[all-commits] [llvm/llvm-project] a5212b: [X86][SSE] combineSubToSubus - remove SSE2 early-out.

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a5212b5c91cc699052125b8a3428ffe0c123837d
      https://github.com/llvm/llvm-project/commit/a5212b5c91cc699052125b8a3428ffe0c123837d
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-01-12 (Tue, 12 Jan 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/psubus.ll

  Log Message:
  -----------
  [X86][SSE] combineSubToSubus - remove SSE2 early-out.

SSE2 truncation codegen has improved over the past few years (mainly due to better shuffle lowering/combining and computeKnownBits) - its no longer necessary to early-out from v8i32/v8i64 truncations.

This was noticed while looking at completing PR40111 and moving combineSubToSubus to DAGCombine entirely.