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
62 // CopyRegSDNode object.
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 number is available from the CopyRegSDNode
71 // EXTRACT_ELEMENT - This is used to get the first or second (determined by
72 // a Constant, which is required to be operand #1), element of the aggregate
73 // value specified as operand #0. This is only for use before legalization,
74 // for values that will be broken into multiple registers.
77 // BUILD_PAIR - This is the opposite of EXTRACT_ELEMENT in some ways. Given
78 // two values of the same integer value type, this produces a value twice as
79 // big. Like EXTRACT_ELEMENT, this can only be used before legalization.
83 // Simple binary arithmetic operators.
84 ADD, SUB, MUL, SDIV, UDIV, SREM, UREM,
87 AND, OR, XOR, SHL, SRA, SRL,
92 // SetCC operator - This evaluates to a boolean (i1) true value if the
93 // condition is true. These nodes are instances of the
94 // SetCCSDNode class, which contains the condition code as extra
98 // addc - Three input, two output operator: (X, Y, C) -> (X+Y+C,
99 // Cout). X,Y are integer inputs of agreeing size, C is a one bit
100 // value, and two values are produced: the sum and a carry out.
103 // Conversion operators. These are all single input single output
104 // operations. For all of these, the result type must be strictly
105 // wider or narrower (depending on the operation) than the source
108 // SIGN_EXTEND - Used for integer types, replicating the sign bit
112 // ZERO_EXTEND - Used for integer types, zeroing the new bits.
115 // TRUNCATE - Completely drop the high bits.
118 // [SU]INT_TO_FP - These operators convert integers (whose interpreted sign
119 // depends on the first letter) to floating point.
123 // FP_TO_[US]INT - Convert a floating point value to a signed or unsigned
128 // FP_ROUND - Perform a rounding operation from the current
129 // precision down to the specified precision.
132 // FP_EXTEND - Extend a smaller FP type into a larger FP type.
135 // Other operators. LOAD and STORE have token chains.
138 // DYNAMIC_STACKALLOC - Allocate some number of bytes on the stack aligned
139 // to a specified boundary. The first operand is the token chain, the
140 // second is the number of bytes to allocate, and the third is the alignment
144 // Control flow instructions. These all have token chains.
146 // BR - Unconditional branch. The first operand is the chain
147 // operand, the second is the MBB to branch to.
150 // BRCOND - Conditional branch. The first operand is the chain,
151 // the second is the condition, the third is the block to branch
152 // to if the condition is true.
155 // RET - Return from function. The first operand is the chain,
156 // and any subsequent operands are the return values for the
157 // function. This operation can have variable number of operands.
160 // CALL - Call to a function pointer. The first operand is the chain, the
161 // second is the destination function pointer (a GlobalAddress for a direct
162 // call). Arguments have already been lowered to explicit DAGs according to
163 // the calling convention in effect here.
166 // MEMSET/MEMCPY/MEMMOVE - The first operand is the chain, and the rest
167 // correspond to the operands of the LLVM intrinsic functions. The only
168 // result is a token chain. The alignment argument is guaranteed to be a
174 // ADJCALLSTACKDOWN/ADJCALLSTACKUP - These operators mark the beginning and
175 // end of a call sequence and indicate how much the stack pointer needs to
176 // be adjusted for that particular call. The first operand is a chain, the
177 // second is a ConstantSDNode of intptr type.
178 ADJCALLSTACKDOWN, // Beginning of a call sequence
179 ADJCALLSTACKUP, // End of a call sequence
182 // BUILTIN_OP_END - This must be the last enum value in this list.
186 //===--------------------------------------------------------------------===//
187 /// ISD::CondCode enum - These are ordered carefully to make the bitfields
188 /// below work out, when considering SETFALSE (something that never exists
189 /// dynamically) as 0. "U" -> Unsigned (for integer operands) or Unordered
190 /// (for floating point), "L" -> Less than, "G" -> Greater than, "E" -> Equal
191 /// to. If the "N" column is 1, the result of the comparison is undefined if
192 /// the input is a NAN.
194 /// All of these (except for the 'always folded ops') should be handled for
195 /// floating point. For integer, only the SETEQ,SETNE,SETLT,SETLE,SETGT,
196 /// SETGE,SETULT,SETULE,SETUGT, and SETUGE opcodes are used.
198 /// Note that these are laid out in a specific order to allow bit-twiddling
199 /// to transform conditions.
