[compiler-rt] [llvm] [RISCV] Allocate Feature Bits for Zilsd/Zclsd/Zcmp (PR #135197)

[Pengcheng Wang via llvm-commits]

wangpc-pp wrote:

> > is it right to land this before kernel supports?
> 
> To provide some context I provided on the toolchains call, with assistance from Kito:
> 
> * Zilsd/Zclsd are 32-bit only, so may take some time to appear in linux, if they ever do.
> * Zcmp is incompatible with Zcd, so may not appear in linux hwcaps if linux focuses on rv64gc (or the profiles that include C+D, which implicitly have Zcd)
> 
> These bitmaps have been proposed because the Hazard3 core wants to skip any heavyweight capabilites spec, and just directly implement the C API's bitmap layout in hardware. This core implements these three extensions, and it is perfectly possible for a SDK to expose something compatible with the C API without it being linux.
> 
> LLVM/GCC implementations are a prerequisite for allocating these bits in the C API, which is why we have this implementation.

Got it! Then I am OK with this, please go ahead!

https://github.com/llvm/llvm-project/pull/135197