1 # remainder.m4 serial 9
2 dnl Copyright (C) 2012-2020 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_REMAINDER],
9 m4_divert_text([DEFAULTS], [gl_remainder_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
12 dnl Test whether remainder() is declared. On IRIX 5.3 it is not declared.
13 AC_CHECK_DECL([remainder], , [HAVE_DECL_REMAINDER=0], [[#include <math.h>]])
16 AC_CACHE_CHECK([whether remainder() can be used without linking with libm],
17 [gl_cv_func_remainder_no_libm],
21 [[#ifndef __NO_MATH_INLINES
22 # define __NO_MATH_INLINES 1 /* for glibc */
27 [[return remainder (x, y) > 1;]])],
28 [gl_cv_func_remainder_no_libm=yes],
29 [gl_cv_func_remainder_no_libm=no])
31 if test $gl_cv_func_remainder_no_libm = no; then
32 AC_CACHE_CHECK([whether remainder() can be used with libm],
33 [gl_cv_func_remainder_in_libm],
39 [[#ifndef __NO_MATH_INLINES
40 # define __NO_MATH_INLINES 1 /* for glibc */
45 [[return remainder (x, y) > 1;]])],
46 [gl_cv_func_remainder_in_libm=yes],
47 [gl_cv_func_remainder_in_libm=no])
50 if test $gl_cv_func_remainder_in_libm = yes; then
54 if test $gl_cv_func_remainder_no_libm = yes \
55 || test $gl_cv_func_remainder_in_libm = yes; then
57 m4_ifdef([gl_FUNC_REMAINDER_IEEE], [
58 if test $gl_remainder_required = ieee && test $REPLACE_REMAINDER = 0; then
59 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
60 AC_CACHE_CHECK([whether remainder works according to ISO C 99 with IEC 60559],
61 [gl_cv_func_remainder_ieee],
64 LIBS="$LIBS $REMAINDER_LIBM"
67 #ifndef __NO_MATH_INLINES
68 # define __NO_MATH_INLINES 1 /* for glibc */
71 /* Compare two numbers with ==.
72 This is a separate function because IRIX 6.5 "cc -O" miscompiles an
75 numeric_equal (double x, double y)
79 static double dummy (double x, double y) { return 0; }
80 int main (int argc, char *argv[])
82 double (* volatile my_remainder) (double, double) = argc ? remainder : dummy;
84 /* Test remainder(...,0.0).
85 This test fails on OSF/1 5.1. */
86 f = my_remainder (2.0, 0.0);
87 if (numeric_equal (f, f))
92 [gl_cv_func_remainder_ieee=yes],
93 [gl_cv_func_remainder_ieee=no],
95 # Guess yes on glibc systems.
96 *-gnu* | gnu*) gl_cv_func_remainder_ieee="guessing yes" ;;
97 # Guess yes on musl systems.
98 *-musl*) gl_cv_func_remainder_ieee="guessing yes" ;;
99 # Guess yes on native Windows.
100 mingw*) gl_cv_func_remainder_ieee="guessing yes" ;;
101 # If we don't know, obey --enable-cross-guesses.
102 *) gl_cv_func_remainder_ieee="$gl_cross_guess_normal" ;;
107 case "$gl_cv_func_remainder_ieee" in
109 *) REPLACE_REMAINDER=1 ;;
116 if test $HAVE_REMAINDER = 0 || test $REPLACE_REMAINDER = 1; then
117 dnl Find libraries needed to link lib/remainder.c.
118 AC_REQUIRE([gl_FUNC_FABS])
119 AC_REQUIRE([gl_FUNC_FMOD])
120 AC_REQUIRE([gl_FUNC_ISNAND])
122 dnl Append $FABS_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
123 case " $REMAINDER_LIBM " in
125 *) REMAINDER_LIBM="$REMAINDER_LIBM $FABS_LIBM" ;;
127 dnl Append $FMOD_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
128 case " $REMAINDER_LIBM " in
130 *) REMAINDER_LIBM="$REMAINDER_LIBM $FMOD_LIBM" ;;
132 dnl Append $ISNAND_LIBM to REMAINDER_LIBM, avoiding gratuitous duplicates.
133 case " $REMAINDER_LIBM " in
134 *" $ISNAND_LIBM "*) ;;
135 *) REMAINDER_LIBM="$REMAINDER_LIBM $ISNAND_LIBM" ;;
138 AC_SUBST([REMAINDER_LIBM])