fix mantissa neg.l %d1 # take abs of exp and clr SE mov.l (%a0),%d4 # load lword 1 to d4 and.l &0xbfffffff,%d4 # and clr SE in d4 and.l &0xbfffffff,(%a0) # and in memory # # Calculate the mantissa multiplier to compensate for the appending of # zeros to the mantissa. # ap_n_fm: lea.l PTENRN(%pc),%a1 # get address of power-of-ten table clr.l %d3 # init table index fmov.s &0x3f800000,%fp1 # init fp1 to 1 mov.l &3,%d2 # init d2 to count bits in counter ap_n_el: asr.l &1,%d0 # shift lsb into carry bcc.b ap_n_en # if 1, mul fp1 by pwrten factor fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) ap_n_en: add.l &12,%d3 # inc d3 to next rtable entry tst.l %d0 # check if d0 is zero bne.b ap_n_el # if not, get next bit fdiv.x %fp1,%fp0 # div mantissa by 10**(no_bits_shifted) # # # Calculate power-of-ten factor from adjusted and shifted exponent. # # Register usage: # # pwrten: # (*) d0: temp # ( ) d1: exponent # (*) d2: {FPCR[6:5],SM,SE} as index in RTABLE; temp # (*) d3: FPCR work copy # ( ) d4: first word of bcd # (*) a1: RTABLE pointer # calc_p: # (*) d0: temp # ( ) d1: exponent # (*) d3: PWRTxx table index # ( ) a0: pointer to working copy of bcd # (*) a1: PWRTxx pointer # (*) fp1: power-of-ten accumulator # # Pwrten calculates the exponent factor in the selected rounding mode # according to the following table: # # Sign of Mant Sign of Exp Rounding Mode PWRTEN Rounding Mode # # ANY ANY RN RN # # + + RP RP # - + RP RM # + - RP RM # - - RP RP # # + + RM RM # - + RM RP # + - RM RP # - - RM RM # # + + RZ RM # - + RZ RM # + - RZ RP # - - RZ RP # # pwrten: mov.l USER_FPCR(%a6),%d3 # get user's FPCR bfextu %d3{&26:&2},%d2 # isolate rounding mode bits mov.l (%a0),%d4 # reload 1st bcd word to d4 asl.l &2,%d2 # format d2 to be bfextu %d4{&0:&2},%d0 # {FPCR[6],FPCR[5],SM,SE} add.l %d0,%d2 # in d2 as index into RTABLE lea.l RTABLE(%pc),%a1 # load rtable base mov.b (%a1,%d2),%d0 # load new rounding bits from table clr.l %d3 # clear d3 to force no exc and extended bfins %d0,%d3{&26:&2} # stuff new rounding bits in FPCR fmov.l %d3,%fpcr # write new FPCR asr.l &1,%d0 # write correct PTENxx table bcc.b not_rp # to a1 lea.l PTENRP(%pc),%a1 # it is RP bra.b calc_p # go to init section not_rp: asr.l &1,%d0 # keep checking bcc.b not_rm lea.l PTENRM(%pc),%a1 # it is RM bra.b calc_p # go to init section not_rm: lea.l PTENRN(%pc),%a1 # it is RN calc_p: mov.l %d1,%d0 # copy exp to d0;use d0 bpl.b no_neg # if exp is negative, neg.l %d0 # invert it or.l &0x40000000,(%a0) # and set SE bit no_neg: clr.l %d3 # table index fmov.s &0x3f800000,%fp1 # init fp1 to 1 e_loop: asr.l &1,%d0 # shift next bit into carry bcc.b e_next # if zero, skip the mul fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) e_next: add.l &12,%d3 # inc d3 to next rtable entry tst.l %d0 # check if d0 is zero bne.b e_loop # not zero, continue shifting # # # Check the sign of the adjusted exp and make the value in fp0 the # same sign. If the exp was pos then multiply fp1*fp0; # else divide fp0/fp1. # # Register Usage: # norm: # ( ) a0: pointer to working bcd value # (*) fp0: mantissa accumulator # ( ) fp1: scaling factor - 10**(abs(exp)) # pnorm: btst &30,(%a0) # test the sign of the exponent beq.b mul # if clear, go to multiply div: fdiv.x %fp1,%fp0 # exp is negative, so divide mant by exp bra.b end_dec mul: fmul.x %fp1,%fp0 # exp is positive, so multiply by exp # # # Clean up and return with result in fp0. # # If the final mul/div in decbin incurred an inex exception, # it will be inex2, but will be reported as inex1 by get_op. # end_dec: fmov.l %fpsr,%d0 # get status register bclr &inex2_bit+8,%d0 # test for inex2 and clear it beq.b no_exc # skip this if no exc ori.w &inx1a_mask,2+USER_FPSR(%a6) # set INEX1/AINEX no_exc: add.l &0x4,%sp # clear 1 lw param fmovm.x (%sp)+,&0x40 # restore fp1 movm.l (%sp)+,&0x3c # restore d2-d5 fmov.l &0x0,%fpcr fmov.l &0x0,%fpsr rts ######################################################################### # bindec(): Converts an input in extended precision format to bcd format# # # # INPUT *************************************************************** # # a0 = pointer to the input extended precision value in memory. # # the input may be either normalized, unnormalized, or # # denormalized. # # d0 = contains the k-factor sign-extended to 32-bits. # # # # OUTPUT ************************************************************** # # FP_SCR0(a6) = bcd format result on the stack. # # # # ALGORITHM *********************************************************** # # # # A1. Set RM and size ext; Set SIGMA = sign of input. # # The k-factor is saved for use in d7. Clear the # # BINDEC_FLG for separating normalized/denormalized # # input. If input is unnormalized or denormalized, # # normalize it. # # # # A2. Set X = abs(input). # # # # A3. Compute ILOG. # # ILOG is the log base 10 of the input value. It is # # approximated by adding e + 0.f when the original # # value is viewed as 2^^e * 1.f in extended precision. # # This value is stored in d6. # # # # A4. Clr INEX bit. # # The operation in A3 above may have set INEX2. # # # # A5. Set ICTR = 0; # # ICTR is a flag used in A13. It must be set before the # # loop entry A6. # # # # A6. Calculate LEN. # # LEN is the number of digits to be displayed. The # # k-factor can dictate either the total number of digits, # # if it is a positive number, or the number of digits # # after the decimal point which are to be included as # # significant. See the 68882 manual for examples. # # If LEN is