X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffloor.m4;h=c176a99c5e77fe69735928665ae89ce8c6364ec4;hb=fa1db0dd22768f09a507674a30beb5b8a87bb35f;hp=62d19fed72ebd2d232695e5c31a1fa34d6ea1377;hpb=226af9532797ac05a819785401323f0858286c3f;p=gnulib.git

diff --git a/m4/floor.m4 b/m4/floor.m4
index 62d19fed7..c176a99c5 100644
--- a/m4/floor.m4
+++ b/m4/floor.m4
@@ -1,5 +1,5 @@
-# floor.m4 serial 6
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# floor.m4 serial 8
+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_FLOOR],
   fi
   m4_ifdef([gl_FUNC_FLOOR_IEEE], [
     if test $gl_floor_required = ieee && test $REPLACE_FLOOR = 0; then
+      AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
       AC_CACHE_CHECK([whether floor works according to ISO C 99 with IEC 60559],
         [gl_cv_func_floor_ieee],
         [
@@ -28,17 +29,25 @@ AC_DEFUN([gl_FUNC_FLOOR],
 #include <math.h>
 ]gl_DOUBLE_MINUS_ZERO_CODE[
 ]gl_DOUBLE_SIGNBIT_CODE[
-int main()
+static double dummy (double f) { return 0; }
+int main (int argc, char *argv[])
 {
+  double (*my_floor) (double) = argc ? floor : dummy;
   /* Test whether floor (-0.0) is -0.0.  */
-  if (signbitd (minus_zerod) && !signbitd (floor (minus_zerod)))
+  if (signbitd (minus_zerod) && !signbitd (my_floor (minus_zerod)))
     return 1;
   return 0;
 }
             ]])],
             [gl_cv_func_floor_ieee=yes],
             [gl_cv_func_floor_ieee=no],
-            [gl_cv_func_floor_ieee="guessing no"])
+            [case "$host_os" in
+                       # Guess yes on glibc systems.
+               *-gnu*) gl_cv_func_floor_ieee="guessing yes" ;;
+                       # If we don't know, assume the worst.
+               *)      gl_cv_func_floor_ieee="guessing no" ;;
+             esac
+            ])
           LIBS="$save_LIBS"
         ])
       case "$gl_cv_func_floor_ieee" in