SelectionDAGNodes.h revision 1080b9ee534579c67f7c99364cc6fa11edbcd919
1//===-- llvm/CodeGen/SelectionDAGNodes.h - SelectionDAG Nodes ---*- 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 SDNode class and derived classes, which are used to 11// represent the nodes and operations present in a SelectionDAG. These nodes 12// and operations are machine code level operations, with some similarities to 13// the GCC RTL representation. 14// 15// Clients should include the SelectionDAG.h file instead of this file directly. 16// 17//===----------------------------------------------------------------------===// 18 19#ifndef LLVM_CODEGEN_SELECTIONDAGNODES_H 20#define LLVM_CODEGEN_SELECTIONDAGNODES_H 21 22#include "llvm/CodeGen/ValueTypes.h" 23#include "llvm/ADT/GraphTraits.h" 24#include "llvm/ADT/GraphTraits.h" 25#include "llvm/ADT/iterator" 26#include "llvm/Support/DataTypes.h" 27#include <cassert> 28#include <vector> 29 30namespace llvm { 31 32class SelectionDAG; 33class GlobalValue; 34class MachineBasicBlock; 35class SDNode; 36template <typename T> struct simplify_type; 37 38/// ISD namespace - This namespace contains an enum which represents all of the 39/// SelectionDAG node types and value types. 40/// 41namespace ISD { 42 //===--------------------------------------------------------------------===// 43 /// ISD::NodeType enum - This enum defines all of the operators valid in a 44 /// SelectionDAG. 45 /// 46 enum NodeType { 47 // Leaf nodes 48 EntryToken, Constant, ConstantFP, GlobalAddress, FrameIndex, ConstantPool, 49 BasicBlock, ExternalSymbol, 50 51 // CopyToReg - This node has chain and child nodes, and an associated 52 // register number. The instruction selector must guarantee that the value 53 // of the value node is available in the virtual register stored in the 54 // CopyRegSDNode object. 55 CopyToReg, 56 57 // CopyFromReg - This node indicates that the input value is a virtual or 58 // physical register that is defined outside of the scope of this 59 // SelectionDAG. The virtual register is available from the 60 // CopyRegSDNode object. 61 CopyFromReg, 62 63 // EXTRACT_ELEMENT - This is used to get the first or second (determined by 64 // a Constant, which is required to be operand #1), element of the aggregate 65 // value specified as operand #0. This is only for use before legalization, 66 // for values that will be broken into multiple registers. 67 EXTRACT_ELEMENT, 68 69 // BUILD_PAIR - This is the opposite of EXTRACT_ELEMENT in some ways. Given 70 // two values of the same integer value type, this produces a value twice as 71 // big. Like EXTRACT_ELEMENT, this can only be used before legalization. 72 BUILD_PAIR, 73 74 75 // Simple binary arithmetic operators. 76 ADD, SUB, MUL, SDIV, UDIV, SREM, UREM, 77 78 // Bitwise operators. 79 AND, OR, XOR, SHL, SRA, SRL, 80 81 // Select operator. 82 SELECT, 83 84 // SetCC operator - This evaluates to a boolean (i1) true value if the 85 // condition is true. These nodes are instances of the 86 // SetCCSDNode class, which contains the condition code as extra 87 // state. 88 SETCC, 89 90 // addc - Three input, two output operator: (X, Y, C) -> (X+Y+C, 91 // Cout). X,Y are integer inputs of agreeing size, C is a one bit 92 // value, and two values are produced: the sum and a carry out. 93 ADDC, SUBB, 94 95 // Conversion operators. These are all single input single output 96 // operations. For all of these, the result type must be strictly 97 // wider or narrower (depending on the operation) than the source 98 // type. 99 100 // SIGN_EXTEND - Used for integer types, replicating the sign bit 101 // into new bits. 102 SIGN_EXTEND, 103 104 // ZERO_EXTEND - Used for integer types, zeroing the new bits. 105 ZERO_EXTEND, 106 107 // TRUNCATE - Completely drop the high bits. 108 TRUNCATE, 109 110 // [SU]INT_TO_FP - These operators convert integers (whose interpreted sign 111 // depends on the first letter) to floating point. 