[llvm] [AMDGPU][MC] GFX9 - allow op_sel in v_interp_p2_f16 (PR #150712)

[Joe Nash via llvm-commits]

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@@ -9310,6 +9310,38 @@ void AMDGPUAsmParser::cvtVOP3Interp(MCInst &Inst, const OperandVector &Operands)
   if (AMDGPU::hasNamedOperand(Opc, AMDGPU::OpName::omod))
     addOptionalImmOperand(Inst, Operands, OptionalIdx,
                           AMDGPUOperand::ImmTyOModSI);
+
+  // Some v_interp instrutions use op_sel[3] for dst.
+  if (AMDGPU::hasNamedOperand(Opc, AMDGPU::OpName::op_sel)) {
+    addOptionalImmOperand(Inst, Operands, OptionalIdx,
+                          AMDGPUOperand::ImmTyOpSel);
+    int OpSelIdx = AMDGPU::getNamedOperandIdx(Opc, AMDGPU::OpName::op_sel);
+    unsigned OpSel = Inst.getOperand(OpSelIdx).getImm();
+
+    const AMDGPU::OpName Ops[] = {AMDGPU::OpName::src0, AMDGPU::OpName::src1,
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Sisyph wrote:

This looks copied from cvtVINTERP. Can you outline it into a helper method?

https://github.com/llvm/llvm-project/pull/150712