[all-commits] [llvm/llvm-project] 065bf1: [DSE] Remove noop stores in MSSA.

[Zoe Carver via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 065bf124fde8fd9d37eba0a387833cdfe9e68d08
      https://github.com/llvm/llvm-project/commit/065bf124fde8fd9d37eba0a387833cdfe9e68d08
  Author: zoecarver <z.zoelec2 at gmail.com>
  Date:   2020-05-30 (Sat, 30 May 2020)

  Changed paths:
    M llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
    M llvm/test/Transforms/DeadStoreElimination/MSSA/atomic.ll
    A llvm/test/Transforms/DeadStoreElimination/MSSA/noop-stores.ll
    M llvm/test/Transforms/DeadStoreElimination/MSSA/simple-todo.ll

  Log Message:
  -----------
  [DSE] Remove noop stores in MSSA.

Adds a simple fast-path check for the pattern:
v = load ptr
store v to ptr

I took the tests from the bugzilla post, I can add more if needed (but I think these should be sufficent).

Refs: https://bugs.llvm.org/show_bug.cgi?id=45795

Differential Revision: https://reviews.llvm.org/D79391