[all-commits] [llvm/llvm-project] a344b3: [GVN] Preserve MemorySSA if it is available.

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a344b382a0f64922c22a4ad048aca925a784942a
      https://github.com/llvm/llvm-project/commit/a344b382a0f64922c22a4ad048aca925a784942a
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-09-03 (Thu, 03 Sep 2020)

  Changed paths:
    M llvm/include/llvm/Transforms/Scalar/GVN.h
    M llvm/lib/Transforms/Scalar/GVN.cpp
    A llvm/test/Transforms/GVN/preserve-memoryssa.ll

  Log Message:
  -----------
  [GVN] Preserve MemorySSA if it is available.

Preserve MemorySSA if it is available before running GVN.

DSE with MemorySSA will run closely after GVN. If GVN and 2 other
passes preserve MemorySSA, DSE can re-use MemorySSA used by LICM
when doing LTO.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D86534