[llvm] [AMDGPU] Add `isAsCheapAsAMove` for `v_pk_mov_b32` (PR #127632)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Shilei Tian (shiltian)

<details>
<summary>Changes</summary>

Credit: @<!-- -->arsenm 

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Full diff: https://github.com/llvm/llvm-project/pull/127632.diff


1 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/VOP3PInstructions.td (+1-1) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/VOP3PInstructions.td b/llvm/lib/Target/AMDGPU/VOP3PInstructions.td
index 21898da1912f5..d5c6e8af109f4 100644
--- a/llvm/lib/Target/AMDGPU/VOP3PInstructions.td
+++ b/llvm/lib/Target/AMDGPU/VOP3PInstructions.td
@@ -1151,7 +1151,7 @@ let isCommutable = 1, isReMaterializable = 1 in {
     defm V_PK_ADD_F32 : VOP3PInst<"v_pk_add_f32", VOP3P_Profile<VOP_V2F32_V2F32_V2F32, VOP3_PACKED>, any_fadd>;
   } // End SubtargetPredicate = HasPackedFP32Ops
 
-  let SubtargetPredicate = HasPkMovB32 in
+  let SubtargetPredicate = HasPkMovB32, isAsCheapAsAMove = 1 in
   defm V_PK_MOV_B32 : VOP3PInst<"v_pk_mov_b32", VOP3P_Profile<VOP_V2I32_V2I32_V2I32, VOP3_PACKED>>;
 } // End isCommutable = 1, isReMaterializable = 1
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/127632