[all-commits] [llvm/llvm-project] e441b7: [SCEV] Look through single value PHIs.

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: e441b7a7a0a72c28daf5a8e594559c667e5b4534
      https://github.com/llvm/llvm-project/commit/e441b7a7a0a72c28daf5a8e594559c667e5b4534
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-08-12 (Wed, 12 Aug 2020)

  Changed paths:
    M llvm/lib/Analysis/ScalarEvolution.cpp
    M llvm/test/Analysis/ScalarEvolution/solve-quadratic-i1.ll
    M llvm/test/Analysis/ScalarEvolution/solve-quadratic-overflow.ll
    M llvm/test/Transforms/LoopStrengthReduce/funclet.ll

  Log Message:
  -----------
  [SCEV] Look through single value PHIs.

Now that SCEVExpander can preserve LCSSA form,
we do not have to worry about LCSSA form when
trying to look through PHIs. SCEVExpander will take
care of inserting LCSSA PHI nodes as required.

This increases precision of the analysis in some cases.

Reviewed By: mkazantsev, bmahjour

Differential Revision: https://reviews.llvm.org/D71539