[PATCH] D55467: [WebAssembly] Optimize Irreducible Control Flow

[Alon Zakai via Phabricator via llvm-commits]

kripken added a comment.

In D55467#1326244 <https://reviews.llvm.org/D55467#1326244>, @kripken wrote:

> In D55467#1326177 <https://reviews.llvm.org/D55467#1326177>, @sunfish wrote:
>
> > Do we know what part of the optimizer or codegen is introducing the irreducible control flow in malloc?
>
>
> Not for malloc - I think @jgravelle-google  may have been looking into that though?


Discussing offline, there is some investigation but the details are not yet clear.

I agree figuring that out is very important - if we can avoid unnecessary irreducible control flow that's great. I think it's a separate issue from this patch, though, since as mentioned above even libc has a few places with source-code level irreducible control flow. We could only fix that by rewriting the source, but even that would just be for libc, and not other user code. So regardless I think we should emit compact code when irreducible code occurs, which is what this patch focuses on.


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