[PATCH] D21271: Fix `InstCombine` to not widen metadata on store-to-load forwarding

[Yichao Yu via llvm-commits]

yuyichao added a comment.

> Can you explain what the problem is


See the test case. The store-to-load forwarding case can return a load instruction too.

> the optimizer is allowed to insert a load anywhere with any metadata as long as it can guarantee it's safe to dereference.


Does it mean that if that store is not merged with something else in a similar way it can be incorrectly optimized?


http://reviews.llvm.org/D21271