112 SINT_TO_FP, 113 UINT_TO_FP, 114 115 // FP_TO_[US]INT - Convert a floating point value to a signed or unsigned 116 // integer. 117 FP_TO_SINT, 118 FP_TO_UINT, 119 120 // FP_ROUND - Perform a rounding operation from the current 121 // precision down to the specified precision. 122 FP_ROUND, 123 124 // FP_EXTEND - Extend a smaller FP type into a larger FP type. 125 FP_EXTEND, 126 127 // Other operators. LOAD and STORE have token chains. 128 LOAD, STORE, 129 130 // DYNAMIC_STACKALLOC - Allocate some number of bytes on the stack aligned 131 // to a specified boundary. The first operand is the token chain, the 132 // second is the number of bytes to allocate, and the third is the alignment 133 // boundary. 134 DYNAMIC_STACKALLOC, 135 136 // Control flow instructions. These all have token chains. 137 138 // BR - Unconditional branch. The first operand is the chain 139 // operand, the second is the MBB to branch to. 140 BR, 141 142 // BRCOND - Conditional branch. The first operand is the chain, 143 // the second is the condition, the third is the block to branch 144 // to if the condition is true. 145 BRCOND, 146 147 // RET - Return from function. The first operand is the chain, 148 // and any subsequent operands are the return values for the 149 // function. This operation can have variable number of operands. 150 RET, 151 152 // CALL - Call to a function pointer. The first operand is the chain, the 153 // second is the destination function pointer (a GlobalAddress for a direct 154 // call). Arguments have already been lowered to explicit DAGs according to 155 // the calling convention in effect here. 156 CALL, 157 158 // ADJCALLSTACKDOWN/ADJCALLSTACKUP - These operators mark the beginning and 159 // end of a call sequence and indicate how much the stack pointer needs to 160 // be adjusted for that particular call. The first operand is a chain, the 161 // second is a ConstantSDNode of intptr type. 162 ADJCALLSTACKDOWN, // Beginning of a call sequence 163 ADJCALLSTACKUP, // End of a call sequence 164 165 166 // BUILTIN_OP_END - This must be the last enum value in this list. 167 BUILTIN_OP_END, 168 }; 169 170 //===--------------------------------------------------------------------===// 171 /// ISD::CondCode enum - These are ordered carefully to make the bitfields 172 /// below work out, when considering SETFALSE (something that never exists 173 /// dynamically) as 0. "U" -> Unsigned (for integer operands) or Unordered 174 /// (for floating point), "L" -> Less than, "G" -> Greater than, "E" -> Equal 175 /// to. If the "N" column is 1, the result of the comparison is undefined if 176 /// the input is a NAN. 177 /// 178 /// All of these (except for the 'always folded ops') should be handled for 179 /// floating point. For integer, only the SETEQ,SETNE,SETLT,SETLE,SETGT, 180 /// SETGE,SETULT,SETULE,SETUGT, and SETUGE opcodes are used. 181 /// 182 /// Note that these are laid out in a specific order to allow bit-twiddling 183 /// to transform conditions. 184 enum CondCode { 185 // Opcode N U L G E Intuitive operation 186 SETFALSE, // 0 0 0 0 Always false (always folded) 187 SETOEQ, // 0 0 0 1 True if ordered and equal 188 SETOGT, // 0 0 1 0 True if ordered and greater than 189 SETOGE, // 0 0 1 1 True if ordered and greater than or equal 190 SETOLT, // 0 1 0 0 True if ordered and less than 191 SETOLE, // 0 1 0 1 True if ordered and less than or equal 192 SETONE, // 0 1 1 0 True if ordered and operands are unequal 193 SETO, // 0 1 1 1 True if ordered (no nans) 194 SETUO, // 1 0 0 0 True if unordered: isnan(X) | isnan(Y) 195 SETUEQ, // 1 0 0 1 True if unordered or equal 196 SETUGT, // 1 0 1 0 True if unordered or greater than 197 SETUGE, // 1 0 1 1 True if unordered, greater than, or equal 198 SETULT, // 1 1 0 0 True if unordered or less than 199 SETULE, // 1 1 0 1 True if unordered, less than, or equal 200 SETUNE, // 1 1 1 0 True if unordered or not equal 201 SETTRUE, // 1 1 1 1 Always true (always folded) 202 // Don't care operations: undefined if the input is a nan. 203 SETFALSE2, // 1 X 0 0 0 Always false (always folded) 204 SETEQ, // 1 X 0 0 1 True if equal 205 SETGT, // 1 X 0 1 0 True if greater than 206 SETGE, // 1 X 0 1 1 True if greater than or equal 207 SETLT, // 1 X 1 0 0 True if less than 208 SETLE, // 1 X 1 0 1 True if less than or equal 209 SETNE, // 1 X 1 1 0 True if not equal 210 SETTRUE2, // 1 X 1 1 1 Always true (always folded) 211 212 SETCC_INVALID, // Marker value. 