computed to be greater than 17, set OPERR in # # USER_FPSR. LEN is stored in d4. # # # # A7. Calculate SCALE. # # SCALE is equal to 10^ISCALE, where ISCALE is the number # # of decimal places needed to insure LEN integer digits # # in the output before conversion to bcd. LAMBDA is the # # sign of ISCALE, used in A9. Fp1 contains # # 10^^(abs(ISCALE)) using a rounding mode which is a # # function of the original rounding mode and the signs # # of ISCALE and X. A table is given in the code. # # # # A8. Clr INEX; Force RZ. # # The operation in A3 above may have set INEX2. # # RZ mode is forced for the scaling operation to insure # # only one rounding error. The grs bits are collected in # # the INEX flag for use in A10. # # # # A9. Scale X -> Y. # # The mantissa is scaled to the desired number of # # significant digits. The excess digits are collected # # in INEX2. # # # # A10. Or in INEX. # # If INEX is set, round error occurred. This is # # compensated for by 'or-ing' in the INEX2 flag to # # the lsb of Y. # # # # A11. Restore original FPCR; set size ext. # # Perform FINT operation in the user's rounding mode. # # Keep the size to extended. # # # # A12. Calculate YINT = FINT(Y) according to user's rounding # # mode. The FPSP routine sintd0 is used. The output # # is in fp0. # # # # A13. Check for LEN digits. # # If the int operation results in more than LEN digits, # # or less than LEN -1 digits, adjust ILOG and repeat from # # A6. This test occurs only on the first pass. If the # # result is exactly 10^LEN, decrement ILOG and divide # # the mantissa by 10. # # # # A14. Convert the mantissa to bcd. # # The binstr routine is used to convert the LEN digit # # mantissa to bcd in memory. The input to binstr is # # to be a fraction; i.e. (mantissa)/10^LEN and adjusted # # such that the decimal point is to the left of bit 63. # # The bcd digits are stored in the correct position in # # the final string area in memory. # # # # A15. Convert the exponent to bcd. # # As in A14 above, the exp is converted to bcd and the # # digits are stored in the final string. # # Test the length of the final exponent string. If the # # length is 4, set operr. # # # # A16. Write sign bits to final string. # # # ######################################################################### set BINDEC_FLG, EXC_TEMP # DENORM flag # Constants in extended precision PLOG2: long 0x3FFD0000,0x9A209A84,0xFBCFF798,0x00000000 PLOG2UP1: long 0x3FFD0000,0x9A209A84,0xFBCFF799,0x00000000 # Constants in single precision FONE: long 0x3F800000,0x00000000,0x00000000,0x00000000 FTWO: long 0x40000000,0x00000000,0x00000000,0x00000000 FTEN: long 0x41200000,0x00000000,0x00000000,0x00000000 F4933: long 0x459A2800,0x00000000,0x00000000,0x00000000 RBDTBL: byte 0,0,0,0 byte 3,3,2,2 byte 3,2,2,3 byte 2,3,3,2 # Implementation Notes: # # The registers are used as follows: # # d0: scratch; LEN input to binstr # d1: scratch # d2: upper 32-bits of mantissa for binstr # d3: scratch;lower 32-bits of mantissa for binstr # d4: LEN # d5: LAMBDA/ICTR # d6: ILOG # d7: k-factor # a0: ptr for original operand/final result # a1: scratch pointer # a2: pointer to FP_X; abs(original value) in ext # fp0: scratch # fp1: scratch # fp2: scratch # F_SCR1: # F_SCR2: # L_SCR1: # L_SCR2: global bindec bindec: movm.l &0x3f20,-(%sp) # {%d2-%d7/%a2} fmovm.x &0x7,-(%sp) # {%fp0-%fp2} # A1. Set RM and size ext. Set SIGMA = sign input; # The k-factor is saved for use in d7. Clear BINDEC_FLG for # separating normalized/denormalized input. If the input # is a denormalized number, set the BINDEC_FLG memory word # to signal denorm. If the input is unnormalized, normalize # the input and test for denormalized result. # fmov.l &rm_mode*0x10,%fpcr # set RM and ext mov.l (%a0),L_SCR2(%a6) # save exponent for sign check mov.l %d0,%d7 # move k-factor to d7 clr.b BINDEC_FLG(%a6) # clr norm/denorm flag cmpi.b STAG(%a6),&DENORM # is input a DENORM? bne.w A2_str # no; input is a NORM # # Normalize the denorm # un_de_norm: mov.w (%a0),%d0 and.w &0x7fff,%d0 # strip sign of normalized exp mov.l 4(%a0),%d1 mov.l 8(%a0),%d2 norm_loop: sub.w &1,%d0 lsl.l &1,%d2 roxl.l &1,%d1 tst.l %d1 bge.b norm_loop # # Test if the normalized input is denormalized # tst.w %d0 bgt.b pos_exp # if greater than zero, it is a norm st BINDEC_FLG(%a6) # set flag for denorm pos_exp: and.w &0x7fff,%d0 # strip sign of normalized exp mov.w %d0,(%a0) mov.l %d1,4(%a0) mov.l %d2,8(%a0) # A2. Set X = abs(input). # A2_str: mov.l (%a0),FP_SCR1(%a6) # move input to work space mov.l 4(%a0),FP_SCR1+4(%a6) # move input to work space mov.l 8(%a0),FP_SCR1+8(%a6) # move input to work space and.l &0x7fffffff,FP_SCR1(%a6) # create abs(X) # A3. Compute ILOG. # ILOG is the log base 10 of the input value. It is approx- # imated by adding e + 0.f when the original value is viewed # as 2^^e * 1.f in extended precision. This value is stored # in d6. # # Register usage: # Input/Output # d0: k-factor/exponent # d2: x/x # d3: x/x # d4: x/x # d5: x/x # d6: x/ILOG # d7: k-factor/Unchanged # a0: ptr for original operand/final result # a1: x/x # a2: x/x # fp0: x/float(ILOG) # fp1: x/x # fp2: x/x # F_SCR1:x/x # F_SCR2:Abs(X)/Abs(X) with $3fff exponent # L_SCR1:x/x # L_SCR2:first word of X packed/Unchanged tst.b BINDEC_FLG(%a6) # check for denorm beq.b A3_cont # if clr, continue with norm mov.l &-4933,%d6 # force ILOG = -4933 bra.b A4_str A3_cont: mov.w FP_SCR1(%a6),%d0 # move exp to d0 mov.w &0x3fff,FP_SCR1(%a6) # replace exponent with 0x3fff fmov.x