[PATCH] D31037: [EarlyCSE] hoist div/rem when sibling op exists (PR31028)

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In https://reviews.llvm.org/D31037#714596, @dberlin wrote:

> I dunno. Does EarlyCSE do any other insertion?


This is my first experience with EarlyCSE, but I don't think there's anything else that moves an instruction. Everything else is killing from what I see.

> I'm somewhat wary.
>  My general feeling is the insertion should be separate from the rest of what it does, but i understand that's hard in earlycse because it does not really produce an analysis.
>  I just feel weird be shoving more stuff in there :)
>  *especially* cost based stuff.

TTI was here of course, but yes, using the cost model is another potential precedent. :)

> I'd actually feel better even if you did this in GVN or something that at least does insertion right now, even if that's not quite a great solution either.

OK, I'll have a (first) look at GVN.


Repository:
  rL LLVM

https://reviews.llvm.org/D31037