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Re: [Patch] Adjust diag-scans in vect-tests to fix fails on AVX/AVX2


> What do you mean no tests require it?  For instance, all of the ones
> that currently pass with with vect_perm?
Current implementation of vect_perm doesn't check for SSSE3 - so any
x86 target is supposed to support permutation.

> Just leave vect_perm alone for now.  That may not be absolutely
> correct either, but it's the good temporary solution that involves
> the minimal amount of churn.
Ok, those were just attempts to adjust dg-scans in slp-perm-9.c, in
which one more loop was vectorized when compiled with -mavx2. In fact,
just SSSE3 isn't enough for vectorization of this loop - it seems that
vector size also matters, so I undid changes in vect_perm and just add
a vect-size check to the test - could you please check if the changes
are ok?

On 17 December 2011 02:17, Richard Henderson <rth@redhat.com> wrote:
> On 12/16/2011 09:44 AM, Michael Zolotukhin wrote:
>>> Why? ?SSSE3 *really can* do arbitrary permutation. ?If you say that
>>> isn't enough, then there's something wrong in the back end, and all
>>> you're doing is papering over a bug.
>> Yes, sure, SSSE3 is enough for that. I checked for AVX in vect_perm
>> just because there is no check for SSSE3 and no tests currently
>> require exactly SSSE3 (without AVX) ?- that's not absolutely correct
>> and I suggest it as a temporary solution - we can weaken this check
>> when a real case will be met (in which SSSE3 is needed without AVX).
>
> What do you mean no tests require it? ?For instance, all of the ones
> that currently pass with with vect_perm?
>
> Just leave vect_perm alone for now. ?That may not be absolutely
> correct either, but it's the good temporary solution that involves
> the minimal amount of churn.
>
>
> r~



-- 
---
Best regards,
Michael V. Zolotukhin,
Software Engineer
Intel Corporation.

Attachment: vec-tests-avx2_fixes-6.patch
Description: Binary data


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