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

Thu Oct 6 08:45:22 PDT 2022

alexfh added a comment.

We started seeing incorrect behavior in some code after this commit. The test case is here: https://gcc.godbolt.org/z/hhj64noKs.

The elimination of `store ptr %9, ptr %0, align 8` at line 362 doesn't seem to be correct, since memory pointed by `%0` could previously be assigned `%44` (e.g. on line 346: `store ptr %44, ptr %0, align 8`), which can hold a different value (line 121): `%44 = load ptr, ptr %2, align 8`. Could you take a look at this?

If you agree that this is a bug, but there is no obvious fix, could you revert the commit while working on a fix?

Thanks!

Repository:
  rG LLVM Github Monorepo

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

https://reviews.llvm.org/D132657