target_clones: molehill or everest?

[Bruce Carneal]

On Tuesday, 7 June 2022 at 15:50:56 UTC, kinke wrote:
> On Tuesday, 7 June 2022 at 14:18:11 UTC, Bruce Carneal wrote:
>> Would adding clang's *target_clones* attribute be difficult?
>
> Hmm, it's apparently not supported in LLVM IR directly; the IR 
> changes for clang are substantial: 
> https://cpp.godbolt.org/z/WT56axqj1
>
> So unless the LLVM API provides a helper (mainly generating the 
> resolver with its conditions depending on some 
> `__cpu_indicator_init()` and `__cpu_model`), it's probably 
> difficult indeed.

Thanks for checking.  I'll look at gcd (thanks Iain) and at 
another CT hack that groups and manages the target funcs manually.