fdatasync: new module

[gnulib.git] / m4 / frexp.m4

diff --git a/m4/frexp.m4 b/m4/frexp.m4
index 1f6d542..f2048f3 100644 (file)
--- 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.
 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"
       [
         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="$save_LIBS"
           [gl_cv_func_frexp_in_libm=yes],
           [gl_cv_func_frexp_in_libm=no])
         LIBS="$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.])
   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])
 ])
   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.])
   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
 ])
 
   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_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])
     ])
         [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 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_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>
 #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 main()
 {

+  int result = 0;

   int i;
   volatile double x;
   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)
   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)
       /* 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.  */
     }
   /* Test on infinite numbers.  */

-  x = 1.0 / 0.0;
+  x = 1.0 / zero;

   {
     int exp;
     double y = frexp (x, &exp);
     if (y != x)
   {
     int exp;
     double y = frexp (x, &exp);
     if (y != x)

-      return 1;
+      result |= 2;

   }
   /* Test on negative zero.  */
   }
   /* Test on negative zero.  */

-  x = -zero;
+  x = minus_zero;

   {
     int exp;
     double y = frexp (x, &exp);
     if (memcmp (&y, &x, sizeof x))
   {
     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
+        ])

     ])
 ])
     ])
 ])