[PATCH] D132657: [DSE] Eliminate noop store even through has clobbering between LoadI and StoreI

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks added a comment.

reduced test case

  define void @f(ptr %arg, ptr %arg1, i1 %arg2) {
  bb:
    %tmp = load ptr, ptr %arg, align 8
    %tmp3 = load ptr, ptr %arg1, align 8
    store ptr %tmp3, ptr %arg, align 8
    store ptr %tmp, ptr %arg1, align 8
    br i1 %arg2, label %bb5, label %bb6
  
  bb5:
    store ptr %tmp, ptr %arg, align 8 ; this store is incorrectly removed
    store ptr %tmp3, ptr %arg1, align 8
    ret void
  
  bb6:
    ret void
  }

we're first swapping the values `%arg` and `%arg1` point to, then conditionally swapping them back to their original values

will revert


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132657/new/

https://reviews.llvm.org/D132657