[PATCH] D58260: [INLINER] allow inlining of blockaddresses if sole uses are callbrs

[Bill Wendling via Phabricator via llvm-commits]

void added a comment.

In D58260#1482993 <https://reviews.llvm.org/D58260#1482993>, @efriedma wrote:

> > But should it?
>
> It seems like a reasonable optimization, depending on the code structure.
>
> > That implies that a blockaddress that's propagated to other functions aren't used by anything other than arithmetic and comparison instructions.
>
> The important thing is that it can also be returned back to the original function, either directly, or indirectly through memory.


Right. My point is that it's equivalent to passing a pointer around, except that the pointer cannot be dereferenced anywhere except the originating function. (For the purposes of what Nick's trying to do, "originating function" includes code that's inlined into a function.) As long as IPSCCP and the like don't violate that constraint, passing the pointer around isn't going to cause semantic changes to the program. (A function that tries to jump to a block address that's not within that function is already undefined and still should be.)

Perhaps I'm missing something though...


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58260/new/

https://reviews.llvm.org/D58260