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

[Juan Manuel Martinez Caamaño via llvm-commits]

================

----------------
jmmartinez wrote:

I've checked out this test, and run it with these RUN-lines:
```bash
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
; RUN: llc -global-isel=0 -mtriple=amdgcn -mcpu=gfx1250 < %s | FileCheck --check-prefix=GFX1250-SDAG %s
; RUN: llc -global-isel=1 -mtriple=amdgcn -mcpu=gfx1250 < %s | FileCheck --check-prefix=GFX1250-GISEL %s
; RUN: llc -global-isel=0 -mtriple=amdgcn -mcpu=gfx90a < %s | FileCheck --check-prefix=GFX90A-SDAG %s
; RUN: llc -global-isel=1 -mtriple=amdgcn -mcpu=gfx90a < %s | FileCheck --check-prefix=GFX90A-GISEL %s
```

The code generated before/after this patch; even after removing the `isGFX125xOnly` condition was the same.

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