-
- /// Handle direct and indirect calls when using PIC. On PIC, when
- /// GOT is smaller than about 64k (small code) the GA target is
- /// loaded with only one instruction. Otherwise GA's target must
- /// be loaded with 3 instructions.
- case MipsISD::JmpLink: {
- if (TM.getRelocationModel() == Reloc::PIC_) {
- unsigned LastOpNum = Node->getNumOperands()-1;
-
- SDValue Chain = Node->getOperand(0);
- SDValue Callee = Node->getOperand(1);
- SDValue InFlag;
-
- // Skip the incomming flag if present
- if (Node->getOperand(LastOpNum).getValueType() == MVT::Glue)
- LastOpNum--;
-
- if ( (isa<GlobalAddressSDNode>(Callee)) ||
- (isa<ExternalSymbolSDNode>(Callee)) )
- {
- /// Direct call for global addresses and external symbols
- SDValue GPReg = CurDAG->getRegister(Mips::GP, MVT::i32);
-
- // Use load to get GOT target
- SDValue Ops[] = { Callee, GPReg, Chain };
- SDValue Load = SDValue(CurDAG->getMachineNode(Mips::LW, dl, MVT::i32,
- MVT::Other, Ops, 3), 0);
- Chain = Load.getValue(1);
-
- // Call target must be on T9
- Chain = CurDAG->getCopyToReg(Chain, dl, Mips::T9, Load, InFlag);
- } else
- /// Indirect call
- Chain = CurDAG->getCopyToReg(Chain, dl, Mips::T9, Callee, InFlag);
-
- // Map the JmpLink operands to JALR
- SDVTList NodeTys = CurDAG->getVTList(MVT::Other, MVT::Glue);
- SmallVector<SDValue, 8> Ops;
- Ops.push_back(CurDAG->getRegister(Mips::T9, MVT::i32));
-
- for (unsigned i = 2, e = LastOpNum+1; i != e; ++i)
- Ops.push_back(Node->getOperand(i));
- Ops.push_back(Chain);
- Ops.push_back(Chain.getValue(1));
-
- // Emit Jump and Link Register
- SDNode *ResNode = CurDAG->getMachineNode(Mips::JALR, dl, NodeTys,
- &Ops[0], Ops.size());
-
- // Replace Chain and InFlag
- ReplaceUses(SDValue(Node, 0), SDValue(ResNode, 0));
- ReplaceUses(SDValue(Node, 1), SDValue(ResNode, 1));
- return ResNode;
- }
- }