[PATCH] D108539: [X86][AVX] Attempt to fold a scaled index into a gather/scatter scale immediate (PR13310)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon created this revision.
RKSimon added reviewers: pengfei, craig.topper, spatel, lebedev.ri.
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If the index operand for a gather/scatter intrinsic is being scaled (self-addition or a shl-by-immediate) then we may be able to fold that scaling into the intrinsic scale immediate value instead.

I did see if we could perform this with X86DAGToDAGISel::matchAddressRecursively, but adding vector support will be a pretty large task for only a minimal benefit.

Fixes PR13310.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D108539

Files:
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/test/CodeGen/X86/masked_gather_scatter.ll

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