-# ldexpl.m4 serial 4
-dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
+# ldexpl.m4 serial 15
+dnl Copyright (C) 2007-2012 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_LDEXPL],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+ AC_REQUIRE([gl_FUNC_ISNANL]) dnl for ISNANL_LIBM
+
+ dnl Persuade glibc <math.h> to declare ldexpl().
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+ dnl Check whether it's declared.
+ dnl MacOS X 10.3 has ldexpl() in libc but doesn't declare it in <math.h>.
+ AC_CHECK_DECL([ldexpl], , [HAVE_DECL_LDEXPL=0], [[#include <math.h>]])
+
LDEXPL_LIBM=
+ if test $HAVE_DECL_LDEXPL = 1; then
+ gl_CHECK_LDEXPL_NO_LIBM
+ if test $gl_cv_func_ldexpl_no_libm = no; then
+ AC_CACHE_CHECK([whether ldexpl() can be used with libm],
+ [gl_cv_func_ldexpl_in_libm],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS -lm"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x;]],
+ [[return ldexpl (x, -1) > 0;]])],
+ [gl_cv_func_ldexpl_in_libm=yes],
+ [gl_cv_func_ldexpl_in_libm=no])
+ LIBS="$save_LIBS"
+ ])
+ if test $gl_cv_func_ldexpl_in_libm = yes; then
+ LDEXPL_LIBM=-lm
+ fi
+ fi
+ if test $gl_cv_func_ldexpl_no_libm = yes \
+ || test $gl_cv_func_ldexpl_in_libm = yes; then
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $LDEXPL_LIBM"
+ gl_FUNC_LDEXPL_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_ldexpl_works" in
+ *yes) gl_func_ldexpl=yes ;;
+ *) gl_func_ldexpl=no; REPLACE_LDEXPL=1 ;;
+ esac
+ else
+ gl_func_ldexpl=no
+ fi
+ if test $gl_func_ldexpl = yes; then
+ AC_DEFINE([HAVE_LDEXPL], [1],
+ [Define if the ldexpl() function is available.])
+ fi
+ fi
+ if test $HAVE_DECL_LDEXPL = 0 || test $gl_func_ldexpl = no; then
+ dnl Find libraries needed to link lib/ldexpl.c.
+ if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+ AC_REQUIRE([gl_FUNC_LDEXP])
+ LDEXPL_LIBM="$LDEXP_LIBM"
+ else
+ LDEXPL_LIBM="$ISNANL_LIBM"
+ fi
+ fi
+ AC_SUBST([LDEXPL_LIBM])
+])
+
+dnl Test whether ldexpl() can be used without linking with libm.
+dnl Set gl_cv_func_ldexpl_no_libm to 'yes' or 'no' accordingly.
+AC_DEFUN([gl_CHECK_LDEXPL_NO_LIBM],
+[
AC_CACHE_CHECK([whether ldexpl() can be used without linking with libm],
[gl_cv_func_ldexpl_no_libm],
[
- AC_TRY_LINK([#include <math.h>
- long double x;],
- [return ldexpl (x, -1) > 0;],
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x;]],
+ [[return ldexpl (x, -1) > 0;]])],
[gl_cv_func_ldexpl_no_libm=yes],
[gl_cv_func_ldexpl_no_libm=no])
])
- if test $gl_cv_func_ldexpl_no_libm = no; then
- AC_CACHE_CHECK([whether ldexpl() can be used with libm],
- [gl_cv_func_ldexpl_in_libm],
- [
- save_LIBS="$LIBS"
- LIBS="$LIBS -lm"
- AC_TRY_LINK([#include <math.h>
- long double x;],
- [return ldexpl (x, -1) > 0;],
- [gl_cv_func_ldexpl_in_libm=yes],
- [gl_cv_func_ldexpl_in_libm=no])
- LIBS="$save_LIBS"
- ])
- if test $gl_cv_func_ldexpl_in_libm = yes; then
- LDEXPL_LIBM=-lm
- fi
- fi
- if test $gl_cv_func_ldexpl_no_libm = yes \
- || test $gl_cv_func_ldexpl_in_libm = yes; then
- save_LIBS="$LIBS"
- LIBS="$LIBS $LDEXPL_LIBM"
- gl_FUNC_LDEXPL_WORKS
- LIBS="$save_LIBS"
- case "$gl_cv_func_ldexpl_works" in
- *yes) gl_func_ldexpl=yes ;;
- *) gl_func_ldexpl=no; REPLACE_LDEXPL=1; LDEXPL_LIBM= ;;
- esac
- else
- gl_func_ldexpl=no
- fi
- if test $gl_func_ldexpl = yes; then
- AC_DEFINE([HAVE_LDEXPL], [1],
- [Define if the ldexpl() function is available.])
- dnl Also check whether it's declared.
- dnl MacOS X 10.3 has ldexpl() in libc but doesn't declare it in <math.h>.
- AC_CHECK_DECL([ldexpl], , [HAVE_DECL_LDEXPL=0], [#include <math.h>])
- else
- HAVE_DECL_LDEXPL=0
- AC_LIBOBJ([ldexpl])
- fi
- AC_SUBST([LDEXPL_LIBM])
])
dnl Test whether ldexpl() works on finite numbers (this fails on AIX 5.1
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether ldexpl works], [gl_cv_func_ldexpl_works],
[
- AC_TRY_RUN([
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
#include <math.h>
-extern long double ldexpl (long double, int);
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double ldexpl (long double, int);
int main()
{
- volatile long double x1 = 1.0;
- volatile long double y1 = ldexpl (x1, -1);
- volatile long double x2 = 1.73205L;
- volatile long double y2 = ldexpl (x2, 0);
- return (y1 != 0.5L) || (y2 != x2);
-}], [gl_cv_func_ldexpl_works=yes], [gl_cv_func_ldexpl_works=no],
- [case "$host_os" in
- aix*) gl_cv_func_ldexpl_works="guessing no";;
- *) gl_cv_func_ldexpl_works="guessing yes";;
- esac
- ])
+ int result = 0;
+ {
+ volatile long double x = 1.0;
+ volatile long double y = ldexpl (x, -1);
+ if (y != 0.5L)
+ result |= 1;
+ }
+ {
+ volatile long double x = 1.73205L;
+ volatile long double y = ldexpl (x, 0);
+ if (y != x)
+ result |= 2;
+ }
+ return result;
+}]])],
+ [gl_cv_func_ldexpl_works=yes],
+ [gl_cv_func_ldexpl_works=no],
+ [
+changequote(,)dnl
+ case "$host_os" in
+ aix | aix[3-6]*) gl_cv_func_ldexpl_works="guessing no";;
+ *) gl_cv_func_ldexpl_works="guessing yes";;
+ esac
+changequote([,])dnl
+ ])
])
])
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