+++ /dev/null
-<!-- Copyright (C) 2003 Red Hat, Inc. -->
-<!-- This material may be distributed only subject to the terms -->
-<!-- and conditions set forth in the Open Publication License, v1.0 -->
-<!-- or later (the latest version is presently available at -->
-<!-- http://www.opencontent.org/openpub/). -->
-<!-- Distribution of the work or derivative of the work in any -->
-<!-- standard (paper) book form is prohibited unless prior -->
-<!-- permission is obtained from the copyright holder. -->
-<HTML
-><HEAD
-><TITLE
->Math library compatibility modes</TITLE
-><meta name="MSSmartTagsPreventParsing" content="TRUE">
-<META
-NAME="GENERATOR"
-CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
-"><LINK
-REL="HOME"
-TITLE="eCos Reference Manual"
-HREF="ecos-ref.html"><LINK
-REL="UP"
-TITLE="C and math library overview"
-HREF="c-and-math-library-overview.html"><LINK
-REL="PREVIOUS"
-TITLE="C and math library overview"
-HREF="c-and-math-library-overview.html"><LINK
-REL="NEXT"
-TITLE="Some implementation details"
-HREF="libc-implementation-details.html"></HEAD
-><BODY
-CLASS="SECT1"
-BGCOLOR="#FFFFFF"
-TEXT="#000000"
-LINK="#0000FF"
-VLINK="#840084"
-ALINK="#0000FF"
-><DIV
-CLASS="NAVHEADER"
-><TABLE
-SUMMARY="Header navigation table"
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TH
-COLSPAN="3"
-ALIGN="center"
->eCos Reference Manual</TH
-></TR
-><TR
-><TD
-WIDTH="10%"
-ALIGN="left"
-VALIGN="bottom"
-><A
-HREF="c-and-math-library-overview.html"
-ACCESSKEY="P"
->Prev</A
-></TD
-><TD
-WIDTH="80%"
-ALIGN="center"
-VALIGN="bottom"
->Chapter 13. C and math library overview</TD
-><TD
-WIDTH="10%"
-ALIGN="right"
-VALIGN="bottom"
-><A
-HREF="libc-implementation-details.html"
-ACCESSKEY="N"
->Next</A
-></TD
-></TR
-></TABLE
-><HR
-ALIGN="LEFT"
-WIDTH="100%"></DIV
-><DIV
-CLASS="SECT1"
-><H1
-CLASS="SECT1"
-><A
-NAME="MATH-LIBRARY-COMPATIBILITY-MODES">Math library compatibility modes</H1
-><P
->This math library is capable of being operated in several
-different compatibility modes. These options deal solely with how
-errors are handled. </P
-><P
->There are 4 compatibility modes: ANSI/POSIX 1003.1;
-IEEE-754; X/Open Portability Guide issue 3 (XPG3); and
-System V Interface Definition Edition 3. </P
-><P
->In IEEE mode, the <TT
-CLASS="FUNCTION"
->matherr()</TT
-> function
-(see below) is never called, no warning messages are printed on
-the stderr output stream, and errno is never set. </P
-><P
->In ANSI/POSIX mode, errno is set correctly,
-but <TT
-CLASS="FUNCTION"
->matherr()</TT
-> is never called and no warning messages
-are printed on the stderr output stream. </P
-><P
->In X/Open mode, errno is set correctly,
-<TT
-CLASS="FUNCTION"
->matherr()</TT
-> is called, but no warning messages are printed
-on the stderr output stream. </P
-><P
->In SVID mode, functions which overflow return
-a value HUGE (defined in <TT
-CLASS="FILENAME"
->math.h</TT
->), which is the maximum
-single precision floating point value (as opposed to
-HUGE_VAL which is meant to stand for infinity). errno is
-set correctly and <TT
-CLASS="FUNCTION"
->matherr()</TT
-> is called. If
-<TT
-CLASS="FUNCTION"
->matherr()</TT
-> returns 0, warning messages are printed on
-the stderr output stream for some errors. </P
-><P
->The mode can be compiled-in as IEEE-only, or any one of the
-above methods settable at run-time. </P
-><DIV
-CLASS="NOTE"
-><BLOCKQUOTE
-CLASS="NOTE"
-><P
-><B
->Note: </B
->This math library assumes that the hardware (or software floating
-point emulation) supports IEEE-754 style arithmetic, 32-bit 2's
-complement integer arithmetic, doubles are in 64-bit IEEE-754 format.</P
-></BLOCKQUOTE
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="AEN10153">matherr()</H2
-><P
->As mentioned above, in X/Open or SVID modes, the user
- can supply a function <TT
-CLASS="FUNCTION"
->matherr()</TT
-> of
- the form:</P
-><TABLE
-BORDER="5"
-BGCOLOR="#E0E0F0"
-WIDTH="70%"
-><TR
-><TD
-><PRE
-CLASS="PROGRAMLISTING"
->int <TT
-CLASS="FUNCTION"
->matherr</TT
->( struct exception *e )</PRE
-></TD
-></TR
-></TABLE
-><P
->where struct exception is defined as:</P
-><TABLE
-BORDER="5"
-BGCOLOR="#E0E0F0"
-WIDTH="70%"
-><TR
-><TD
-><PRE
-CLASS="PROGRAMLISTING"
->struct exception {
- int type;
- char *name;
- double arg1, arg2, retval;
-}; </PRE
-></TD
-></TR
-></TABLE
-><P
->type is the exception type and is one of:</P
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->DOMAIN</DT
-><DD
-><P
->argument domain exception</P
-></DD
-><DT
->SING</DT
-><DD
-><P
->argument singularity</P
-></DD
-><DT
->OVERFLOW</DT
-><DD
