# HG changeset patch # User Bruno Haible # Date 1318888281 -7200 # Node ID b8acd8099b2581e54c0936922f8854d8f6b78a8f # Parent ae7cb951d5b4f3276ef83ebf99525fdc91de4aa4 New module 'fmaf'. * lib/math.in.h (fmaf): New declaration. * lib/fmaf.c: New file. * m4/fmaf.m4: New file. * m4/math_h.m4 (gl_MATH_H): Test whethern fmaf is declared. (gl_MATH_H_DEFAULTS): Initialize GNULIB_FMAF, HAVE_FMAF, REPLACE_FMAF. * modules/math (Makefile.am): Substitute GNULIB_FMAF, HAVE_FMAF, REPLACE_FMAF. * modules/fmaf: New file. * doc/posix-functions/fmaf.texi: Mention the new module and the various bugs. diff --git a/ChangeLog b/ChangeLog --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,17 @@ 2011-11-05 Bruno Haible + New module 'fmaf'. + * lib/math.in.h (fmaf): New declaration. + * lib/fmaf.c: New file. + * m4/fmaf.m4: New file. + * m4/math_h.m4 (gl_MATH_H): Test whethern fmaf is declared. + (gl_MATH_H_DEFAULTS): Initialize GNULIB_FMAF, HAVE_FMAF, REPLACE_FMAF. + * modules/math (Makefile.am): Substitute GNULIB_FMAF, HAVE_FMAF, + REPLACE_FMAF. + * modules/fmaf: New file. + * doc/posix-functions/fmaf.texi: Mention the new module and the various + bugs. + Tests for module 'fma'. * modules/fma-tests: New file. * tests/test-fma1.c: New file. diff --git a/doc/posix-functions/fmaf.texi b/doc/posix-functions/fmaf.texi --- a/doc/posix-functions/fmaf.texi +++ b/doc/posix-functions/fmaf.texi @@ -4,15 +4,18 @@ POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/fmaf.html} -Gnulib module: --- +Gnulib module: fmaf Portability problems fixed by Gnulib: @itemize +@item +This function is missing on some platforms: +FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 4.0, Solaris 9, MSVC 9, Interix 3.5. +@item +This function produces wrong results on some platforms: +glibc 2.11, MacOS X 10.5, FreeBSD 6.4/x86, OSF/1 5.1, Cygwin 1.5, mingw. @end itemize Portability problems not fixed by Gnulib: @itemize -@item -This function is missing on some platforms: -FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 4.0, Solaris 9, MSVC 9, Interix 3.5. @end itemize diff --git a/lib/fmaf.c b/lib/fmaf.c new file mode 100644 --- /dev/null +++ b/lib/fmaf.c @@ -0,0 +1,20 @@ +/* Fused multiply-add. + Copyright (C) 2011 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +/* Written by Bruno Haible , 2011. */ + +#define USE_FLOAT +#include "fma.c" diff --git a/lib/math.in.h b/lib/math.in.h --- a/lib/math.in.h +++ b/lib/math.in.h @@ -507,6 +507,29 @@ #endif +#if @GNULIB_FMAF@ +# if @REPLACE_FMAF@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef fmaf +# define fmaf rpl_fmaf +# endif +_GL_FUNCDECL_RPL (fmaf, float, (float x, float y, float z)); +_GL_CXXALIAS_RPL (fmaf, float, (float x, float y, float z)); +# else +# if !@HAVE_FMAF@ +_GL_FUNCDECL_SYS (fmaf, float, (float x, float y, float z)); +# endif +_GL_CXXALIAS_SYS (fmaf, float, (float x, float y, float z)); +# endif +_GL_CXXALIASWARN (fmaf); +#elif defined GNULIB_POSIXCHECK +# undef fmaf +# if HAVE_RAW_DECL_FMAF +_GL_WARN_ON_USE (fmaf, "fmaf is unportable - " + "use gnulib module fmaf for portability"); +# endif +#endif + #if @GNULIB_FMA@ # if @REPLACE_FMA@ # if !