SelectionDAG.h revision c3aea74ae5e29973c739b15cad3b8e0c408c35ed
1//===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file declares the SelectionDAG class, and transitively defines the 11// SDNode class and subclasses. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_CODEGEN_SELECTIONDAG_H 16#define LLVM_CODEGEN_SELECTIONDAG_H 17 18#include "llvm/CodeGen/SelectionDAGNodes.h" 19#include <map> 20#include <string> // FIXME remove eventually, turning map into const char* map. 21 22namespace llvm { 23 class TargetLowering; 24 class TargetMachine; 25 class MachineFunction; 26 27/// SelectionDAG class - This is used to represent a portion of an LLVM function 28/// in a low-level Data Dependence DAG representation suitable for instruction 29/// selection. This DAG is constructed as the first step of instruction 30/// selection in order to allow implementation of machine specific optimizations 31/// and code simplifications. 32/// 33/// The representation used by the SelectionDAG is a target-independent 34/// representation, which has some similarities to the GCC RTL representation, 35/// but is significantly more simple, powerful, and is a graph form instead of a 36/// linear form. 37/// 38class SelectionDAG { 39 TargetLowering &TLI; 40 MachineFunction &MF; 41 42 // Root - The root of the entire DAG. EntryNode - The starting token. 43 SDOperand Root, EntryNode; 44 45 // AllNodes - All of the nodes in the DAG 46 std::vector<SDNode*> AllNodes; 47 48 // ValueNodes - track SrcValue nodes 49 std::map<std::pair<const Value*, int>, SDNode*> ValueNodes; 50 51public: 52 SelectionDAG(TargetLowering &tli, MachineFunction &mf) : TLI(tli), MF(mf) { 53 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other); 54 } 55 ~SelectionDAG(); 56 57 MachineFunction &getMachineFunction() const { return MF; } 58 const TargetMachine &getTarget() const; 59 TargetLowering &getTargetLoweringInfo() const { return TLI; } 60 61 /// viewGraph - Pop up a ghostview window with the DAG rendered using 'dot'. 62 /// 63 void viewGraph(); 64 65 66 typedef std::vector<SDNode*>::const_iterator allnodes_iterator; 67 allnodes_iterator allnodes_begin() const { return AllNodes.begin(); } 68 allnodes_iterator allnodes_end() const { return AllNodes.end(); } 69 70 /// getRoot - Return the root tag of the SelectionDAG. 71 /// 72 const SDOperand &getRoot() const { return Root; } 73 74 /// getEntryNode - Return the token chain corresponding to the entry of the 75 /// function. 76 const SDOperand &getEntryNode() const { return EntryNode; } 77 78 /// setRoot - Set the current root tag of the SelectionDAG. 79 /// 80 const SDOperand &setRoot(SDOperand N) { return Root = N; } 81 82 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is 83 /// compatible with the target instruction selector, as indicated by the 84 /// TargetLowering object. 85 /// 86 /// Note that this is an involved process that may invalidate pointers into 87 /// the graph. 88 void Legalize(); 89 90 /// RemoveDeadNodes - This method deletes all unreachable nodes in the 91 /// SelectionDAG, including nodes (like loads) that have uses of their token 92 /// chain but no other uses and no side effect. If a node is passed in as an 93 /// argument, it is used as the seed for node deletion. 94 void RemoveDeadNodes(SDNode *N = 0); 95 96 SDOperand getConstant(uint64_t Val, MVT::ValueType VT); 97 SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT); 98 SDOperand getConstantFP(double Val, MVT::ValueType VT); 99 SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT); 100 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT); 101 SDOperand getFrameIndex(int FI, MVT::ValueType VT); 102 SDOperand getConstantPool(unsigned CPIdx, MVT::ValueType VT); 103 SDOperand getBasicBlock(MachineBasicBlock *MBB); 104 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT); 105 SDOperand getValueType(MVT::ValueType); 106 SDOperand getRegister(unsigned Reg, MVT::ValueType VT); 107 108 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) { 109 return getNode(ISD::CopyToReg, MVT::Other, Chain, 110 getRegister(Reg, N.getValueType()), N); 111 } 112 113 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) { 114 std::vector<MVT::ValueType> ResultTys; 115 