1 //===-- llvm/CodeGen/SelectionDAGNodes.h - SelectionDAG Nodes ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
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.
15 // Clients should include the SelectionDAG.h file instead of this file directly.
17 //===----------------------------------------------------------------------===//
19 #ifndef LLVM_CODEGEN_SELECTIONDAGNODES_H
20 #define LLVM_CODEGEN_SELECTIONDAGNODES_H
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"
34 class MachineBasicBlock;
36 template <typename T> struct simplify_type;
38 /// ISD namespace - This namespace contains an enum which represents all of the
39 /// SelectionDAG node types and value types.
42 //===--------------------------------------------------------------------===//
43 /// ISD::NodeType enum - This enum defines all of the operators valid in a
47 // EntryToken - This is the marker used to indicate the start of the region.
50 // Token factor - This node is takes multiple tokens as input and produces a
51 // single token result. This is used to represent the fact that the operand
52 // operators are independent of each other.
55 // Various leaf nodes.
56 Constant, ConstantFP, GlobalAddress, FrameIndex, ConstantPool,
57 BasicBlock, ExternalSymbol,
59 // CopyToReg - This node has chain and child nodes, and an associated
60 // register number. The instruction selector must guarantee that the value
61 // of the value node is available in the register stored in the RegSDNode
65 // CopyFromReg - This node indicates that the input value is a virtual or
66 // physical register that is defined outside of the scope of this
67 // SelectionDAG. The register is available from the RegSDNode object.
70 // ImplicitDef - This node indicates that the specified register is
71 // implicitly defined by some operation (e.g. its a live-in argument). This
72 // register is indicated in the RegSDNode object. The only operand to this
73 // is the token chain coming in, the only result is the token chain going
77 // EXTRACT_ELEMENT - This is used to get the first or second (determined by
78 // a Constant, which is required to be operand #1), element of the aggregate
79 // value specified as operand #0. This is only for use before legalization,
80 // for values that will be broken into multiple registers.
83 // BUILD_PAIR - This is the opposite of EXTRACT_ELEMENT in some ways. Given
84 // two values of the same integer value type, this produces a value twice as
85 // big. Like EXTRACT_ELEMENT, this can only be used before legalization.
89 // Simple binary arithmetic operators.
90 ADD, SUB, MUL, SDIV, UDIV, SREM, UREM,
93 AND, OR, XOR, SHL, SRA, SRL,
98 // SetCC operator - This evaluates to a boolean (i1) true value if the
99 // condition is true. These nodes are instances of the
100 // SetCCSDNode class, which contains the condition code as extra
104 // addc - Three input, two output operator: (X, Y, C) -> (X+Y+C,
105 // Cout). X,Y are integer inputs of agreeing size, C is a one bit
106 // value, and two values are produced: the sum and a carry out.
109 // Conversion operators. These are all single input single output
110 // operations. For all of these, the result type must be strictly
111 // wider or narrower (depending on the operation) than the source
114 // SIGN_EXTEND - Used for integer types, replicating the sign bit
118 // ZERO_EXTEND - Used for integer types, zeroing the new bits.
121 // TRUNCATE - Completely drop the high bits.
124 // [SU]INT_TO_FP - These operators convert integers (whose interpreted sign
125 // depends on the first letter) to floating point.
129 // FP_TO_[US]INT - Convert a floating point value to a signed or unsigned
134 // FP_ROUND - Perform a rounding operation from the current
135 // precision down to the specified precision.
138 // FP_EXTEND - Extend a smaller FP type into a larger FP type.
141 // Other operators. LOAD and STORE have token chains as their first
142 // operand, then the same operands as an LLVM load/store instruction.
145 // EXTLOAD, SEXTLOAD, ZEXTLOAD - These three operators are instances of the
146 // MVTSDNode. All of these load a value from memory and extend them to a
147 // larger value (e.g. load a byte into a word register). All three of these
148 // have two operands, a chain and a pointer to load from. The extra value
149 // type is the source type being loaded.
151 // SEXTLOAD loads the integer operand and sign extends it to a larger
152 // integer result type.
153 // ZEXTLOAD loads the integer operand and zero extends it to a larger
154 // integer result type.
155 // EXTLOAD is used for two things: floating point extending loads, and
156 // integer extending loads where it doesn't matter what the high
157 // bits are set to. The code generator is allowed to codegen this
158 // into whichever operation is more efficient.