(defined __cplusplus && defined GNULIB_NAMESPACE) diff --git a/m4/fmaf.m4 b/m4/fmaf.m4 new file mode 100644 --- /dev/null +++ b/m4/fmaf.m4 @@ -0,0 +1,167 @@ +# fmaf.m4 serial 1 +dnl Copyright (C) 2011 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_DEFUN([gl_FUNC_FMAF], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + + dnl Determine FMAF_LIBM. + gl_MATHFUNC([fmaf], [float], [(float, float, float)]) + if test $gl_cv_func_fmaf_no_libm = yes \ + || test $gl_cv_func_fmaf_in_libm = yes; then + gl_FUNC_FMAF_WORKS + case "$gl_cv_func_fmaf_works" in + *no) REPLACE_FMAF=1 ;; + esac + else + HAVE_FMAF=0 + fi + if test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1; then + dnl Find libraries needed to link lib/fmaf.c. + AC_REQUIRE([gl_FUNC_FREXPF]) + AC_REQUIRE([gl_FUNC_LDEXPF]) + AC_REQUIRE([gl_FUNC_FEGETROUND]) + FMAF_LIBM= + dnl Append $FREXPF_LIBM to FMAF_LIBM, avoiding gratuitous duplicates. + case " $FMAF_LIBM " in + *" $FREXPF_LIBM "*) ;; + *) FMAF_LIBM="$FMAF_LIBM $FREXPF_LIBM" ;; + esac + dnl Append $LDEXPF_LIBM to FMAF_LIBM, avoiding gratuitous duplicates. + case " $FMAF_LIBM " in + *" $LDEXPF_LIBM "*) ;; + *) FMAF_LIBM="$FMAF_LIBM $LDEXPF_LIBM" ;; + esac + dnl Append $FEGETROUND_LIBM to FMAF_LIBM, avoiding gratuitous duplicates. + case " $FMAF_LIBM " in + *" $FEGETROUND_LIBM "*) ;; + *) FMAF_LIBM="$FMAF_LIBM $FEGETROUND_LIBM" ;; + esac + fi + AC_SUBST([FMAF_LIBM]) +]) + +dnl Test whether fmaf() has any of the 7 known bugs of glibc 2.11.3 on x86_64. +AC_DEFUN([gl_FUNC_FMAF_WORKS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_REQUIRE([gl_FUNC_LDEXPF]) + save_LIBS="$LIBS" + LIBS="$LIBS $FMAF_LIBM $LDEXPF_LIBM" + AC_CACHE_CHECK([whether fmaf works], [gl_cv_func_fmaf_works], + [ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ +#include +#include +float p0 = 0.0f; +int main() +{ + int failed_tests = 0; + /* These tests fail with glibc 2.11.3 on x86_64. */ + { + volatile float x = 1.5f; /* 3 * 2^-1 */ + volatile float y = x; + volatile float z = ldexpf (1.0f, FLT_MANT_DIG + 1); /* 2^25 */ + /* x * y + z with infinite precision: 2^25 + 9 * 2^-2. + Lies between (2^23 + 0) * 2^2 and (2^23 + 1) * 2^2 + and is closer to (2^23 + 1) * 2^2, therefore the rounding + must round up and produce (2^23 + 1) * 2^2. */ + volatile float expected = z + 4.0f; + volatile float result = fmaf (x, y, z); + if (result != expected) + failed_tests |= 1; + } + { + volatile float x = 1.25f; /* 2^0 + 2^-2 */ + volatile float y = - x; + volatile float z = ldexpf (1.0f, FLT_MANT_DIG + 1); /* 2^25 */ + /* x * y + z with infinite precision: 2^25 - 2^0 - 2^-1 - 2^-4. + Lies between (2^24 - 1) * 2^1 and 2^24 * 2^1 + and is closer to (2^24 - 1) * 2^1, therefore the rounding + must round down and produce (2^24 - 1) * 2^1. */ + volatile float expected = (ldexpf (1.0f, FLT_MANT_DIG) - 1.0f) * 2.0f; + volatile float result = fmaf (x, y, z); + if (result != expected) + failed_tests |= 2; + } + { + volatile float x = 1.0f + ldexpf (1.0f, 1 - FLT_MANT_DIG); /* 2^0 + 2^-23 */ + volatile float y = x; + volatile float z = 4.0f; /* 2^2 */ + /* x * y + z with infinite precision: 2^2 + 2^0 + 2^-22 + 2^-46. + Lies between (2^23 + 2^21) * 2^-21 