213 }; 214 215 /// isSignedIntSetCC - Return true if this is a setcc instruction that 216 /// performs a signed comparison when used with integer operands. 217 inline bool isSignedIntSetCC(CondCode Code) { 218 return Code == SETGT || Code == SETGE || Code == SETLT || Code == SETLE; 219 } 220 221 /// isUnsignedIntSetCC - Return true if this is a setcc instruction that 222 /// performs an unsigned comparison when used with integer operands. 223 inline bool isUnsignedIntSetCC(CondCode Code) { 224 return Code == SETUGT || Code == SETUGE || Code == SETULT || Code == SETULE; 225 } 226 227 /// isTrueWhenEqual - Return true if the specified condition returns true if 228 /// the two operands to the condition are equal. Note that if one of the two 229 /// operands is a NaN, this value is meaningless. 230 inline bool isTrueWhenEqual(CondCode Cond) { 231 return ((int)Cond & 1) != 0; 232 } 233 234 /// getUnorderedFlavor - This function returns 0 if the condition is always 235 /// false if an operand is a NaN, 1 if the condition is always true if the 236 /// operand is a NaN, and 2 if the condition is undefined if the operand is a 237 /// NaN. 238 inline unsigned getUnorderedFlavor(CondCode Cond) { 239 return ((int)Cond >> 3) & 3; 240 } 241 242 /// getSetCCInverse - Return the operation corresponding to !(X op Y), where 243 /// 'op' is a valid SetCC operation. 244 CondCode getSetCCInverse(CondCode Operation, bool isInteger); 245 246 /// getSetCCSwappedOperands - Return the operation corresponding to (Y op X) 247 /// when given the operation for (X op Y). 248 CondCode getSetCCSwappedOperands(CondCode Operation); 249 250 /// getSetCCOrOperation - Return the result of a logical OR between different 251 /// comparisons of identical values: ((X op1 Y) | (X op2 Y)). This 252 /// function returns SETCC_INVALID if it is not possible to represent the 253 /// resultant comparison. 254 CondCode getSetCCOrOperation(CondCode Op1, CondCode Op2, bool isInteger); 255 256 /// getSetCCAndOperation - Return the result of a logical AND between 257 /// different comparisons of identical values: ((X op1 Y) & (X op2 Y)). This 258 /// function returns SETCC_INVALID if it is not possible to represent the 259 /// resultant comparison. 260 CondCode getSetCCAndOperation(CondCode Op1, CondCode Op2, bool isInteger); 261} // end llvm::ISD namespace 262 263 264//===----------------------------------------------------------------------===// 265/// SDOperand - Unlike LLVM values, Selection DAG nodes may return multiple 266/// values as the result of a computation. Many nodes return multiple values, 267/// from loads (which define a token and a return value) to ADDC (which returns 268/// a result and a carry value), to calls (which may return an arbitrary number 269/// of values). 270/// 271/// As such, each use of a SelectionDAG computation must indicate the node that 272/// computes it as well as which return value to use from that node. This pair 273/// of information is represented with the SDOperand value type. 274/// 275class SDOperand { 276public: 277 SDNode *Val; // The node defining the value we are using. 278 unsigned ResNo; // Which return value of the node we are using. 279 280 SDOperand() : Val(0) {} 281 SDOperand(SDNode *val, unsigned resno) : Val(val), ResNo(resno) {} 282 283 bool operator==(const SDOperand &O) const { 284 return Val == O.Val && ResNo == O.ResNo; 285 } 286 bool operator!