159 EXTLOAD, SEXTLOAD, ZEXTLOAD,
161 // TRUNCSTORE - This operators truncates (for integer) or rounds (for FP) a
162 // value and stores it to memory in one operation. This can be used for
163 // either integer or floating point operands, and the stored type
164 // represented as the 'extra' value type in the MVTSDNode representing the
165 // operator. This node has the same three operands as a standard store.
168 // DYNAMIC_STACKALLOC - Allocate some number of bytes on the stack aligned
169 // to a specified boundary. The first operand is the token chain, the
170 // second is the number of bytes to allocate, and the third is the alignment
174 // Control flow instructions. These all have token chains.
176 // BR - Unconditional branch. The first operand is the chain
177 // operand, the second is the MBB to branch to.
180 // BRCOND - Conditional branch. The first operand is the chain,
181 // the second is the condition, the third is the block to branch
182 // to if the condition is true.
185 // RET - Return from function. The first operand is the chain,
186 // and any subsequent operands are the return values for the
187 // function. This operation can have variable number of operands.
190 // CALL - Call to a function pointer. The first operand is the chain, the
191 // second is the destination function pointer (a GlobalAddress for a direct
192 // call). Arguments have already been lowered to explicit DAGs according to
193 // the calling convention in effect here.
196 // MEMSET/MEMCPY/MEMMOVE - The first operand is the chain, and the rest
197 // correspond to the operands of the LLVM intrinsic functions. The only
198 // result is a token chain. The alignment argument is guaranteed to be a
204 // ADJCALLSTACKDOWN/ADJCALLSTACKUP - These operators mark the beginning and
205 // end of a call sequence and indicate how much the stack pointer needs to
206 // be adjusted for that particular call. The first operand is a chain, the
207 // second is a ConstantSDNode of intptr type.
208 ADJCALLSTACKDOWN, // Beginning of a call sequence
209 ADJCALLSTACKUP, // End of a call sequence
212 // BUILTIN_OP_END - This must be the last enum value in this list.
216 //===--------------------------------------------------------------------===//
217 /// ISD::CondCode enum - These are ordered carefully to make the bitfields
218 /// below work out, when considering SETFALSE (something that never exists
219 /// dynamically) as 0. "U" -> Unsigned (for integer operands) or Unordered
220 /// (for floating point), "L" -> Less than, "G" -> Greater than, "E" -> Equal
221 /// to. If the "N" column is 1, the result of the comparison is undefined if
222 /// the input is a NAN.
224 /// All of these (except for the 'always folded ops') should be handled for
225 /// floating point. For integer, only the SETEQ,SETNE,SETLT,SETLE,SETGT,
226 /// SETGE,SETULT,SETULE,SETUGT, and SETUGE opcodes are used.
228 /// Note that these are laid out in a specific order to allow bit-twiddling
229 /// to transform conditions.
231 // Opcode N U L G E Intuitive operation
232 SETFALSE, // 0 0 0 0 Always false (always folded)
233 SETOEQ, // 0 0 0 1 True if ordered and equal
234 SETOGT, // 0 0 1 0 True if ordered and greater than
235 SETOGE, // 0 0 1 1 True if ordered and greater than or equal
236 SETOLT, // 0 1 0 0 True if ordered and less than
237 SETOLE, // 0 1 0 1 True if ordered and less than or equal
238 SETONE, // 0 1 1 0 True if ordered and operands are unequal
239 SETO, // 0 1 1 1 True if ordered (no nans)
240 SETUO, // 1 0 0 0 True if unordered: isnan(X) | isnan(Y)
241 SETUEQ, // 1 0 0 1 True if unordered or equal
242 SETUGT, // 1 0 1 0 True if unordered or greater than
243 SETUGE, // 1 0 1 1 True if unordered, greater than, or equal
244 SETULT, // 1 1 0 0 True if unordered or less than
245 SETULE, // 1 1 0 1 True if unordered, less than, or equal
246 SETUNE, // 1 1 1 0 True if unordered or not equal
247 SETTRUE, // 1 1 1 1 Always true (always folded)
248 // Don't care operations: undefined if the input is a nan.
