SelectionDAG.h revision d6a80778e5a5fab339036b2f462d3039efe28a08
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 getTargetFrameIndex(int FI, MVT::ValueType VT); 103 SDOperand getConstantPool(Constant *C, MVT::ValueType VT); 104 SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT); 105 SDOperand getBasicBlock(MachineBasicBlock *MBB); 106 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT); 107 SDOperand getValueType(MVT::ValueType); 108 SDOperand getRegister(unsigned Reg, MVT::ValueType VT); 109 110 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) { 111 return getNode(ISD::CopyToReg, MVT::Other, Chain, 112 getRegister(Reg, N.getValueType()), N); 113 } 114 115 // This version of the getCopyToReg method takes an extra operand, which 116 // indicates that there is potentially an incoming flag value (if Flag is not 117 // null) and that there should be a flag result. 118 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N, 119 SDOperand Flag) { 120 std::vector<MVT::ValueType> VTs; 121 VTs.push_back(MVT::Other); 122 VTs.push_back(MVT::Flag); 123 std::vector<SDOperand> Ops; 124 Ops.push_back(Chain); 125 Ops.push_back(getRegister(Reg, N.getValueType())); 126 Ops.push_back(N); 127 if (Flag.Val) Ops.push_back(Flag); 128 return getNode(ISD::CopyToReg, VTs, Ops); 129 } 130 131 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) { 132 std::vector<MVT::ValueType> ResultTys; 133 ResultTys.push_back(VT); 134 ResultTys.push_back(MVT::Other); 135 std::vector<SDOperand> Ops; 136 Ops.push_back(Chain); 137 Ops.push_back(getRegister(Reg, VT)); 138 return getNode(ISD::CopyFromReg, ResultTys, Ops); 139 } 140 141 // This version of the getCopyFromReg method takes an extra operand, which 142 // indicates that there is potentially an incoming flag value (if Flag is not 143 // null) and that there should be a flag result. 144 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT, 145 SDOperand Flag) { 146 std::vector<MVT::ValueType> ResultTys; 147 ResultTys.push_back(VT); 148 ResultTys.push_back(MVT::Other); 149 ResultTys.push_back(MVT::Flag); 150 std::vector<SDOperand> Ops; 151 Ops.push_back(Chain); 152 Ops.push_back(getRegister(Reg, VT)); 153 if (Flag.Val) Ops.push_back(Flag); 154 return getNode(ISD::CopyFromReg, ResultTys, Ops); 155 } 156 157 SDOperand getImplicitDef(SDOperand Chain, unsigned Reg, MVT::ValueType VT) { 158 return getNode(ISD::ImplicitDef, MVT::Other, Chain, getRegister(Reg, VT)); 159 } 160 161 /// getCall - Note that this destroys the vector of RetVals passed in. 162 /// 163 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain, 164 SDOperand Callee, bool isTailCall = false) { 165 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, Chain, 166 Callee); 167 NN->setValueTypes(RetVals); 168 AllNodes.push_back(NN); 169 return NN; 170 } 171 172 /// getCall - This is identical to the one above, and should be used for calls 173 /// where arguments are passed in physical registers. This destroys the 174 /// RetVals and ArgsInRegs vectors. 175 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain, 176 SDOperand Callee, std::vector<SDOperand> &ArgsInRegs, 177 bool isTailCall = false) { 178 ArgsInRegs.insert(ArgsInRegs.begin(), Callee); 179 ArgsInRegs.insert(ArgsInRegs.begin(), Chain); 180 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, ArgsInRegs); 181 NN->setValueTypes(RetVals); 182 AllNodes.push_back(NN); 183 return NN; 184 } 185 186 SDOperand getCondCode(ISD::CondCode Cond); 187 188 /// getZeroExtendInReg - Return the expression required to zero extend the Op 189 /// value assuming it was the smaller SrcTy value. 190 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy); 191 192 /// getNode - Gets or creates the specified node. 193 /// 194 SDOperand getNode(unsigned Opcode, MVT::ValueType VT); 195 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N); 196 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 197 SDOperand N1, SDOperand N2); 198 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 199 SDOperand N1, SDOperand N2, SDOperand N3); 200 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 201 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4); 202 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 203 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4, 204 SDOperand N5); 205 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, 206 std::vector<SDOperand> &Children); 207 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys, 208 std::vector<SDOperand> &Ops); 209 210 /// getSetCC - Helper function to make it easier to build SetCC's if you just 211 /// have an ISD::CondCode instead of an SDOperand. 212 /// 213 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS, 214 ISD::CondCode Cond) { 215 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond)); 216 } 217 218 /// getSelectCC - Helper function to make it easier to build SelectCC's if you 219 /// just have an ISD::CondCode instead of an SDOperand. 220 /// 221 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS, 222 SDOperand True, SDOperand False, ISD::CondCode Cond) { 223 MVT::ValueType VT = True.getValueType(); 224 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond)); 225 } 226 227 /// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC 228 /// nodes. 229 /// 230 SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS, 231 SDOperand RHS, SDOperand True, SDOperand False) { 232 std::vector<SDOperand> Ops; 233 Ops.push_back(Chain); 234 Ops.push_back(CCNode); 235 Ops.push_back(LHS); 236 Ops.push_back(RHS); 237 Ops.push_back(True); 238 Ops.push_back(False); 239 return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops); 240 } 241 242 /// getLoad - Loads are not normal binary operators: their result type is not 243 /// determined by their operands, and they produce a value AND a token chain. 