=(const SDOperand &O) const { 287 return !operator==(O); 288 } 289 bool operator<(const SDOperand &O) const { 290 return Val < O.Val || (Val == O.Val && ResNo < O.ResNo); 291 } 292 293 SDOperand getValue(unsigned R) const { 294 return SDOperand(Val, R); 295 } 296 297 /// getValueType - Return the ValueType of the referenced return value. 298 /// 299 inline MVT::ValueType getValueType() const; 300 301 // Forwarding methods - These forward to the corresponding methods in SDNode. 302 inline unsigned getOpcode() const; 303 inline unsigned getNumOperands() const; 304 inline const SDOperand &getOperand(unsigned i) const; 305}; 306 307 308/// simplify_type specializations - Allow casting operators to work directly on 309/// SDOperands as if they were SDNode*'s. 310template<> struct simplify_type<SDOperand> { 311 typedef SDNode* SimpleType; 312 static SimpleType getSimplifiedValue(const SDOperand &Val) { 313 return static_cast<SimpleType>(Val.Val); 314 } 315}; 316template<> struct simplify_type<const SDOperand> { 317 typedef SDNode* SimpleType; 318 static SimpleType getSimplifiedValue(const SDOperand &Val) { 319 return static_cast<SimpleType>(Val.Val); 320 } 321}; 322 323 324/// SDNode - Represents one node in the SelectionDAG. 325/// 326class SDNode { 327 unsigned NodeType; 328 std::vector<SDOperand> Operands; 329 330 /// Values - The types of the values this node defines. SDNode's may define 331 /// multiple values simultaneously. 332 std::vector<MVT::ValueType> Values; 333 334 /// Uses - These are all of the SDNode's that use a value produced by this 335 /// node. 336 std::vector<SDNode*> Uses; 337public: 338 339 //===--------------------------------------------------------------------===// 340 // Accessors 341 // 342 unsigned getOpcode() const { return NodeType; } 343 344 size_t use_size() const { return Uses.size(); } 345 bool use_empty() const { return Uses.empty(); } 346 bool hasOneUse() const { return Uses.size() == 1; } 347 348 /// getNumOperands - Return the number of values used by this operation. 349 /// 350 unsigned getNumOperands() const { return Operands.size(); } 351 352 const SDOperand &getOperand(unsigned Num) { 353 assert(Num < Operands.size() && "Invalid child # of SDNode!"); 354 return Operands[Num]; 355 } 356 357 const SDOperand &getOperand(unsigned Num) const { 358 assert(Num < Operands.size() && "Invalid child # of SDNode!"); 359 return Operands[Num]; 360 } 361 362 /// getNumValues - Return the number of values defined/returned by this 363 /// operator. 364 /// 365 unsigned getNumValues() const { return Values.size(); } 366 367 /// getValueType - Return the type of a specified result. 368 /// 369 MVT::ValueType getValueType(unsigned ResNo) const { 370 assert(ResNo < Values.size() && "Illegal result number!"); 371 return Values[ResNo]; 372 } 373 374 void dump() const; 375 376 static bool classof(const SDNode *) { return true; } 377 378protected: 379 friend class SelectionDAG; 380 381 SDNode(unsigned NT, MVT::ValueType VT) : NodeType(NT) { 382 Values.reserve(1); 383 Values.push_back(VT); 384 } 385 386 SDNode(unsigned NT, SDOperand Op) 387 : NodeType(NT) { 388 Operands.reserve(1); Operands.push_back(Op); 389 Op.Val->Uses.push_back(this); 390 } 391 SDNode(unsigned NT, SDOperand N1, SDOperand N2) 392 : NodeType(NT) { 393 Operands.reserve(2); Operands.push_back(N1); Operands.push_back(N2); 394 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this); 395 } 396 SDNode(unsigned NT, SDOperand N1, SDOperand N2, SDOperand N3) 397 : NodeType(NT) { 398 Operands.reserve(3); Operands.push_back(N1); Operands.push_back(N2); 399 Operands.push_back(N3); 400 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this); 401 N3.Val->Uses.push_back(this); 402 } 403 SDNode(unsigned NT, std::vector<SDOperand> &Nodes) : NodeType(NT) { 404 Operands.swap(Nodes); 405 for (unsigned i = 0, e = Nodes.size(); i != e; ++i) 406 Nodes[i].Val->Uses.push_back(this); 407 } 408 409 virtual ~SDNode() { 410 // FIXME: Drop uses. 411 } 412 413 void setValueTypes(MVT::ValueType VT) { 414 Values.reserve(1); 415 Values.push_back(VT); 416 } 417 void