249 SETFALSE2, // 1 X 0 0 0 Always false (always folded)
250 SETEQ, // 1 X 0 0 1 True if equal
251 SETGT, // 1 X 0 1 0 True if greater than
252 SETGE, // 1 X 0 1 1 True if greater than or equal
253 SETLT, // 1 X 1 0 0 True if less than
254 SETLE, // 1 X 1 0 1 True if less than or equal
255 SETNE, // 1 X 1 1 0 True if not equal
256 SETTRUE2, // 1 X 1 1 1 Always true (always folded)
258 SETCC_INVALID, // Marker value.
261 /// isSignedIntSetCC - Return true if this is a setcc instruction that
262 /// performs a signed comparison when used with integer operands.
263 inline bool isSignedIntSetCC(CondCode Code) {
264 return Code == SETGT || Code == SETGE || Code == SETLT || Code == SETLE;
267 /// isUnsignedIntSetCC - Return true if this is a setcc instruction that
268 /// performs an unsigned comparison when used with integer operands.
269 inline bool isUnsignedIntSetCC(CondCode Code) {
270 return Code == SETUGT || Code == SETUGE || Code == SETULT || Code == SETULE;
273 /// isTrueWhenEqual - Return true if the specified condition returns true if
274 /// the two operands to the condition are equal. Note that if one of the two
275 /// operands is a NaN, this value is meaningless.
276 inline bool isTrueWhenEqual(CondCode Cond) {
277 return ((int)Cond & 1) != 0;
280 /// getUnorderedFlavor - This function returns 0 if the condition is always
281 /// false if an operand is a NaN, 1 if the condition is always true if the
282 /// operand is a NaN, and 2 if the condition is undefined if the operand is a
284 inline unsigned getUnorderedFlavor(CondCode Cond) {
285 return ((int)Cond >> 3) & 3;
288 /// getSetCCInverse - Return the operation corresponding to !(X op Y), where
289 /// 'op' is a valid SetCC operation.
290 CondCode getSetCCInverse(CondCode Operation, bool isInteger);
292 /// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
293 /// when given the operation for (X op Y).
294 CondCode getSetCCSwappedOperands(CondCode Operation);
296 /// getSetCCOrOperation - Return the result of a logical OR between different
297 /// comparisons of identical values: ((X op1 Y) | (X op2 Y)). This
298 /// function returns SETCC_INVALID if it is not possible to represent the
299 /// resultant comparison.
300 CondCode getSetCCOrOperation(CondCode Op1, CondCode Op2, bool isInteger);
302 /// getSetCCAndOperation - Return the result of a logical AND between
303 /// different comparisons of identical values: ((X op1 Y) & (X op2 Y)). This
304 /// function returns SETCC_INVALID if it is not possible to represent the
305 /// resultant comparison.
306 CondCode getSetCCAndOperation(CondCode Op1, CondCode Op2, bool isInteger);
307 } // end llvm::ISD namespace
310 //===----------------------------------------------------------------------===//
311 /// SDOperand - Unlike LLVM values, Selection DAG nodes may return multiple
312 /// values as the result of a computation. Many nodes return multiple values,
313 /// from loads (which define a token and a return value) to ADDC (which returns
314 /// a result and a carry value), to calls (which may return an arbitrary number
317 /// As such, each use of a SelectionDAG computation must indicate the node that
318 /// computes it as well as which return value to use from that node. This pair
319 /// of information is represented with the SDOperand value type.
323 SDNode *Val; // The node defining the value we are using.
324 unsigned ResNo; // Which return value of the node we are using.
326 SDOperand() : Val(0) {}
327 SDOperand(SDNode *val, unsigned resno) : Val(val), ResNo(resno) {}
329 bool operator==(const SDOperand &O) const {
330 return Val == O.Val && ResNo == O.ResNo;
332 bool operator!=(const SDOperand &O) const {
333 return !operator==(O);
335 bool operator<(const SDOperand &O) const {
336 return Val < O.Val || (Val == O.Val && ResNo < O.ResNo);
339 SDOperand getValue(unsigned R) const {
340 return SDOperand(Val, R);
343 /// getValueType - Return the ValueType of the referenced return value.
345 inline MVT::ValueType getValueType() const;
347 // Forwarding methods - These forward to the corresponding methods in SDNode.
348 inline unsigned getOpcode() const;
349 inline unsigned getNumOperands() const;
350 inline const SDOperand &getOperand(unsigned i) const;
352 /// hasOneUse - Return true if there is exactly one operation using this
353 /// result value of the defining operator.