and (2^23 + 2^21 + 1) * 2^-21 + and is closer to (2^23 + 2^21 + 1) * 2^-21, therefore the rounding + must round up and produce (2^23 + 2^21 + 1) * 2^-21. */ + volatile float expected = 4.0f + 1.0f + ldexpf (1.0f, 3 - FLT_MANT_DIG); + volatile float result = fmaf (x, y, z); + if (result != expected) + failed_tests |= 4; + } + { + volatile float x = 1.0f + ldexpf (1.0f, 1 - FLT_MANT_DIG); /* 2^0 + 2^-23 */ + volatile float y = - x; + volatile float z = 8.0f; /* 2^3 */ + /* x * y + z with infinite precision: 2^2 + 2^1 + 2^0 - 2^-22 - 2^-46. + Lies between (2^23 + 2^22 + 2^21 - 1) * 2^-21 and + (2^23 + 2^22 + 2^21) * 2^-21 and is closer to + (2^23 + 2^22 + 2^21 - 1) * 2^-21, therefore the rounding + must round down and produce (2^23 + 2^22 + 2^21 - 1) * 2^-21. */ + volatile float expected = 7.0f - ldexpf (1.0f, 3 - FLT_MANT_DIG); + volatile float result = fmaf (x, y, z); + if (result != expected) + failed_tests |= 8; + } + { + volatile float x = 1.25f; /* 2^0 + 2^-2 */ + volatile float y = - 0.75f; /* - 2^0 + 2^-2 */ + volatile float z = ldexpf (1.0f, FLT_MANT_DIG); /* 2^24 */ + /* x * y + z with infinite precision: 2^24 - 2^0 + 2^-4. + Lies between (2^24 - 2^0) and 2^24 and is closer to (2^24 - 2^0), + therefore the rounding must round down and produce (2^24 - 2^0). */ + volatile float expected = ldexpf (1.0f, FLT_MANT_DIG) - 1.0f; + volatile float result = fmaf (x, y, z); + if (result != expected) + failed_tests |= 16; + } + if ((FLT_MANT_DIG % 2) == 0) + { + volatile float x = 1.0f + ldexpf (1.0f, - FLT_MANT_DIG / 2); /* 2^0 + 2^-12 */ + volatile float y = x; + volatile float z = ldexpf (1.0f, FLT_MIN_EXP - FLT_MANT_DIG); /* 2^-149 */ + /* x * y + z with infinite precision: 2^0 + 2^-11 + 2^-24 + 2^-149. + Lies between (2^23 + 2^12 + 0) * 2^-23 and (2^23 + 2^12 + 1) * 2^-23 + and is closer to (2^23 + 2^12 + 1) * 2^-23, therefore the rounding + must round up and produce (2^23 + 2^12 + 1) * 2^-23. */ + volatile float expected = + 1.0f + ldexpf (1.0f, 1 - FLT_MANT_DIG / 2) + ldexpf (1.0f, 1 - FLT_MANT_DIG); + volatile float result = fmaf (x, y, z); + if (result != expected) + failed_tests |= 32; + } + { + float minus_inf = -1.0f / p0; + volatile float x = ldexpf (1.0f, FLT_MAX_EXP - 1); + volatile float y = ldexpf (1.0f, FLT_MAX_EXP - 1); + volatile float z = minus_inf; + volatile float result = fmaf (x, y, z); + if (!(result == minus_inf)) + failed_tests |= 64; + } + return failed_tests; +}]])], + [gl_cv_func_fmaf_works=yes], + [gl_cv_func_fmaf_works=no], + [dnl Guess no, even on glibc systems. + gl_cv_func_fmaf_works="guessing no" + ]) + ]) + LIBS="$save_LIBS" +]) + +# Prerequisites of lib/fmaf.c. +AC_DEFUN([gl_PREREQ_FMAF], [:]) diff --git a/m4/math_h.m4 b/m4/math_h.m4 --- a/m4/math_h.m4 +++ b/m4/math_h.m4 @@ -1,4 +1,4 @@ -# math_h.m4 serial 54 +# math_h.m4 serial 55 dnl Copyright (C) 2007-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -41,7 +41,7 @@ gl_WARN_ON_USE_PREPARE([[#include ]], [acosf acosl asinf asinl atanf atanl ceilf ceill copysign copysignf copysignl cosf cosl coshf - expf expl fabsf floorf floorl fma fmodf frexpf frexpl + expf expl fabsf floorf floorl fma fmaf fmodf frexpf frexpl