[all-commits] [llvm/llvm-project] 8c5edf: [SCEV] don't query getSCEV() for incomplete phis

[Chen Zheng via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 8c5edf50234f52e0de37df3e4e7cec92bdb70e12
      https://github.com/llvm/llvm-project/commit/8c5edf50234f52e0de37df3e4e7cec92bdb70e12
  Author: Chen Zheng <czhengsz at cn.ibm.com>
  Date:   2020-08-01 (Sat, 01 Aug 2020)

  Changed paths:
    M llvm/include/llvm/IR/Instructions.h
    M llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp
    A llvm/test/Transforms/LoopStrengthReduce/Power/incomplete-phi.ll
    A llvm/test/Transforms/LoopStrengthReduce/Power/lit.local.cfg

  Log Message:
  -----------
  [SCEV] don't query getSCEV() for incomplete phis

querying getSCEV() for incomplete phis leads to wrong cache value in `ExprToIVMap`,
because incomplete phis may be simplified to same value before get SCEV expression.

Reviewed By: lebedev.ri, mkazantsev

Differential Revision: https://reviews.llvm.org/D77560