354 inline bool hasOneUse() const;
358 /// simplify_type specializations - Allow casting operators to work directly on
359 /// SDOperands as if they were SDNode*'s.
360 template<> struct simplify_type<SDOperand> {
361 typedef SDNode* SimpleType;
362 static SimpleType getSimplifiedValue(const SDOperand &Val) {
363 return static_cast<SimpleType>(Val.Val);
366 template<> struct simplify_type<const SDOperand> {
367 typedef SDNode* SimpleType;
368 static SimpleType getSimplifiedValue(const SDOperand &Val) {
369 return static_cast<SimpleType>(Val.Val);
374 /// SDNode - Represents one node in the SelectionDAG.
378 std::vector<SDOperand> Operands;
380 /// Values - The types of the values this node defines. SDNode's may define
381 /// multiple values simultaneously.
382 std::vector<MVT::ValueType> Values;
384 /// Uses - These are all of the SDNode's that use a value produced by this
386 std::vector<SDNode*> Uses;
389 //===--------------------------------------------------------------------===//
392 unsigned getOpcode() const { return NodeType; }
394 size_t use_size() const { return Uses.size(); }
395 bool use_empty() const { return Uses.empty(); }
396 bool hasOneUse() const { return Uses.size() == 1; }
398 /// hasNUsesOfValue - Return true if there are exactly NUSES uses of the
399 /// indicated value. This method ignores uses of other values defined by this
401 bool hasNUsesOfValue(unsigned NUses, unsigned Value);
403 /// getNumOperands - Return the number of values used by this operation.
405 unsigned getNumOperands() const { return Operands.size(); }
407 const SDOperand &getOperand(unsigned Num) {
408 assert(Num < Operands.size() && "Invalid child # of SDNode!");
409 return Operands[Num];
412 const SDOperand &getOperand(unsigned Num) const {
413 assert(Num < Operands.size() && "Invalid child # of SDNode!");
414 return Operands[Num];
417 /// getNumValues - Return the number of values defined/returned by this
420 unsigned getNumValues() const { return Values.size(); }
422 /// getValueType - Return the type of a specified result.
424 MVT::ValueType getValueType(unsigned ResNo) const {
425 assert(ResNo < Values.size() && "Illegal result number!");
426 return Values[ResNo];
429 /// getOperationName - Return the opcode of this operation for printing.
431 const char* getOperationName() const;
434 static bool classof(const SDNode *) { return true; }
437 friend class SelectionDAG;
439 SDNode(unsigned NT, MVT::ValueType VT) : NodeType(NT) {
441 Values.push_back(VT);
444 SDNode(unsigned NT, SDOperand Op)
446 Operands.reserve(1); Operands.push_back(Op);
447 Op.Val->Uses.push_back(this);
449 SDNode(unsigned NT, SDOperand N1, SDOperand N2)
451 Operands.reserve(2); Operands.push_back(N1); Operands.push_back(N2);
452 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this);
454 SDNode(unsigned NT, SDOperand N1, SDOperand N2, SDOperand N3)
456 Operands.reserve(3); Operands.push_back(N1); Operands.push_back(N2);
457 Operands.push_back(N3);
458 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this);
459 N3.Val->Uses.push_back(this);
461 SDNode(unsigned NT, std::vector<SDOperand> &Nodes) : NodeType(NT) {
462 Operands.swap(Nodes);
463 for (unsigned i = 0, e = Operands.size(); i != e; ++i)
464 Operands[i].Val->Uses.push_back(this);
471 void setValueTypes(MVT::ValueType VT) {
473 Values.push_back(VT);
475 void setValueTypes(MVT::ValueType VT1, MVT::ValueType VT2) {
477 Values.push_back(VT1);
478 Values.push_back(VT2);
480 /// Note: this method destroys the vector passed in.
481 void setValueTypes(std::vector<MVT::ValueType> &VTs) {
482 std::swap(Values, VTs);
485 void removeUser(SDNode *User) {
486 // Remove this user from the operand's use list.
487 for (unsigned i = Uses.size(); ; --i) {
488 assert(i != 0 && "Didn't find user!");
489 if (Uses[i-1] == User) {
490 Uses.erase(Uses.begin()+i-1);
498 // Define inline functions from the SDOperand class.
