[llvm] [AMDGPU] SelectionDAG support for vector type set 0 to multiple sgpr64 (PR #128017)

[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)' 41cece8c86399dd1ffcb6b7a8b50c10083fe5a40 34567eced88459d8f64a945af33bde84feb7f91e llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp llvm/lib/Target/AMDGPU/SIFoldOperands.cpp llvm/test/CodeGen/AMDGPU/adjust-writemask-cse.ll llvm/test/CodeGen/AMDGPU/agpr-copy-no-free-registers.ll llvm/test/CodeGen/AMDGPU/atomic-optimizer-strict-wqm.ll llvm/test/CodeGen/AMDGPU/bitreverse-inline-immediates.ll llvm/test/CodeGen/AMDGPU/blender-no-live-segment-at-def-implicit-def.ll llvm/test/CodeGen/AMDGPU/bug-cselect-b64.ll llvm/test/CodeGen/AMDGPU/cluster_stores.ll llvm/test/CodeGen/AMDGPU/collapse-endcf.ll llvm/test/CodeGen/AMDGPU/fcanonicalize.f16.ll llvm/test/CodeGen/AMDGPU/fcanonicalize.ll llvm/test/CodeGen/AMDGPU/fix-sgpr-copies-nondeterminism.ll llvm/test/CodeGen/AMDGPU/flat-scratch.ll llvm/test/CodeGen/AMDGPU/gfx-callable-return-types.ll llvm/test/CodeGen/AMDGPU/hazard-recognizer-src-shared-base.ll llvm/test/CodeGen/AMDGPU/identical-subrange-spill-infloop.ll llvm/test/CodeGen/AMDGPU/imm.ll llvm/test/CodeGen/AMDGPU/indirect-addressing-si.ll llvm/test/CodeGen/AMDGPU/issue92561-restore-undef-scc-verifier-error.ll llvm/test/CodeGen/AMDGPU/issue98474-need-live-out-undef-subregister-def.ll llvm/test/CodeGen/AMDGPU/llvm.amdgcn.mfma.ll llvm/test/CodeGen/AMDGPU/max-hard-clause-length.ll llvm/test/CodeGen/AMDGPU/memcpy-crash-issue63986.ll llvm/test/CodeGen/AMDGPU/mfma-loop.ll llvm/test/CodeGen/AMDGPU/module-lds-false-sharing.ll llvm/test/CodeGen/AMDGPU/no-dup-inst-prefetch.ll llvm/test/CodeGen/AMDGPU/no-fold-accvgpr-mov.ll llvm/test/CodeGen/AMDGPU/scalar-float-sop2.ll llvm/test/CodeGen/AMDGPU/scheduler-rp-calc-one-successor-two-predecessors-bug.ll llvm/test/CodeGen/AMDGPU/set_kill_i1_for_floation_point_comparison.ll llvm/test/CodeGen/AMDGPU/si-optimize-vgpr-live-range-dbg-instr.ll llvm/test/CodeGen/AMDGPU/si-scheduler-exports.ll llvm/test/CodeGen/AMDGPU/smfmac_no_agprs.ll llvm/test/CodeGen/AMDGPU/splitkit-getsubrangeformask.ll llvm/test/CodeGen/AMDGPU/tuple-allocation-failure.ll llvm/test/CodeGen/AMDGPU/vni8-across-blocks.ll llvm/test/CodeGen/AMDGPU/vopc_dpp.ll llvm/test/CodeGen/AMDGPU/waterfall_kills_scc.ll llvm/test/CodeGen/AMDGPU/wqm.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/128017