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.
144 // DYNAMIC_STACKALLOC - Allocate some number of bytes on the stack aligned
145 // to a specified boundary. The first operand is the token chain, the
146 // second is the number of bytes to allocate, and the third is the alignment
150 // Control flow instructions. These all have token chains.
152 // BR - Unconditional branch. The first operand is the chain
153 // operand, the second is the MBB to branch to.
156 // BRCOND - Conditional branch. The first operand is the chain,
157 // the second is the condition, the third is the block to branch
158 // to if the condition is true.
161 // RET - Return from function. The first operand is the chain,
162 // and any subsequent operands are the return values for the
163 // function. This operation can have variable number of operands.
166 // CALL - Call to a function pointer. The first operand is the chain, the
167 // second is the destination function pointer (a GlobalAddress for a direct
168 // call). Arguments have already been lowered to explicit DAGs according to
169 // the calling convention in effect here.
172 // MEMSET/MEMCPY/MEMMOVE - The first operand is the chain, and the rest
173 // correspond to the operands of the LLVM intrinsic functions. The only
174 // result is a token chain. The alignment argument is guaranteed to be a
180 // ADJCALLSTACKDOWN/ADJCALLSTACKUP - These operators mark the beginning and
181 // end of a call sequence and indicate how much the stack pointer needs to
182 // be adjusted for that particular call. The first operand is a chain, the
183 // second is a ConstantSDNode of intptr type.
184 ADJCALLSTACKDOWN, // Beginning of a call sequence
185 ADJCALLSTACKUP, // End of a call sequence
188 // BUILTIN_OP_END - This must be the last enum value in this list.
192 //===--------------------------------------------------------------------===//
193 /// ISD::CondCode enum - These are ordered carefully to make the bitfields
194 /// below work out, when considering SETFALSE (something that never exists
195 /// dynamically) as 0. "U" -> Unsigned (for integer operands) or Unordered
196 /// (for floating point), "L" -> Less than, "G" -> Greater than, "E" -> Equal
197 /// to. If the "N" column is 1, the result of the comparison is undefined if
198 /// the input is a NAN.
200 /// All of these (except for the 'always folded ops') should be handled for
201 /// floating point. For integer, only the SETEQ,SETNE,SETLT,SETLE,SETGT,
202 /// SETGE,SETULT,SETULE,SETUGT, and SETUGE opcodes are used.
204 /// Note that these are laid out in a specific order to allow bit-twiddling
205 /// to transform conditions.
207 // Opcode N U L G E Intuitive operation
208 SETFALSE, // 0 0 0 0 Always false (always folded)
209 SETOEQ, // 0 0 0 1 True if ordered and equal
210 SETOGT, // 0 0 1 0 True if ordered and greater than
211 SETOGE, // 0 0 1 1 True if ordered and greater than or equal
212 SETOLT, // 0 1 0 0 True if ordered and less than
213 SETOLE, // 0 1 0 1 True if ordered and less than or equal
214 SETONE, // 0 1 1 0 True if ordered and operands are unequal
215 SETO, // 0 1 1 1 True if ordered (no nans)
216 SETUO, // 1 0 0 0 True if unordered: isnan(X) | isnan(Y)
217 SETUEQ, // 1 0 0 1 True if unordered or equal
218 SETUGT, // 1 0 1 0 True if unordered or greater than
219 SETUGE, // 1 0 1 1 True if unordered, greater than, or equal
220 SETULT, // 1 1 0 0 True if unordered or less than
221 SETULE, // 1 1 0 1 True if unordered, less than, or equal
222 SETUNE, // 1 1 1 0 True if unordered or not equal
223 SETTRUE, // 1 1 1 1 Always true (always folded)
224 // Don't care operations: undefined if the input is a nan.
225 SETFALSE2, // 1 X 0 0 0 Always false (always folded)
226 SETEQ, // 1 X 0 0 1 True if equal
227 SETGT, // 1 X 0 1 0 True if greater than
228 SETGE, // 1 X 0 1 1 True if greater than or equal
229 SETLT, // 1 X 1 0 0 True if less than
230 SETLE, // 1 X 1 0 1 True if less than or equal
231 SETNE, // 1 X 1 1 0 True if not equal
232 SETTRUE2, // 1 X 1 1 1 Always true (always folded)
234 SETCC_INVALID, // Marker value.
237 /// isSignedIntSetCC - Return true if this is a setcc instruction that
238 /// performs a signed comparison when used with integer operands.
239 inline bool isSignedIntSetCC(CondCode Code) {
240 return Code == SETGT || Code == SETGE || Code == SETLT || Code == SETLE;
243 /// isUnsignedIntSetCC - Return true if this is a setcc instruction that
244 /// performs an unsigned comparison when used with integer operands.
