109 lines
3.7 KiB
Plaintext
109 lines
3.7 KiB
Plaintext
# modff.m4
|
|
# serial 15
|
|
dnl Copyright (C) 2011-2024 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_FUNC_MODFF],
|
|
[
|
|
m4_divert_text([DEFAULTS], [gl_modff_required=plain])
|
|
AC_REQUIRE([gl_MATH_H_DEFAULTS])
|
|
AC_REQUIRE([gl_FUNC_MODF])
|
|
|
|
dnl Persuade glibc <math.h> to declare modff().
|
|
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
|
|
|
|
dnl Test whether modff() exists. We cannot assume that modff(), if it
|
|
dnl exists, is defined in the same library as modf(). This is not the case
|
|
dnl on FreeBSD, NetBSD, OpenBSD.
|
|
gl_MATHFUNC([modff], [float], [(float, float *)])
|
|
if test $gl_cv_func_modff_no_libm = yes \
|
|
|| test $gl_cv_func_modff_in_libm = yes; then
|
|
:
|
|
m4_ifdef([gl_FUNC_MODFF_IEEE], [
|
|
if test $gl_modff_required = ieee && test $REPLACE_MODFF = 0; then
|
|
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
|
|
AC_CACHE_CHECK([whether modff works according to ISO C 99 with IEC 60559],
|
|
[gl_cv_func_modff_ieee],
|
|
[
|
|
saved_LIBS="$LIBS"
|
|
LIBS="$LIBS $MODFF_LIBM"
|
|
AC_RUN_IFELSE(
|
|
[AC_LANG_SOURCE([[
|
|
#ifndef __NO_MATH_INLINES
|
|
# define __NO_MATH_INLINES 1 /* for glibc */
|
|
#endif
|
|
#include <math.h>
|
|
]gl_FLOAT_MINUS_ZERO_CODE[
|
|
]gl_FLOAT_SIGNBIT_CODE[
|
|
/* Compare two numbers with ==.
|
|
This is a separate function because IRIX 6.5 "cc -O" miscompiles an
|
|
'x == x' test. */
|
|
static int
|
|
numeric_equal (float x, float y)
|
|
{
|
|
return x == y;
|
|
}
|
|
static float dummy (float x, float *iptr) { return 0; }
|
|
float zero;
|
|
float minus_one = - 1.0f;
|
|
int main (int argc, char *argv[])
|
|
{
|
|
float (* volatile my_modff) (float, float *) = argc ? modff : dummy;
|
|
int result = 0;
|
|
float i;
|
|
float f;
|
|
/* Test modff(NaN,...).
|
|
This test fails on NetBSD 5.1, OpenBSD 6.7, Solaris 9, Cygwin. */
|
|
f = my_modff (zero / zero, &i);
|
|
if (numeric_equal (f, f))
|
|
result |= 1;
|
|
/* Test modff(-Inf,...).
|
|
This test fails on IRIX 6.5, OSF/1 5.1, mingw. */
|
|
f = my_modff (minus_one / zero, &i);
|
|
if (!(f == 0.0f) || (signbitf (minus_zerof) && !signbitf (f)))
|
|
result |= 2;
|
|
return result;
|
|
}
|
|
]])],
|
|
[gl_cv_func_modff_ieee=yes],
|
|
[gl_cv_func_modff_ieee=no],
|
|
[case "$host_os" in
|
|
# Guess yes on glibc systems.
|
|
*-gnu* | gnu*) gl_cv_func_modff_ieee="guessing yes" ;;
|
|
# Guess yes on musl systems.
|
|
*-musl* | midipix*) gl_cv_func_modff_ieee="guessing yes" ;;
|
|
# Guess yes on MSVC, no on mingw.
|
|
windows*-msvc*) gl_cv_func_modff_ieee="guessing yes" ;;
|
|
mingw* | windows*) AC_EGREP_CPP([Known], [
|
|
#ifdef _MSC_VER
|
|
Known
|
|
#endif
|
|
],
|
|
[gl_cv_func_modff_ieee="guessing yes"],
|
|
[gl_cv_func_modff_ieee="guessing no"])
|
|
;;
|
|
# If we don't know, obey --enable-cross-guesses.
|
|
*) gl_cv_func_modff_ieee="$gl_cross_guess_normal" ;;
|
|
esac
|
|
])
|
|
LIBS="$saved_LIBS"
|
|
])
|
|
case "$gl_cv_func_modff_ieee" in
|
|
*yes) ;;
|
|
*) REPLACE_MODFF=1 ;;
|
|
esac
|
|
fi
|
|
])
|
|
else
|
|
HAVE_MODFF=0
|
|
fi
|
|
if test $HAVE_MODFF = 0 || test $REPLACE_MODFF = 1; then
|
|
dnl Find libraries needed to link lib/modff.c.
|
|
MODFF_LIBM="$MODF_LIBM"
|
|
fi
|
|
AC_SUBST([MODFF_LIBM])
|
|
])
|