[all-commits] [llvm/llvm-project] d83a96: [DAG] Make it clear mul(x, x) knownbits bit[1] == 0...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d83a96f59f93290aa7771388498bb620974de6b7
      https://github.com/llvm/llvm-project/commit/d83a96f59f93290aa7771388498bb620974de6b7
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-02-01 (Tue, 01 Feb 2022)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/test/CodeGen/X86/combine-mul.ll

  Log Message:
  -----------
  [DAG] Make it clear mul(x,x) knownbits bit[1] == 0 check should be for x is undef only

As raised on rGffd0e464b4b9, if x is poison, this fold is still ok.