Mercurial > gnulib
view m4/roundf.m4 @ 40177:dcd889592b62
dtoastr,ftoastr,ldtoastr: port to c-strtod changes
Decouple these modules from c-strtod. Nowadays it’s reasonable to
assume the C99 signatures for strtod and strtold. Programs that
require stricter adherence to C99 should also use the strtod and
strtold modules as needed, and we no longer need the
HAVE_C99_STRTOLD macro.
* NEWS: Mention this.
* lib/ftoastr.c (STRTOF) [LENGTH == 3]: Assume strtold.
* m4/c-strtod.m4 (gl_C_STRTOLD): Do not define HAVE_C99_STRTOLD.
* modules/dtoastr, modules/ftoastr, modules/ldtoastr:
(Files): Remove m4/c-strtod.m4.
(configure.ac): Do not require gl_C99_STRTOLD, which no longer
exists.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Sat, 02 Feb 2019 13:01:55 -0800 |
parents | e2e6dc79463b |
children |
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# roundf.m4 serial 21 dnl Copyright (C) 2007-2019 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_ROUNDF], [ m4_divert_text([DEFAULTS], [gl_roundf_required=plain]) AC_REQUIRE([gl_MATH_H_DEFAULTS]) dnl Persuade glibc <math.h> to declare roundf(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = roundf (x);], [extern #ifdef __cplusplus "C" #endif float roundf (float); ]) if test "$ROUNDF_LIBM" != missing; then HAVE_ROUNDF=1 dnl Also check whether it's declared. dnl IRIX 6.5 has roundf() in libm but doesn't declare it in <math.h>. AC_CHECK_DECLS([roundf], , [HAVE_DECL_ROUNDF=0], [[#include <math.h>]]) dnl Test whether roundf() produces correct results. On mingw, for dnl x = 1/2 - 2^-25, the system's roundf() returns a wrong result. AC_REQUIRE([AC_PROG_CC]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether roundf works], [gl_cv_func_roundf_works], [ save_LIBS="$LIBS" LIBS="$LIBS $ROUNDF_LIBM" AC_RUN_IFELSE([AC_LANG_SOURCE([[ #include <float.h> #include <math.h> extern #ifdef __cplusplus "C" #endif float roundf (float); #ifdef _MSC_VER # pragma fenv_access (off) #endif int main() { /* 2^FLT_MANT_DIG. */ static const float TWO_MANT_DIG = /* Assume FLT_MANT_DIG <= 3 * 31. Use the identity n = floor(n/3) + floor((n+1)/3) + floor((n+2)/3). */ (float) (1U << (FLT_MANT_DIG / 3)) * (float) (1U << ((FLT_MANT_DIG + 1) / 3)) * (float) (1U << ((FLT_MANT_DIG + 2) / 3)); volatile float x = 0.5f - 0.5f / TWO_MANT_DIG; return (x < 0.5f && roundf (x) != 0.0f); }]])], [gl_cv_func_roundf_works=yes], [gl_cv_func_roundf_works=no], [case "$host_os" in # Guess yes on MSVC, no on mingw. mingw*) AC_EGREP_CPP([Known], [ #ifdef _MSC_VER Known #endif ], [gl_cv_func_roundf_works="guessing yes"], [gl_cv_func_roundf_works="guessing no"]) ;; *) gl_cv_func_roundf_works="guessing yes" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_roundf_works" in *no) REPLACE_ROUNDF=1 ;; esac m4_ifdef([gl_FUNC_ROUNDF_IEEE], [ if test $gl_roundf_required = ieee && test $REPLACE_ROUNDF = 0; then AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether roundf works according to ISO C 99 with IEC 60559], [gl_cv_func_roundf_ieee], [ save_LIBS="$LIBS" LIBS="$LIBS $ROUNDF_LIBM" AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include <math.h> extern #ifdef __cplusplus "C" #endif float roundf (float); ]gl_FLOAT_MINUS_ZERO_CODE[ ]gl_FLOAT_SIGNBIT_CODE[ static float dummy (float f) { return 0; } int main (int argc, char *argv[]) { float (* volatile my_roundf) (float) = argc ? roundf : dummy; int result = 0; /* Test whether roundf (-0.0f) is -0.0f. */ if (signbitf (minus_zerof) && !signbitf (my_roundf (minus_zerof))) result |= 1; /* Test whether roundf (-0.3f) is -0.0f. */ if (signbitf (-0.3f) && !signbitf (my_roundf (-0.3f))) result |= 2; return result; } ]])], [gl_cv_func_roundf_ieee=yes], [gl_cv_func_roundf_ieee=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_roundf_ieee="guessing yes" ;; # Guess yes on MSVC, no on mingw. mingw*) AC_EGREP_CPP([Known], [ #ifdef _MSC_VER Known #endif ], [gl_cv_func_roundf_ieee="guessing yes"], [gl_cv_func_roundf_ieee="guessing no"]) ;; # If we don't know, assume the worst. *) gl_cv_func_roundf_ieee="guessing no" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_roundf_ieee" in *yes) ;; *) REPLACE_ROUNDF=1 ;; esac fi ]) else HAVE_ROUNDF=0 HAVE_DECL_ROUNDF=0 fi if test $HAVE_ROUNDF = 0 || test $REPLACE_ROUNDF = 1; then dnl Find libraries needed to link lib/roundf.c. AC_CHECK_DECLS([ceilf, floorf], , , [[#include <math.h>]]) if test "$ac_cv_have_decl_floorf" = yes \ && test "$ac_cv_have_decl_ceilf" = yes; then gl_FUNC_FLOORF_LIBS gl_FUNC_CEILF_LIBS if test "$FLOORF_LIBM" != '?' && test "$CEILF_LIBM" != '?'; then AC_DEFINE([HAVE_FLOORF_AND_CEILF], [1], [Define if the both the floorf() and ceilf() functions exist.]) ROUNDF_LIBM= dnl Append $FLOORF_LIBM to ROUNDF_LIBM, avoiding gratuitous duplicates. case " $ROUNDF_LIBM " in *" $FLOORF_LIBM "*) ;; *) ROUNDF_LIBM="$ROUNDF_LIBM $FLOORF_LIBM" ;; esac dnl Append $CEILF_LIBM to ROUNDF_LIBM, avoiding gratuitous duplicates. case " $ROUNDF_LIBM " in *" $CEILF_LIBM "*) ;; *) ROUNDF_LIBM="$ROUNDF_LIBM $CEILF_LIBM" ;; esac else ROUNDF_LIBM= fi else ROUNDF_LIBM= fi fi AC_SUBST([ROUNDF_LIBM]) ])