[all-commits] [llvm/llvm-project] af0332: [ARM] Disable sign extended SSAT pattern recognition.

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: af0332498405b3a4074cef09845bbacfd4fd594f
      https://github.com/llvm/llvm-project/commit/af0332498405b3a4074cef09845bbacfd4fd594f
  Author: David Green <david.green at arm.com>
  Date:   2021-01-22 (Fri, 22 Jan 2021)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/test/CodeGen/ARM/ssat.ll
    M llvm/test/CodeGen/ARM/usat.ll

  Log Message:
  -----------
  [ARM] Disable sign extended SSAT pattern recognition.

I may have given bad advice, and skipping sext_inreg when matching SSAT
patterns is not valid on it's own. It at least needs to sext_inreg the
input again, but as far as I can tell is still only valid based on
demanded bits. For the moment disable that part of the combine,
hopefully reimplementing it in the future more correctly.