commit 17d355768ce4c65c78260b3d3f1b54cb085e7ae2
author Simon Pilgrim <llvm-dev@redking.me.uk> Wed Mar 13 16:37:30 2019 +0000
committer Simon Pilgrim <llvm-dev@redking.me.uk> Wed Mar 13 16:37:30 2019 +0000
tree b36b929cd3edb60344a388852a688fc9a4d74de0
parent ed761d68673372e6405a73e08e375ac0219fad82

[X86][AVX] Add combineConcatVectors support to improve subvector handling

Attempt to combine CONCAT_VECTORS nodes, which we only really have pre-legalization.

This encourages a lot of X86ISD::SUBV_BROADCAST generation, so I've added SimplifyDemandedVectorEltsForTargetNode handling for this at the same time.

The X86ISD::VTRUNC regression in shuffle-vs-trunc-256-widen.ll will be handled in a future commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356064 91177308-0d34-0410-b5e6-96231b3b80d8