Imported Upstream version 1.5

[debian/gzip] / m4 / frexp.m4

diff --git a/m4/frexp.m4 b/m4/frexp.m4
index 3a450f6561e98f118f893fb79f839e90674492c2..4162195e5372f4ff00461fcb7576e8ff987952f9 100644 (file)
--- a/m4/frexp.m4
+++ b/m4/frexp.m4
@@ -1,5 +1,5 @@
-# frexp.m4 serial 7
-dnl Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+# frexp.m4 serial 13
+dnl Copyright (C) 2007-2012 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.


@@ -7,25 +7,19 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_FREXP],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
 AC_DEFUN([gl_FUNC_FREXP],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])

+  AC_REQUIRE([gl_CHECK_FREXP_NO_LIBM])

   FREXP_LIBM=
   FREXP_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;],
-        [gl_cv_func_frexp_no_libm=yes],
-        [gl_cv_func_frexp_no_libm=no])
-    ])

   if test $gl_cv_func_frexp_no_libm = no; then
     AC_CACHE_CHECK([whether frexp() can be used with libm],
       [gl_cv_func_frexp_in_libm],
       [
         save_LIBS="$LIBS"
         LIBS="$LIBS -lm"
   if test $gl_cv_func_frexp_no_libm = no; then
     AC_CACHE_CHECK([whether frexp() can be used with libm],
       [gl_cv_func_frexp_in_libm],
       [
         save_LIBS="$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"


@@ -50,8 +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])
 ])


@@ -59,15 +51,7 @@ AC_DEFUN([gl_FUNC_FREXP],
 AC_DEFUN([gl_FUNC_FREXP_NO_LIBM],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
 AC_DEFUN([gl_FUNC_FREXP_NO_LIBM],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])

-  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;],
-        [gl_cv_func_frexp_no_libm=yes],
-        [gl_cv_func_frexp_no_libm=no])
-    ])
+  AC_REQUIRE([gl_CHECK_FREXP_NO_LIBM])

   if test $gl_cv_func_frexp_no_libm = yes; then
     gl_FUNC_FREXP_WORKS
     case "$gl_cv_func_frexp_works" in
   if test $gl_cv_func_frexp_no_libm = yes; then
     gl_FUNC_FREXP_WORKS
     case "$gl_cv_func_frexp_works" in


@@ -82,31 +66,69 @@ 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
 ])
 

+dnl Test whether frexp() can be used without linking with libm.
+dnl Set gl_cv_func_frexp_no_libm to 'yes' or 'no' accordingly.
+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_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])
+    ])
+])
+

 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_DEFUN([gl_FUNC_FREXP_WORKS],
 [
   AC_REQUIRE([AC_PROG_CC])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

+  AC_CHECK_FUNCS_ONCE([alarm])

   AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works],
     [
   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>

+#if HAVE_ALARM
+# include <unistd.h>
+#endif
+/* 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;
   double zero = 0.0;

+#if HAVE_ALARM
+  /* NeXTstep 3.3 frexp() runs into an endless loop when called on an infinite
+     number.  Let the test fail in this case.  */
+  alarm (5);
+#endif

   /* Test on denormalized numbers.  */
   for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
     ;
   /* Test on denormalized numbers.  */
   for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
     ;


@@ -117,30 +139,32 @@ 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
+        ])

     ])
 ])
     ])
 ])