[all-commits] [llvm/llvm-project] 74b98a: [X86] Fold ZERO_EXTEND_VECTOR_INREG(BUILD_VECTOR(X...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 74b98ab1dbd55f33a9e8e8215884e8712326ab3b
      https://github.com/llvm/llvm-project/commit/74b98ab1dbd55f33a9e8e8215884e8712326ab3b
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-02-06 (Sun, 06 Feb 2022)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/vector-shift-ashr-128.ll
    M llvm/test/CodeGen/X86/vector-shift-ashr-256.ll
    M llvm/test/CodeGen/X86/vector-shift-ashr-512.ll

  Log Message:
  -----------
  [X86] Fold ZERO_EXTEND_VECTOR_INREG(BUILD_VECTOR(X,Y,?,?)) -> BUILD_VECTOR(X,0,Y,0)

Helps avoid some unnecessary shift by splat amount extensions before shuffle combining gets limited by with one use checks