[all-commits] [llvm/llvm-project] be1669: [RLEV] Pick a correct insert point when incoming i...

[Philip Reames via All-commits]

  Branch: refs/heads/release/15.x
  Home:   https://github.com/llvm/llvm-project
  Commit: be1669163f67dcb517c3053b90fa2fe26e564db4
      https://github.com/llvm/llvm-project/commit/be1669163f67dcb517c3053b90fa2fe26e564db4
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2022-09-04 (Sun, 04 Sep 2022)

  Changed paths:
    M llvm/lib/Transforms/Utils/LoopUtils.cpp
    M llvm/test/Transforms/IndVarSimplify/rewrite-loop-exit-value.ll

  Log Message:
  -----------
  [RLEV] Pick a correct insert point when incoming instruction is itself a phi node

This fixes https://github.com/llvm/llvm-project/issues/57336. It was exposed by a recent SCEV change, but appears to have been a long standing issue.

Note that the whole insert into the loop instead of a split exit edge is slightly contrived to begin with; it's there solely because IndVarSimplify preserves the CFG.

Differential Revision: https://reviews.llvm.org/D132571

(cherry picked from commit c37b1a5f764380f83ba08ae0cebca2b162123eb6)