newlib-cygwin/newlib/libm/common/s_fma.c

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2009-03-25 Craig Howland <howland@LGSInnovations.com> * libc/include/math.h: (llround, llroundf): Declare. * libm/common/s_llround.c: New file, implementing llround(). * libm/common/sf_llround.c: New file, implementing llroundf(). * libm/common/sf_lround.c: Remove spurious cast in _DOUBLE_IS_32BITS version of function. * libm/common/sf_lrint.c: Ditto. * libm/common/sf_logb.c: Corrected return for subnormal argument by replacing existing function with a version created from sf_ilogb.c. * libm/common/s_logb.c: Ditto, except starting point s_ilogb.c. Also added documentation for logb() and logbf(). * libm/common/s_signbit.c: Add signbit() documentation. * libm/common/s_log2.c: Update return values to match what w_log2.c has, since log2 uses log(); add note about being derived instead of direct. * libm/common/sf_fma.c: Add casts to attempt to get correct results, as well as comments pointing out problems with the implementation. * libm/common/s_fma.c: Add fma() and fmaf() documentation. * libm/common/sf_remquo.c: Incorrect quotient returns for large values corrected by discarding existing function and replacing with Sun verion, with some enhancements. * libm/common/s_remquo.c: Ditto. Add remquo() and remquof() documentation. * libm/common/s_fmax.c: Add fmax() and fmaxf() documentation. * libm/common/s_fmin.c: Add fmin() and fminf() documentation. * libm/common/s_fdim.c: Return NAN for NAN arg, add fdim() and fdimf() documentation. * libm/common/sf_fdim.c: Return NAN for NAN arg, HUGE_VALF for inf arg. * libm/common/s_trunc.c: Add trunc() and truncf() documentation. * libm/common/s_rint.c: Add rint() and rintf() documentation. * libm/common/s_round.c: Add round() and roundf() documentation. * libm/common/s_scalbn.c: Add scalbln() and scalblnf() documentation. * libm/common/s_infinity.c: Add infinity() and infinityf() documentation. * libm/common/s_lround.c: Add lround(), lroundf(), llround(), and llroundf() documentation. * libm/common/s_lrint.c: Add lrint(), lrintf(), llrint(), and llrintf() documentation. * libm/common/isgreater.c: New file for documenting math.h function-like macros isgreater(), isgreaterequal(), isless(), islessequal(), islessgreater(), and isunordered(). * libm/common/s_isnan.c: Add documentation for function-like macros fpclassify(), isfinite(), isinf(), isnan(), and isnormal(). * libm/common/s_nearbyint.c: Add nearbyint() and nearbyintf() documentation. * libm/common/Makefile.am: Add s_llround.c (src); sf_llround.c (fsrc); s_fdim.def, s_fma.def, s_fmax.def, s_fmin.def, s_logb.def, s_lrint.def, s_lround.def, s_nearbyint.def, s_remquo.def, s_rint.def, s_round.def, s_signbit.def, s_trunc.def, and isgreater.def (chobj); re-name all existing chew files (chobj) to match source file base names (put in underscores), delete all special targets for chew files (leaving all to be generated by rule). * libm/common/Makefile.in: regenerate. * libm/math/w_exp2.c: Add "base 2" to documentation description (and delete TRAD_SYNOPSIS). * libm/math/w_gamma.c: Add tgamma() and tgammaf() documentation, along with some history behind the function names. * libm/math/math.tex: Add includes for newly-added documentation (see .def additions to common/Makefile.am and math/Makefile.am in this ChangeLog list), adjusted existing .def file names to match source file base names (added underscores); add mention of HUGE_VALF; rename "Version of library" section to "Error Handling" and add some text about floating-point exception; added section "Standards Compliance And Portability". * libm/math/Makefile.am: Add w_exp2.def (chobj); re-name all existing chew files (chobj) to match source file base names, delete all special targets for chew files (leaving all to be generated by rule). * libm/math/Makefile.in: regenerated * doc/makedoc.c: Change silent ignoring of commands < 5 characters to a failure when reading macro file for commands < 4 characters; add -v (verbose) option for printing some debugging information; get rid of spurious translation of "@*" to "*" (no source files used @*, so no existing doc pages were affected); clean up some compiler warnings. * doc/doc.str: add BUGS and SEEALSO sections (to match texi2pod.pl which has them); Remove ITEM command (redundant with makedoc built-in "o", not used in any present source file so nothing is lost, anyway). * HOWTO: New file to hold information for maintainers regarding how to do things. Initial sections on documentation and ELIX levels.
2009-03-26 03:13:24 +08:00
/*
FUNCTION
<<fma>>, <<fmaf>>--floating multiply add
INDEX
fma
INDEX
fmaf
ANSI_SYNOPSIS
#include <math.h>
double fma(double <[x]>, double <[y]>, double <[z]>);
float fmaf(float <[x]>, float <[y]>, float <[z]>);
DESCRIPTION
The <<fma>> functions compute (<[x]> * <[y]>) + <[z]>, rounded as one ternary
operation: they compute the value (as if) to infinite precision and round once
to the result format, according to the rounding mode characterized by the value
of FLT_ROUNDS. That is, they are supposed to do this: see below.
RETURNS
The <<fma>> functions return (<[x]> * <[y]>) + <[z]>, rounded as one ternary
operation.
BUGS
This implementation does not provide the function that it should, purely
returning "(<[x]> * <[y]>) + <[z]>;" with no attempt at all to provide the
simulated infinite precision intermediates which are required. DO NOT USE THEM.
If double has enough more precision than float, then <<fmaf>> should provide
the expected numeric results, as it does use double for the calculation. But
since this is not the case for all platforms, this manual cannot determine
if it is so for your case.
PORTABILITY
ANSI C, POSIX.
*/
2002-06-08 05:59:57 +08:00
#include "fdlibm.h"
#ifndef _DOUBLE_IS_32BITS
#ifdef __STDC__
double fma(double x, double y, double z)
#else
double fma(x,y)
double x;
double y;
double z;
#endif
{
/* Implementation defined. */
return (x * y) + z;
}
#endif /* _DOUBLE_IS_32BITS */