-# truncl.m4 serial 5
-dnl Copyright (C) 2007-2008, 2010 Free Software Foundation, Inc.
+# truncl.m4 serial 11
+dnl Copyright (C) 2007-2008, 2010-2013 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_TRUNCL],
[
+ m4_divert_text([DEFAULTS], [gl_truncl_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
dnl Persuade glibc <math.h> to declare truncl().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
dnl Test whether truncl() is declared.
- AC_CHECK_DECLS([truncl], , , [#include <math.h>])
+ AC_CHECK_DECLS([truncl], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_truncl" = yes; then
dnl Test whether truncl() can be used without libm.
TRUNCL_LIBM=?
*yes) ;;
*) REPLACE_TRUNCL=1 ;;
esac
+ m4_ifdef([gl_FUNC_TRUNCL_IEEE], [
+ if test $gl_truncl_required = ieee && test $REPLACE_TRUNCL = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether truncl works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_truncl_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $TRUNCL_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
+]gl_LONG_DOUBLE_SIGNBIT_CODE[
+static long double dummy (long double f) { return 0; }
+int main (int argc, char *argv[])
+{
+ long double (*my_truncl) (long double) = argc ? truncl : dummy;
+ /* Test whether truncl (-0.3L) is -0.0L. */
+ if (signbitl (minus_zerol) && !signbitl (my_truncl (-0.3L)))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_truncl_ieee=yes],
+ [gl_cv_func_truncl_ieee=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_truncl_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_truncl_ieee="guessing no" ;;
+ esac
+ ])
+ 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])
- TRUNCL_LIBM=
+ dnl Find libraries needed to link lib/truncl.c.
+ if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+ AC_REQUIRE([gl_FUNC_TRUNC])
+ TRUNCL_LIBM="$TRUNC_LIBM"
+ else
+ TRUNCL_LIBM=
+ fi
fi
AC_SUBST([TRUNCL_LIBM])
])