[all-commits] [llvm/llvm-project] 28d7ba: [IndVars] Use more precise context when eliminatin...

[max-azul via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 28d7ba15435f055562d18ee7111db4adbaf28fae
      https://github.com/llvm/llvm-project/commit/28d7ba15435f055562d18ee7111db4adbaf28fae
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2020-11-25 (Wed, 25 Nov 2020)

  Changed paths:
    M llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
    M llvm/test/Transforms/IndVarSimplify/widen-loop-comp.ll

  Log Message:
  -----------
  [IndVars] Use more precise context when eliminating narrowing

When deciding to widen narrow use, we may need to prove some facts
about it. For proof, the context is used. Currently we take the instruction
being widened as the context.

However, we may be more precise here if we take as context the point that
dominates all users of instruction being widened.

Differential Revision: https://reviews.llvm.org/D90456
Reviewed By: skatkov