-><P
->overflow range exception</P
-></DD
-><DT
->UNDERFLOW</DT
-><DD
-><P
->underflow range exception</P
-></DD
-><DT
->TLOSS</DT
-><DD
-><P
->total loss of significance</P
-></DD
-><DT
->PLOSS</DT
-><DD
-><P
->partial loss of significance</P
-></DD
-></DL
-></DIV
-><P
-><TT
-CLASS="PARAMETER"
-><I
->name</I
-></TT
-> is a string containing the name of the
-function</P
-><P
-><TT
-CLASS="PARAMETER"
-><I
->arg1</I
-></TT
-> and <TT
-CLASS="PARAMETER"
-><I
->arg2</I
-></TT
-> are the
-arguments passed to the function</P
-><P
-><TT
-CLASS="PARAMETER"
-><I
->retval</I
-></TT
-> is the default value that will be returned
-by the function, and can be changed by <TT
-CLASS="FUNCTION"
->matherr()</TT
-></P
-><DIV
-CLASS="NOTE"
-><BLOCKQUOTE
-CLASS="NOTE"
-><P
-><B
->Note: </B
->matherr must have “C” linkage, not “C++” linkage.</P
-></BLOCKQUOTE
-></DIV
-><P
->If matherr returns zero, or the user doesn't supply
-their own matherr, then the following <SPAN
-CLASS="emphasis"
-><I
-CLASS="EMPHASIS"
->usually</I
-></SPAN
-> happens
-in SVID mode:</P
-><DIV
-CLASS="TABLE"
-><A
-NAME="AEN10199"><P
-><B
->Table 13-1. Behavior of math exception handling</B
-></P
-><TABLE
-BORDER="1"
-CLASS="CALSTABLE"
-><THEAD
-><TR
-><TH
-ALIGN="LEFT"
-VALIGN="TOP"
->Type</TH
-><TH
-ALIGN="LEFT"
-VALIGN="TOP"
->Behavior</TH
-></TR
-></THEAD
-><TBODY
-><TR
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->DOMAIN</TD
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->0.0 returned,
-errno=EDOM, and a message printed on stderr</TD
-></TR
-><TR
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->SING</TD
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->HUGE of appropriate
-sign is returned, errno=EDOM, and a message is printed
-on stderr</TD
-></TR
-><TR
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->OVERFLOW</TD
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->HUGE of
-appropriate sign is returned, and errno=ERANGE</TD
-></TR
-><TR
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->UNDERFLOW</TD
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->0.0 is
-returned and errno=ERANGE</TD
-></TR
-><TR
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->TLOSS</TD
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->0.0 is returned,
-errno=ERANGE, and a message is printed on stderr</TD
-></TR
-><TR
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->PLOSS</TD
-><TD
-ALIGN="LEFT"
-VALIGN="TOP"
->The current
-implementation doesn't return this type</TD
-></TR
-></TBODY
-></TABLE
-></DIV
-><P
->X/Open mode is similar except that the message is
-not printed on stderr and HUGE_VAL is used in place of
-HUGE</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="AEN10226">Thread-safety and re-entrancy</H2
-><P
->With the appropriate configuration options set below, the
-math library is fully thread-safe if:</P
-><P
-></P
-><UL
-><LI
-><P
->Depending on the compatibility mode, the
- setting of the errno variable from the C library is
- thread-safe</P
-></LI
-><LI
-><P
->Depending on the compatibility mode, sending error messages
-to the stderr output stream using the C library
-<TT
-CLASS="FUNCTION"
->fputs()</TT
->
- function is thread-safe </P
-></LI
-><LI
-><P
->Depending on the compatibility mode, the user-supplied
-<TT
-CLASS="FUNCTION"
->matherr()</TT
->
- function and anything it depends on are thread-safe </P
-></LI
-></UL
-><P
->In addition, with the exception of the <TT
-CLASS="FUNCTION"
->gamma*()</TT
-> and <TT
-CLASS="FUNCTION"
->lgamma*()</TT
-> functions,
-the math library is reentrant (and thus safe to use from interrupt handlers)
-if the Math library is always in IEEE mode.</P
-></DIV
-></DIV
-><DIV
-CLASS="NAVFOOTER"
-><HR
-ALIGN="LEFT"
-WIDTH="100%"><TABLE
-SUMMARY="Footer navigation table"
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
-><A
-HREF="c-and-math-library-overview.html"
-ACCESSKEY="P"
->Prev</A
-></TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-><A
-HREF="ecos-ref.html"
-ACCESSKEY="H"
->Home</A
-></TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
-><A
-HREF="libc-implementation-details.html"
-ACCESSKEY="N"
->Next</A
-></TD
-></TR
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
->C and math library overview</TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-><A
-HREF="c-and-math-library-overview.html"
-ACCESSKEY="U"
->Up</A
-></TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
->Some implementation details</TD
-></TR
-></TABLE
-></DIV
-></BODY
-></HTML
->
\ No newline at end of file
projects / karo-tx-redboot.git / blobdiff