[PATCH] D71979: [X86] Add X86ISD::PCMPGT to SimplifyMultipleUseDemandedBitsForTargetNode.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: RKSimon, spatel.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

If only the sign bit is demanded, and the LHS is all zeroes, then
we can bypass the PCMPGT.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71979

Files:
  llvm/lib/Target/X86/X86ISelLowering.cpp
  llvm/test/CodeGen/X86/sadd_sat.ll
  llvm/test/CodeGen/X86/sadd_sat_vec.ll
  llvm/test/CodeGen/X86/ssub_sat.ll
  llvm/test/CodeGen/X86/ssub_sat_vec.ll

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