[all-commits] [llvm/llvm-project] 58b966: [LSR] Fix bug - check if loop has preheader before...

[syzaara via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 58b9666dc1a09819377ae585b4718ef2ea951970
      https://github.com/llvm/llvm-project/commit/58b9666dc1a09819377ae585b4718ef2ea951970
  Author: Zaara Syeda <syzaara at ca.ibm.com>
  Date:   2022-07-07 (Thu, 07 Jul 2022)

  Changed paths:
    M llvm/lib/Transforms/Utils/LoopUtils.cpp
    M llvm/test/Transforms/LoopStrengthReduce/remove_scev_indvars.ll

  Log Message:
  -----------
  [LSR] Fix bug - check if loop has preheader before calling isInductionPHI

Fix bug exposed by https://reviews.llvm.org/D125990
rewriteLoopExitValues calls InductionDescriptor::isInductionPHI which requires
the PHI node to have an incoming edge from the loop preheader. This adds checks
before calling InductionDescriptor::isInductionPHI to see that the loop has a
preheader. Also did some refactoring.

Differential Revision: https://reviews.llvm.org/D129297