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"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/raw_ostream.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, CodeGenOpt::Level OptLevel)
45 : SelectionDAGISel(TM, OptLevel),
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";
56 SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
57 std::vector<SDValue> &OutOps);
59 // Include the pieces autogenerated from the target description.
60 #include "MSP430GenDAGISel.inc"
63 SDNode *Select(SDValue Op);
64 bool SelectAddr(SDValue Op, SDValue Addr, SDValue &Base, SDValue &Disp);
70 } // end anonymous namespace
72 /// createMSP430ISelDag - This pass converts a legalized DAG into a
73 /// MSP430-specific DAG, ready for instruction scheduling.
75 FunctionPass *llvm::createMSP430ISelDag(MSP430TargetMachine &TM,
76 CodeGenOpt::Level OptLevel) {
77 return new MSP430DAGToDAGISel(TM, OptLevel);
80 // FIXME: This is pretty dummy routine and needs to be rewritten in the future.
81 bool MSP430DAGToDAGISel::SelectAddr(SDValue Op, SDValue Addr,
82 SDValue &Base, SDValue &Disp) {
83 // Try to match frame address first.
84 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
85 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
86 Disp = CurDAG->getTargetConstant(0, MVT::i16);
90 switch (Addr.getOpcode()) {
92 // Operand is a result from ADD with constant operand which fits into i16.
93 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
94 uint64_t CVal = CN->getZExtValue();
95 // Offset should fit into 16 bits.
96 if (((CVal << 48) >> 48) == CVal) {
97 SDValue N0 = Addr.getOperand(0);
98 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N0))
99 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16);
103 Disp = CurDAG->getTargetConstant(CVal, MVT::i16);
108 case MSP430ISD::Wrapper:
109 SDValue N0 = Addr.getOperand(0);
110 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) {
111 Base = CurDAG->getTargetGlobalAddress(G->getGlobal(),
112 MVT::i16, G->getOffset());
113 Disp = CurDAG->getTargetConstant(0, MVT::i16);
115 } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(N0)) {
116 Base = CurDAG->getTargetExternalSymbol(E->getSymbol(), MVT::i16);
117 Disp = CurDAG->getTargetConstant(0, MVT::i16);
123 Disp = CurDAG->getTargetConstant(0, MVT::i16);
129 bool MSP430DAGToDAGISel::
130 SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
131 std::vector<SDValue> &OutOps) {
133 switch (ConstraintCode) {
134 default: return true;
136 if (!SelectAddr(Op, Op, Op0, Op1))
141 OutOps.push_back(Op0);
142 OutOps.push_back(Op1);
146 /// InstructionSelect - This callback is invoked by
147 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
148 void MSP430DAGToDAGISel::InstructionSelect() {
151 // Codegen the basic block.
152 DEBUG(errs() << "===== Instruction selection begins:\n");
155 DEBUG(errs() << "===== Instruction selection ends:\n");
157 CurDAG->RemoveDeadNodes();
160 SDNode *MSP430DAGToDAGISel::Select(SDValue Op) {
161 SDNode *Node = Op.getNode();
162 DebugLoc dl = Op.getDebugLoc();
164 // Dump information about the Node being selected
165 DEBUG(errs().indent(Indent) << "Selecting: ");
166 DEBUG(Node->dump(CurDAG));
167 DEBUG(errs() << "\n");
170 // If we have a custom node, we already have selected!
171 if (Node->isMachineOpcode()) {
172 DEBUG(errs().indent(Indent-2) << "== ";
179 // Few custom selection stuff.
180 switch (Node->getOpcode()) {
182 case ISD::FrameIndex: {
183 assert(Op.getValueType() == MVT::i16);
184 int FI = cast<FrameIndexSDNode>(Node)->getIndex();
185 SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i16);
186 if (Node->hasOneUse())
187 return CurDAG->SelectNodeTo(Node, MSP430::ADD16ri, MVT::i16,
188 TFI, CurDAG->getTargetConstant(0, MVT::i16));
189 return CurDAG->getMachineNode(MSP430::ADD16ri, dl, MVT::i16,
190 TFI, CurDAG->getTargetConstant(0, MVT::i16));
194 // Select the default instruction
195 SDNode *ResNode = SelectCode(Op);
197 DEBUG(errs() << std::string(Indent-2, ' ') << "=> ");
198 if (ResNode == NULL || ResNode == Op.getNode())
199 DEBUG(Op.getNode()->dump(CurDAG));
201 DEBUG(ResNode->dump(CurDAG));
202 DEBUG(errs() << "\n");