X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffrexp.m4;h=f2048f3be37bc58d5e2b8d27069a86f9e197b1c1;hb=64da7b6c00400c0a5e5b02df98faec97c0954a3c;hp=1f6d5427be2a795c8c4563111dd28b4fca0e65b0;hpb=ac01a4aaec3f7b63a8110268615b9b7f4e9f41f4;p=gnulib.git

diff --git a/m4/frexp.m4 b/m4/frexp.m4
index 1f6d5427b..f2048f3be 100644
--- a/m4/frexp.m4
+++ b/m4/frexp.m4
@@ -1,5 +1,5 @@
-# frexp.m4 serial 8
-dnl Copyright (C) 2007-2010 Free Software Foundation, Inc.
+# frexp.m4 serial 12
+dnl Copyright (C) 2007-2011 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.
@@ -15,9 +15,11 @@ AC_DEFUN([gl_FUNC_FREXP],
       [
         save_LIBS="$LIBS"
         LIBS="$LIBS -lm"
-        AC_TRY_LINK([#include <math.h>
-                     double x;],
-                    [int e; return frexp (x, &e) > 0;],
+        AC_LINK_IFELSE(
+          [AC_LANG_PROGRAM(
+             [[#include <math.h>
+               double x;]],
+             [[int e; return frexp (x, &e) > 0;]])],
           [gl_cv_func_frexp_in_libm=yes],
           [gl_cv_func_frexp_in_libm=no])
         LIBS="$save_LIBS"
@@ -42,8 +44,6 @@ AC_DEFUN([gl_FUNC_FREXP],
   if test $gl_func_frexp = yes; then
     AC_DEFINE([HAVE_FREXP], [1],
       [Define if the frexp() function is available and works.])
-  else
-    AC_LIBOBJ([frexp])
   fi
   AC_SUBST([FREXP_LIBM])
 ])
@@ -66,8 +66,6 @@ AC_DEFUN([gl_FUNC_FREXP_NO_LIBM],
   if test $gl_func_frexp_no_libm = yes; then
     AC_DEFINE([HAVE_FREXP_IN_LIBC], [1],
       [Define if the frexp() function is available in libc.])
-  else
-    AC_LIBOBJ([frexp])
   fi
 ])
 
@@ -78,9 +76,11 @@ AC_DEFUN([gl_CHECK_FREXP_NO_LIBM],
   AC_CACHE_CHECK([whether frexp() can be used without linking with libm],
     [gl_cv_func_frexp_no_libm],
     [
-      AC_TRY_LINK([#include <math.h>
-                   double x;],
-                  [int e; return frexp (x, &e) > 0;],
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[#include <math.h>
+             double x;]],
+           [[int e; return frexp (x, &e) > 0;]])],
         [gl_cv_func_frexp_no_libm=yes],
         [gl_cv_func_frexp_no_libm=no])
     ])
@@ -88,23 +88,37 @@ AC_DEFUN([gl_CHECK_FREXP_NO_LIBM],
 
 dnl Test whether frexp() works also on denormalized numbers (this fails e.g. on
 dnl NetBSD 3.0), on infinite numbers (this fails e.g. on IRIX 6.5 and mingw),
-dnl and on negative zero (this fails e.g. on NetBSD 4.99).
+dnl and on negative zero (this fails e.g. on NetBSD 4.99 and mingw).
 AC_DEFUN([gl_FUNC_FREXP_WORKS],
 [
   AC_REQUIRE([AC_PROG_CC])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works],
     [
-      AC_TRY_RUN([
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
 #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 result = 0;
   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)
@@ -116,30 +130,32 @@ int main()
       /* On machines with IEEE754 arithmetic: x = 1.11254e-308, exp = -1022.
          On NetBSD: y = 0.75. Correct: y = 0.5.  */
       if (y != 0.5)
-        return 1;
+        result |= 1;
     }
   /* Test on infinite numbers.  */
-  x = 1.0 / 0.0;
+  x = 1.0 / zero;
   {
     int exp;
     double y = frexp (x, &exp);
     if (y != x)
-      return 1;
+      result |= 2;
   }
   /* Test on negative zero.  */
-  x = -zero;
+  x = minus_zero;
   {
     int exp;
     double y = frexp (x, &exp);
     if (memcmp (&y, &x, sizeof x))
-      return 1;
+      result |= 4;
   }
-  return 0;
-}], [gl_cv_func_frexp_works=yes], [gl_cv_func_frexp_works=no],
-      [case "$host_os" in
-         netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
-         *)                        gl_cv_func_frexp_works="guessing yes";;
-       esac
-      ])
+  return result;
+}]])],
+        [gl_cv_func_frexp_works=yes],
+        [gl_cv_func_frexp_works=no],
+        [case "$host_os" in
+           netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
+           *)                        gl_cv_func_frexp_works="guessing yes";;
+         esac
+        ])
     ])
 ])