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# floor.m4 serial 8
dnl Copyright (C) 2007, 2009-2017 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_FLOOR],
[
m4_divert_text([DEFAULTS], [gl_floor_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
dnl Test whether floor() can be used without libm.
gl_FUNC_FLOOR_LIBS
if test "$FLOOR_LIBM" = "?"; then
FLOOR_LIBM=
fi
m4_ifdef([gl_FUNC_FLOOR_IEEE], [
if test $gl_floor_required = ieee && test $REPLACE_FLOOR = 0; then
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether floor works according to ISO C 99 with IEC 60559],
[gl_cv_func_floor_ieee],
[
save_LIBS="$LIBS"
LIBS="$LIBS $FLOOR_LIBM"
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
]gl_DOUBLE_MINUS_ZERO_CODE[
]gl_DOUBLE_SIGNBIT_CODE[
static double dummy (double f) { return 0; }
int main (int argc, char *argv[])
{
double (*my_floor) (double) = argc ? floor : dummy;
/* Test whether floor (-0.0) is -0.0. */
if (signbitd (minus_zerod) && !signbitd (my_floor (minus_zerod)))
return 1;
return 0;
}
]])],
[gl_cv_func_floor_ieee=yes],
[gl_cv_func_floor_ieee=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_floor_ieee="guessing yes" ;;
# If we don't know, assume the worst.
*) gl_cv_func_floor_ieee="guessing no" ;;
esac
])
LIBS="$save_LIBS"
])
case "$gl_cv_func_floor_ieee" in
*yes) ;;
*) REPLACE_FLOOR=1 ;;
esac
fi
])
if test $REPLACE_FLOOR = 1; then
dnl No libraries are needed to link lib/floor.c.
FLOOR_LIBM=
fi
AC_SUBST([FLOOR_LIBM])
])
# Determines the libraries needed to get the floor() function.
# Sets FLOOR_LIBM.
AC_DEFUN([gl_FUNC_FLOOR_LIBS],
[
gl_CACHE_VAL_SILENT([gl_cv_func_floor_libm], [
gl_cv_func_floor_libm=?
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
double x;]],
[[x = floor(x);]])],
[gl_cv_func_floor_libm=])
if test "$gl_cv_func_floor_libm" = "?"; then
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
double x;]],
[[x = floor(x);]])],
[gl_cv_func_floor_libm="-lm"])
LIBS="$save_LIBS"
fi
])
FLOOR_LIBM="$gl_cv_func_floor_libm"
])
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