[all-commits] [llvm/llvm-project] 417fe5: Revert "[SLP] Check with target before vectorizing...

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 417fe52e6fb44c727eb4a63b6eb49377b692bdd8
      https://github.com/llvm/llvm-project/commit/417fe52e6fb44c727eb4a63b6eb49377b692bdd8
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2023-03-28 (Tue, 28 Mar 2023)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
    M llvm/test/Transforms/SLPVectorizer/AArch64/ext-trunc.ll
    M llvm/test/Transforms/SLPVectorizer/AArch64/gather-reduce.ll
    M llvm/test/Transforms/SLPVectorizer/AArch64/getelementptr.ll
    M llvm/test/Transforms/SLPVectorizer/AArch64/vector-getelementptr.ll
    R llvm/test/Transforms/SLPVectorizer/SystemZ/gep-indices.ll
    M llvm/test/Transforms/SLPVectorizer/X86/load-merge-inseltpoison.ll
    M llvm/test/Transforms/SLPVectorizer/X86/load-merge.ll
    M llvm/test/Transforms/SLPVectorizer/X86/minimum-sizes.ll
    M llvm/test/Transforms/SLPVectorizer/X86/opaque-ptr.ll
    M llvm/test/Transforms/SLPVectorizer/X86/partail.ll

  Log Message:
  -----------
  Revert "[SLP] Check with target before vectorizing GEP Indices."

This reverts commit 1387a13e1d0bac94457626ef3e7427c84caf6e65.

This introduced performance regressions on AArch64, when the cost of a
vector GEP + extracts is offset by the benefits of vectorizing the rest
of the tree.

The test in llvm/test/Transforms/SLPVectorizer/AArch64/vector-getelementptr.ll
illustrates the issue. It was extracted from code that regressed a SPEC
benchmark by 15%.