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Re: [PATCH] Fix PR37053: Move tweaks of commutative precedence to target hook

On Fri, 2009-06-26 at 18:15 +0400, Maxim Kuvyrkov wrote:
> The attached patch fixes PR37053 
> (
> The problem was introduced by patch for PR28690 
> (, rtlanal.c 
> hunk); this hunk causes ICE on m68k (and, possibly, other) architectures.
> My first impulse was to remove the pointer tweak; but, well, if PowerPC 
> really benefits from it,

I will say we worked for a long time coming up with the patch we did so
that it didn't affect other arches.  In particular, HJ ran a lot of
performance tests to make sure it didn't degrade performance on x86.
I will also note, that without this patch, SPEC2000 performance degrades
by about 30% across the entire benchmark suite and 500% on galgel on
POWER6, so yeah, we benefit from it. :)

> ..., let's make it a hook.
> The attached patch does just that.  Bootstrapped on x86_64-linux-gnu and 
> cross-build to powerpc-linux-gnu (with no new warnings in logs); ok to 
> apply?

I'll let others comment on whether they want a target hook solution or not.
If they don't, I'm willing to work with you to come up with something that
works for both of us.

In the mean time, I have asked Luis to test your patch on POWER6 to ensure
there are no performance degradations.  It doesn't look like there should
be, but...


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