FP_SCR1(%a6),%fp0 # now fp0 has 1.f sub.w &0x3fff,%d0 # strip off bias fadd.w %d0,%fp0 # add in exp fsub.s FONE(%pc),%fp0 # subtract off 1.0 fbge.w pos_res # if pos, branch fmul.x PLOG2UP1(%pc),%fp0 # if neg, mul by LOG2UP1 fmov.l %fp0,%d6 # put ILOG in d6 as a lword bra.b A4_str # go move out ILOG pos_res: fmul.x PLOG2(%pc),%fp0 # if pos, mul by LOG2 fmov.l %fp0,%d6 # put ILOG in d6 as a lword # A4. Clr INEX bit. # The operation in A3 above may have set INEX2. A4_str: fmov.l &0,%fpsr # zero all of fpsr - nothing needed # A5. Set ICTR = 0; # ICTR is a flag used in A13. It must be set before the # loop entry A6. The lower word of d5 is used for ICTR. clr.w %d5 # clear ICTR # A6. Calculate LEN. # LEN is the number of digits to be displayed. The k-factor # can dictate either the total number of digits, if it is # a positive number, or the number of digits after the # original decimal point which are to be included as # significant. See the 68882 manual for examples. # If LEN is computed to be greater than 17, set OPERR in # USER_FPSR. LEN is stored in d4. # # Register usage: # Input/Output # d0: exponent/Unchanged # d2: x/x/scratch # d3: x/x # d4: exc picture/LEN # d5: ICTR/Unchanged # d6: ILOG/Unchanged # d7: k-factor/Unchanged # a0: ptr for original operand/final result # a1: x/x # a2: x/x # fp0: float(ILOG)/Unchanged # fp1: x/x # fp2: x/x # F_SCR1:x/x # F_SCR2:Abs(X) with $3fff exponent/Unchanged # L_SCR1:x/x # L_SCR2:first word of X packed/Unchanged A6_str: tst.l %d7 # branch on sign of k ble.b k_neg # if k <= 0, LEN = ILOG + 1 - k mov.l %d7,%d4 # if k > 0, LEN = k bra.b len_ck # skip to LEN check k_neg: mov.l %d6,%d4 # first load ILOG to d4 sub.l %d7,%d4 # subtract off k addq.l &1,%d4 # add in the 1 len_ck: tst.l %d4 # LEN check: branch on sign of LEN ble.b LEN_ng # if neg, set LEN = 1 cmp.l %d4,&17 # test if LEN > 17 ble.b A7_str # if not, forget it mov.l &17,%d4 # set max LEN = 17 tst.l %d7 # if negative, never set OPERR ble.b A7_str # if positive, continue or.l &opaop_mask,USER_FPSR(%a6) # set OPERR & AIOP in USER_FPSR bra.b A7_str # finished here LEN_ng: mov.l &1,%d4 # min LEN is 1 # A7. Calculate SCALE. # SCALE is equal to 10^ISCALE, where ISCALE is the number # of decimal places needed to insure LEN integer digits # in the output before conversion to bcd. LAMBDA is the sign # of ISCALE, used in A9. Fp1 contains 10^^(abs(ISCALE)) using # the rounding mode as given in the following table (see # Coonen, p. 7.23 as ref.; however, the SCALE variable is # of opposite sign in bindec.sa from Coonen). # # Initial USE # FPCR[6:5] LAMBDA SIGN(X) FPCR[6:5] # ---------------------------------------------- # RN 00 0 0 00/0 RN # RN 00 0 1 00/0 RN # RN 00 1 0 00/0 RN # RN 00 1 1 00/0 RN # RZ 01 0 0 11/3 RP # RZ 01 0 1 11/3 RP # RZ 01 1 0 10/2 RM # RZ 01 1 1 10/2 RM # RM 10 0 0 11/3 RP # RM 10 0 1 10/2 RM # RM 10 1 0 10/2 RM # RM 10 1 1 11/3 RP # RP 11 0 0 10/2 RM # RP 11 0 1 11/3 RP # RP 11 1 0 11/3 RP # RP 11 1 1 10/2 RM # # Register usage: # Input/Output # d0: exponent/scratch - final is 0 # d2: x/0 or 24 for A9 # d3: x/scratch - offset ptr into PTENRM array # d4: LEN/Unchanged # d5: 0/ICTR:LAMBDA # d6: ILOG/ILOG or k if ((k<=0)&(ILOG 0, skip this cmp.l %d7,%d6 # test k - ILOG blt.b k_pos # if ILOG >= k, skip this mov.l %d7,%d6 # if ((k<0) & (ILOG < k)) ILOG = k k_pos: mov.l %d6,%d0 # calc ILOG + 1 - LEN in d0 addq.l &1,%d0 # add the 1 sub.l %d4,%d0 # sub off LEN swap %d5 # use upper word of d5 for LAMBDA clr.w %d5 # set it zero initially clr.w %d2 # set up d2 for very small case tst.l %d0 # test sign of ISCALE bge.b iscale # if pos, skip next inst addq.w &1,%d5 # if neg, set LAMBDA true cmp.l %d0,&0xffffecd4 # test iscale <= -4908 bgt.b no_inf # if false, skip rest add.l &24,%d0 # add in 24 to iscale mov.l &24,%d2 # put 24 in d2 for A9 no_inf: neg.l %d0 # and take abs of ISCALE iscale: fmov.s FONE(%pc),%fp1 # init fp1 to 1 bfextu USER_FPCR(%a6){&26:&2},%d1 # get initial rmode bits lsl.w &1,%d1 # put them in bits 2:1 add.w %d5,%d1 # add in LAMBDA lsl.w &1,%d1 # put them in bits 3:1 tst.l L_SCR2(%a6) # test sign of original x bge.b x_pos # if pos, don't set bit 0 addq.l &1,%d1 # if neg, set bit 0 x_pos: lea.l RBDTBL(%pc),%a2 # load rbdtbl base mov.b (%a2,%d1),%d3 # load d3 with new rmode lsl.l &4,%d3 # put bits in proper position fmov.l %d3,%fpcr # load bits into fpu lsr.l &4,%d3 # put bits in proper position tst.b %d3 # decode new rmode for pten table bne.b not_rn # if zero, it is RN lea.l PTENRN(%pc),%a1 # load a1 with RN table base bra.b rmode # exit decode not_rn: lsr.b &1,%d3 # get lsb in carry bcc.b not_rp2 # if carry clear, it is RM lea.l PTENRP(%pc),%a1 # load a1 with RP table base bra.b rmode # exit decode not_rp2: lea.l PTENRM(%pc),%a1 # load a1 with RM table base rmode: clr.l %d3 # clr table index e_loop2: lsr.l &1,%d0 # shift next bit into carry bcc.b e_next2 # if zero, skip the mul fmul.x (%a1,%d3),%fp1 # mul by 10**(d3_bit_no) e_next2: add.l &12,%d3 # inc d3 to next pwrten table entry tst.l %d0 # test if ISCALE is zero bne.b e_loop2 # if not, loop # A8. Clr INEX; Force RZ. # The operation in A3 above may have set INEX2. # RZ mode is forced for the scaling operation to insure # only one rounding error. The grs bits are collected in # the INEX flag for use in A10. # # Register usage: # Input/Output fmov.l &0,%fpsr # clr INEX fmov.l &rz_mode*0x10,%fpcr # set RZ rounding mode # A9. Scale X -> Y. # The mantissa is scaled to the desired number of significant # digits. The excess digits are collected