From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 8 Nov 2006 06:25:34 +0000 (+0000)
Subject: * lib/autoconf/types.m4 (AC_TYPE_LONG_LONG_INT): Detect bug in
X-Git-Tag: AUTOCONF-2.61~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4bb5b9260b97a92e7d7a16bd515ae2558828a25f;p=thirdparty%2Fautoconf.git

* lib/autoconf/types.m4 (AC_TYPE_LONG_LONG_INT): Detect bug in
Tandem NonStop Kernel (OSS) cc -O circa 2004, reported by
Matthew Woehlke.
---

diff --git a/ChangeLog b/ChangeLog
index 9a14f1fa6..46c90f750 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2006-11-07  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* lib/autoconf/types.m4 (AC_TYPE_LONG_LONG_INT): Detect bug in
+	Tandem NonStop Kernel (OSS) cc -O circa 2004, reported by
+	Matthew Woehlke.
+
 2006-10-28  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
 	* tests/torture.at (Configuring subdirectories): Do not skip
diff --git a/lib/autoconf/types.m4 b/lib/autoconf/types.m4
index 606eafeba..ab2f6b962 100644
--- a/lib/autoconf/types.m4
+++ b/lib/autoconf/types.m4
@@ -480,10 +480,34 @@ AC_DEFUN([AC_TYPE_LONG_LONG_INT],
 	    int i = 63;]],
 	  [[long long int llmax = 9223372036854775807ll;
 	    return ((ll << 63) | (ll >> 63) | (ll < i) | (ll > i)
-		    | llmax / ll | llmax % ll);]])],
-       [ac_cv_type_long_long_int=yes],
+		    | (llmax / ll) | (llmax % ll));]])],
+       [dnl This catches a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004.
+	dnl If cross compiling, assume the bug isn't important, since
+	dnl nobody cross compiles for this platform as far as we know.
+	AC_RUN_IFELSE(
+	  [AC_LANG_PROGRAM(
+	     [[@%:@include <limits.h>
+	       @%:@ifndef LLONG_MAX
+	       @%:@ define HALF \
+			(1LL << (sizeof (long long int) * CHAR_BIT - 2))
+	       @%:@ define LLONG_MAX (HALF - 1 + HALF)
+	       @%:@endif]],
+	     [[long long int n = 1;
+	       int i;
+	       for (i = 0; ; i++)
+		 {
+		   long long int m = n << i;
+		   if (m >> i != n)
+		     return 1;
+		   if (LLONG_MAX / 2 < m)
+		     break;
+		 }
+	       return 0;]])],
+	  [ac_cv_type_long_long_int=yes],
+	  [ac_cv_type_long_long_int=no],
+	  [ac_cv_type_long_long_int=cross-compiling])],
        [ac_cv_type_long_long_int=no])])
-  if test $ac_cv_type_long_long_int = yes; then
+  if test $ac_cv_type_long_long_int != no; then
     AC_DEFINE([HAVE_LONG_LONG_INT], 1,
       [Define to 1 if the system has the type `long long int'.])
   fi