500 inline unsigned SDOperand::getOpcode() const {
501 return Val->getOpcode();
503 inline MVT::ValueType SDOperand::getValueType() const {
504 return Val->getValueType(ResNo);
506 inline unsigned SDOperand::getNumOperands() const {
507 return Val->getNumOperands();
509 inline const SDOperand &SDOperand::getOperand(unsigned i) const {
510 return Val->getOperand(i);
512 inline bool SDOperand::hasOneUse() const {
513 return Val->hasNUsesOfValue(1, ResNo);
517 class ConstantSDNode : public SDNode {
520 friend class SelectionDAG;
521 ConstantSDNode(uint64_t val, MVT::ValueType VT)
522 : SDNode(ISD::Constant, VT), Value(val) {
526 uint64_t getValue() const { return Value; }
528 int64_t getSignExtended() const {
529 unsigned Bits = MVT::getSizeInBits(getValueType(0));
530 return ((int64_t)Value << (64-Bits)) >> (64-Bits);
533 bool isNullValue() const { return Value == 0; }
534 bool isAllOnesValue() const {
535 return Value == (1ULL << MVT::getSizeInBits(getValueType(0)))-1;
538 static bool classof(const ConstantSDNode *) { return true; }
539 static bool classof(const SDNode *N) {
540 return N->getOpcode() == ISD::Constant;
544 class ConstantFPSDNode : public SDNode {
547 friend class SelectionDAG;
548 ConstantFPSDNode(double val, MVT::ValueType VT)
549 : SDNode(ISD::ConstantFP, VT), Value(val) {
553 double getValue() const { return Value; }
555 /// isExactlyValue - We don't rely on operator== working on double values, as
556 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
557 /// As such, this method can be used to do an exact bit-for-bit comparison of
558 /// two floating point values.
559 bool isExactlyValue(double V) const {
573 static bool classof(const ConstantFPSDNode *) { return true; }
574 static bool classof(const SDNode *N) {
575 return N->getOpcode() == ISD::ConstantFP;
579 class GlobalAddressSDNode : public SDNode {
580 GlobalValue *TheGlobal;
582 friend class SelectionDAG;
583 GlobalAddressSDNode(const GlobalValue *GA, MVT::ValueType VT)
584 : SDNode(ISD::GlobalAddress, VT) {
585 TheGlobal = const_cast<GlobalValue*>(GA);
589 GlobalValue *getGlobal() const { return TheGlobal; }
591 static bool classof(const GlobalAddressSDNode *) { return true; }
592 static bool classof(const SDNode *N) {
593 return N->getOpcode() == ISD::GlobalAddress;
598 class FrameIndexSDNode : public SDNode {
601 friend class SelectionDAG;
602 FrameIndexSDNode(int fi, MVT::ValueType VT)
603 : SDNode(ISD::FrameIndex, VT), FI(fi) {}
606 int getIndex() const { return FI; }
608 static bool classof(const FrameIndexSDNode *) { return true; }
609 static bool classof(const SDNode *N) {
610 return N->getOpcode() == ISD::FrameIndex;
614 class ConstantPoolSDNode : public SDNode {
617 friend class SelectionDAG;
618 ConstantPoolSDNode(unsigned cpi, MVT::ValueType VT)
619 : SDNode(ISD::ConstantPool, VT), CPI(cpi) {}
622 unsigned getIndex() const { return CPI; }
624 static bool classof(const ConstantPoolSDNode *) { return true; }
625 static bool classof(const SDNode *N) {
626 return N->getOpcode() == ISD::ConstantPool;
630 class BasicBlockSDNode : public SDNode {
631 MachineBasicBlock *MBB;
633 friend class SelectionDAG;
634 BasicBlockSDNode(MachineBasicBlock *mbb)
635 : SDNode(ISD::BasicBlock, MVT::Other), MBB(mbb) {}
638 MachineBasicBlock *getBasicBlock() const { return MBB; }
640 static bool classof(const BasicBlockSDNode *) { return true; }
641 static bool classof(const SDNode *N) {
642 return N->getOpcode() == ISD::BasicBlock;
647 class RegSDNode : public SDNode {
650 friend class SelectionDAG;
651 RegSDNode(unsigned Opc, MVT::ValueType VT, SDOperand Chain,
652 SDOperand Src, unsigned reg)
653 : SDNode(Opc, Chain, Src), Reg(reg) {
