Re: [Patch] Testsuite fixes for failures caused by patch for PR 80925 - loop peeling and alignment

[Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>]

Richard Biener <richard.guenther@gmail.com> writes:

> On Fri, Jul 28, 2017 at 8:22 PM, Steve Ellcey <sellcey@cavium.com> wrote:
>> On Fri, 2017-07-28 at 09:47 +0200, Richard Biener wrote:
>>> On Fri, Jul 28, 2017 at 12:16 AM, Steve Ellcey <sellcey@cavium.com> wrote:
>>> >
>>> > Any comments from the power and/or vectorizer folks?
>>> On one side I'm inclined to simplify the testsuite by adding
>>> --param vect-max-peeling-for-alignment=0 in addition to
>>> -fno-vect-cost-model we already pass and override that in the
>>> tests that specifically exercise peeling for alignment (do we have
>>> any?).
>>> OTOH that would remove quite some testing coverage of prologue
>>> peeling.
>>>
>>> So ideally testresults would be clean with both no such --param
>>> and that --param added...
>>>
>>> I think most of the testcases you needed to adjust have nothing
>>> to do with peeling for alignment thus adding this --param just for
>>> those (and simplifying their dump scanning accordingly) is another
>>> pragmatic option.
>>>
>>> Adding yet another target (vect_peel_align) is IMHO not good,
>>> especially as this one depends on cost tuning and not HW
>>> features, so it's impossible(?) to dynamically compute it
>>> with a test compile for example (we _do_ want a clean
>>> vect.exp with any vector HW / tuning switch you add).
>>
>> How about something like the following.  I only fixed two of the tests,
>> I can follow up with more if this approach seems reasonable.  I tested
>> this on aarch64 and x86_64.
>
> Looks good to me.
>
> Richard.
>
>> Steve Ellcey
>> sellcey@cavium.com
>>
>>
>> 2017-07-28  Steve Ellcey  <sellcey@cavium.com>
>>
>>         PR tree-optimization/80925
>>         * gcc.dg/vect/no-section-anchors-vect-69.c: Add
>>         --param vect-max-peeling-for-alignment=0 option.
>>         Remove unaligned access and peeling checks.
>>         * gcc.dg/vect/section-anchors-vect-69.c: Ditto.

This broke the test on Solaris/SPARC:

+FAIL: gcc.dg/vect/no-section-anchors-vect-69.c scan-tree-dump-times vect "vectorized 4 loops" 1

both 32 and 64-bit.  The dump now has

no-section-anchors-vect-69.c:39:5: note: vectorized 3 loops in function.

and (compared to the gcc-7 branch)

no-section-anchors-vect-69.c:44:3: note: not vectorized: unsupported unaligned store.tmp1[2].a.n[1][2][i_74]

	Rainer

-- 
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Rainer Orth, Center for Biotechnology, Bielefeld University