[all-commits] [llvm/llvm-project] f82cf6: [indvars] Fix pr52276 (missing one use check)

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f82cf6187fbe9584ba0a8d9bf4d703498df249e6
      https://github.com/llvm/llvm-project/commit/f82cf6187fbe9584ba0a8d9bf4d703498df249e6
  Author: Philip Reames <listmail at philipreames.com>
  Date:   2021-10-25 (Mon, 25 Oct 2021)

  Changed paths:
    M llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
    M llvm/test/Transforms/IndVarSimplify/finite-exit-comparisons.ll

  Log Message:
  -----------
  [indvars] Fix pr52276 (missing one use check)

The recently added logic to canonicalize exit conditions to unsigned relies on facts which hold about the use (i.e. exit test).  Applying this blindly to the icmp is not legal, as there may be another use which never reaches the exit.  Restrict ourselves to case where we have a single use.