in INEX2. If mul, # Check d2 for excess 10 exponential value. If not zero, # the iscale value would have caused the pwrten calculation # to overflow. Only a negative iscale can cause this, so # multiply by 10^(d2), which is now only allowed to be 24, # with a multiply by 10^8 and 10^16, which is exact since # 10^24 is exact. If the input was denormalized, we must # create a busy stack frame with the mul command and the # two operands, and allow the fpu to complete the multiply. # # Register usage: # Input/Output # d0: FPCR with RZ mode/Unchanged # d2: 0 or 24/unchanged # d3: x/x # d4: LEN/Unchanged # d5: ICTR:LAMBDA # d6: ILOG/Unchanged # d7: k-factor/Unchanged # a0: ptr for original operand/final result # a1: ptr to PTENRM array/Unchanged # a2: x/x # fp0: float(ILOG)/X adjusted for SCALE (Y) # fp1: 10^ISCALE/Unchanged # fp2: x/x # F_SCR1:x/x # F_SCR2:Abs(X) with $3fff exponent/Unchanged # L_SCR1:x/x # L_SCR2:first word of X packed/Unchanged A9_str: fmov.x (%a0),%fp0 # load X from memory fabs.x %fp0 # use abs(X) tst.w %d5 # LAMBDA is in lower word of d5 bne.b sc_mul # if neg (LAMBDA = 1), scale by mul fdiv.x %fp1,%fp0 # calculate X / SCALE -> Y to fp0 bra.w A10_st # branch to A10 sc_mul: tst.b BINDEC_FLG(%a6) # check for denorm beq.w A9_norm # if norm, continue with mul # for DENORM, we must calculate: # fp0 = input_op * 10^ISCALE * 10^24 # since the input operand is a DENORM, we can't multiply it directly. # so, we do the multiplication of the exponents and mantissas separately. # in this way, we avoid underflow on intermediate stages of the # multiplication and guarantee a result without exception. fmovm.x &0x2,-(%sp) # save 10^ISCALE to stack mov.w (%sp),%d3 # grab exponent andi.w &0x7fff,%d3 # clear sign ori.w &0x8000,(%a0) # make DENORM exp negative add.w (%a0),%d3 # add DENORM exp to 10^ISCALE exp subi.w &0x3fff,%d3 # subtract BIAS add.w 36(%a1),%d3 subi.w &0x3fff,%d3 # subtract BIAS add.w 48(%a1),%d3 subi.w &0x3fff,%d3 # subtract BIAS bmi.w sc_mul_err # is result is DENORM, punt!!! andi.w &0x8000,(%sp) # keep sign or.w %d3,(%sp) # insert new exponent andi.w &0x7fff,(%a0) # clear sign bit on DENORM again mov.l 0x8(%a0),-(%sp) # put input op mantissa on stk mov.l 0x4(%a0),-(%sp) mov.l &0x3fff0000,-(%sp) # force exp to zero fmovm.x (%sp)+,&0x80 # load normalized DENORM into fp0 fmul.x (%sp)+,%fp0 # fmul.x 36(%a1),%fp0 # multiply fp0 by 10^8 # fmul.x 48(%a1),%fp0 # multiply fp0 by 10^16 mov.l 36+8(%a1),-(%sp) # get 10^8 mantissa mov.l 36+4(%a1),-(%sp) mov.l &0x3fff0000,-(%sp) # force exp to zero mov.l 48+8(%a1),-(%sp) # get 10^16 mantissa mov.l 48+4(%a1),-(%sp) mov.l &0x3fff0000,-(%sp)# force exp to zero fmul.x (%sp)+,%fp0 # multiply fp0 by 10^8 fmul.x (%sp)+,%fp0 # multiply fp0 by 10^16 bra.b A10_st sc_mul_err: bra.b sc_mul_err A9_norm: tst.w %d2 # test for small exp case beq.b A9_con # if zero, continue as normal fmul.x 36(%a1),%fp0 # multiply fp0 by 10^8 fmul.x 48(%a1),%fp0 # multiply fp0 by 10^16 A9_con: fmul.x %fp1,%fp0 # calculate X * SCALE -> Y to fp0 # A10. Or in INEX. # If INEX is set, round error occurred. This is compensated # for by 'or-ing' in the INEX2 flag to the lsb of Y. # # Register usage: # Input/Output # d0: FPCR with RZ mode/FPSR with INEX2 isolated # d2: x/x # d3: x/x # d4: LEN/Unchanged # d5: ICTR:LAMBDA # d6: ILOG/Unchanged # d7: k-factor/Unchanged # a0: ptr for original operand/final result # a1: ptr to PTENxx array/Unchanged # a2: x/ptr to FP_SCR1(a6) # fp0: Y/Y with lsb adjusted # fp1: 10^ISCALE/Unchanged # fp2: x/x A10_st: fmov.l %fpsr,%d0 # get FPSR fmov.x %fp0,FP_SCR1(%a6) # move Y to memory lea.l FP_SCR1(%a6),%a2 # load a2 with ptr to FP_SCR1 btst &9,%d0 # check if INEX2 set beq.b A11_st # if clear, skip rest or.l &1,8(%a2) # or in 1 to lsb of mantissa fmov.x FP_SCR1(%a6),%fp0 # write adjusted Y back to fpu # A11. Restore original FPCR; set size ext. # Perform FINT operation in the user's rounding mode. Keep # the size to extended. The sintdo entry point in the sint # routine expects the FPCR value to be in USER_FPCR for # mode and precision. The original FPCR is saved in L_SCR1. A11_st: mov.l USER_FPCR(%a6),L_SCR1(%a6) # save it for later and.l &0x00000030,USER_FPCR(%a6) # set size to ext, # ;block exceptions # A12. Calculate YINT = FINT(Y) according to user's rounding mode. # The FPSP routine sintd0 is used. The output is in fp0. # # Register usage: # Input/Output # d0: FPSR with AINEX cleared/FPCR with size set to ext # d2: x/x/scratch # d3: x/x # d4: LEN/Unchanged # d5: ICTR:LAMBDA/Unchanged # d6: ILOG/Unchanged # d7: k-factor/Unchanged # a0: ptr for original operand/src ptr for sintdo # a1: ptr to PTENxx array/Unchanged # a2: ptr to FP_SCR1(a6)/Unchanged # a6: temp pointer to FP_SCR1(a6) - orig value saved and restored # fp0: Y/YINT # fp1: 10^ISCALE/Unchanged # fp2: x/x # F_SCR1:x/x # F_SCR2:Y adjusted for inex/Y with original exponent # L_SCR1:x/original USER_FPCR # L_SCR2:first word of X packed/Unchanged A12_st: movm.l &0xc0c0,-(%sp) # save regs used by sintd0 {%d0-%d1/%a0-%a1} mov.l L_SCR1(%a6),-(%sp) mov.l L_SCR2(%a6),-(%sp) lea.l FP_SCR1(%a6),%a0 # a0 is ptr to FP_SCR1(a6) fmov.x %fp0,(%a0) # move Y to memory at FP_SCR1(a6) tst.l L_SCR2(%a6) # test sign of original operand bge.b do_fint12 # if pos, use Y or.l &0x80000000,(%a0) # if neg, use -Y do_fint12: mov.l USER_FPSR(%a6),-(%sp) # bsr sintdo # sint routine returns int in fp0 fmov.l USER_FPCR(%a6),%fpcr fmov.l &0x0,%fpsr # clear the AEXC bits!!! ## mov.l USER_FPCR(%a6),%d0 # ext prec/keep rnd