ResultTys.push_back(VT); 116 ResultTys.push_back(MVT::Other); 117 std::vector<SDOperand> Ops; 118 Ops.push_back(Chain); 119 Ops.push_back(getRegister(Reg, VT)); 120 return getNode(ISD::CopyFromReg, ResultTys, Ops); 121 } 122 123 SDOperand getImplicitDef(SDOperand Chain, unsigned Reg, MVT::ValueType VT) { 124 return getNode(ISD::ImplicitDef, MVT::Other, Chain, getRegister(Reg, VT)); 125 } 126 127 /// getCall - Note that this destroys the vector of RetVals passed in. 128 /// 129 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain, 130 SDOperand Callee, bool isTailCall = false) { 131 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, Chain, 132 Callee); 133 NN->setValueTypes(RetVals); 134 AllNodes.push_back(NN); 135 return NN; 136 } 137 138 /// getCall - This is identical to the one above, and should be used for calls 139 /// where arguments are passed in physical registers. This destroys the 140 /// RetVals and ArgsInRegs vectors. 141 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain, 142 SDOperand Callee, std::vector<SDOperand> &ArgsInRegs, 143 bool isTailCall = false) { 144 ArgsInRegs.insert(ArgsInRegs.begin(), Callee); 145 ArgsInRegs.insert(ArgsInRegs.begin(), Chain); 146 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, ArgsInRegs); 147 NN->setValueTypes(RetVals); 148 AllNodes.push_back(NN); 149 return NN; 150 } 151 152 SDOperand getCondCode(ISD::CondCode Cond); 153 154 /// getZeroExtendInReg - Return the expression required to zero extend the Op 155 /// value assuming it was the smaller SrcTy value. 156 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy); 157 158 /// getNode - Gets or creates the specified node. 159 /// 160 SDOperand getNode(unsigned Opcode, MVT::ValueType VT); 161 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N); 162 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 163 SDOperand N1, SDOperand N2); 164 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 165 SDOperand N1, SDOperand N2, SDOperand N3); 166 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 167 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4); 168 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 169 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4, 170 SDOperand N5); 171 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 172 std::vector<SDOperand> &Children); 173 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys, 174 std::vector<SDOperand> &Ops); 175 176 /// getSetCC - Helper function to make it easier to build SetCC's if you just 177 /// have an ISD::CondCode instead of an SDOperand. 178 /// 179 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS, 180 ISD::CondCode Cond) { 181 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond)); 182 } 183 184 /// getSelectCC - Helper function to make it easier to build SelectCC's if you 185 /// just have an ISD::CondCode instead of an SDOperand. 186 /// 187 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS, 188 SDOperand True, SDOperand False, ISD::CondCode Cond) { 189 MVT::ValueType VT = True.getValueType(); 190 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond)); 191 } 192 193 /// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC 194 /// nodes. 195 /// 196 SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS, 197 SDOperand RHS, SDOperand True, SDOperand False) { 198 std::vector<SDOperand> Ops; 199 Ops.push_back(Chain); 200 Ops.push_back(CCNode); 201 Ops.push_back(LHS); 202 Ops.push_back(RHS); 203 Ops.push_back(True); 204 Ops.push_back(False); 205 return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops); 206 } 207 208 /// getLoad - Loads are not normal binary operators: their result type is not 209 /// determined by their operands, and they produce a value AND a token chain. 210 /// 211 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr, 212 SDOperand SV); 213 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain, 214 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT); 215 216 // getSrcValue - construct a node to track a Value* through the backend 217 SDOperand getSrcValue(const Value* I, int offset = 0); 218 219 220 /// SelectNodeTo - These are used for target selectors to *mutate* the 221 /// specified node to have the specified return type, Target opcode, and 222 /// operands. Note that target opcodes are stored as 223 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. 