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[PATCH] Update changes.html about -Wno-aggressive-loop-optimizations
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Richard Biener <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 22 Mar 2013 11:26:27 +0100
- Subject: [PATCH] Update changes.html about -Wno-aggressive-loop-optimizations
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
This new warning switch hasn't been mentioned in changes.html, the following
patch fixes that. Is this ok, or do you have better wording?
--- htdocs/gcc-4.8/changes.html 14 Mar 2013 01:13:56 -0000 1.108
+++ htdocs/gcc-4.8/changes.html 22 Mar 2013 10:22:37 -0000
@@ -32,7 +32,12 @@ the number of iterations of loops using
standards. This may cause non-conforming programs to no longer work as
expected, such as SPEC CPU 2006 464.h264ref and 416.gamess. A new
option, <code>-fno-aggressive-loop-optimizations</code>, was added
-to disable this aggressive analysis.</p>
+to disable this aggressive analysis. In some loops that have known
+constant number of iterations, but undefined behavior is known to occur
+in the loop before reaching or during the last iteration, GCC will warn
+about the undefined behavior in the loop instead of deriving lower upper
+bound of the number of iterations for the loop. The warning
+can be disabled with <code>-Wno-aggressive-loop-optimizations</code>.</p>
<p>On ARM, a bug has been fixed in GCC's implementation of the AAPCS
rules for the layout of vectors that could lead to wrong code being
Jakub