mode ## andi.l &0x00000030,%d0 ## fmov.l %d0,%fpcr fint.x FP_SCR1(%a6),%fp0 # do fint() fmov.l %fpsr,%d0 or.w %d0,FPSR_EXCEPT(%a6) ## fmov.l &0x0,%fpcr ## fmov.l %fpsr,%d0 # don't keep ccodes ## or.w %d0,FPSR_EXCEPT(%a6) mov.b (%sp),USER_FPSR(%a6) add.l &4,%sp mov.l (%sp)+,L_SCR2(%a6) mov.l (%sp)+,L_SCR1(%a6) movm.l (%sp)+,&0x303 # restore regs used by sint {%d0-%d1/%a0-%a1} mov.l L_SCR2(%a6),FP_SCR1(%a6) # restore original exponent mov.l L_SCR1(%a6),USER_FPCR(%a6) # restore user's FPCR # A13. Check for LEN digits. # If the int operation results in more than LEN digits, # or less than LEN -1 digits, adjust ILOG and repeat from # A6. This test occurs only on the first pass. If the # result is exactly 10^LEN, decrement ILOG and divide # the mantissa by 10. The calculation of 10^LEN cannot # be inexact, since all powers of ten up to 10^27 are exact # in extended precision, so the use of a previous power-of-ten # table will introduce no error. # # # Register usage: # Input/Output # d0: FPCR with size set to ext/scratch final = 0 # d2: x/x # d3: x/scratch final = x # d4: LEN/LEN adjusted # d5: ICTR:LAMBDA/LAMBDA:ICTR # d6: ILOG/ILOG adjusted # d7: k-factor/Unchanged # a0: pointer into memory for packed bcd string formation # a1: ptr to PTENxx array/Unchanged # a2: ptr to FP_SCR1(a6)/Unchanged # fp0: int portion of Y/abs(YINT) adjusted # fp1: 10^ISCALE/Unchanged # fp2: x/10^LEN # F_SCR1:x/x # F_SCR2:Y with original exponent/Unchanged # L_SCR1:original USER_FPCR/Unchanged # L_SCR2:first word of X packed/Unchanged A13_st: swap %d5 # put ICTR in lower word of d5 tst.w %d5 # check if ICTR = 0 bne not_zr # if non-zero, go to second test # # Compute 10^(LEN-1) # fmov.s FONE(%pc),%fp2 # init fp2 to 1.0 mov.l %d4,%d0 # put LEN in d0 subq.l &1,%d0 # d0 = LEN -1 clr.l %d3 # clr table index l_loop: lsr.l &1,%d0 # shift next bit into carry bcc.b l_next # if zero, skip the mul fmul.x (%a1,%d3),%fp2 # mul by 10**(d3_bit_no) l_next: add.l &12,%d3 # inc d3 to next pwrten table entry tst.l %d0 # test if LEN is zero bne.b l_loop # if not, loop # # 10^LEN-1 is computed for this test and A14. If the input was # denormalized, check only the case in which YINT > 10^LEN. # tst.b BINDEC_FLG(%a6) # check if input was norm beq.b A13_con # if norm, continue with checking fabs.x %fp0 # take abs of YINT bra test_2 # # Compare abs(YINT) to 10^(LEN-1) and 10^LEN # A13_con: fabs.x %fp0 # take abs of YINT fcmp.x %fp0,%fp2 # compare abs(YINT) with 10^(LEN-1) fbge.w test_2 # if greater, do next test subq.l &1,%d6 # subtract 1 from ILOG mov.w &1,%d5 # set ICTR fmov.l &rm_mode*0x10,%fpcr # set rmode to RM fmul.s FTEN(%pc),%fp2 # compute 10^LEN bra.w A6_str # return to A6 and recompute YINT test_2: fmul.s FTEN(%pc),%fp2 # compute 10^LEN fcmp.x %fp0,%fp2 # compare abs(YINT) with 10^LEN fblt.w A14_st # if less, all is ok, go to A14 fbgt.w fix_ex # if greater, fix and redo fdiv.s FTEN(%pc),%fp0 # if equal, divide by 10 addq.l &1,%d6 # and inc ILOG bra.b A14_st # and continue elsewhere fix_ex: addq.l &1,%d6 # increment ILOG by 1 mov.w &1,%d5 # set ICTR fmov.l &rm_mode*0x10,%fpcr # set rmode to RM bra.w A6_str # return to A6 and recompute YINT # # Since ICTR <> 0, we have already been through one adjustment, # and shouldn't have another; this is to check if abs(YINT) = 10^LEN # 10^LEN is again computed using whatever table is in a1 since the # value calculated cannot be inexact. # not_zr: fmov.s FONE(%pc),%fp2 # init fp2 to 1.0 mov.l %d4,%d0 # put LEN in d0 clr.l %d3 # clr table index z_loop: lsr.l &1,%d0 # shift next bit into carry bcc.b z_next # if zero, skip the mul fmul.x (%a1,%d3),%fp2 # mul by 10**(d3_bit_no) z_next: add.l &12,%d3 # inc d3 to next pwrten table entry tst.l %d0 # test if LEN is zero bne.b z_loop # if not, loop fabs.x %fp0 # get abs(YINT) fcmp.x %fp0,%fp2 # check if abs(YINT) = 10^LEN fbneq.w A14_st # if not, skip this fdiv.s FTEN(%pc),%fp0 # divide abs(YINT) by 10 addq.l &1,%d6 # and inc ILOG by 1 addq.l &1,%d4 # and inc LEN fmul.s FTEN(%pc),%fp2 # if LEN++, the get 10^^LEN # A14. Convert the mantissa to bcd. # The binstr routine is used to convert the LEN digit # mantissa to bcd in memory. The input to binstr is # to be a fraction; i.e. (mantissa)/10^LEN and adjusted # such that the decimal point is to the left of bit 63. # The bcd digits are stored in the correct position in # the final string area in memory. # # # Register usage: # Input/Output # d0: x/LEN call to binstr - final is 0 # d1: x/0 # d2: x/ms 32-bits of mant of abs(YINT) # d3: x/ls 32-bits of mant of abs(YINT) # d4: LEN/Unchanged # d5: ICTR:LAMBDA/LAMBDA:ICTR # d6: ILOG # d7: k-factor/Unchanged # a0: pointer into memory for packed bcd string formation # /ptr to first mantissa byte in result string # a1: ptr to PTENxx array/Unchanged # a2: ptr to FP_SCR1(a6)/Unchanged # fp0: int portion of Y/abs(YINT) adjusted # fp1: 10^ISCALE/Unchanged # fp2: 10^LEN/Unchanged # F_SCR1:x/Work area for final result # F_SCR2:Y with original exponent/Unchanged # L_SCR1:original USER_FPCR/Unchanged # L_SCR2:first word of X packed/Unchanged A14_st: fmov.l &rz_mode*0x10,%fpcr # force rz for conversion fdiv.x %fp2,%fp0 # divide abs(YINT) by 10^LEN lea.l FP_SCR0(%a6),%a0 fmov.x %fp0,(%a0) # move abs(YINT)/10^LEN to memory mov.l 4(%a0),%d2 # move 2nd word of FP_RES to d2 mov.l 8(%a0),%d3 # move 3rd word of FP_RES to d3 clr.l 4(%a0) # zero word 2 of FP_RES clr.l 8(%a0) # zero word 3 of FP_RES mov.l (%a0),%d0 # move exponent to d0 swap %d0 # put exponent in lower word beq.b no_sft # if