201 // Opcode N U L G E Intuitive operation
202 SETFALSE, // 0 0 0 0 Always false (always folded)
203 SETOEQ, // 0 0 0 1 True if ordered and equal
204 SETOGT, // 0 0 1 0 True if ordered and greater than
205 SETOGE, // 0 0 1 1 True if ordered and greater than or equal
206 SETOLT, // 0 1 0 0 True if ordered and less than
207 SETOLE, // 0 1 0 1 True if ordered and less than or equal
208 SETONE, // 0 1 1 0 True if ordered and operands are unequal
209 SETO, // 0 1 1 1 True if ordered (no nans)
210 SETUO, // 1 0 0 0 True if unordered: isnan(X) | isnan(Y)
211 SETUEQ, // 1 0 0 1 True if unordered or equal
212 SETUGT, // 1 0 1 0 True if unordered or greater than
213 SETUGE, // 1 0 1 1 True if unordered, greater than, or equal
214 SETULT, // 1 1 0 0 True if unordered or less than
215 SETULE, // 1 1 0 1 True if unordered, less than, or equal
216 SETUNE, // 1 1 1 0 True if unordered or not equal
217 SETTRUE, // 1 1 1 1 Always true (always folded)
218 // Don't care operations: undefined if the input is a nan.
219 SETFALSE2, // 1 X 0 0 0 Always false (always folded)
220 SETEQ, // 1 X 0 0 1 True if equal
221 SETGT, // 1 X 0 1 0 True if greater than
222 SETGE, // 1 X 0 1 1 True if greater than or equal
223 SETLT, // 1 X 1 0 0 True if less than
224 SETLE, // 1 X 1 0 1 True if less than or equal
225 SETNE, // 1 X 1 1 0 True if not equal
226 SETTRUE2, // 1 X 1 1 1 Always true (always folded)
228 SETCC_INVALID, // Marker value.
231 /// isSignedIntSetCC - Return true if this is a setcc instruction that
232 /// performs a signed comparison when used with integer operands.
233 inline bool isSignedIntSetCC(CondCode Code) {
234 return Code == SETGT || Code == SETGE || Code == SETLT || Code == SETLE;
237 /// isUnsignedIntSetCC - Return true if this is a setcc instruction that
238 /// performs an unsigned comparison when used with integer operands.
239 inline bool isUnsignedIntSetCC(CondCode Code) {
240 return Code == SETUGT || Code == SETUGE || Code == SETULT || Code == SETULE;
243 /// isTrueWhenEqual - Return true if the specified condition returns true if
244 /// the two operands to the condition are equal. Note that if one of the two
245 /// operands is a NaN, this value is meaningless.
246 inline bool isTrueWhenEqual(CondCode Cond) {
247 return ((int)Cond & 1) != 0;
250 /// getUnorderedFlavor - This function returns 0 if the condition is always
251 /// false if an operand is a NaN, 1 if the condition is always true if the
252 /// operand is a NaN, and 2 if the condition is undefined if the operand is a
254 inline unsigned getUnorderedFlavor(CondCode Cond) {
255 return ((int)Cond >> 3) & 3;
258 /// getSetCCInverse - Return the operation corresponding to !(X op Y), where
259 /// 'op' is a valid SetCC operation.
260 CondCode getSetCCInverse(CondCode Operation, bool isInteger);
262 /// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
263 /// when given the operation for (X op Y).
264 CondCode getSetCCSwappedOperands(CondCode Operation);
266 /// getSetCCOrOperation - Return the result of a logical OR between different
267 /// comparisons of identical values: ((X op1 Y) | (X op2 Y)). This
268 /// function returns SETCC_INVALID if it is not possible to represent the
269 /// resultant comparison.
270 CondCode getSetCCOrOperation(CondCode Op1, CondCode Op2, bool isInteger);
272 /// getSetCCAndOperation - Return the result of a logical AND between
273 /// different comparisons of identical values: ((X op1 Y) & (X op2 Y)). This
274 /// function returns SETCC_INVALID if it is not possible to represent the
275 /// resultant comparison.
