[llvm] [AMDGPU] using divergent/uniform information in ISel of zext (PR #174539)

[Juan Manuel Martinez Caamaño via llvm-commits]

https://github.com/jmmartinez commented:

Could you add a test that showcases the code that you want to optimize, such that if we do not apply the fix, the generated code changes ?

https://github.com/llvm/llvm-project/pull/174539