245 inline bool isUnsignedIntSetCC(CondCode Code) {
246 return Code == SETUGT || Code == SETUGE || Code == SETULT || Code == SETULE;
249 /// isTrueWhenEqual - Return true if the specified condition returns true if
250 /// the two operands to the condition are equal. Note that if one of the two
251 /// operands is a NaN, this value is meaningless.
252 inline bool isTrueWhenEqual(CondCode Cond) {
253 return ((int)Cond & 1) != 0;
256 /// getUnorderedFlavor - This function returns 0 if the condition is always
257 /// false if an operand is a NaN, 1 if the condition is always true if the
258 /// operand is a NaN, and 2 if the condition is undefined if the operand is a
260 inline unsigned getUnorderedFlavor(CondCode Cond) {
261 return ((int)Cond >> 3) & 3;
264 /// getSetCCInverse - Return the operation corresponding to !(X op Y), where
265 /// 'op' is a valid SetCC operation.
266 CondCode getSetCCInverse(CondCode Operation, bool isInteger);
268 /// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
269 /// when given the operation for (X op Y).
270 CondCode getSetCCSwappedOperands(CondCode Operation);
272 /// getSetCCOrOperation - Return the result of a logical OR between different
273 /// 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 getSetCCOrOperation(CondCode Op1, CondCode Op2, bool isInteger);
278 /// getSetCCAndOperation - Return the result of a logical AND between
279 /// different comparisons of identical values: ((X op1 Y) & (X op2 Y)). This
280 /// function returns SETCC_INVALID if it is not possible to represent the
281 /// resultant comparison.
282 CondCode getSetCCAndOperation(CondCode Op1, CondCode Op2, bool isInteger);
283 } // end llvm::ISD namespace
286 //===----------------------------------------------------------------------===//
287 /// SDOperand - Unlike LLVM values, Selection DAG nodes may return multiple
288 /// values as the result of a computation. Many nodes return multiple values,
289 /// from loads (which define a token and a return value) to ADDC (which returns
290 /// a result and a carry value), to calls (which may return an arbitrary number
293 /// As such, each use of a SelectionDAG computation must indicate the node that
294 /// computes it as well as which return value to use from that node. This pair
295 /// of information is represented with the SDOperand value type.
299 SDNode *Val; // The node defining the value we are using.
300 unsigned ResNo; // Which return value of the node we are using.
302 SDOperand() : Val(0) {}
303 SDOperand(SDNode *val, unsigned resno) : Val(val), ResNo(resno) {}
305 bool operator==(const SDOperand &O) const {
306 return Val == O.Val && ResNo == O.ResNo;
308 bool operator!=(const SDOperand &O) const {
309 return !operator==(O);
311 bool operator<(const SDOperand &O) const {
312 return Val < O.Val || (Val == O.Val && ResNo < O.ResNo);
315 SDOperand getValue(unsigned R) const {
316 return SDOperand(Val, R);
319 /// getValueType - Return the ValueType of the referenced return value.
321 inline MVT::ValueType getValueType() const;
323 // Forwarding methods - These forward to the corresponding methods in SDNode.
324 inline unsigned getOpcode() const;
325 inline unsigned getNumOperands() const;
326 inline const SDOperand &getOperand(unsigned i) const;
330 /// simplify_type specializations - Allow casting operators to work directly on
331 /// SDOperands as if they were SDNode*'s.
332 template<> struct simplify_type<SDOperand> {
333 typedef SDNode* SimpleType;
334 static SimpleType getSimplifiedValue(const SDOperand &Val) {
335 return static_cast<SimpleType>(Val.Val);
338 template<> struct simplify_type<const SDOperand> {
339 typedef SDNode* SimpleType;
340 static SimpleType getSimplifiedValue(const SDOperand &Val) {
341 return static_cast<SimpleType>(Val.Val);
346 /// SDNode - Represents one node in the SelectionDAG.
350 std::vector<SDOperand> Operands;
352 /// Values - The types of the values this node defines. SDNode's may define
353 /// multiple values simultaneously.
354 std::vector<MVT::ValueType> Values;
356 /// Uses - These are all of the SDNode's that use a value produced by this
358 std::vector<SDNode*> Uses;
361 //===--------------------------------------------------------------------===//
364 unsigned getOpcode() const { return NodeType; }
366 size_t use_size() const { return Uses.size(); }
367 bool use_empty() const { return Uses.empty(); }
368 bool hasOneUse() const { return Uses.size() == 1; }
370 /// hasNUsesOfValue - Return true if there are exactly NUSES uses of the
371 /// indicated value. This method ignores uses of other values defined by this
373 bool hasNUsesOfValue(unsigned NUses, unsigned Value);
375 /// getNumOperands - Return the number of values used by this operation.
