[clang] [llvm] [RISCV] Preliminary P-ext intrinsics support (PR #174068)

[via llvm-commits]

sihuan wrote:

> For such simple operation I would prefer just use operator to implement on header, e.g.
> 
> ```c
> static __inline__
> int8x4_t __attribute__((__always_inline__, __nodebug__)) __riscv_padd_i8x4(int8x4_t rs1, int8x4_t rs2)
> {
>   return rs1 + rs2;
> }
> ```

Thank you for the suggestion. I agree that I likely over-complicated the implementation. I will refactor the patch.

https://github.com/llvm/llvm-project/pull/174068