[llvm] [SLP]Gather scalarized calls (PR #125070)

[via llvm-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)' fe7e280820c8f4a46f49357097d7f6897bd31d41 1eddb79f67089ab21164bade85e11250c47cfdeb llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp llvm/test/Transforms/SLPVectorizer/AArch64/accelerate-vector-functions-inseltpoison.ll llvm/test/Transforms/SLPVectorizer/AArch64/accelerate-vector-functions.ll llvm/test/Transforms/SLPVectorizer/NVPTX/vectorizable-intrinsic.ll llvm/test/Transforms/SLPVectorizer/RISCV/math-function.ll llvm/test/Transforms/SLPVectorizer/X86/alternate-calls-inseltpoison.ll llvm/test/Transforms/SLPVectorizer/X86/alternate-calls.ll llvm/test/Transforms/SLPVectorizer/X86/call.ll llvm/test/Transforms/SLPVectorizer/X86/extract_in_tree_user.ll llvm/test/Transforms/SLPVectorizer/X86/intrinsic.ll llvm/test/Transforms/SLPVectorizer/X86/intrinsic_with_scalar_param.ll llvm/test/Transforms/SLPVectorizer/X86/powi-regression.ll llvm/test/Transforms/SLPVectorizer/X86/powi.ll llvm/test/Transforms/SLPVectorizer/X86/sin-sqrt.ll
``````````

</details>


The following files introduce new uses of undef:
 - llvm/test/Transforms/SLPVectorizer/RISCV/math-function.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/125070