From: Richard Henderson <rth@redhat.com>
Date: Sat, 11 Aug 2001 20:13:46 +0000 (-0700)
Subject: extend.texi (Arrays and pointers implementation): Discourage relying on sign-extensio... 
X-Git-Tag: prereleases/libstdc++-3.0.95~2728
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58f4de4f271c66738b406b43cff19661ec5d9b5a;p=thirdparty%2Fgcc.git

extend.texi (Arrays and pointers implementation): Discourage relying on sign-extension of pointers.

        * doc/extend.texi (Arrays and pointers implementation): Discourage
        relying on sign-extension of pointers.

From-SVN: r44805
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c23a962195cc..481c55cf8aa7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2001-08-11  Richard Henderson  <rth@redhat.com>
+
+	* doc/extend.texi (Arrays and pointers implementation): Discourage
+	relying on sign-extension of pointers.
+
 2001-08-11  H.J. Lu <hjl@gnu.org>
 
 	* config/mips/linux.h (EXTRA_SECTIONS): Remove in_ctors and
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 12b9e71bd5f8..2951096078e4 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -202,7 +202,9 @@ IEC 60559 conformant implementation (F.9).}
 vice versa (6.3.2.3).}
 
 A cast from pointer to integer discards most-significant bits if the
-pointer representation is larger than the integer type, sign-extends
+pointer representation is larger than the integer type,
+sign-extends@footnote{Future versions of GCC may zero-extend, or use
+a target-defined @code{ptr_extend} pattern.  Do not rely on sign extension.}
 if the pointer representation is smaller than the integer type, otherwise
 the bits are unchanged.
 @c ??? We've always claimed that pointers were unsigned entities.