[llvm-branch-commits] [llvm] AMDGPU: Replace ptr addrspace(4) undef uses with poison in tests (PR #131095)

[via llvm-branch-commits]

github-actions[bot] wrote:

<!--LLVM CODE FORMAT COMMENT: {undef deprecator}-->


:warning: undef deprecator found issues in your code. :warning:

<details>
<summary>
You can test this locally with the following command:
</summary>

``````````bash
git diff -U0 --pickaxe-regex -S '([^a-zA-Z0-9#_-]undef[^a-zA-Z0-9_-]|UndefValue::get)' 8d6e244811b467787ccadf639f856714dc3bac82 18928ef44f187d2c47963c9a9b976e5926cee45e llvm/test/CodeGen/AMDGPU/GlobalISel/function-returns.ll llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-call-non-fixed.ll llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-call.ll llvm/test/CodeGen/AMDGPU/agpr-copy-no-free-registers.ll llvm/test/CodeGen/AMDGPU/attr-amdgpu-num-sgpr.ll llvm/test/CodeGen/AMDGPU/branch-relaxation.ll llvm/test/CodeGen/AMDGPU/bug-v4f64-subvector.ll llvm/test/CodeGen/AMDGPU/call-argument-types.ll llvm/test/CodeGen/AMDGPU/function-returns.ll llvm/test/CodeGen/AMDGPU/gfx-callable-argument-types.ll llvm/test/CodeGen/AMDGPU/insert_vector_elt.ll llvm/test/CodeGen/AMDGPU/multi-divergent-exit-region.ll llvm/test/CodeGen/AMDGPU/opencl-printf.ll llvm/test/CodeGen/AMDGPU/spill-m0.ll llvm/test/CodeGen/AMDGPU/splitkit-getsubrangeformask.ll llvm/test/CodeGen/AMDGPU/uniform-crash.ll
``````````

</details>


The following files introduce new uses of undef:
 - llvm/test/CodeGen/AMDGPU/splitkit-getsubrangeformask.ll

[Undef](https://llvm.org/docs/LangRef.html#undefined-values) is now deprecated and should only be used in the rare cases where no replacement is possible. For example, a load of uninitialized memory yields `undef`. You should use `poison` values for placeholders instead.

In tests, avoid using `undef` and having tests that trigger undefined behavior. If you need an operand with some unimportant value, you can add a new argument to the function and use that instead.

For example, this is considered a bad practice:
```llvm
define void @fn() {
  ...
  br i1 undef, ...
}
```

Please use the following instead:
```llvm
define void @fn(i1 %cond) {
  ...
  br i1 %cond, ...
}
```

Please refer to the [Undefined Behavior Manual](https://llvm.org/docs/UndefinedBehavior.html) for more information.



https://github.com/llvm/llvm-project/pull/131095