Maybe we should get rid of ifuncs

[Zack Weinberg]

On Tue Apr 23, 2024 at 2:39 PM EDT, enh wrote:
> one thing i think is interesting (having been looking at ifuncs while
> adding riscv64 support to Android) is that afaict bionic [Android's
> libc] is basically the only current user. every library i'm aware of
> (and certainly every library that's part of the OS) does _not_ use
> ifuncs, if only because iOS/macOS has no equivalent (and Windows
> too?), and if you've got to have the manual function pointer
> manipulation implementation for them...

I assume you meant "every library that's *not* part of the OS"?

> that said, for llvm at least there's work on function multi-versioning
> where the compiler basically writes the ifunc resolver. but (a) that's
> not quite finished yet (?) and (b) i haven't seen anyone _use_ it yet
> and (c) is at least by definition of being machine-generated pretty
> regular.

Do you know where to find the llvm work in progress?

zw