[PATCH] D108139: [X86] Freeze vXi8 shl(x,1) -> add(x,x) vector fold (PR50468)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon created this revision.
RKSimon added reviewers: craig.topper, pengfei, spatel, lebedev.ri.
Herald added a subscriber: hiraditya.
RKSimon requested review of this revision.
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We don't have any vXi8 shift instructions (other than on XOP which is handled separately), so replace the  shl(x,1) ->add(x,x) fold with shl(x,1) ->add(freeze(x),freeze(x)) to avoid the undef issues identified in PR50468.

Split off from D106675 <https://reviews.llvm.org/D106675> as I'm still looking at whether we can fix the vXi16/i32/i64 issues with the D106679 <https://reviews.llvm.org/D106679> alternative.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D108139

Files:
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/test/CodeGen/X86/bitreverse.ll
  llvm/test/CodeGen/X86/combine-bitreverse.ll
  llvm/test/CodeGen/X86/vector-bitreverse.ll
  llvm/test/CodeGen/X86/vector-fshl-rot-128.ll
  llvm/test/CodeGen/X86/vector-fshl-rot-256.ll
  llvm/test/CodeGen/X86/vector-fshl-rot-512.ll
  llvm/test/CodeGen/X86/vector-fshr-128.ll
  llvm/test/CodeGen/X86/vector-fshr-256.ll
  llvm/test/CodeGen/X86/vector-fshr-rot-128.ll
  llvm/test/CodeGen/X86/vector-fshr-rot-256.ll
  llvm/test/CodeGen/X86/vector-fshr-rot-512.ll
  llvm/test/CodeGen/X86/vector-rotate-128.ll
  llvm/test/CodeGen/X86/vector-rotate-256.ll

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