-# ldexpl.m4 serial 7
-dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
+# ldexpl.m4 serial 16
+dnl Copyright (C) 2007-2013 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>])
+ dnl Mac OS 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 $HAVE_DECL_LDEXPL = 1; then
gl_CHECK_LDEXPL_NO_LIBM
[
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
- AC_TRY_LINK([#include <math.h>
- long double x;],
- [return ldexpl (x, -1) > 0;],
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x;]],
+ [[return ldexpl (x, -1) > 0;]])],
[gl_cv_func_ldexpl_in_libm=yes],
[gl_cv_func_ldexpl_in_libm=no])
LIBS="$save_LIBS"
LIBS="$save_LIBS"
case "$gl_cv_func_ldexpl_works" in
*yes) gl_func_ldexpl=yes ;;
- *) gl_func_ldexpl=no; REPLACE_LDEXPL=1; LDEXPL_LIBM= ;;
+ *) gl_func_ldexpl=no; REPLACE_LDEXPL=1 ;;
esac
else
gl_func_ldexpl=no
fi
fi
if test $HAVE_DECL_LDEXPL = 0 || test $gl_func_ldexpl = no; then
- AC_LIBOBJ([ldexpl])
+ 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="$ISNANL_LIBM"
+ fi
fi
AC_SUBST([LDEXPL_LIBM])
])
AC_CACHE_CHECK([whether ldexpl() can be used without linking with libm],
[gl_cv_func_ldexpl_no_libm],
[
- AC_TRY_LINK([#include <math.h>
- long double x;],
- [return ldexpl (x, -1) > 0;],
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x;]],
+ [[return ldexpl (x, -1) > 0;]])],
[gl_cv_func_ldexpl_no_libm=yes],
[gl_cv_func_ldexpl_no_libm=no])
])
])
dnl Test whether ldexpl() works on finite numbers (this fails on AIX 5.1
-dnl and MacOS X 10.4/PowerPC).
+dnl and Mac OS X 10.4/PowerPC).
AC_DEFUN([gl_FUNC_LDEXPL_WORKS],
[
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether ldexpl works], [gl_cv_func_ldexpl_works],
[
- AC_TRY_RUN([
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
#include <math.h>
-extern long double ldexpl (long double, int);
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double ldexpl (long double, int);
int main()
{
- volatile long double x1 = 1.0;
- volatile long double y1 = ldexpl (x1, -1);
- volatile long double x2 = 1.73205L;
- volatile long double y2 = ldexpl (x2, 0);
- return (y1 != 0.5L) || (y2 != x2);
-}], [gl_cv_func_ldexpl_works=yes], [gl_cv_func_ldexpl_works=no],
- [
+ int result = 0;
+ {
+ volatile long double x = 1.0;
+ volatile long double y = ldexpl (x, -1);
+ if (y != 0.5L)
+ result |= 1;
+ }
+ {
+ volatile long double x = 1.73205L;
+ volatile long double y = ldexpl (x, 0);
+ if (y != x)
+ result |= 2;
+ }
+ return result;
+}]])],
+ [gl_cv_func_ldexpl_works=yes],
+ [gl_cv_func_ldexpl_works=no],
+ [
changequote(,)dnl
- case "$host_os" in
- aix | aix[3-6]*) gl_cv_func_ldexpl_works="guessing no";;
- *) gl_cv_func_ldexpl_works="guessing yes";;
- esac
+ 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
- ])
+ ])
])
])