[llvm-branch-commits] [llvm] release/18.x: [llvm][LoongArch] Improve loongarch_lasx_xvpermi_q instrinsic (#82984) (PR #83540)

[Xi Ruoyao via llvm-branch-commits]

xry111 wrote:

I have some doubt about this change.

To me if the user requests `xvpermi.q` via the `loongarch_lasx_xvpermi_q` intrinsic, we should give her/him the `xvpermi.q` instruction.  If (s)he is passing an invalid operand then (s)he is invoking the undefined behavior herself/himself and we don't need to guarantee a thing.

So to me we should not merge this and we should revert this change for main.  Or am I missing something?  @xen0n @heiher @SixWeining @MaskRay 

https://github.com/llvm/llvm-project/pull/83540