2 dnl Copyright (C) 2007, 2009-2011 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_CEILL],
9 m4_divert_text([DEFAULTS], [gl_ceill_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
13 dnl Persuade glibc <math.h> to declare ceill().
14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
16 dnl Test whether ceill() is declared.
17 AC_CHECK_DECLS([ceill], , , [[#include <math.h>]])
18 if test "$ac_cv_have_decl_ceill" = yes; then
19 dnl Test whether ceill() can be used without libm.
21 if test "$CEILL_LIBM" = "?"; then
22 dnl Sun C 5.0 on Solaris declares ceill() and has it in the system-wide
23 dnl libm.so, but not in the libm.so that the compiler uses.
26 m4_ifdef([gl_FUNC_CEILL_IEEE], [
27 if test $gl_ceill_required = ieee && test $REPLACE_CEILL = 0; then
28 AC_CACHE_CHECK([whether ceill works according to ISO C 99 with IEC 60559],
29 [gl_cv_func_ceill_ieee],
32 LIBS="$LIBS $CEILL_LIBM"
35 #ifndef __NO_MATH_INLINES
36 # define __NO_MATH_INLINES 1 /* for glibc */
39 ]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
40 ]gl_LONG_DOUBLE_SIGNBIT_CODE[
41 static long double dummy (long double f) { return 0; }
42 int main (int argc, char *argv[])
44 long double (*my_ceill) (long double) = argc ? ceill : dummy;
45 /* Test whether ceill (-0.3L) is -0.0L. */
46 if (signbitl (minus_zerol) && !signbitl (my_ceill (-0.3L)))
51 [gl_cv_func_ceill_ieee=yes],
52 [gl_cv_func_ceill_ieee=no],
53 [gl_cv_func_ceill_ieee="guessing no"])
56 case "$gl_cv_func_ceill_ieee" in
65 if test $HAVE_DECL_CEILL = 0 || test $REPLACE_CEILL = 1; then
66 dnl Find libraries needed to link lib/ceill.c.
67 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
68 AC_REQUIRE([gl_FUNC_CEIL])
69 CEILL_LIBM="$CEIL_LIBM"
74 AC_SUBST([CEILL_LIBM])
77 # Determines the libraries needed to get the ceill() function.
79 AC_DEFUN([gl_FUNC_CEILL_LIBS],
81 gl_CACHE_VAL_SILENT([gl_cv_func_ceill_libm], [
82 gl_cv_func_ceill_libm=?
85 [[#ifndef __NO_MATH_INLINES
86 # define __NO_MATH_INLINES 1 /* for glibc */
91 [gl_cv_func_ceill_libm=])
92 if test "$gl_cv_func_ceill_libm" = "?"; then
97 [[#ifndef __NO_MATH_INLINES
98 # define __NO_MATH_INLINES 1 /* for glibc */
103 [gl_cv_func_ceill_libm="-lm"])
107 CEILL_LIBM="$gl_cv_func_ceill_libm"