X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fisnanl.m4;h=25daecaedc3c24c0d4347a213b31dedd12aed0be;hb=c861b874f3926ab75f12d66ea194a60775b83fc9;hp=fb63ac45511d55f6f155eb5d099129182cd78a22;hpb=98f80c292346b7d5fb8f92ff7bac252a6ac3800c;p=gnulib.git

diff --git a/m4/isnanl.m4 b/m4/isnanl.m4
index fb63ac455..25daecaed 100644
--- a/m4/isnanl.m4
+++ b/m4/isnanl.m4
@@ -1,5 +1,5 @@
-# isnanl.m4 serial 11
-dnl Copyright (C) 2007-2009 Free Software Foundation, Inc.
+# isnanl.m4 serial 12
+dnl Copyright (C) 2007-2010 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.
@@ -133,20 +133,30 @@ AC_DEFUN([gl_FUNC_ISNANL_WORKS],
   ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
 typedef union { unsigned int word[NWORDS]; long double value; }
         memory_long_double;
+/* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the
+   runtime type conversion.  */
+#ifdef __sgi
+static long double NaNl ()
+{
+  double zero = 0.0;
+  return zero / zero;
+}
+#else
+# define NaNl() (0.0L / 0.0L)
+#endif
 int main ()
 {
   memory_long_double m;
   unsigned int i;
 
-  /* gcc-3.4.3 on IRIX 6.5 appears to have a problem with this.  */
-  if (!isnanl (0.0L / 0.0L))
+  if (!isnanl (NaNl ()))
     return 1;
 
   /* The isnanl function should be immune against changes in the sign bit and
      in the mantissa bits.  The xor operation twiddles a bit that can only be
      a sign bit or a mantissa bit (since the exponent never extends to
      bit 31).  */
-  m.value = 0.0L / 0.0L;
+  m.value = NaNl ();
   m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
   for (i = 0; i < NWORDS; i++)
     m.word[i] |= 1;