[PATCH] D45330: [WIP][IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

In https://reviews.llvm.org/D45330#1062304, @dberlin wrote:

> So, predicateinfo is one of the fastest passes (or was) that we had. I'm not horribly worried about speed (i could make it faster, too).
>  It was faster than anything else we do that isn't lazy (IE it's faster than computing dominators, etc).
>  It wasn't even really measurable except on hundreds of thousands or millions of blocks.
>
> I did have plans to try to turn it back into a virtual form at some point (which would make it faster), i think i found an not horrible way of doing it.
>
> The one overall comment i'd have here is that SCCP is fairly limited in how it can use this, because of how limited the lattice is.
>  IPVRP would be a better bet, IMHO.


Yep. One of the slightly longer-term things I want to do is either make IPSCCP use a lattice including (integer) ranges or have a separate pass doing value range propagation. Do you think having it as a separate pass would be beneficial?

> That said,

Looks like the comment got cut off here?


https://reviews.llvm.org/D45330