[PATCH] D88979: [InstCombine] combineLoadToOperationType(): don't fold int<->ptr cast into load

Sun Oct 11 09:45:09 PDT 2020

lebedev.ri added a comment.

In D88979#2323935 <https://reviews.llvm.org/D88979#2323935>, @nikic wrote:

> LGTM

@nlopes does this look good to you?

> Looking through other uses of isNoopCast(), I don't think it makes sense to push this change into it, as many other usages do need it to work with ptrtoint/inttoptr (some of them using it specifically for them). The comment above the function indicates that "no-op" is to be understood as "generates no code" here. Possibly it could do with a rename.

I think i don't agree with you there.
I agree with @nlopes, the end goal will be to basically disallow fusing of `inttoptr`/`ptrtoint` into loads, 
disallow dropping inttoptr-of-ptrtoint/ptrtoint-of-inttoptr, etc.
And all that eventually boils down to updating `CastInst::isNoopCast()`/`CastInst::isEliminableCastPair()`.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D88979/new/

https://reviews.llvm.org/D88979