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Re: [PATCH, PR52252] Alternative way of vectorization for load groups of size 2 and 3.


Testing finished. No new regressions.
Is the following patch ok?

2014-06-11  Evgeny Stupachenko  <evstupac@gmail.com>

        * config/i386/i386.c (ix86_reassociation_width): Add alternative for
        vector case.
        * config/i386/i386.h (TARGET_VECTOR_PARALLEL_EXECUTION): New.
        * config/i386/x86-tune.def (X86_TUNE_VECTOR_PARALLEL_EXECUTION): New.
        * tree-vect-data-refs.c (vect_shift_permute_load_chain): New.
        Introduces alternative way of loads group permutaions.
        (vect_transform_grouped_load): Try alternative way of permutations.

Thanks,
Evgeny

On Tue, Jun 10, 2014 at 4:43 PM, Evgeny Stupachenko <evstupac@gmail.com> wrote:
> ix86_reassociation_width checks INTEGRAL_MODE_P and FLOAT_MODE_P which
> include vector mode.
> I'll try to separate this into scalar and vector part, but it will
> require more testing (under the testing now).
> What about the rest of the patch?
>
> Thanks,
> Evgeny
>
> On Thu, Jun 5, 2014 at 3:54 PM, Ramana Radhakrishnan
> <ramana.radhakrishnan@arm.com> wrote:
>> On 06/05/14 12:43, Evgeny Stupachenko wrote:
>>>
>>> New hook is related to vector instructions only. Vector instructions
>>> could be sequential in pipeline, but scalar - parallel. For x86
>>> architectures TARGET_SCHED_REASSOC_WIDTH does not give required
>>> differentiation.
>>> General hooks could be potentially reused in other algorithms/by other
>>> architectures.
>>
>>
>> It already takes a "mode" argument. Couldn't you use a vector mode to work
>> this out ?
>>
>> If it is not enough then please be more specific about the documentation of
>> this hook about where it is useful so that it's easy for people reading the
>> documentation to understand at a glance what purpose it serves.
>>
>>
>> Ramana
>>
>>
>>>
>>> Thanks,
>>> Evgeny
>>>
>>> On Thu, Jun 5, 2014 at 2:04 PM, Ramana Radhakrishnan
>>> <ramana.gcc@googlemail.com> wrote:
>>>>
>>>> On Wed, May 28, 2014 at 2:09 PM, Evgeny Stupachenko <evstupac@gmail.com>
>>>> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> The patch introduces alternative way of permutations for load groups
>>>>> of size 2 and 3 which should be faster on architectures with low
>>>>> parallelism.
>>>>> The patch gives 2 times gain on Silvermont to the test from PR52252
>>>>> (in addition to already committed 3 times gain).
>>>>>
>>>>> Patch passes bootstrap on x86. Make check is in progress.
>>>>
>>>>
>>>> Why do we need a new hook ? Can't you derive this information from
>>>> something which is equally badly named TARGET_SCHED_REASSOC_WIDTH
>>>> though used in the reassociation logic but also serves a similar
>>>> purpose ?
>>>>
>>>> Also the documentation of this hook is incomplete at best and wrong at
>>>> worst as this is not applied everywhere in the vectorizer but just for
>>>> this special case for load store permuting. Implying this is useful
>>>> everywhere in the vectorizer does not appear to be correct.
>>>>
>>>> regards
>>>> Ramana
>>>>
>>>>
>>>>
>>>>
>>>>>
>>>>> ChangeLog:
>>>>>
>>>>> 2014-05-28  Evgeny Stupachenko  <evstupac@gmail.com>
>>>>>
>>>>>          * config/i386/i386.c (ix86_have_vector_parallel_execution):
>>>>> New.
>>>>>          (TARGET_VECTORIZE_HAVE_VECTOR_PARALLEL_EXECUTION): New.
>>>>>          * config/i386/i386.h (TARGET_VECTOR_PARALLEL_EXECUTION): New.
>>>>>          * config/i386/x86-tune.def
>>>>> (X86_TUNE_VECTOR_PARALLEL_EXECUTION): New.
>>>>>          * target.def (have_vector_parallel_execution): New.
>>>>>          * doc/tm.texi.in (have_vector_parallel_execution)): New.
>>>>>          * doc/tm.texi: Regenerate.
>>>>>          * targhooks.c (default_have_vector_parallel_execution): New.
>>>>>          * tree-vect-data-refs.c (vect_shift_permute_load_chain): New.
>>>>>          Introduces alternative way of loads group permutaions.
>>>>>          (vect_transform_grouped_load): Try alternative way of
>>>>> permutaions.
>>>>>
>>>>> Evgeny
>>>
>>>
>>

Attachment: vect_groups1.patch
Description: Binary data


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