1 //===-- MSP430ISelDAGToDAG.cpp - A dag to dag inst selector for MSP430 ----===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines an instruction selector for the MSP430 target.
12 //===----------------------------------------------------------------------===//
15 #include "MSP430ISelLowering.h"
16 #include "MSP430TargetMachine.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Function.h"
19 #include "llvm/Intrinsics.h"
20 #include "llvm/CallingConv.h"
21 #include "llvm/Constants.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGISel.h"
28 #include "llvm/Target/TargetLowering.h"
29 #include "llvm/Support/Compiler.h"
30 #include "llvm/Support/Debug.h"
35 /// MSP430DAGToDAGISel - MSP430 specific code to select MSP430 machine
36 /// instructions for SelectionDAG operations.
39 class MSP430DAGToDAGISel : public SelectionDAGISel {
40 MSP430TargetLowering &Lowering;
41 const MSP430Subtarget &Subtarget;
44 MSP430DAGToDAGISel(MSP430TargetMachine &TM)
45 : SelectionDAGISel(TM),
46 Lowering(*TM.getTargetLowering()),
47 Subtarget(*TM.getSubtargetImpl()) { }
49 virtual void InstructionSelect();
51 virtual const char *getPassName() const {
52 return "MSP430 DAG->DAG Pattern Instruction Selection";
55 // Include the pieces autogenerated from the target description.
56 #include "MSP430GenDAGISel.inc"
59 SDNode *Select(SDValue Op);
60 bool SelectAddr(SDValue Op, SDValue Addr, SDValue &Base, SDValue &Disp);
66 } // end anonymous namespace
68 /// createMSP430ISelDag - This pass converts a legalized DAG into a
69 /// MSP430-specific DAG, ready for instruction scheduling.
71 FunctionPass *llvm::createMSP430ISelDag(MSP430TargetMachine &TM) {
72 return new MSP430DAGToDAGISel(TM);
75 // FIXME: This is pretty dummy routine and needs to be rewritten in the future.
76 bool MSP430DAGToDAGISel::SelectAddr(SDValue Op, SDValue Addr,
77 SDValue &Base, SDValue &Disp) {
78 // Try to match frame address first.
79 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
80 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
81 Disp = CurDAG->getTargetConstant(0, MVT::i16);
85 switch (Addr.getOpcode()) {
87 // Operand is a result from ADD with constant operand which fits into i16.
88 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
89 uint64_t CVal = CN->getZExtValue();
90 // Offset should fit into 16 bits.
91 if (((CVal << 48) >> 48) == CVal) {
92 SDValue N0 = Addr.getOperand(0);
93 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N0))
94 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
98 Disp = CurDAG->getTargetConstant(CVal, MVT::i16);
103 case MSP430ISD::Wrapper:
104 SDValue N0 = Addr.getOperand(0);
105 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) {
106 Base = CurDAG->getTargetGlobalAddress(G->getGlobal(),
107 MVT::i16, G->getOffset());
108 Disp = CurDAG->getTargetConstant(0, MVT::i16);
110 } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(N0)) {
111 Base = CurDAG->getTargetExternalSymbol(E->getSymbol(), MVT::i16);
112 Disp = CurDAG->getTargetConstant(0, MVT::i16);
118 Disp = CurDAG->getTargetConstant(0, MVT::i16);
125 /// InstructionSelect - This callback is invoked by
126 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
127 void MSP430DAGToDAGISel::InstructionSelect() {
130 // Select target instructions for the DAG.
133 CurDAG->RemoveDeadNodes();
136 SDNode *MSP430DAGToDAGISel::Select(SDValue Op) {
137 SDNode *Node = Op.getNode();
138 DebugLoc dl = Op.getDebugLoc();
140 // Dump information about the Node being selected
142 DOUT << std::string(Indent, ' ') << "Selecting: ";
143 DEBUG(Node->dump(CurDAG));
148 // If we have a custom node, we already have selected!
149 if (Node->isMachineOpcode()) {
151 DOUT << std::string(Indent-2, ' ') << "== ";
152 DEBUG(Node->dump(CurDAG));
159 // Few custom selection stuff.
160 switch (Node->getOpcode()) {
162 case ISD::FrameIndex: {
163 assert(Op.getValueType() == MVT::i16);
164 int FI = cast<FrameIndexSDNode>(Node)->getIndex();
165 SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i16);
166 if (Node->hasOneUse())
167 return CurDAG->SelectNodeTo(Node, MSP430::ADD16ri, MVT::i16,
168 TFI, CurDAG->getTargetConstant(0, MVT::i16));
169 return CurDAG->getTargetNode(MSP430::ADD16ri, dl, MVT::i16,
170 TFI, CurDAG->getTargetConstant(0, MVT::i16));
174 // Select the default instruction
175 SDNode *ResNode = SelectCode(Op);
178 DOUT << std::string(Indent-2, ' ') << "=> ";
179 if (ResNode == NULL || ResNode == Op.getNode())
180 DEBUG(Op.getNode()->dump(CurDAG));
182 DEBUG(ResNode->dump(CurDAG));