zero, don't shift sub.l &0x3ffd,%d0 # sub bias less 2 to make fract tst.l %d0 # check if > 1 bgt.b no_sft # if so, don't shift neg.l %d0 # make exp positive m_loop: lsr.l &1,%d2 # shift d2:d3 right, add 0s roxr.l &1,%d3 # the number of places dbf.w %d0,m_loop # given in d0 no_sft: tst.l %d2 # check for mantissa of zero bne.b no_zr # if not, go on tst.l %d3 # continue zero check beq.b zer_m # if zero, go directly to binstr no_zr: clr.l %d1 # put zero in d1 for addx add.l &0x00000080,%d3 # inc at bit 7 addx.l %d1,%d2 # continue inc and.l &0xffffff80,%d3 # strip off lsb not used by 882 zer_m: mov.l %d4,%d0 # put LEN in d0 for binstr call addq.l &3,%a0 # a0 points to M16 byte in result bsr binstr # call binstr to convert mant # A15. Convert the exponent to bcd. # As in A14 above, the exp is converted to bcd and the # digits are stored in the final string. # # Digits are stored in L_SCR1(a6) on return from BINDEC as: # # 32 16 15 0 # ----------------------------------------- # | 0 | e3 | e2 | e1 | e4 | X | X | X | # ----------------------------------------- # # And are moved into their proper places in FP_SCR0. If digit e4 # is non-zero, OPERR is signaled. In all cases, all 4 digits are # written as specified in the 881/882 manual for packed decimal. # # Register usage: # Input/Output # d0: x/LEN call to binstr - final is 0 # d1: x/scratch (0);shift count for final exponent packing # d2: x/ms 32-bits of exp fraction/scratch # d3: x/ls 32-bits of exp fraction # d4: LEN/Unchanged # d5: ICTR:LAMBDA/LAMBDA:ICTR # d6: ILOG # d7: k-factor/Unchanged # a0: ptr to result string/ptr to L_SCR1(a6) # a1: ptr to PTENxx array/Unchanged # a2: ptr to FP_SCR1(a6)/Unchanged # fp0: abs(YINT) adjusted/float(ILOG) # fp1: 10^ISCALE/Unchanged # fp2: 10^LEN/Unchanged # F_SCR1:Work area for final result/BCD result # F_SCR2:Y with original exponent/ILOG/10^4 # L_SCR1:original USER_FPCR/Exponent digits on return from binstr # L_SCR2:first word of X packed/Unchanged A15_st: tst.b BINDEC_FLG(%a6) # check for denorm beq.b not_denorm ftest.x %fp0 # test for zero fbeq.w den_zero # if zero, use k-factor or 4933 fmov.l %d6,%fp0 # float ILOG fabs.x %fp0 # get abs of ILOG bra.b convrt den_zero: tst.l %d7 # check sign of the k-factor blt.b use_ilog # if negative, use ILOG fmov.s F4933(%pc),%fp0 # force exponent to 4933 bra.b convrt # do it use_ilog: fmov.l %d6,%fp0 # float ILOG fabs.x %fp0 # get abs of ILOG bra.b convrt not_denorm: ftest.x %fp0 # test for zero fbneq.w not_zero # if zero, force exponent fmov.s FONE(%pc),%fp0 # force exponent to 1 bra.b convrt # do it not_zero: fmov.l %d6,%fp0 # float ILOG fabs.x %fp0 # get abs of ILOG convrt: fdiv.x 24(%a1),%fp0 # compute ILOG/10^4 fmov.x %fp0,FP_SCR1(%a6) # store fp0 in memory mov.l 4(%a2),%d2 # move word 2 to d2 mov.l 8(%a2),%d3 # move word 3 to d3 mov.w (%a2),%d0 # move exp to d0 beq.b x_loop_fin # if zero, skip the shift sub.w &0x3ffd,%d0 # subtract off bias neg.w %d0 # make exp positive x_loop: lsr.l &1,%d2 # shift d2:d3 right roxr.l &1,%d3 # the number of places dbf.w %d0,x_loop # given in d0 x_loop_fin: clr.l %d1 # put zero in d1 for addx add.l &0x00000080,%d3 # inc at bit 6 addx.l %d1,%d2 # continue inc and.l &0xffffff80,%d3 # strip off lsb not used by 882 mov.l &4,%d0 # put 4 in d0 for binstr call lea.l L_SCR1(%a6),%a0 # a0 is ptr to L_SCR1 for exp digits bsr binstr # call binstr to convert exp mov.l L_SCR1(%a6),%d0 # load L_SCR1 lword to d0 mov.l &12,%d1 # use d1 for shift count lsr.l %d1,%d0 # shift d0 right by 12 bfins %d0,FP_SCR0(%a6){&4:&12} # put e3:e2:e1 in FP_SCR0 lsr.l %d1,%d0 # shift d0 right by 12 bfins %d0,FP_SCR0(%a6){&16:&4} # put e4 in FP_SCR0 tst.b %d0 # check if e4 is zero beq.b A16_st # if zero, skip rest or.l &opaop_mask,USER_FPSR(%a6) # set OPERR & AIOP in USER_FPSR # A16. Write sign bits to final string. # Sigma is bit 31 of initial value; RHO is bit 31 of d6 (ILOG). # # Register usage: # Input/Output # d0: x/scratch - final is x # d2: x/x # d3: x/x # d4: LEN/Unchanged # d5: ICTR:LAMBDA/LAMBDA:ICTR # d6: ILOG/ILOG adjusted # d7: k-factor/Unchanged # a0: ptr to L_SCR1(a6)/Unchanged # a1: ptr to PTENxx array/Unchanged # a2: ptr to FP_SCR1(a6)/Unchanged # fp0: float(ILOG)/Unchanged # fp1: 10^ISCALE/Unchanged # fp2: 10^LEN/Unchanged # F_SCR1:BCD result with correct signs # F_SCR2:ILOG/10^4 # L_SCR1:Exponent digits on return from binstr # L_SCR2:first word of X packed/Unchanged A16_st: clr.l %d0 # clr d0 for collection of signs and.b &0x0f,FP_SCR0(%a6) # clear first nibble of FP_SCR0 tst.l L_SCR2(%a6) # check sign of original mantissa bge.b mant_p # if pos, don't set SM mov.l &2,%d0 # move 2 in to d0 for SM mant_p: tst.l %d6 # check sign of ILOG bge.b wr_sgn # if pos, don't set SE addq.l &1,%d0 # set bit 0 in d0 for SE wr_sgn: bfins %d0,FP_SCR0(%a6){&0:&2} # insert SM and SE into FP_SCR0 # Clean up and restore all registers used. fmov.l &0,%fpsr # clear possible inex2/ainex bits fmovm.x (%sp)+,&0xe0 # {%fp0-%fp2} movm.l (%sp)+,&0x4fc # {%d2-%d7/%a2} rts global PTENRN PTENRN: long 0x40020000,0xA0000000,0x00000000 # 10 ^ 1 long 0x40050000,0xC8000000,0x00000000 # 10 ^ 2 long 0x400C0000,0x9C400000,0x00000000 # 10 ^ 4 long 0x40190000,0xBEBC2000,0x00000000 # 10 ^ 8 long 0x40340000,0x8E1BC9BF,0x04000000 # 10 ^ 16 long 0x40690000,0x9DC5ADA8,0x2B70B59E # 10 ^ 32 long 0x40D30000,0xC2781F49,0xFFCFA6D5 # 10 ^ 64 long 0x41A80000,0x93BA47C9,0x80E98CE0 # 10 ^ 128 long 0x43510000,0xAA7EEBFB,0x9DF9DE8E # 10 ^ 256 long 0x46A30000,0xE319A0AE,0xA60E91C7 # 10 ^ 512 long 