[PATCH] D106222: [X86] Don't use known bits to simplify shuffles.

[Eli Friedman via Phabricator via llvm-commits]

efriedma created this revision.
efriedma added reviewers: aqjune, craig.topper, xiangzhangllvm, RKSimon.
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This reverts commit 2a419a0b9957ebac9e11e4b43bc9fbe42a9207df <https://reviews.llvm.org/rG2a419a0b9957ebac9e11e4b43bc9fbe42a9207df>.

The result of a shufflevector must not propagate poison from any element other than the one noted in the shuffle mask.

The regressions outside of fptoui-may-overflow.ll can probably be recovered some other way.

See https://reviews.llvm.org/D106053 for more background.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106222

Files:
  llvm/include/llvm/CodeGen/SelectionDAG.h
  llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/test/CodeGen/X86/fptoui-may-overflow.ll
  llvm/test/CodeGen/X86/oddshuffles.ll
  llvm/test/CodeGen/X86/vector_splat-const-shift-of-constmasked.ll

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