-# truncl.m4 serial 5
-dnl Copyright (C) 2007-2008, 2010 Free Software Foundation, Inc.
+# truncl.m4 serial 7
+dnl Copyright (C) 2007-2008, 2010-2011 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_TRUNCL],
[
+ m4_divert_text([DEFAULTS], [gl_truncl_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
dnl Persuade glibc <math.h> to declare truncl().
*yes) ;;
*) REPLACE_TRUNCL=1 ;;
esac
+ m4_ifdef([gl_FUNC_TRUNCL_IEEE], [
+ if test $gl_truncl_required = ieee && test $REPLACE_TRUNCL = 0; then
+ AC_CACHE_CHECK([whether truncl works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_truncl_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $TRUNCL_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
+]gl_LONG_DOUBLE_SIGNBIT_CODE[
+int main()
+{
+ /* Test whether truncl (-0.3L) is -0.0L. */
+ if (signbitl (minus_zerol) && !signbitl (truncl (-0.3L)))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_truncl_ieee=yes],
+ [gl_cv_func_truncl_ieee=no],
+ [gl_cv_func_truncl_ieee="guessing no"])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_truncl_ieee" in
+ *yes) ;;
+ *) REPLACE_TRUNCL=1 ;;
+ esac
+ fi
+ ])
else
HAVE_DECL_TRUNCL=0
fi
if test $HAVE_DECL_TRUNCL = 0 || test $REPLACE_TRUNCL = 1; then
- AC_LIBOBJ([truncl])
+ dnl No libraries are needed to link lib/truncl.c.
TRUNCL_LIBM=
fi
AC_SUBST([TRUNCL_LIBM])