AMDGPU: Support commuting a FrameIndex operand

llvm-svn: 281369

llvm/lib/CodeGen/MachineInstr.cpp

@@ -175,6 +175,16 @@ void MachineOperand::ChangeToMCSymbol(MCSymbol *Sym) {
   Contents.Sym = Sym;
 }
 
+void MachineOperand::ChangeToFrameIndex(int Idx) {
+  assert((!isReg() || !isTied()) &&
+         "Cannot change a tied operand into a FrameIndex");
+
+  removeRegFromUses();
+
+  OpKind = MO_FrameIndex;
+  setIndex(Idx);
+}
+
 /// ChangeToRegister - Replace this operand with a new register operand of
 /// the specified value.  If an operand is known to be an register already,
 /// the setReg method should be used.