setValueTypes(MVT::ValueType VT1, MVT::ValueType VT2) { 418 Values.reserve(2); 419 Values.push_back(VT1); 420 Values.push_back(VT2); 421 } 422 /// Note: this method destroys the vector passed in. 423 void setValueTypes(std::vector<MVT::ValueType> &VTs) { 424 std::swap(Values, VTs); 425 } 426 427 void removeUser(SDNode *User) { 428 // Remove this user from the operand's use list. 429 for (unsigned i = Uses.size(); ; --i) { 430 assert(i != 0 && "Didn't find user!"); 431 if (Uses[i-1] == User) { 432 Uses.erase(Uses.begin()+i-1); 433 break; 434 } 435 } 436 } 437}; 438 439 440// Define inline functions from the SDOperand class. 441 442inline unsigned SDOperand::getOpcode() const { 443 return Val->getOpcode(); 444} 445inline MVT::ValueType SDOperand::getValueType() const { 446 return Val->getValueType(ResNo); 447} 448inline unsigned SDOperand::getNumOperands() const { 449 return Val->getNumOperands(); 450} 451inline const SDOperand &SDOperand::getOperand(unsigned i) const { 452 return Val->getOperand(i); 453} 454 455 456 457class ConstantSDNode : public SDNode { 458 uint64_t Value; 459protected: 460 friend class SelectionDAG; 461 ConstantSDNode(uint64_t val, MVT::ValueType VT) 462 : SDNode(ISD::Constant, VT), Value(val) { 463 } 464public: 465 466 uint64_t getValue() const { return Value; } 467 468 int64_t getSignExtended() const { 469 unsigned Bits = MVT::getSizeInBits(getValueType(0)); 470 return ((int64_t)Value << (64-Bits)) >> (64-Bits); 471 } 472 473 bool isNullValue() const { return Value == 0; } 474 bool isAllOnesValue() const { 475 return Value == (1ULL << MVT::getSizeInBits(getValueType(0)))-1; 476 } 477 478 static bool classof(const ConstantSDNode *) { return true; } 479 static bool classof(const SDNode *N) { 480 return N->getOpcode() == ISD::Constant; 481 } 482}; 483 484class ConstantFPSDNode : public SDNode { 485 double Value; 486protected: 487 friend class SelectionDAG; 488 ConstantFPSDNode(double val, MVT::ValueType VT) 489 : SDNode(ISD::ConstantFP, VT), Value(val) { 490 } 491public: 492 493 double getValue() const { return Value; } 494 495 /// isExactlyValue - We don't rely on operator== working on double values, as 496 /// it returns true for things that are clearly not equal, like -0.0 and 0.0. 497 /// As such, this method can be used to do an exact bit-for-bit comparison of 498 /// two floating point values. 499 bool isExactlyValue(double V) const { 500 union { 501 double V; 502 uint64_t I; 503 } T1; 504 T1.V = Value; 505 union { 506 double V; 507 uint64_t I; 508 } T2; 509 T2.V = V; 510 return T1.I == T2.I; 511 } 512 513 static bool classof(const ConstantFPSDNode *) { return true; } 514 static bool classof(const SDNode *N) { 515 return N->getOpcode() == ISD::ConstantFP; 516 } 517}; 518 519class GlobalAddressSDNode : public SDNode { 520 GlobalValue *TheGlobal; 521protected: 522 friend class SelectionDAG; 523 GlobalAddressSDNode(const GlobalValue *GA, MVT::ValueType VT) 524 : SDNode(ISD::GlobalAddress, VT) { 525 TheGlobal = const_cast<GlobalValue*>(GA); 526 } 527public: 528 529 GlobalValue *getGlobal() const { return TheGlobal; } 530 531 static bool classof(const GlobalAddressSDNode *) { return true; } 532 static bool classof(const SDNode *N) { 533 return N->getOpcode() == ISD::GlobalAddress; 534 } 535}; 536 537 538class FrameIndexSDNode : public SDNode { 539 int FI; 540protected: 541 friend class SelectionDAG; 542 FrameIndexSDNode(int fi, MVT::ValueType VT) 543 : SDNode(ISD::FrameIndex, VT), FI(fi) {} 544public: 545 546 int getIndex() const { return FI; } 547 548 static bool classof(const FrameIndexSDNode *) { return true; } 549 static bool classof(const SDNode *N) { 550 return N->getOpcode() == ISD::FrameIndex; 551 } 552}; 553 554class ConstantPoolSDNode : public SDNode { 555 unsigned CPI; 556protected: 557 friend class SelectionDAG; 558 ConstantPoolSDNode(unsigned cpi, MVT::ValueType VT) 559 : SDNode(ISD::ConstantPool, VT), CPI(cpi) {} 560public: 561 562 unsigned getIndex() const { return CPI; } 