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# float_h.m4
# serial 15
dnl Copyright (C) 2007, 2009-2025 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.
dnl This file is offered as-is, without any warranty.
AC_DEFUN([gl_FLOAT_H],
[
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST])
GL_GENERATE_FLOAT_H=false
REPLACE_FLOAT_LDBL=0
case "$host_os" in
aix* | beos* | openbsd* | mirbsd* | irix*)
GL_GENERATE_FLOAT_H=true
;;
freebsd* | dragonfly*)
case "$host_cpu" in
changequote(,)dnl
i[34567]86 )
changequote([,])dnl
GL_GENERATE_FLOAT_H=true
;;
x86_64 )
# On x86_64 systems, the C compiler may still be generating
# 32-bit code.
AC_COMPILE_IFELSE(
[AC_LANG_SOURCE(
[[#if defined __LP64__ || defined __x86_64__ || defined __amd64__
int ok;
#else
error fail
#endif
]])],
[],
[GL_GENERATE_FLOAT_H=true])
;;
esac
;;
linux*)
case "$host_cpu" in
powerpc*)
GL_GENERATE_FLOAT_H=true
;;
esac
;;
esac
case "$host_os" in
aix* | freebsd* | dragonfly* | linux*)
if $GL_GENERATE_FLOAT_H; then
REPLACE_FLOAT_LDBL=1
fi
;;
esac
dnl Test for completeness w.r.t. ISO C 23.
REPLACE_FLOAT_SNAN=0
AC_CACHE_CHECK([whether float.h conforms to ISO C23],
[gl_cv_header_float_h_isoc23],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <float.h>
int x[] = { FLT_DECIMAL_DIG, DBL_DECIMAL_DIG, LDBL_DECIMAL_DIG };
float maxf = FLT_NORM_MAX;
double maxd = DBL_NORM_MAX;
long double maxl = LDBL_NORM_MAX;
]],
[[float sf = FLT_SNAN;
double sd = DBL_SNAN;
long double sl = LDBL_SNAN;
return (sf != 0) + (sd != 0) + (sl != 0);
]])],
[gl_cv_header_float_h_isoc23=yes],
[gl_cv_header_float_h_isoc23=no])
])
if test $gl_cv_header_float_h_isoc23 != yes; then
GL_GENERATE_FLOAT_H=true
REPLACE_FLOAT_SNAN=1
fi
dnl Test against glibc-2.7 Linux/SPARC64 bug.
REPLACE_ITOLD=0
AC_CACHE_CHECK([whether conversion from 'int' to 'long double' works],
[gl_cv_func_itold_works],
[
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
int i = -1;
volatile long double ld;
int main ()
{
ld += i * 1.0L;
if (ld > 0)
return 1;
return 0;
}]])],
[gl_cv_func_itold_works=yes],
[gl_cv_func_itold_works=no],
[case "$host" in
sparc*-*-linux*)
AC_COMPILE_IFELSE(
[AC_LANG_SOURCE(
[[#if defined __LP64__ || defined __arch64__
int ok;
#else
error fail
#endif
]])],
[gl_cv_func_itold_works="guessing no"],
[gl_cv_func_itold_works="guessing yes"])
;;
# Guess yes on native Windows.
mingw* | windows*)
gl_cv_func_itold_works="guessing yes" ;;
*)
gl_cv_func_itold_works="guessing yes" ;;
esac
])
])
case "$gl_cv_func_itold_works" in
*no)
REPLACE_ITOLD=1
dnl We add the workaround to <float.h> but also to <math.h>,
dnl to increase the chances that the fix function gets pulled in.
GL_GENERATE_FLOAT_H=true
;;
esac
if $GL_GENERATE_FLOAT_H; then
gl_NEXT_HEADERS([float.h])
fi
AC_SUBST([REPLACE_ITOLD])
])
|
