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Re: [committed] Fix stack slot coalescing at -O0 (PR target/43808)
- From: Richard Guenther <richard dot guenther at gmail dot com>
- To: Paolo Bonzini <bonzini at gnu dot org>
- Cc: Jakub Jelinek <jakub at redhat dot com>, gcc-patches at gcc dot gnu dot org
- Date: Wed, 10 Nov 2010 12:15:18 +0100
- Subject: Re: [committed] Fix stack slot coalescing at -O0 (PR target/43808)
- References: <20101109191112.GV29412@tyan-ft48-01.lab.bos.redhat.com> <4CD9DE5C.3020005@gnu.org>
On Wed, Nov 10, 2010 at 12:50 AM, Paolo Bonzini <bonzini@gnu.org> wrote:
> On 11/09/2010 08:11 PM, Jakub Jelinek wrote:
>>
>> Hi!
>>
>> If -O0 is used together with passes that use alias into in the RTL
>> (e.g. scheduling), we may miscompile code
>
> Why not disable most optimization passes at -O0 independent of flags (maybe
> even give a hard error) instead? ?It would be a bigger patch, but this set
> of flags makes no sense.
If we want unit-testing of some sort then we should make sure passes
work regardless of what earlier optimization passes did. So instead of
adding more optimize checks I'd rather remove more of them.
Richard.
> Paolo
>