[llvm] [AMDGPU][True16] si-fold-operand selecting srcidx for v_mov_b16_t16_e64 (PR #162101)

[Brox Chen via llvm-commits]

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@@ -932,7 +932,8 @@ static MachineOperand *lookUpCopyChain(const SIInstrInfo &TII,
   for (MachineInstr *SubDef = MRI.getVRegDef(SrcReg);
        SubDef && TII.isFoldableCopy(*SubDef);
        SubDef = MRI.getVRegDef(Sub->getReg())) {
-    unsigned SrcIdx = TII.getFoldableCopySrcIdx(*SubDef);
+    const int SrcIdx =
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broxigarchen wrote:

test added in previous patch https://github.com/llvm/llvm-project/pull/161764/files#diff-fdc17816dfff25251b0acd60e624921d50180b5c2fd5e1c6673a7a57def7f5e4

https://github.com/llvm/llvm-project/pull/162101