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Re: [PATCH, PR52252] Alternative way of vectorization for load groups of size 2 and 3.
- From: Ramana Radhakrishnan <ramana dot gcc at googlemail dot com>
- To: Evgeny Stupachenko <evstupac at gmail dot com>
- Cc: Richard Biener <rguenther at suse dot de>, Uros Bizjak <ubizjak at gmail dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, Jakub Jelinek <jakub at redhat dot com>
- Date: Thu, 5 Jun 2014 11:04:18 +0100
- Subject: Re: [PATCH, PR52252] Alternative way of vectorization for load groups of size 2 and 3.
- Authentication-results: sourceware.org; auth=none
- References: <CAOvf_xz4y6u9-YZCdTM8j3Awm7pdARvyb-58=obT+U9Tkt0HNg at mail dot gmail dot com>
- Reply-to: ramrad01 at arm dot com
On Wed, May 28, 2014 at 2:09 PM, Evgeny Stupachenko <firstname.lastname@example.org> wrote:
> The patch introduces alternative way of permutations for load groups
> of size 2 and 3 which should be faster on architectures with low
> 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
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.
> 2014-05-28 Evgeny Stupachenko <email@example.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.