MSP430ISelDAGToDAG.cpp revision 0d370dcf2d8b7092355935d7d52e7236dd745345
1//===-- MSP430ISelDAGToDAG.cpp - A dag to dag inst selector for MSP430 ----===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines an instruction selector for the MSP430 target. 11// 12//===----------------------------------------------------------------------===// 13 14#include "MSP430.h" 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 <queue> 32#include <set> 33using namespace llvm; 34 35/// MSP430DAGToDAGISel - MSP430 specific code to select MSP430 machine 36/// instructions for SelectionDAG operations. 37/// 38namespace { 39 class MSP430DAGToDAGISel : public SelectionDAGISel { 40 MSP430TargetLowering &Lowering; 41 const MSP430Subtarget &Subtarget; 42 43 public: 44 MSP430DAGToDAGISel(MSP430TargetMachine &TM, CodeGenOpt::Level OptLevel) 45 : SelectionDAGISel(TM, OptLevel), 46 Lowering(*TM.getTargetLowering()), 47 Subtarget(*TM.getSubtargetImpl()) { } 48 49 virtual void InstructionSelect(); 50 51 virtual const char *getPassName() const { 52 return "MSP430 DAG->DAG Pattern Instruction Selection"; 53 } 54 55 // Include the pieces autogenerated from the target description. 56 #include "MSP430GenDAGISel.inc" 57 58 private: 59 SDNode *Select(SDValue Op); 60 bool SelectAddr(SDValue Op, SDValue Addr, SDValue &Base, SDValue &Disp); 61 62 #ifndef NDEBUG 63 unsigned Indent; 64 #endif 65 }; 66} // end anonymous namespace 67 68/// createMSP430ISelDag - This pass converts a legalized DAG into a 69/// MSP430-specific DAG, ready for instruction scheduling. 70/// 71FunctionPass *llvm::createMSP430ISelDag(MSP430TargetMachine &TM, 72 CodeGenOpt::Level OptLevel) { 73 return new MSP430DAGToDAGISel(TM, OptLevel); 74} 75 76// FIXME: This is pretty dummy routine and needs to be rewritten in the future. 77bool MSP430DAGToDAGISel::SelectAddr(SDValue Op, SDValue Addr, 78 SDValue &Base, SDValue &Disp) { 79 // Try to match frame address first. 80 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) { 81 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16); 82 Disp = CurDAG->getTargetConstant(0, MVT::i16); 83 return true; 84 } 85 86 switch (Addr.getOpcode()) { 87 case ISD::ADD: 88 // Operand is a result from ADD with constant operand which fits into i16. 89 if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) { 90 uint64_t CVal = CN->getZExtValue(); 91 // Offset should fit into 16 bits. 92 if (((CVal << 48) >> 48) == CVal) { 93 SDValue N0 = Addr.getOperand(0); 94 if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N0)) 95 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i16); 96 else 97 Base = N0; 98 99 Disp = CurDAG->getTargetConstant(CVal, MVT::i16); 100 return true; 101 } 102 } 103 break; 104 case MSP430ISD::Wrapper: 105 SDValue N0 = Addr.getOperand(0); 106 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(N0)) { 107 Base = CurDAG->getTargetGlobalAddress(G->getGlobal(), 108 MVT::i16, G->getOffset()); 109 Disp = CurDAG->getTargetConstant(0, MVT::i16); 110 return true; 111 } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(N0)) { 112 Base = CurDAG->getTargetExternalSymbol(E->getSymbol(), MVT::i16); 113 Disp = CurDAG->getTargetConstant(0, MVT::i16); 114 } 115 break; 116 }; 117 118 Base = Addr; 119 Disp = CurDAG->getTargetConstant(0, MVT::i16); 120 121 return true; 122} 123 124 125 126/// InstructionSelect - This callback is invoked by 127/// SelectionDAGISel when it has created a SelectionDAG for us to codegen. 128void MSP430DAGToDAGISel::InstructionSelect() { 129 DEBUG(BB->dump()); 130 131 // Codegen the basic block. 132#ifndef NDEBUG 133 DOUT << "===== Instruction selection begins:\n"; 134 Indent = 0; 135#endif 136 SelectRoot(*CurDAG); 137#ifndef NDEBUG 138 DOUT << "===== Instruction selection ends:\n"; 139#endif 140 141 CurDAG->RemoveDeadNodes(); 142} 143 144SDNode *MSP430DAGToDAGISel::Select(SDValue Op) { 145 SDNode *Node = Op.getNode(); 146 DebugLoc dl = Op.getDebugLoc(); 147 148 // Dump information about the Node being selected 149 #ifndef NDEBUG 150 DOUT << std::string(Indent, ' ') << "Selecting: "; 151 DEBUG(Node->dump(CurDAG)); 152 DOUT << "\n"; 153 Indent += 2; 154 #endif 155 156 // If we have a custom node, we already have selected! 157 if (Node->isMachineOpcode()) { 158 #ifndef NDEBUG 159 DOUT << std::string(Indent-2, ' ') << "== "; 160 DEBUG(Node->dump(CurDAG)); 161 DOUT << "\n"; 162 Indent -= 2; 163 #endif 164 return NULL; 165 } 166 167 // Few custom selection stuff. 168 switch (Node->getOpcode()) { 169 default: break; 170 case ISD::FrameIndex: { 171 assert(Op.getValueType() == MVT::i16); 172 int FI = cast<FrameIndexSDNode>(Node)->getIndex(); 173 SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i16); 174 if (Node->hasOneUse()) 175 return CurDAG->SelectNodeTo(Node, MSP430::ADD16ri, MVT::i16, 176 TFI, CurDAG->getTargetConstant(0, MVT::i16)); 177 return CurDAG->getTargetNode(MSP430::ADD16ri, dl, MVT::i16, 178 TFI, CurDAG->getTargetConstant(0, MVT::i16)); 179 } 180 } 181 182 // Select the default instruction 183 SDNode *ResNode = SelectCode(Op); 184 185 #ifndef NDEBUG 186 DOUT << std::string(Indent-2, ' ') << "=> "; 187 if (ResNode == NULL || ResNode == Op.getNode()) 188 DEBUG(Op.getNode()->dump(CurDAG)); 189 else 190 DEBUG(ResNode->dump(CurDAG)); 191 DOUT << "\n"; 192 Indent -= 2; 193 #endif 194 195 return ResNode; 196} 197