X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffrexp.m4;h=bb9c4390d9154b5d700e2cdf9ad6387a960a636c;hb=74f73e82d45826c2ba8e533ff3ec75fcf9e17361;hp=530fdbcee55b0b0532440dff39600e9639926c16;hpb=37059fdaaacaaa2e4c03f1768f919186f5f263c4;p=gnulib.git

diff --git a/m4/frexp.m4 b/m4/frexp.m4
index 530fdbcee..bb9c4390d 100644
--- a/m4/frexp.m4
+++ b/m4/frexp.m4
@@ -104,12 +104,24 @@ AC_DEFUN([gl_FUNC_FREXP_WORKS],
 #include <float.h>
 #include <math.h>
 #include <string.h>
+/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
+   ICC 10.0 has a bug when optimizing the expression -zero.
+   The expression -DBL_MIN * DBL_MIN does not work when cross-compiling
+   to PowerPC on MacOS X 10.5.  */
+#if defined __hpux || defined __sgi || defined __ICC
+static double
+compute_minus_zero (void)
+{
+  return -DBL_MIN * DBL_MIN;
+}
+# define minus_zero compute_minus_zero ()
+#else
+double minus_zero = -0.0;
+#endif
 int main()
 {
   int i;
   volatile double x;
-/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
-   So we use -zero instead.  */
   double zero = 0.0;
   /* Test on denormalized numbers.  */
   for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
@@ -132,7 +144,7 @@ int main()
       return 1;
   }
   /* Test on negative zero.  */
-  x = -zero;
+  x = minus_zero;
   {
     int exp;
     double y = frexp (x, &exp);