276 CondCode getSetCCAndOperation(CondCode Op1, CondCode Op2, bool isInteger);
277 } // end llvm::ISD namespace
280 //===----------------------------------------------------------------------===//
281 /// SDOperand - Unlike LLVM values, Selection DAG nodes may return multiple
282 /// values as the result of a computation. Many nodes return multiple values,
283 /// from loads (which define a token and a return value) to ADDC (which returns
284 /// a result and a carry value), to calls (which may return an arbitrary number
287 /// As such, each use of a SelectionDAG computation must indicate the node that
288 /// computes it as well as which return value to use from that node. This pair
289 /// of information is represented with the SDOperand value type.
293 SDNode *Val; // The node defining the value we are using.
294 unsigned ResNo; // Which return value of the node we are using.
296 SDOperand() : Val(0) {}
297 SDOperand(SDNode *val, unsigned resno) : Val(val), ResNo(resno) {}
299 bool operator==(const SDOperand &O) const {
300 return Val == O.Val && ResNo == O.ResNo;
302 bool operator!=(const SDOperand &O) const {
303 return !operator==(O);
305 bool operator<(const SDOperand &O) const {
306 return Val < O.Val || (Val == O.Val && ResNo < O.ResNo);
309 SDOperand getValue(unsigned R) const {
310 return SDOperand(Val, R);
313 /// getValueType - Return the ValueType of the referenced return value.
315 inline MVT::ValueType getValueType() const;
317 // Forwarding methods - These forward to the corresponding methods in SDNode.
318 inline unsigned getOpcode() const;
319 inline unsigned getNumOperands() const;
320 inline const SDOperand &getOperand(unsigned i) const;
324 /// simplify_type specializations - Allow casting operators to work directly on
325 /// SDOperands as if they were SDNode*'s.
326 template<> struct simplify_type<SDOperand> {
327 typedef SDNode* SimpleType;
328 static SimpleType getSimplifiedValue(const SDOperand &Val) {
329 return static_cast<SimpleType>(Val.Val);
332 template<> struct simplify_type<const SDOperand> {
333 typedef SDNode* SimpleType;
334 static SimpleType getSimplifiedValue(const SDOperand &Val) {
335 return static_cast<SimpleType>(Val.Val);
340 /// SDNode - Represents one node in the SelectionDAG.
344 std::vector<SDOperand> Operands;
346 /// Values - The types of the values this node defines. SDNode's may define
347 /// multiple values simultaneously.
348 std::vector<MVT::ValueType> Values;
350 /// Uses - These are all of the SDNode's that use a value produced by this
352 std::vector<SDNode*> Uses;
355 //===--------------------------------------------------------------------===//
358 unsigned getOpcode() const { return NodeType; }
360 size_t use_size() const { return Uses.size(); }
361 bool use_empty() const { return Uses.empty(); }
362 bool hasOneUse() const { return Uses.size() == 1; }
364 /// hasNUsesOfValue - Return true if there are exactly NUSES uses of the
365 /// indicated value. This method ignores uses of other values defined by this
367 bool hasNUsesOfValue(unsigned NUses, unsigned Value);
369 /// getNumOperands - Return the number of values used by this operation.
371 unsigned getNumOperands() const { return Operands.size(); }
373 const SDOperand &getOperand(unsigned Num) {
374 assert(Num < Operands.size() && "Invalid child # of SDNode!");
375 return Operands[Num];
378 const SDOperand &getOperand(unsigned Num) const {
379 assert(Num < Operands.size() && "Invalid child # of SDNode!");
380 return Operands[Num];
383 /// getNumValues - Return the number of values defined/returned by this
386 unsigned getNumValues() const { return Values.size(); }
388 /// getValueType - Return the type of a specified result.
390 MVT::ValueType getValueType(unsigned ResNo) const {
391 assert(ResNo < Values.size() && "Illegal result number!");
392 return Values[ResNo];
395 /// getOperationName - Return the opcode of this operation for printing.