224 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc, 225 SDOperand Op1); 226 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc, 227 SDOperand Op1, SDOperand Op2); 228 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc, 229 SDOperand Op1, SDOperand Op2, SDOperand Op3); 230 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc, 231 SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4); 232 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc, 233 SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4, 234 SDOperand Op5); 235 void SelectNodeTo(SDNode *N, MVT::ValueType VT1, MVT::ValueType VT2, 236 unsigned TargetOpc, SDOperand Op1, SDOperand Op2); 237 238 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 239 SDOperand Op1) { 240 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1); 241 } 242 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 243 SDOperand Op1, SDOperand Op2) { 244 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2); 245 } 246 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 247 SDOperand Op1, SDOperand Op2, SDOperand Op3) { 248 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3); 249 } 250 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 251 SDOperand Op1, SDOperand Op2, SDOperand Op3, 252 SDOperand Op4) { 253 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4); 254 } 255 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 256 SDOperand Op1, SDOperand Op2, SDOperand Op3, 257 SDOperand Op4, SDOperand Op5) { 258 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5); 259 } 260 261 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead. 262 /// This can cause recursive merging of nodes in the DAG. 263 /// 264 void ReplaceAllUsesWith(SDNode *From, SDNode *To); 265 266 void dump() const; 267 268private: 269 void RemoveNodeFromCSEMaps(SDNode *N); 270 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N); 271 void DeleteNodeIfDead(SDNode *N, void *NodeSet); 272 273 /// SimplifySetCC - Try to simplify a setcc built with the specified operands 274 /// and cc. If unable to simplify it, return a null SDOperand. 275 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1, 276 SDOperand N2, ISD::CondCode Cond); 277 278 /// SimplifySelectCC - Try to simplify a select_cc built with the specified 279 /// operands and cc. This can be used to simplify both the select_cc node, 280 /// and a select node whose first operand is a setcc. 281 SDOperand SimplifySelectCC(SDOperand N1, SDOperand N2, SDOperand N3, 282 SDOperand N4, ISD::CondCode CC); 283 284 // Maps to auto-CSE operations. 285 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >, 286 SDNode *> UnaryOps; 287 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >, 288 SDNode *> BinaryOps; 289 290 std::vector<RegisterSDNode*> RegNodes; 291 std::vector<CondCodeSDNode*> CondCodeNodes; 292 293 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >, 294 SDNode *> Loads; 295 296 std::map<const GlobalValue*, SDNode*> GlobalValues; 297 std::map<const GlobalValue*, SDNode*> TargetGlobalValues; 298 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants; 299 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants; 300 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs; 301 std::map<int, SDNode*> FrameIndices; 302 std::map<unsigned, SDNode*> ConstantPoolIndices; 303 std::map<MachineBasicBlock *, SDNode*> BBNodes; 304 std::vector<SDNode*> ValueTypeNodes; 305 std::map<std::string, SDNode*> ExternalSymbols; 306 std::map<std::pair<unsigned, 307 std::pair<MVT::ValueType, std::vector<SDOperand> > >, 308 SDNode*> OneResultNodes; 309 std::map<std::pair<unsigned, 310 std::pair<std::vector<MVT::ValueType>, 311 std::vector<SDOperand> > >, 312 SDNode*> ArbitraryNodes; 313}; 314 315template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> { 316 typedef SelectionDAG::allnodes_iterator nodes_iterator; 317 static nodes_iterator nodes_begin(SelectionDAG *G) { 318 return G->allnodes_begin(); 319 } 320 static nodes_iterator nodes_end(SelectionDAG *G) { 321 return G->allnodes_end(); 322 } 323}; 324 325} 326 327#endif 328