0x4D480000,0xC9767586,0x81750C17 # 10 ^ 1024 long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 # 10 ^ 2048 long 0x75250000,0xC4605202,0x8A20979B # 10 ^ 4096 global PTENRP PTENRP: long 0x40020000,0xA0000000,0x00000000 # 10 ^ 1 long 0x40050000,0xC8000000,0x00000000 # 10 ^ 2 long 0x400C0000,0x9C400000,0x00000000 # 10 ^ 4 long 0x40190000,0xBEBC2000,0x00000000 # 10 ^ 8 long 0x40340000,0x8E1BC9BF,0x04000000 # 10 ^ 16 long 0x40690000,0x9DC5ADA8,0x2B70B59E # 10 ^ 32 long 0x40D30000,0xC2781F49,0xFFCFA6D6 # 10 ^ 64 long 0x41A80000,0x93BA47C9,0x80E98CE0 # 10 ^ 128 long 0x43510000,0xAA7EEBFB,0x9DF9DE8E # 10 ^ 256 long 0x46A30000,0xE319A0AE,0xA60E91C7 # 10 ^ 512 long 0x4D480000,0xC9767586,0x81750C18 # 10 ^ 1024 long 0x5A920000,0x9E8B3B5D,0xC53D5DE5 # 10 ^ 2048 long 0x75250000,0xC4605202,0x8A20979B # 10 ^ 4096 global PTENRM PTENRM: long 0x40020000,0xA0000000,0x00000000 # 10 ^ 1 long 0x40050000,0xC8000000,0x00000000 # 10 ^ 2 long 0x400C0000,0x9C400000,0x00000000 # 10 ^ 4 long 0x40190000,0xBEBC2000,0x00000000 # 10 ^ 8 long 0x40340000,0x8E1BC9BF,0x04000000 # 10 ^ 16 long 0x40690000,0x9DC5ADA8,0x2B70B59D # 10 ^ 32 long 0x40D30000,0xC2781F49,0xFFCFA6D5 # 10 ^ 64 long 0x41A80000,0x93BA47C9,0x80E98CDF # 10 ^ 128 long 0x43510000,0xAA7EEBFB,0x9DF9DE8D # 10 ^ 256 long 0x46A30000,0xE319A0AE,0xA60E91C6 # 10 ^ 512 long 0x4D480000,0xC9767586,0x81750C17 # 10 ^ 1024 long 0x5A920000,0x9E8B3B5D,0xC53D5DE4 # 10 ^ 2048 long 0x75250000,0xC4605202,0x8A20979A # 10 ^ 4096 ######################################################################### # binstr(): Converts a 64-bit binary integer to bcd. # # # # INPUT *************************************************************** # # d2:d3 = 64-bit binary integer # # d0 = desired length (LEN) # # a0 = pointer to start in memory for bcd characters # # (This pointer must point to byte 4 of the first # # lword of the packed decimal memory string.) # # # # OUTPUT ************************************************************** # # a0 = pointer to LEN bcd digits representing the 64-bit integer. # # # # ALGORITHM *********************************************************** # # The 64-bit binary is assumed to have a decimal point before # # bit 63. The fraction is multiplied by 10 using a mul by 2 # # shift and a mul by 8 shift. The bits shifted out of the # # msb form a decimal digit. This process is iterated until # # LEN digits are formed. # # # # A1. Init d7 to 1. D7 is the byte digit counter, and if 1, the # # digit formed will be assumed the least significant. This is # # to force the first byte formed to have a 0 in the upper 4 bits. # # # # A2. Beginning of the loop: # # Copy the fraction in d2:d3 to d4:d5. # # # # A3. Multiply the fraction in d2:d3 by 8 using bit-field # # extracts and shifts. The three msbs from d2 will go into d1. # # # # A4. Multiply the fraction in d4:d5 by 2 using shifts. The msb # # will be collected by the carry. # # # # A5. Add using the carry the 64-bit quantities in d2:d3 and d4:d5 # # into d2:d3. D1 will contain the bcd digit formed. # # # # A6. Test d7. If zero, the digit formed is the ms digit. If non- # # zero, it is the ls digit. Put the digit in its place in the # # upper word of d0. If it is the ls digit, write the word # # from d0 to memory. # # # # A7. Decrement d6 (LEN counter) and repeat the loop until zero. # # # ######################################################################### # Implementation Notes: # # The registers are used as follows: # # d0: LEN counter # d1: temp used to form the digit # d2: upper 32-bits of fraction for mul by 8 # d3: lower 32-bits of fraction for mul by 8 # d4: upper 32-bits of fraction for mul by 2 # d5: lower 32-bits of fraction for mul by 2 # d6: temp for bit-field extracts # d7: byte digit formation word;digit count {0,1} # a0: pointer into memory for packed bcd string formation # global binstr binstr: movm.l &0xff00,-(%sp) # {%d0-%d7} # # A1: Init d7 # mov.l &1,%d7 # init d7 for second digit subq.l &1,%d0 # for dbf d0 would have LEN+1 passes # # A2. Copy d2:d3 to d4:d5. Start loop. # loop: mov.l %d2,%d4 # copy the fraction before muls mov.l %d3,%d5 # to d4:d5 # # A3. Multiply d2:d3 by 8; extract msbs into d1. # bfextu %d2{&0:&3},%d1 # copy 3 msbs of d2 into d1 asl.l &3,%d2 # shift d2 left by 3 places bfextu %d3{&0:&3},%d6 # copy 3 msbs of d3 into d6 asl.l &3,%d3 # shift d3 left by 3 places or.l %d6,%d2 # or in msbs from d3 into d2 # # A4. Multiply d4:d5 by 2; add carry out to d1. # asl.l &1,%d5 # mul d5 by 2 roxl.l &1,%d4 # mul d4 by 2 swap %d6 # put 0 in d6 lower word addx.w %d6,%d1 # add in extend from mul by 2 # # A5. Add mul by 8 to mul by 2. D1 contains the digit formed. # add.l %d5,%d3 # add lower 32 bits nop # ERRATA FIX #13 (Rev. 1.2 6/6/90) addx.l %d4,%d2 # add with extend upper 32 bits nop # ERRATA FIX #13 (Rev. 1.2 6/6/90) addx.w %d6,%d1 # add in extend from add to d1 swap %d6 # with d6 = 0; put 0 in upper word # # A6. Test d7 and branch. # tst.w %d7 # if zero, store digit & to loop beq.b first_d # if non-zero, form byte & write sec_d: swap %d7 # bring first digit to word d7b asl.w &4,%d7 # first digit in upper 4 bits d7b add.w %d1,%d7 # add in ls digit to d7b mov.b %d7,(%a0)+ # store d7b byte in memory swap %d7 # put LEN counter in word d7a clr.w %d7 # set d7a to signal no digits done dbf.w %d0,loop # do loop some more! bra.b end_bstr # finished, so exit first_d: swap %d7 # put digit word in d7b mov.w %d1,%d7 # put new digit in d7b swap %d7 # put LEN counter in word d7a addq.w &1,%d7 # set d7a to