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"
33 /// MSP430DAGToDAGISel - MSP430 specific code to select MSP430 machine
34 /// instructions for SelectionDAG operations.
37 class MSP430DAGToDAGISel : public SelectionDAGISel {
38 MSP430TargetLowering &Lowering;
39 const MSP430Subtarget &Subtarget;
42 MSP430DAGToDAGISel(MSP430TargetMachine &TM, CodeGenOpt::Level OptLevel)
43 : SelectionDAGISel(TM, OptLevel),
44 Lowering(*TM.getTargetLowering()),
45 Subtarget(*TM.getSubtargetImpl()) { }
47 virtual void InstructionSelect();
49 virtual const char *getPassName() const {
50 return "MSP430 DAG->DAG Pattern Instruction Selection";
53 // Include the pieces autogenerated from the target description.
54 #include "MSP430GenDAGISel.inc"
57 SDNode *Select(SDValue Op);
58 bool SelectAddr(SDValue Op, SDValue Addr, SDValue &Base, SDValue &Disp);
64 } // end anonymous namespace
66 /// createMSP430ISelDag - This pass converts a legalized DAG into a
67 /// MSP430-specific DAG, ready for instruction scheduling.
69 FunctionPass *llvm::createMSP430ISelDag(MSP430TargetMachine &TM,
70 CodeGenOpt::Level OptLevel) {
71 return new MSP430DAGToDAGISel(TM, OptLevel);
74 // FIXME: This is pretty dummy routine and needs to be rewritten in the future.
75 bool MSP430DAGToDAGISel::SelectAddr(SDValue Op, SDValue Addr,
76 SDValue &Base, SDValue &Disp) {
77 // Try to match frame address first.
78 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
79 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
80 Disp = CurDAG->getTargetConstant(0, MVT::i16);
84 switch (Addr.getOpcode()) {
86 // Operand is a result from ADD with constant operand which fits into i16.
87 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
88 uint64_t CVal = CN->getZExtValue();
89 // Offset should fit into 16 bits.
90 if (((CVal << 48) >> 48) == CVal) {
91 SDValue N0 = Addr.getOperand(0);
92 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N0))
93 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
97 Disp = CurDAG->getTargetConstant(CVal, MVT::i16);
102 case MSP430ISD::Wrapper:
103 SDValue N0 = Addr.getOperand(0);
104 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) {
105 Base = CurDAG->getTargetGlobalAddress(G->getGlobal(),
106 MVT::i16, G->getOffset());
107 Disp = CurDAG->getTargetConstant(0, MVT::i16);
109 } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(N0)) {
110 Base = CurDAG->getTargetExternalSymbol(E->getSymbol(), MVT::i16);
111 Disp = CurDAG->getTargetConstant(0, MVT::i16);
117 Disp = CurDAG->getTargetConstant(0, MVT::i16);
124 /// InstructionSelect - This callback is invoked by
125 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
126 void MSP430DAGToDAGISel::InstructionSelect() {
129 // Codegen the basic block.
131 DOUT << "===== Instruction selection begins:\n";
136 DOUT << "===== Instruction selection ends:\n";
139 CurDAG->RemoveDeadNodes();
142 SDNode *MSP430DAGToDAGISel::Select(SDValue Op) {
143 SDNode *Node = Op.getNode();
144 DebugLoc dl = Op.getDebugLoc();
146 // Dump information about the Node being selected
148 DOUT << std::string(Indent, ' ') << "Selecting: ";
149 DEBUG(Node->dump(CurDAG));
154 // If we have a custom node, we already have selected!
155 if (Node->isMachineOpcode()) {
157 DOUT << std::string(Indent-2, ' ') << "== ";
158 DEBUG(Node->dump(CurDAG));
165 // Few custom selection stuff.
166 switch (Node->getOpcode()) {
168 case ISD::FrameIndex: {
169 assert(Op.getValueType() == MVT::i16);
170 int FI = cast<FrameIndexSDNode>(Node)->getIndex();
171 SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i16);
172 if (Node->hasOneUse())
173 return CurDAG->SelectNodeTo(Node, MSP430::ADD16ri, MVT::i16,
174 TFI, CurDAG->getTargetConstant(0, MVT::i16));
175 return CurDAG->getTargetNode(MSP430::ADD16ri, dl, MVT::i16,
176 TFI, CurDAG->getTargetConstant(0, MVT::i16));
180 // Select the default instruction
181 SDNode *ResNode = SelectCode(Op);
184 DOUT << std::string(Indent-2, ' ') << "=> ";
185 if (ResNode == NULL || ResNode == Op.getNode())
186 DEBUG(Op.getNode()->dump(CurDAG));
188 DEBUG(ResNode->dump(CurDAG));