[PATCH] D31900: [AddDiscriminators] Assign discriminators to memset/memcpy/memmove intrinsic calls.

[Dehao Chen via Phabricator via llvm-commits]

danielcdh added a comment.

Thanks for explaining. My understanding is that memcpy will introduce new basic block, which will share the same discriminator with other basic block without this patch. As a result, that basic block is incorrectly annotated so that the block placement is suboptimal. If my understanding is correct, could you include a that in the unittest?

The reason I'm careful on adding new discriminator is that as we are encoding discriminator, we have limited bit to represent the base discriminator. We only want to set new discriminator when it can improve profile quality, which is valid if we can have a test showing how this can improve profile quality.


https://reviews.llvm.org/D31900