397 const char* getOperationName() const;
400 static bool classof(const SDNode *) { return true; }
403 friend class SelectionDAG;
405 SDNode(unsigned NT, MVT::ValueType VT) : NodeType(NT) {
407 Values.push_back(VT);
410 SDNode(unsigned NT, SDOperand Op)
412 Operands.reserve(1); Operands.push_back(Op);
413 Op.Val->Uses.push_back(this);
415 SDNode(unsigned NT, SDOperand N1, SDOperand N2)
417 Operands.reserve(2); Operands.push_back(N1); Operands.push_back(N2);
418 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this);
420 SDNode(unsigned NT, SDOperand N1, SDOperand N2, SDOperand N3)
422 Operands.reserve(3); Operands.push_back(N1); Operands.push_back(N2);
423 Operands.push_back(N3);
424 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this);
425 N3.Val->Uses.push_back(this);
427 SDNode(unsigned NT, std::vector<SDOperand> &Nodes) : NodeType(NT) {
428 Operands.swap(Nodes);
429 for (unsigned i = 0, e = Operands.size(); i != e; ++i)
430 Operands[i].Val->Uses.push_back(this);
437 void setValueTypes(MVT::ValueType VT) {
439 Values.push_back(VT);
441 void setValueTypes(MVT::ValueType VT1, MVT::ValueType VT2) {
443 Values.push_back(VT1);
444 Values.push_back(VT2);
446 /// Note: this method destroys the vector passed in.
447 void setValueTypes(std::vector<MVT::ValueType> &VTs) {
448 std::swap(Values, VTs);
451 void removeUser(SDNode *User) {
452 // Remove this user from the operand's use list.
453 for (unsigned i = Uses.size(); ; --i) {
454 assert(i != 0 && "Didn't find user!");
455 if (Uses[i-1] == User) {
456 Uses.erase(Uses.begin()+i-1);
464 // Define inline functions from the SDOperand class.
466 inline unsigned SDOperand::getOpcode() const {
467 return Val->getOpcode();
469 inline MVT::ValueType SDOperand::getValueType() const {
470 return Val->getValueType(ResNo);
472 inline unsigned SDOperand::getNumOperands() const {
473 return Val->getNumOperands();
475 inline const SDOperand &SDOperand::getOperand(unsigned i) const {
476 return Val->getOperand(i);
481 class ConstantSDNode : public SDNode {
484 friend class SelectionDAG;
485 ConstantSDNode(uint64_t val, MVT::ValueType VT)
486 : SDNode(ISD::Constant, VT), Value(val) {
490 uint64_t getValue() const { return Value; }
492 int64_t getSignExtended() const {
493 unsigned Bits = MVT::getSizeInBits(getValueType(0));
494 return ((int64_t)Value << (64-Bits)) >> (64-Bits);
497 bool isNullValue() const { return Value == 0; }
498 bool isAllOnesValue() const {
499 return Value == (1ULL << MVT::getSizeInBits(getValueType(0)))-1;
502 static bool classof(const ConstantSDNode *) { return true; }
503 static bool classof(const SDNode *N) {
504 return N->getOpcode() == ISD::Constant;
508 class ConstantFPSDNode : public SDNode {
511 friend class SelectionDAG;
512 ConstantFPSDNode(double val, MVT::ValueType VT)
513 : SDNode(ISD::ConstantFP, VT), Value(val) {
517 double getValue() const { return Value; }
519 /// isExactlyValue - We don't rely on operator== working on double values, as
520 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
521 /// As such, this method can be used to do an exact bit-for-bit comparison of
522 /// two floating point values.
523 bool isExactlyValue(double V) const {
537 static bool classof(const ConstantFPSDNode *) { return true; }
538 static bool classof(const SDNode *N) {
539 return N->getOpcode() == ISD::ConstantFP;
543 class GlobalAddressSDNode : public SDNode {
544 GlobalValue *TheGlobal;
546 friend class SelectionDAG;
547 GlobalAddressSDNode(const GlobalValue *GA, MVT::ValueType VT)
548 : SDNode(ISD::GlobalAddress, VT) {
549 TheGlobal = const_cast<GlobalValue*>(GA);
553 GlobalValue *getGlobal() const { return TheGlobal; }
555 static bool classof(const GlobalAddressSDNode *) { return true; }
556 static bool classof(const SDNode *N) {
557 return N->getOpcode() == ISD::GlobalAddress;
562 class FrameIndexSDNode : public SDNode {
565 friend class SelectionDAG;
566 FrameIndexSDNode(int fi, MVT::ValueType VT)
567 : SDNode(ISD::FrameIndex, VT), FI(fi) {}
570 int getIndex() const { return FI; }
572 static bool classof(const FrameIndexSDNode *) { return true; }
573 static bool classof(const SDNode *N) {
574 return N->getOpcode() == ISD::FrameIndex;
578 class ConstantPoolSDNode : public SDNode {
581 friend class SelectionDAG;
582 ConstantPoolSDNode(unsigned cpi, MVT::ValueType VT)
583 : SDNode(ISD::ConstantPool, VT), CPI(cpi) {}
586 unsigned getIndex() const { return CPI; }
588 static bool classof(const ConstantPoolSDNode *) { return true; }
589 static bool classof(const SDNode *N) {
590 return N->getOpcode() == ISD::ConstantPool;
594 class BasicBlockSDNode : public SDNode {
595 MachineBasicBlock *MBB;
597 friend class SelectionDAG;
598 BasicBlockSDNode(MachineBasicBlock *mbb)
599 : SDNode(ISD::BasicBlock, MVT::Other), MBB(mbb) {}
602 MachineBasicBlock *getBasicBlock() const { return MBB; }
604 static bool classof(const BasicBlockSDNode *) { return true; }
605 static bool classof(const SDNode *N) {
606 return N->getOpcode() == ISD::BasicBlock;
611 class CopyRegSDNode : public SDNode {
614 friend class SelectionDAG;
615 CopyRegSDNode(SDOperand Chain, SDOperand Src, unsigned reg)
616 : SDNode(ISD::CopyToReg, Chain, Src), Reg(reg) {
617 setValueTypes(MVT::Other); // Just a token chain.