563 564 static bool classof(const ConstantPoolSDNode *) { return true; } 565 static bool classof(const SDNode *N) { 566 return N->getOpcode() == ISD::ConstantPool; 567 } 568}; 569 570class BasicBlockSDNode : public SDNode { 571 MachineBasicBlock *MBB; 572protected: 573 friend class SelectionDAG; 574 BasicBlockSDNode(MachineBasicBlock *mbb) 575 : SDNode(ISD::BasicBlock, MVT::Other), MBB(mbb) {} 576public: 577 578 MachineBasicBlock *getBasicBlock() const { return MBB; } 579 580 static bool classof(const BasicBlockSDNode *) { return true; } 581 static bool classof(const SDNode *N) { 582 return N->getOpcode() == ISD::BasicBlock; 583 } 584}; 585 586 587class CopyRegSDNode : public SDNode { 588 unsigned Reg; 589protected: 590 friend class SelectionDAG; 591 CopyRegSDNode(SDOperand Chain, SDOperand Src, unsigned reg) 592 : SDNode(ISD::CopyToReg, Chain, Src), Reg(reg) { 593 setValueTypes(MVT::Other); // Just a token chain. 594 } 595 CopyRegSDNode(unsigned reg, MVT::ValueType VT) 596 : SDNode(ISD::CopyFromReg, VT), Reg(reg) { 597 } 598public: 599 600 unsigned getReg() const { return Reg; } 601 602 static bool classof(const CopyRegSDNode *) { return true; } 603 static bool classof(const SDNode *N) { 604 return N->getOpcode() == ISD::CopyToReg || 605 N->getOpcode() == ISD::CopyFromReg; 606 } 607}; 608 609class ExternalSymbolSDNode : public SDNode { 610 const char *Symbol; 611protected: 612 friend class SelectionDAG; 613 ExternalSymbolSDNode(const char *Sym, MVT::ValueType VT) 614 : SDNode(ISD::ExternalSymbol, VT), Symbol(Sym) { 615 } 616public: 617 618 const char *getSymbol() const { return Symbol; } 619 620 static bool classof(const ExternalSymbolSDNode *) { return true; } 621 static bool classof(const SDNode *N) { 622 return N->getOpcode() == ISD::ExternalSymbol; 623 } 624}; 625 626class SetCCSDNode : public SDNode { 627 ISD::CondCode Condition; 628protected: 629 friend class SelectionDAG; 630 SetCCSDNode(ISD::CondCode Cond, SDOperand LHS, SDOperand RHS) 631 : SDNode(ISD::SETCC, LHS, RHS), Condition(Cond) { 632 setValueTypes(MVT::i1); 633 } 634public: 635 636 ISD::CondCode getCondition() const { return Condition; } 637 638 static bool classof(const SetCCSDNode *) { return true; } 639 static bool classof(const SDNode *N) { 640 return N->getOpcode() == ISD::SETCC; 641 } 642}; 643 644 645class SDNodeIterator : public forward_iterator<SDNode, ptrdiff_t> { 646 SDNode *Node; 647 unsigned Operand; 648 649 SDNodeIterator(SDNode *N, unsigned Op) : Node(N), Operand(Op) {} 650public: 651 bool operator==(const SDNodeIterator& x) const { 652 return Operand == x.Operand; 653 } 654 bool operator!=(const SDNodeIterator& x) const { return !operator==(x); } 655 656 const SDNodeIterator &operator=(const SDNodeIterator &I) { 657 assert(I.Node == Node && "Cannot assign iterators to two different nodes!"); 658 Operand = I.Operand; 659 return *this; 660 } 661 662 pointer operator*() const { 663 return Node->getOperand(Operand).Val; 664 } 665 pointer operator->() const { return operator*(); } 666 667 SDNodeIterator& operator++() { // Preincrement 668 ++Operand; 669 return *this; 670 } 671 SDNodeIterator operator++(int) { // Postincrement 672 SDNodeIterator tmp = *this; ++*this; return tmp; 673 } 674 675 static SDNodeIterator begin(SDNode *N) { return SDNodeIterator(N, 0); } 676 static SDNodeIterator end (SDNode *N) { 677 return SDNodeIterator(N, N->getNumOperands()); 678 } 679 680 unsigned getOperand() const { return Operand; } 681 const SDNode *getNode() const { return Node; } 682}; 683 684template <> struct GraphTraits<SDNode*> { 685 typedef SDNode NodeType; 686 typedef SDNodeIterator ChildIteratorType; 687 static inline NodeType *getEntryNode(SDNode *N) { return N; } 688 static inline ChildIteratorType child_begin(NodeType *N) { 689 return SDNodeIterator::begin(N); 690 } 691 static inline ChildIteratorType child_end(NodeType *N) { 692 return SDNodeIterator::end(N); 693 } 694}; 695 696 697 698 699} // end llvm namespace 700 701#endif 702