| This is a workaround to keep LLVM from incorrectly removing stores in rare |
| cases. It has not yet been committed, and -- due to the direction we seem to |
| want to take MSSA in -- probably never will be. |
| |
| It should be sufficient to work around the problem until we agree on a good way |
| forward. |
| |
| Additional context: https://reviews.llvm.org/D43269 |
| |
| This is rebased to r327695 by gbiv@chromium.org. |
| |
| diff --git a/lib/Analysis/MemorySSA.cpp b/lib/Analysis/MemorySSA.cpp |
| index ce8504b87a7..9ff7aa316b1 100644 |
| --- a/lib/Analysis/MemorySSA.cpp |
| +++ b/lib/Analysis/MemorySSA.cpp |
| @@ -246,13 +246,13 @@ static ClobberAlias instructionClobbersQuery(MemoryDef *MD, |
| |
| if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(DefInst)) { |
| // These intrinsics will show up as affecting memory, but they are just |
| - // markers. |
| + // markers, mostly. |
| switch (II->getIntrinsicID()) { |
| case Intrinsic::lifetime_start: |
| if (UseCS) |
| return {false, NoAlias}; |
| AR = AA.alias(MemoryLocation(II->getArgOperand(1)), UseLoc); |
| - return {AR == MustAlias, AR}; |
| + return {AR != NoAlias, AR}; |
| case Intrinsic::lifetime_end: |
| case Intrinsic::invariant_start: |
| case Intrinsic::invariant_end: |
