2 dnl Copyright (C) 2007, 2009-2013 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_FLOOR],
9 m4_divert_text([DEFAULTS], [gl_floor_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 dnl Test whether floor() can be used without libm.
13 if test "$FLOOR_LIBM" = "?"; then
16 m4_ifdef([gl_FUNC_FLOOR_IEEE], [
17 if test $gl_floor_required = ieee && test $REPLACE_FLOOR = 0; then
18 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
19 AC_CACHE_CHECK([whether floor works according to ISO C 99 with IEC 60559],
20 [gl_cv_func_floor_ieee],
23 LIBS="$LIBS $FLOOR_LIBM"
26 #ifndef __NO_MATH_INLINES
27 # define __NO_MATH_INLINES 1 /* for glibc */
30 ]gl_DOUBLE_MINUS_ZERO_CODE[
31 ]gl_DOUBLE_SIGNBIT_CODE[
32 static double dummy (double f) { return 0; }
33 int main (int argc, char *argv[])
35 double (*my_floor) (double) = argc ? floor : dummy;
36 /* Test whether floor (-0.0) is -0.0. */
37 if (signbitd (minus_zerod) && !signbitd (my_floor (minus_zerod)))
42 [gl_cv_func_floor_ieee=yes],
43 [gl_cv_func_floor_ieee=no],
45 # Guess yes on glibc systems.
46 *-gnu*) gl_cv_func_floor_ieee="guessing yes" ;;
47 # If we don't know, assume the worst.
48 *) gl_cv_func_floor_ieee="guessing no" ;;
53 case "$gl_cv_func_floor_ieee" in
59 if test $REPLACE_FLOOR = 1; then
60 dnl No libraries are needed to link lib/floor.c.
63 AC_SUBST([FLOOR_LIBM])
66 # Determines the libraries needed to get the floor() function.
68 AC_DEFUN([gl_FUNC_FLOOR_LIBS],
70 gl_CACHE_VAL_SILENT([gl_cv_func_floor_libm], [
71 gl_cv_func_floor_libm=?
74 [[#ifndef __NO_MATH_INLINES
75 # define __NO_MATH_INLINES 1 /* for glibc */
80 [gl_cv_func_floor_libm=])
81 if test "$gl_cv_func_floor_libm" = "?"; then
86 [[#ifndef __NO_MATH_INLINES
87 # define __NO_MATH_INLINES 1 /* for glibc */
92 [gl_cv_func_floor_libm="-lm"])
96 FLOOR_LIBM="$gl_cv_func_floor_libm"