X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffloor.m4;h=a6e7ec8115d0385ecccf8c40802461b35c318f89;hb=70ab74b3b42a82654b16bc75242bf9b96daa9794;hp=568310785b7ce605d2d7ab37eff45642dec2a31e;hpb=d60f3b0c6b0f93a601acd1cfd3923f94ca05abb0;p=gnulib.git

diff --git a/m4/floor.m4 b/m4/floor.m4
index 568310785..a6e7ec811 100644
--- a/m4/floor.m4
+++ b/m4/floor.m4
@@ -1,5 +1,5 @@
-# floor.m4 serial 5
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# floor.m4 serial 8
+dnl Copyright (C) 2007, 2009-2012 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
@@ -48,7 +57,7 @@ int main()
     fi
   ])
   if test $REPLACE_FLOOR = 1; then
-    AC_LIBOBJ([floor])
+    dnl No libraries are needed to link lib/floor.c.
     FLOOR_LIBM=
   fi
   AC_SUBST([FLOOR_LIBM])