X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=m4%2Fceil.m4;h=c6175610b0089aba838902c88fa086c3a87d41e8;hb=029232c5b2ad6acc689946308c66406f4a912b88;hp=157407745b12524b16e594a24b409450591a52f5;hpb=37567e965cc8cd3c73f22bc21453ce311f78fe72;p=gnulib.git

diff --git a/m4/ceil.m4 b/m4/ceil.m4
index 157407745..c6175610b 100644
--- a/m4/ceil.m4
+++ b/m4/ceil.m4
@@ -1,5 +1,5 @@
-# ceil.m4 serial 6
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# ceil.m4 serial 9
+dnl Copyright (C) 2007, 2009-2013 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.
@@ -15,6 +15,7 @@ AC_DEFUN([gl_FUNC_CEIL],
   fi
   m4_ifdef([gl_FUNC_CEIL_IEEE], [
     if test $gl_ceil_required = ieee && test $REPLACE_CEIL = 0; then
+      AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
       AC_CACHE_CHECK([whether ceil works according to ISO C 99 with IEC 60559],
         [gl_cv_func_ceil_ieee],
         [
@@ -28,17 +29,29 @@ AC_DEFUN([gl_FUNC_CEIL],
 #include <math.h>
 ]gl_DOUBLE_MINUS_ZERO_CODE[
 ]gl_DOUBLE_SIGNBIT_CODE[
-int main()
+static double dummy (double f) { return 0; }
+int main (int argc, char *argv[])
 {
+  double (*my_ceil) (double) = argc ? ceil : dummy;
+  int result = 0;
   /* Test whether ceil (-0.0) is -0.0.  */
-  if (signbitd (minus_zerod) && !signbitd (ceil (minus_zerod)))
-    return 1;
-  return 0;
+  if (signbitd (minus_zerod) && !signbitd (my_ceil (minus_zerod)))
+    result |= 1;
+  /* Test whether ceil (-0.3) is -0.0.  */
+  if (signbitd (-0.3) && !signbitd (my_ceil (-0.3)))
+    result |= 2;
+  return result;
 }
             ]])],
             [gl_cv_func_ceil_ieee=yes],
             [gl_cv_func_ceil_ieee=no],
-            [gl_cv_func_ceil_ieee="guessing no"])
+            [case "$host_os" in
+                       # Guess yes on glibc systems.
+               *-gnu*) gl_cv_func_ceil_ieee="guessing yes" ;;
+                       # If we don't know, assume the worst.
+               *)      gl_cv_func_ceil_ieee="guessing no" ;;
+             esac
+            ])
           LIBS="$save_LIBS"
         ])
       case "$gl_cv_func_ceil_ieee" in