[all-commits] [llvm/llvm-project] e80828: [IndVars] avoid crash in LFTR when assuming an add...

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e808289fe6432c044567a9b3b6999089eb8d1e2b
      https://github.com/llvm/llvm-project/commit/e808289fe6432c044567a9b3b6999089eb8d1e2b
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-04-27 (Tue, 27 Apr 2021)

  Changed paths:
    M llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
    M llvm/test/Transforms/IndVarSimplify/lftr.ll

  Log Message:
  -----------
  [IndVars] avoid crash in LFTR when assuming an add recurrence

The test is a crasher reduced from:
https://llvm.org/PR49993

linearFunctionTestReplace() assumes that we have an add recurrence,
so check for that as a condition of matching a loop counter.

Differential Revision: https://reviews.llvm.org/D101291