[PATCH] D25276: [LoopVectorizer] Interleaved-mem-accesses analysis and getPtrStride

[silviu.baranga@arm.com via llvm-commits]

sbaranga added a comment.

In https://reviews.llvm.org/D25276#567145, @dorit wrote:

> Agreed?


SGTM

> Yes; but my point was that when ShouldCheckWrap=false we never get to consider adding new runtime checks in getPtrStride, even if Assume=true. Unless I'm missing something?

Assume=true can add more run-time checks than just for what ShouldCheckWrap checks, so it is possible for this to happen. ShouldCheckWrap will check wrapping for something that has an linear expression, while Assume=true can add checks that would make the expression of the pointer linear (this would happen in the previous example). If you look at the implementation of getPtrStride, the PSE.getAsAddRec(Ptr) convert the expression of the pointer to something linear (strided) using runtime checks, while PSE.setNoOverflow will only check the pointer wrapping with runtime checks.

-Silviu


https://reviews.llvm.org/D25276