[PATCH] D77736: [DSE] Lift post-dominance for objs not accessible in caller.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: dmgreen, bryant, asbirlea, Tyker, efriedma, george.burgess.iv.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

We can eliminate MemoryDefs of objects not accessible after the function
returns (e.g. alloca), if there are no reads between the MemoryDef and
any function exits. We can stop traversing paths that completely
overwrite the memory location of the MemoryDef.

This patch was split off D73763 <https://reviews.llvm.org/D73763>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D77736

Files:
  llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
  llvm/test/Transforms/DeadStoreElimination/MSSA/memset-missing-debugloc.ll
  llvm/test/Transforms/DeadStoreElimination/MSSA/memset-unknown-sizes.ll
  llvm/test/Transforms/DeadStoreElimination/MSSA/multiblock-malloc-free.ll
  llvm/test/Transforms/DeadStoreElimination/MSSA/multiblock-memintrinsics.ll
  llvm/test/Transforms/DeadStoreElimination/MSSA/multiblock-multipath.ll
  llvm/test/Transforms/DeadStoreElimination/MSSA/multiblock-simple.ll

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