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Diffstat (limited to 'gnulib/m4/fmaf.m4')
| m--------- | gnulib | 0 | ||||
| -rw-r--r-- | gnulib/m4/fmaf.m4 | 167 |
2 files changed, 167 insertions, 0 deletions
diff --git a/gnulib b/gnulib deleted file mode 160000 -Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1 diff --git a/gnulib/m4/fmaf.m4 b/gnulib/m4/fmaf.m4 new file mode 100644 index 0000000..9d6eb37 --- /dev/null +++ b/gnulib/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 <float.h> +#include <math.h> +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], [:]) |