[all-commits] [llvm/llvm-project] c59bc2: [NewGVN][PHIOFOPS] Relax conditions when checking ...

[ManuelJBrito via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c59bc230e738036050f4c9b1ebde88699eec74bf
      https://github.com/llvm/llvm-project/commit/c59bc230e738036050f4c9b1ebde88699eec74bf
  Author: ManuelJBrito <manuel.brito at tecnico.ulisboa.pt>
  Date:   2023-08-01 (Tue, 01 Aug 2023)

  Changed paths:
    M llvm/lib/Transforms/Scalar/NewGVN.cpp
    M llvm/test/Transforms/NewGVN/phi-of-ops-loads.ll
    M llvm/test/Transforms/NewGVN/storeoverstore.ll

  Log Message:
  -----------
  [NewGVN][PHIOFOPS] Relax conditions when checking safety of memory accesses

Currently, we consider any instruction that might read from memory to be unsafe for phi-of-ops.
This patch refines that by walking the clobbering memDefs until we either hit a block that
strictly dominates the phi block (safe) or we hit a clobbering memPhi (unsafe).

Differential Revision: https://reviews.llvm.org/D156055