arch/blackfin/lib/muldi3.c

   1 /*
   2  * U-boot - muldi3.c contains routines for mult and div
   3  *
   4  * Copyright (c) 2005-2007 Analog Devices Inc.
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  22  * MA 02110-1301 USA
  23  */
  24
  25 /* Generic function got from GNU gcc package, libgcc2.c */
  26 #ifndef SI_TYPE_SIZE
  27 #define SI_TYPE_SIZE 32
  28 #endif
  29 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
  30 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
  31 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
  32 #define BITS_PER_UNIT 8
  33
  34 #if !defined (umul_ppmm)
  35 #define umul_ppmm(w1, w0, u, v)                                         \
  36 do {                                                                    \
  37         USItype __x0, __x1, __x2, __x3;                                 \
  38         USItype __ul, __vl, __uh, __vh;                                 \
  39                                                                         \
  40         __ul = __ll_lowpart (u);                                        \
  41         __uh = __ll_highpart (u);                                       \
  42         __vl = __ll_lowpart (v);                                        \
  43         __vh = __ll_highpart (v);                                       \
  44                                                                         \
  45         __x0 = (USItype) __ul * __vl;                                   \
  46         __x1 = (USItype) __ul * __vh;                                   \
  47         __x2 = (USItype) __uh * __vl;                                   \
  48         __x3 = (USItype) __uh * __vh;                                   \
  49                                                                         \
  50         __x1 += __ll_highpart (__x0);/* this can't give carry */        \
  51         __x1 += __x2;   /* but this indeed can */                       \
  52         if (__x1 < __x2)        /* did we get it? */                    \
  53                 __x3 += __ll_B; /* yes, add it in the proper pos. */    \
  54                                                                         \
  55         (w1) = __x3 + __ll_highpart (__x1);                             \
  56         (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);      \
  57 } while (0)
  58 #endif
  59
  60 #if !defined (__umulsidi3)
  61 #define __umulsidi3(u, v)                                               \
  62         ({DIunion __w;                                                  \
  63         umul_ppmm (__w.s.high, __w.s.low, u, v);                        \
  64         __w.ll; })
  65 #endif
  66
  67 typedef unsigned int USItype __attribute__ ((mode(SI)));
  68 typedef int SItype __attribute__ ((mode(SI)));
  69 typedef int DItype __attribute__ ((mode(DI)));
  70 typedef int word_type __attribute__ ((mode(__word__)));
  71
  72 struct DIstruct {
  73         SItype low, high;
  74 };
  75 typedef union {
  76         struct DIstruct s;
  77         DItype ll;
  78 } DIunion;
  79
  80 DItype __muldi3(DItype u, DItype v)
  81 {
  82         DIunion w;
  83         DIunion uu, vv;
  84
  85         uu.ll = u, vv.ll = v;
  86         /*  panic("kernel panic for __muldi3"); */
  87         w.ll = __umulsidi3(uu.s.low, vv.s.low);
  88         w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
  89                      + (USItype) uu.s.high * (USItype) vv.s.low);
  90
  91         return w.ll;
  92 }