[llvm] [AMDGPU] Fix OpenCL conformance test failures for ctlz. (PR #83170)

[Leon Clark via llvm-commits]

PeddleSpam wrote:

> > The version with the shift works fine for ctlz_zero_undef (and it would still be good to generate it since it's usually shorter) but not ctlz.
> 
> See #83039 which optimizes generic codegen for ctlz_zero_undef to use the version with the shift.

Thanks, I'll take a look.

https://github.com/llvm/llvm-project/pull/83170