[all-commits] [llvm/llvm-project] d9ca44: [IndVars] Break backedge and replace PHIs if loop ...

[Max Kazantsev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d9ca444835e67960df927d5b8cade57776fdd8cb
      https://github.com/llvm/llvm-project/commit/d9ca444835e67960df927d5b8cade57776fdd8cb
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2021-09-13 (Mon, 13 Sep 2021)

  Changed paths:
    M llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
    M llvm/test/Transforms/IndVarSimplify/eliminate-backedge.ll

  Log Message:
  -----------
  [IndVars] Break backedge and replace PHIs if loop exits on 1st iteration

Implement TODO in optimizeLoopExits. Now if we have proved that some loop exit
is taken on 1st iteration, we make all branches in the following exiting blocks
always branch out of the loop and their conditions simplified away.

Patch by Dmitry Makogon!

Differential Revision: https://reviews.llvm.org/D108910
Reviewed By: lebedev.ri