619 CopyRegSDNode(unsigned reg, MVT::ValueType VT)
620 : SDNode(ISD::CopyFromReg, VT), Reg(reg) {
624 unsigned getReg() const { return Reg; }
626 static bool classof(const CopyRegSDNode *) { return true; }
627 static bool classof(const SDNode *N) {
628 return N->getOpcode() == ISD::CopyToReg ||
629 N->getOpcode() == ISD::CopyFromReg;
633 class ExternalSymbolSDNode : public SDNode {
636 friend class SelectionDAG;
637 ExternalSymbolSDNode(const char *Sym, MVT::ValueType VT)
638 : SDNode(ISD::ExternalSymbol, VT), Symbol(Sym) {
642 const char *getSymbol() const { return Symbol; }
644 static bool classof(const ExternalSymbolSDNode *) { return true; }
645 static bool classof(const SDNode *N) {
646 return N->getOpcode() == ISD::ExternalSymbol;
650 class SetCCSDNode : public SDNode {
651 ISD::CondCode Condition;
653 friend class SelectionDAG;
654 SetCCSDNode(ISD::CondCode Cond, SDOperand LHS, SDOperand RHS)
655 : SDNode(ISD::SETCC, LHS, RHS), Condition(Cond) {
656 setValueTypes(MVT::i1);
660 ISD::CondCode getCondition() const { return Condition; }
662 static bool classof(const SetCCSDNode *) { return true; }
663 static bool classof(const SDNode *N) {
664 return N->getOpcode() == ISD::SETCC;
669 class SDNodeIterator : public forward_iterator<SDNode, ptrdiff_t> {
673 SDNodeIterator(SDNode *N, unsigned Op) : Node(N), Operand(Op) {}
675 bool operator==(const SDNodeIterator& x) const {
676 return Operand == x.Operand;
678 bool operator!=(const SDNodeIterator& x) const { return !operator==(x); }
680 const SDNodeIterator &operator=(const SDNodeIterator &I) {
681 assert(I.Node == Node && "Cannot assign iterators to two different nodes!");
686 pointer operator*() const {
687 return Node->getOperand(Operand).Val;
689 pointer operator->() const { return operator*(); }
691 SDNodeIterator& operator++() { // Preincrement
695 SDNodeIterator operator++(int) { // Postincrement
696 SDNodeIterator tmp = *this; ++*this; return tmp;
699 static SDNodeIterator begin(SDNode *N) { return SDNodeIterator(N, 0); }
700 static SDNodeIterator end (SDNode *N) {
701 return SDNodeIterator(N, N->getNumOperands());
704 unsigned getOperand() const { return Operand; }
705 const SDNode *getNode() const { return Node; }
708 template <> struct GraphTraits<SDNode*> {
709 typedef SDNode NodeType;
710 typedef SDNodeIterator ChildIteratorType;
711 static inline NodeType *getEntryNode(SDNode *N) { return N; }
712 static inline ChildIteratorType child_begin(NodeType *N) {
713 return SDNodeIterator::begin(N);
715 static inline ChildIteratorType child_end(NodeType *N) {
716 return SDNodeIterator::end(N);
723 } // end llvm namespace