Re: PATCH COMMITTED: gcc 4.2 support for -Wstrict-overflow/-fstrict-overflow

[Ian Lance Taylor <iant at google dot com>]

"Andrew Pinski" <pinskia@gmail.com> writes:

> On 11 Mar 2007 21:40:24 -0700, Ian Lance Taylor <iant@google.com> wrote:
> > I have just committed the gcc 4.2 patch which adds support for
> > -Wstrict-overflow and -fstrict-overflow, as previously approved.  A
> > bunch of testing was required.  Lucky for me that Mark's release
> > candidate was delayed.
> 
> Wait, this still introduces a missed optimization regression as
> mentioned by Richard Guenther so why did you apply it before that was
> resolved?

It's not quite fair to call PR 31130 a missed optimization regression.
The optimization is not missed.  It just doesn't happen in the VRP
pass itself.  And in particular the optimization is not missed with
regard to gcc 4.1, so even specific to VRP it is not a missed
optimization for 4.2.

I am of course continuing to look at PR 31130, but please don't permit
your personal dislike of -Wstrict-overflow color your description of
the issues.  A missed optimization regression is one that shows up in
the generated assembly code.

Ian