244 /// 245 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr, 246 SDOperand SV); 247 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain, 248 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT); 249 250 // getSrcValue - construct a node to track a Value* through the backend 251 SDOperand getSrcValue(const Value* I, int offset = 0); 252 253 254 /// SelectNodeTo - These are used for target selectors to *mutate* the 255 /// specified node to have the specified return type, Target opcode, and 256 /// operands. Note that target opcodes are stored as 257 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. 258 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT); 259 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT, 260 SDOperand Op1); 261 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT, 262 SDOperand Op1, SDOperand Op2); 263 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT, 264 SDOperand Op1, SDOperand Op2, SDOperand Op3); 265 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT, 266 SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4); 267 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT, 268 SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4, 269 SDOperand Op5); 270 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1, 271 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2); 272 void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1, 273 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2, 274 SDOperand Op3); 275 276 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 277 SDOperand Op1) { 278 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1); 279 } 280 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 281 SDOperand Op1, SDOperand Op2) { 282 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2); 283 } 284 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1, 285 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2) { 286 std::vector<MVT::ValueType> ResultTys; 287 ResultTys.push_back(VT1); 288 ResultTys.push_back(VT2); 289 std::vector<SDOperand> Ops; 290 Ops.push_back(Op1); 291 Ops.push_back(Op2); 292 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops); 293 } 294 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 295 SDOperand Op1, SDOperand Op2, SDOperand Op3) { 296 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3); 297 } 298 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 299 SDOperand Op1, SDOperand Op2, SDOperand Op3, 300 SDOperand Op4) { 301 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4); 302 } 303 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 304 SDOperand Op1, SDOperand Op2, SDOperand Op3, 305 SDOperand Op4, SDOperand Op5) { 306 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5); 307 } 308 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT, 309 std::vector<SDOperand> &Ops) { 310 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Ops); 311 } 312 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1, 313 MVT::ValueType VT2, std::vector<SDOperand> &Ops) { 314 std::vector<MVT::ValueType> ResultTys; 315 ResultTys.push_back(VT1); 316 ResultTys.push_back(VT2); 317 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops); 318 } 319 320 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead. 321 /// This can cause recursive merging of nodes in the DAG. Use the first 322 /// version if 'From' is known to have a single result, use the second 323 /// if you have two nodes with identical results, use the third otherwise. 324 /// 325 void ReplaceAllUsesWith(SDOperand From, SDOperand Op); 326 void ReplaceAllUsesWith(SDNode *From, SDNode *To); 327 void ReplaceAllUsesWith(SDNode *From, const std::vector<SDOperand> &To); 328 329 330 /// DeleteNode - Remove the specified node from the system. This node must 331 /// have no referrers. 332 void DeleteNode(SDNode *N); 333 334 void dump() const; 335 336private: 337 void RemoveNodeFromCSEMaps(SDNode *N); 338 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N); 339 void DeleteNodeIfDead(SDNode *N, void *NodeSet); 340 341 /// SimplifySetCC - Try to simplify a setcc built with the specified operands 342 /// and cc. If unable to simplify it, return a null SDOperand. 343 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1, 344 SDOperand N2, ISD::CondCode Cond); 345 346 /// SimplifySelectCC - Try to simplify a select_cc built with the specified 347 /// operands and cc. This can be used to simplify both the select_cc node, 348 /// and a select node whose first operand is a setcc. 349 SDOperand SimplifySelectCC(SDOperand N1, SDOperand N2, SDOperand N3, 350 SDOperand N4, ISD::CondCode CC); 351 352 // Maps to auto-CSE operations. 353 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >, 354 SDNode *> UnaryOps; 355 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >, 356 SDNode *> BinaryOps; 357 358 std::map<std::pair<unsigned, MVT::ValueType>, RegisterSDNode*> RegNodes; 359 std::vector<CondCodeSDNode*> CondCodeNodes; 360 361 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >, 362 SDNode *> Loads; 363 364 std::map<const GlobalValue*, SDNode*> GlobalValues; 365 std::map<const GlobalValue*, SDNode*> TargetGlobalValues; 366 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants; 367 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants; 368 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs; 369 std::map<int, SDNode*> FrameIndices, TargetFrameIndices; 370 std::map<Constant *, SDNode*> ConstantPoolIndices; 371 std::map<Constant *, SDNode*> TargetConstantPoolIndices; 372 std::map<MachineBasicBlock *, SDNode*> BBNodes; 373 std::vector<SDNode*> ValueTypeNodes; 374 std::map<std::string, SDNode*> ExternalSymbols; 375 std::map<std::pair<unsigned, 376 std::pair<MVT::ValueType, std::vector<SDOperand> > >, 377 SDNode*> OneResultNodes; 378 std::map<std::pair<unsigned, 379 std::pair<std::vector<MVT::ValueType>, 380 std::vector<SDOperand> > >, 381 SDNode*> ArbitraryNodes; 382}; 383 384template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> { 385 typedef SelectionDAG::allnodes_iterator nodes_iterator; 386 static nodes_iterator nodes_begin(SelectionDAG *G) { 387 return G->allnodes_begin(); 388 } 389 static nodes_iterator nodes_end(SelectionDAG *G) { 390 return G->allnodes_end(); 391 } 392}; 393 394} 395 396#endif 397