signal first digit done dbf.w %d0,loop # do loop some more! swap %d7 # put last digit in string lsl.w &4,%d7 # move it to upper 4 bits mov.b %d7,(%a0)+ # store it in memory string # # Clean up and return with result in fp0. # end_bstr: movm.l (%sp)+,&0xff # {%d0-%d7} rts ######################################################################### # XDEF **************************************************************** # # facc_in_b(): dmem_read_byte failed # # facc_in_w(): dmem_read_word failed # # facc_in_l(): dmem_read_long failed # # facc_in_d(): dmem_read of dbl prec failed # # facc_in_x(): dmem_read of ext prec failed # # # # facc_out_b(): dmem_write_byte failed # # facc_out_w(): dmem_write_word failed # # facc_out_l(): dmem_write_long failed # # facc_out_d(): dmem_write of dbl prec failed # # facc_out_x(): dmem_write of ext prec failed # # # # XREF **************************************************************** # # _real_access() - exit through access error handler # # # # INPUT *************************************************************** # # None # # # # OUTPUT ************************************************************** # # None # # # # ALGORITHM *********************************************************** # # Flow jumps here when an FP data fetch call gets an error # # result. This means the operating system wants an access error frame # # made out of the current exception stack frame. # # So, we first call restore() which makes sure that any updated # # -(an)+ register gets returned to its pre-exception value and then # # we change the stack to an access error stack frame. # # # ######################################################################### facc_in_b: movq.l &0x1,%d0 # one byte bsr.w restore # fix An mov.w &0x0121,EXC_VOFF(%a6) # set FSLW bra.w facc_finish facc_in_w: movq.l &0x2,%d0 # two bytes bsr.w restore # fix An mov.w &0x0141,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_in_l: movq.l &0x4,%d0 # four bytes bsr.w restore # fix An mov.w &0x0101,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_in_d: movq.l &0x8,%d0 # eight bytes bsr.w restore # fix An mov.w &0x0161,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_in_x: movq.l &0xc,%d0 # twelve bytes bsr.w restore # fix An mov.w &0x0161,EXC_VOFF(%a6) # set FSLW bra.b facc_finish ################################################################ facc_out_b: movq.l &0x1,%d0 # one byte bsr.w restore # restore An mov.w &0x00a1,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_out_w: movq.l &0x2,%d0 # two bytes bsr.w restore # restore An mov.w &0x00c1,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_out_l: movq.l &0x4,%d0 # four bytes bsr.w restore # restore An mov.w &0x0081,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_out_d: movq.l &0x8,%d0 # eight bytes bsr.w restore # restore An mov.w &0x00e1,EXC_VOFF(%a6) # set FSLW bra.b facc_finish facc_out_x: mov.l &0xc,%d0 # twelve bytes bsr.w restore # restore An mov.w &0x00e1,EXC_VOFF(%a6) # set FSLW # here's where we actually create the access error frame from the # current exception stack frame. facc_finish: mov.l USER_FPIAR(%a6),EXC_PC(%a6) # store current PC fmovm.x EXC_FPREGS(%a6),&0xc0 # restore fp0-fp1 fmovm.l USER_FPCR(%a6),%fpcr,%fpsr,%fpiar # restore ctrl regs movm.l EXC_DREGS(%a6),&0x0303 # restore d0-d1/a0-a1 unlk %a6 mov.l (%sp),-(%sp) # store SR, hi(PC) mov.l 0x8(%sp),0x4(%sp) # store lo(PC) mov.l 0xc(%sp),0x8(%sp) # store EA mov.l &0x00000001,0xc(%sp) # store FSLW mov.w 0x6(%sp),0xc(%sp) # fix FSLW (size) mov.w &0x4008,0x6(%sp) # store voff btst &0x5,(%sp) # supervisor or user mode? beq.b facc_out2 # user bset &0x2,0xd(%sp) # set supervisor TM bit facc_out2: bra.l _real_access ################################################################## # if the effective addressing mode was predecrement or postincrement, # the emulation has already changed its value to the correct post- # instruction value. but since we're exiting to the access error # handler, then AN must be returned to its pre-instruction value. # we do that here. restore: mov.b EXC_OPWORD+0x1(%a6),%d1 andi.b &0x38,%d1 # extract opmode cmpi.b %d1,&0x18 # postinc? beq.w rest_inc cmpi.b %d1,&0x20 # predec? beq.w rest_dec rts rest_inc: mov.b EXC_OPWORD+0x1(%a6),%d1 andi.w &0x0007,%d1 # fetch An mov.w (tbl_rest_inc.b,%pc,%d1.w*2),%d1 jmp (tbl_rest_inc.b,%pc,%d1.w*1) tbl_rest_inc: short ri_a0 - tbl_rest_inc short ri_a1 - tbl_rest_inc short ri_a2 - tbl_rest_inc short ri_a3 - tbl_rest_inc short ri_a4 - tbl_rest_inc short ri_a5 - tbl_rest_inc short ri_a6 - tbl_rest_inc short ri_a7 - tbl_rest_inc ri_a0: sub.l %d0,EXC_DREGS+0x8(%a6) # fix stacked a0 rts ri_a1: sub.l %d0,EXC_DREGS+0xc(%a6) # fix stacked a1 rts ri_a2: sub.l %d0,%a2 # fix a2 rts ri_a3: sub.l %d0,%a3 # fix a3 rts ri_a4: sub.l %d0,%a4 # fix a4 rts ri_a5: sub.l %d0,%a5 # fix a5 rts ri_a6: sub.l %d0,(%a6) # fix stacked a6 rts # if it's a fmove out instruction, we don't have to fix a7 # because we hadn't changed it yet. if it's an opclass two # instruction (data moved in) and the exception was in supervisor # mode, then also also wasn't updated. if it was user mode, then # restore the correct a7 which is in the USP currently. ri_a7: cmpi.b EXC_VOFF(%a6),&0x30 # move in or out? bne.b ri_a7_done # out btst &0x5,EXC_SR(%a6) # user or supervisor? bne.b ri_a7_done # supervisor movc %usp,%a0 # restore USP sub.l %d0,%a0 movc %a0,%usp ri_a7_done: rts # need to invert adjustment value if the was predec rest_dec: neg.l %d0 bra.b rest_inc