[PATCH] D32423: Simplify barriers of null and undef

[Piotr Padlewski via Phabricator via llvm-commits]

Prazek added a comment.

In https://reviews.llvm.org/D32423#735352, @davide wrote:

> I guess the patch is implemented correctly, but, can you please provide an example of clang emitting such construct?


Check out https://reviews.llvm.org/D32378
Clang will add barriers for some of pointer casts and pointer compares, so it is important to propagate null.
Propagating undef is only to make sure barriers don't limit optimizations like DCE etc.


https://reviews.llvm.org/D32423