2 dnl Copyright (C) 2010-2012 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_LOGL],
9 AC_REQUIRE([gl_MATH_H_DEFAULTS])
10 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
12 dnl Persuade glibc <math.h> to declare logl().
13 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
16 AC_CACHE_CHECK([whether logl() can be used without linking with libm],
17 [gl_cv_func_logl_no_libm],
21 [[#ifndef __NO_MATH_INLINES
22 # define __NO_MATH_INLINES 1 /* for glibc */
25 long double (*funcptr) (long double) = logl;
27 [[return funcptr (x) > 1
29 [gl_cv_func_logl_no_libm=yes],
30 [gl_cv_func_logl_no_libm=no])
32 if test $gl_cv_func_logl_no_libm = no; then
33 AC_CACHE_CHECK([whether logl() can be used with libm],
34 [gl_cv_func_logl_in_libm],
40 [[#ifndef __NO_MATH_INLINES
41 # define __NO_MATH_INLINES 1 /* for glibc */
44 long double (*funcptr) (long double) = logl;
46 [[return funcptr (x) > 1
48 [gl_cv_func_logl_in_libm=yes],
49 [gl_cv_func_logl_in_libm=no])
52 if test $gl_cv_func_logl_in_libm = yes; then
56 if test $gl_cv_func_logl_no_libm = yes \
57 || test $gl_cv_func_logl_in_libm = yes; then
58 dnl Also check whether it's declared.
59 dnl MacOS X 10.3 has logl() in libc but doesn't declare it in <math.h>.
60 AC_CHECK_DECL([logl], , [HAVE_DECL_LOGL=0], [[#include <math.h>]])
62 LIBS="$LIBS $LOGL_LIBM"
65 case "$gl_cv_func_logl_works" in
73 if test $HAVE_LOGL = 0 || test $REPLACE_LOGL = 1; then
74 dnl Find libraries needed to link lib/logl.c.
75 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
76 AC_REQUIRE([gl_FUNC_LOG])
79 if test $HAVE_LOGL = 0; then
80 AC_REQUIRE([gl_FUNC_FREXPL])
81 AC_REQUIRE([gl_FUNC_ISNANL])
82 AC_REQUIRE([gl_FUNC_FLOORL])
83 dnl Append $FREXPL_LIBM to LOGL_LIBM, avoiding gratuitous duplicates.
84 case " $LOGL_LIBM " in
85 *" $FREXPL_LIBM "*) ;;
86 *) LOGL_LIBM="$LOGL_LIBM $FREXPL_LIBM" ;;
88 dnl Append $ISNANL_LIBM to LOGL_LIBM, avoiding gratuitous duplicates.
89 case " $LOGL_LIBM " in
90 *" $ISNANL_LIBM "*) ;;
91 *) LOGL_LIBM="$LOGL_LIBM $ISNANL_LIBM" ;;
93 dnl Append $FLOORL_LIBM to LOGL_LIBM, avoiding gratuitous duplicates.
94 case " $LOGL_LIBM " in
95 *" $FLOORL_LIBM "*) ;;
96 *) LOGL_LIBM="$LOGL_LIBM $FLOORL_LIBM" ;;
101 AC_SUBST([LOGL_LIBM])
104 dnl Test whether logl() works.
105 dnl On OSF/1 5.1, logl(-0.0L) is NaN.
106 AC_DEFUN([gl_FUNC_LOGL_WORKS],
108 AC_REQUIRE([AC_PROG_CC])
109 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
110 AC_CACHE_CHECK([whether logl works], [gl_cv_func_logl_works],
115 volatile long double x;
126 [gl_cv_func_logl_works=yes],
127 [gl_cv_func_logl_works=no],
129 osf*) gl_cv_func_logl_works="guessing no";;
130 *) gl_cv_func_logl_works="guessing yes";;