656 RegSDNode(unsigned Opc, MVT::ValueType VT, SDOperand Chain,
658 : SDNode(Opc, Chain), Reg(reg) {
661 RegSDNode(unsigned Opc, MVT::ValueType VT, unsigned reg)
662 : SDNode(Opc, VT), Reg(reg) {
666 unsigned getReg() const { return Reg; }
668 static bool classof(const RegSDNode *) { return true; }
669 static bool classof(const SDNode *N) {
670 return N->getOpcode() == ISD::CopyToReg ||
671 N->getOpcode() == ISD::CopyFromReg ||
672 N->getOpcode() == ISD::ImplicitDef;
676 class ExternalSymbolSDNode : public SDNode {
679 friend class SelectionDAG;
680 ExternalSymbolSDNode(const char *Sym, MVT::ValueType VT)
681 : SDNode(ISD::ExternalSymbol, VT), Symbol(Sym) {
685 const char *getSymbol() const { return Symbol; }
687 static bool classof(const ExternalSymbolSDNode *) { return true; }
688 static bool classof(const SDNode *N) {
689 return N->getOpcode() == ISD::ExternalSymbol;
693 class SetCCSDNode : public SDNode {
694 ISD::CondCode Condition;
696 friend class SelectionDAG;
697 SetCCSDNode(ISD::CondCode Cond, SDOperand LHS, SDOperand RHS)
698 : SDNode(ISD::SETCC, LHS, RHS), Condition(Cond) {
699 setValueTypes(MVT::i1);
703 ISD::CondCode getCondition() const { return Condition; }
705 static bool classof(const SetCCSDNode *) { return true; }
706 static bool classof(const SDNode *N) {
707 return N->getOpcode() == ISD::SETCC;
711 /// MVTSDNode - This class is used for operators that require an extra
712 /// value-type to be kept with the node.
713 class MVTSDNode : public SDNode {
714 MVT::ValueType ExtraValueType;
716 friend class SelectionDAG;
717 MVTSDNode(unsigned Opc, MVT::ValueType VT,
718 SDOperand Op0, SDOperand Op1, MVT::ValueType EVT)
719 : SDNode(Opc, Op0, Op1), ExtraValueType(EVT) {
722 MVTSDNode(unsigned Opc, MVT::ValueType VT,
723 SDOperand Op0, SDOperand Op1, SDOperand Op2, MVT::ValueType EVT)
724 : SDNode(Opc, Op0, Op1, Op2), ExtraValueType(EVT) {
729 MVT::ValueType getExtraValueType() const { return ExtraValueType; }
731 static bool classof(const MVTSDNode *) { return true; }
732 static bool classof(const SDNode *N) {
734 N->getOpcode() == ISD::EXTLOAD ||
735 N->getOpcode() == ISD::SEXTLOAD ||
736 N->getOpcode() == ISD::ZEXTLOAD ||
737 N->getOpcode() == ISD::TRUNCSTORE;
741 class SDNodeIterator : public forward_iterator<SDNode, ptrdiff_t> {
745 SDNodeIterator(SDNode *N, unsigned Op) : Node(N), Operand(Op) {}
747 bool operator==(const SDNodeIterator& x) const {
748 return Operand == x.Operand;
750 bool operator!=(const SDNodeIterator& x) const { return !operator==(x); }
752 const SDNodeIterator &operator=(const SDNodeIterator &I) {
753 assert(I.Node == Node && "Cannot assign iterators to two different nodes!");
758 pointer operator*() const {
759 return Node->getOperand(Operand).Val;
761 pointer operator->() const { return operator*(); }
763 SDNodeIterator& operator++() { // Preincrement
767 SDNodeIterator operator++(int) { // Postincrement
768 SDNodeIterator tmp = *this; ++*this; return tmp;
771 static SDNodeIterator begin(SDNode *N) { return SDNodeIterator(N, 0); }
772 static SDNodeIterator end (SDNode *N) {
773 return SDNodeIterator(N, N->getNumOperands());
776 unsigned getOperand() const { return Operand; }
777 const SDNode *getNode() const { return Node; }
780 template <> struct GraphTraits<SDNode*> {
781 typedef SDNode NodeType;
782 typedef SDNodeIterator ChildIteratorType;
783 static inline NodeType *getEntryNode(SDNode *N) { return N; }
784 static inline ChildIteratorType child_begin(NodeType *N) {
785 return SDNodeIterator::begin(N);
787 static inline ChildIteratorType child_end(NodeType *N) {
788 return SDNodeIterator::end(N);
795 } // end llvm namespace