ldexpf ldexpl logb logf logl log10f modff powf rint rintf rintl round roundf roundl sinf sinl sinhf sqrtf sqrtl tanf tanl tanhf trunc truncf truncl]) @@ -81,6 +81,7 @@ GNULIB_FLOORF=0; AC_SUBST([GNULIB_FLOORF]) GNULIB_FLOORL=0; AC_SUBST([GNULIB_FLOORL]) GNULIB_FMA=0; AC_SUBST([GNULIB_FMA]) + GNULIB_FMAF=0; AC_SUBST([GNULIB_FMAF]) GNULIB_FMODF=0; AC_SUBST([GNULIB_FMODF]) GNULIB_FREXPF=0; AC_SUBST([GNULIB_FREXPF]) GNULIB_FREXP=0; AC_SUBST([GNULIB_FREXP]) @@ -135,6 +136,7 @@ HAVE_EXPL=1; AC_SUBST([HAVE_EXPL]) HAVE_FABSF=1; AC_SUBST([HAVE_FABSF]) HAVE_FMA=1; AC_SUBST([HAVE_FMA]) + HAVE_FMAF=1; AC_SUBST([HAVE_FMAF]) HAVE_FMODF=1; AC_SUBST([HAVE_FMODF]) HAVE_FREXPF=1; AC_SUBST([HAVE_FREXPF]) HAVE_ISNANF=1; AC_SUBST([HAVE_ISNANF]) @@ -186,6 +188,7 @@ REPLACE_FLOORF=0; AC_SUBST([REPLACE_FLOORF]) REPLACE_FLOORL=0; AC_SUBST([REPLACE_FLOORL]) REPLACE_FMA=0; AC_SUBST([REPLACE_FMA]) + REPLACE_FMAF=0; AC_SUBST([REPLACE_FMAF]) REPLACE_FREXPF=0; AC_SUBST([REPLACE_FREXPF]) REPLACE_FREXP=0; AC_SUBST([REPLACE_FREXP]) REPLACE_FREXPL=0; AC_SUBST([REPLACE_FREXPL]) diff --git a/modules/fmaf b/modules/fmaf new file mode 100644 --- /dev/null +++ b/modules/fmaf @@ -0,0 +1,42 @@ +Description: +fmaf() function: fused multiply-add. + +Files: +lib/fmaf.c +lib/fma.c +lib/float+.h +m4/fmaf.m4 +m4/fegetround.m4 +m4/mathfunc.m4 + +Depends-on: +math +float [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] +stdbool [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] +verify [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] +isfinite [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] +integer_length [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] +frexpf [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] +ldexpf [test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1] + +configure.ac: +gl_FUNC_FMAF +if test $HAVE_FMAF = 0 || test $REPLACE_FMAF = 1; then + AC_LIBOBJ([fmaf]) + gl_PREREQ_FMAF +fi +gl_MATH_MODULE_INDICATOR([fmaf]) + +Makefile.am: + +Include: + + +Link: +$(FMAF_LIBM) + +License: +LGPL + +Maintainer: +Bruno Haible diff --git a/modules/math b/modules/math --- a/modules/math +++ b/modules/math @@ -51,6 +51,7 @@ -e 's/@''GNULIB_FLOORF''@/$(GNULIB_FLOORF)/g' \ -e 's/@''GNULIB_FLOORL''@/$(GNULIB_FLOORL)/g' \ -e 's/@''GNULIB_FMA''@/$(GNULIB_FMA)/g' \ + -e 's/@''GNULIB_FMAF''@/$(GNULIB_FMAF)/g' \ -e 's/@''GNULIB_FMODF''@/$(GNULIB_FMODF)/g' \ -e 's/@''GNULIB_FREXPF''@/$(GNULIB_FREXPF)/g' \ -e 's/@''GNULIB_FREXP''@/$(GNULIB_FREXP)/g' \ @@ -105,6 +106,7 @@ -e 's|@''HAVE_EXPL''@|$(HAVE_EXPL)|g' \ -e 's|@''HAVE_FABSF''@|$(HAVE_FABSF)|g' \ -e 's|@''HAVE_FMA''@|$(HAVE_FMA)|g' \ + -e 's|@''HAVE_FMAF''@|$(HAVE_FMAF)|g' \ -e 's|@''HAVE_FMODF''@|$(HAVE_FMODF)|g' \ -e 's|@''HAVE_FREXPF''@|$(HAVE_FREXPF)|g' \ -e 's|@''HAVE_ISNANF''@|$(HAVE_ISNANF)|g' \ @@ -157,6 +159,7 @@ -e 's|@''REPLACE_FLOORF''@|$(REPLACE_FLOORF)|g' \ -e 's|@''REPLACE_FLOORL''@|$(REPLACE_FLOORL)|g' \ -e 's|@''REPLACE_FMA''@|$(REPLACE_FMA)|g' \ + -e 's|@''REPLACE_FMAF''@|$(REPLACE_FMAF)|g' \ -e 's|@''REPLACE_FREXPF''@|$(REPLACE_FREXPF)|g' \ -e 's|@''REPLACE_FREXP''@|$(REPLACE_FREXP)|g' \ -e 's|@''REPLACE_FREXPL''@|$(REPLACE_FREXPL)|g' \