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-rw-r--r--gnulib-m4/ldexpl.m488
1 files changed, 88 insertions, 0 deletions
diff --git a/gnulib-m4/ldexpl.m4 b/gnulib-m4/ldexpl.m4
new file mode 100644
index 00000000..8ba85c61
--- /dev/null
+++ b/gnulib-m4/ldexpl.m4
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+# ldexpl.m4 serial 4
+dnl Copyright (C) 2007-2009 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])
+ 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;],
+ [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 $gl_func_ldexpl = yes; then
+ AC_DEFINE([HAVE_LDEXPL], [1],
+ [Define if the ldexpl() function is available.])
+ dnl Also check whether it's declared.
+ dnl MacOS X 10.3 has ldexpl() in libc but doesn't declare it in <math.h>.
+ AC_CHECK_DECL([ldexpl], , [HAVE_DECL_LDEXPL=0], [#include <math.h>])
+ else
+ HAVE_DECL_LDEXPL=0
+ AC_LIBOBJ([ldexpl])
+ fi
+ AC_SUBST([LDEXPL_LIBM])
+])
+
+dnl Test whether ldexpl() works on finite numbers (this fails on AIX 5.1
+dnl and MacOS X 10.4/PowerPC).
+AC_DEFUN([gl_FUNC_LDEXPL_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether ldexpl works], [gl_cv_func_ldexpl_works],
+ [
+ AC_TRY_RUN([
+#include <math.h>
+extern long double ldexpl (long double, int);
+int main()
+{
+ volatile long double x1 = 1.0;
+ volatile long double y1 = ldexpl (x1, -1);
+ volatile long double x2 = 1.73205L;
+ volatile long double y2 = ldexpl (x2, 0);
+ return (y1 != 0.5L) || (y2 != x2);
+}], [gl_cv_func_ldexpl_works=yes], [gl_cv_func_ldexpl_works=no],
+ [case "$host_os" in
+ aix*) gl_cv_func_ldexpl_works="guessing no";;
+ *) gl_cv_func_ldexpl_works="guessing yes";;
+ esac
+ ])
+ ])
+])