[all-commits] [llvm/llvm-project] ff91b2: [X86] Promote i16 CTTZ/CTTZ_ZERO_UNDEF always.

Craig Topper via All-commits all-commits at lists.llvm.org
Wed Aug 3 13:12:34 PDT 2022

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ff91b2d9df8098fca31684c8595087ec9f921eda
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2022-08-03 (Wed, 03 Aug 2022)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/bmi-intrinsics-fast-isel.ll
    M llvm/test/CodeGen/X86/clz.ll
    M llvm/test/CodeGen/X86/lzcnt-tzcnt.ll

  Log Message:
  [X86] Promote i16 CTTZ/CTTZ_ZERO_UNDEF always.

If we're going to emit a rep prefix before bsf as proposed in
D130956, it makes sense to promote i16 operations to i32 to avoid
the false depedency of tzcntw.

Reviewed By: skan, pengfei

Differential Revision: https://reviews.llvm.org/D130995

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