[all-commits] [llvm/llvm-project] 1020d1: [InstSimplify] Handle nsw shl -> poison patterns

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1020d161565df48ec454509724e60ab8fbbdfd66
      https://github.com/llvm/llvm-project/commit/1020d161565df48ec454509724e60ab8fbbdfd66
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-02-23 (Tue, 23 Feb 2021)

  Changed paths:
    M llvm/lib/Analysis/InstructionSimplify.cpp
    M llvm/test/Transforms/InstCombine/known-signbit-shift.ll
    M llvm/test/Transforms/InstSimplify/icmp-constant.ll

  Log Message:
  -----------
  [InstSimplify] Handle nsw shl -> poison patterns

Pulled out from D90479 - this recognises invalid nsw shl patterns with signbit changes that result in poison.

Differential Revision: https://reviews.llvm.org/D97305