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

[Evgeny Stupachenko]

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.

ChangeLog:

2014-05-28  Evgeny Stupachenko  <evstu...@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

vect_groups.patch
Description: Binary data