striconveh: Simplify last commit.

[gnulib.git] / m4 / isfinite.m4

diff --git a/m4/isfinite.m4 b/m4/isfinite.m4
index 4fb557b..dfdbc3e 100644 (file)
--- a/m4/isfinite.m4
+++ b/m4/isfinite.m4
@@ -1,5 +1,5 @@
-# isfinite.m4 serial 3
-dnl Copyright (C) 2007-2008 Free Software Foundation, Inc.
+# isfinite.m4 serial 7
+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.
@@ -30,7 +30,6 @@ AC_DEFUN([gl_ISFINITE],
     AC_LIBOBJ([isfinite])
     ISFINITE_LIBM=
   fi
-  AC_SUBST([REPLACE_ISFINITE])
   AC_SUBST([ISFINITE_LIBM])
 ])
 
@@ -44,11 +43,11 @@ dnl   pseudo-denormals on ia64.
 AC_DEFUN([gl_ISFINITEL_WORKS],
 [
   AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([AC_C_BIGENDIAN])
+  AC_REQUIRE([gl_BIGENDIAN])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CACHE_CHECK([whether isfinite(long double) works], [gl_cv_func_isfinitel_works],
     [
-      AC_TRY_RUN([
+      AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <float.h>
 #include <limits.h>
 #include <math.h>
@@ -56,6 +55,17 @@ AC_DEFUN([gl_ISFINITEL_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;
@@ -65,7 +75,7 @@ int main ()
      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;
@@ -138,7 +148,7 @@ int main ()
 #endif
 
   return 0;
-}], [gl_cv_func_isfinitel_works=yes], [gl_cv_func_isfinitel_works=no],
+}]])], [gl_cv_func_isfinitel_works=yes], [gl_cv_func_isfinitel_works=no],
       [case "$host_cpu" in
                                # Guess no on ia64, x86_64, i386.
          ia64 | x86_64 | i*86) gl_cv_func_isnanl_works="guessing no";;