377 unsigned getNumOperands() const { return Operands.size(); }
379 const SDOperand &getOperand(unsigned Num) {
380 assert(Num < Operands.size() && "Invalid child # of SDNode!");
381 return Operands[Num];
384 const SDOperand &getOperand(unsigned Num) const {
385 assert(Num < Operands.size() && "Invalid child # of SDNode!");
386 return Operands[Num];
389 /// getNumValues - Return the number of values defined/returned by this
392 unsigned getNumValues() const { return Values.size(); }
394 /// getValueType - Return the type of a specified result.
396 MVT::ValueType getValueType(unsigned ResNo) const {
397 assert(ResNo < Values.size() && "Illegal result number!");
398 return Values[ResNo];
401 /// getOperationName - Return the opcode of this operation for printing.
403 const char* getOperationName() const;
406 static bool classof(const SDNode *) { return true; }
409 friend class SelectionDAG;
411 SDNode(unsigned NT, MVT::ValueType VT) : NodeType(NT) {
413 Values.push_back(VT);
416 SDNode(unsigned NT, SDOperand Op)
418 Operands.reserve(1); Operands.push_back(Op);
419 Op.Val->Uses.push_back(this);
421 SDNode(unsigned NT, SDOperand N1, SDOperand N2)
423 Operands.reserve(2); Operands.push_back(N1); Operands.push_back(N2);
424 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this);
426 SDNode(unsigned NT, SDOperand N1, SDOperand N2, SDOperand N3)
428 Operands.reserve(3); Operands.push_back(N1); Operands.push_back(N2);
429 Operands.push_back(N3);
430 N1.Val->Uses.push_back(this); N2.Val->Uses.push_back(this);
431 N3.Val->Uses.push_back(this);
433 SDNode(unsigned NT, std::vector<SDOperand> &Nodes) : NodeType(NT) {
434 Operands.swap(Nodes);
435 for (unsigned i = 0, e = Operands.size(); i != e; ++i)
436 Operands[i].Val->Uses.push_back(this);
443 void setValueTypes(MVT::ValueType VT) {
445 Values.push_back(VT);
447 void setValueTypes(MVT::ValueType VT1, MVT::ValueType VT2) {
449 Values.push_back(VT1);
450 Values.push_back(VT2);
452 /// Note: this method destroys the vector passed in.
453 void setValueTypes(std::vector<MVT::ValueType> &VTs) {
454 std::swap(Values, VTs);
457 void removeUser(SDNode *User) {
458 // Remove this user from the operand's use list.
459 for (unsigned i = Uses.size(); ; --i) {
460 assert(i != 0 && "Didn't find user!");
461 if (Uses[i-1] == User) {
462 Uses.erase(Uses.begin()+i-1);
470 // Define inline functions from the SDOperand class.
472 inline unsigned SDOperand::getOpcode() const {
473 return Val->getOpcode();
475 inline MVT::ValueType SDOperand::getValueType() const {
476 return Val->getValueType(ResNo);
478 inline unsigned SDOperand::getNumOperands() const {
479 return Val->getNumOperands();
481 inline const SDOperand &SDOperand::getOperand(unsigned i) const {
482 return Val->getOperand(i);
487 class ConstantSDNode : public SDNode {
490 friend class SelectionDAG;
491 ConstantSDNode(uint64_t val, MVT::ValueType VT)
492 : SDNode(ISD::Constant, VT), Value(val) {
496 uint64_t getValue() const { return Value; }
498 int64_t getSignExtended() const {
499 unsigned Bits = MVT::getSizeInBits(getValueType(0));
500 return ((int64_t)Value << (64-Bits)) >> (64-Bits);
503 bool isNullValue() const { return Value == 0; }
504 bool isAllOnesValue() const {
505 return Value == (1ULL << MVT::getSizeInBits(getValueType(0)))-1;
508 static bool classof(const ConstantSDNode *) { return true; }
509 static bool classof(const SDNode *N) {
510 return N->getOpcode() == ISD::Constant;
514 class ConstantFPSDNode : public SDNode {
517 friend class SelectionDAG;
518 ConstantFPSDNode(double val, MVT::ValueType VT)
519 : SDNode(ISD::ConstantFP, VT), Value(val) {
523 double getValue() const { return Value; }
525 /// isExactlyValue - We don't rely on operator== working on double values, as
526 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
527 /// As such, this method can be used to do an exact bit-for-bit comparison of
528 /// two floating point values.
529 bool isExactlyValue(double V) const {
543 static bool classof(const ConstantFPSDNode *) { return true; }
544 static bool classof(const SDNode *N) {
545 return N->getOpcode() == ISD::ConstantFP;
549 class GlobalAddressSDNode : public SDNode {
550 GlobalValue *TheGlobal;
552 friend class SelectionDAG;
553 GlobalAddressSDNode(const GlobalValue *GA, MVT::ValueType VT)
554 : SDNode(ISD::GlobalAddress, VT) {
555 TheGlobal = const_cast<GlobalValue*>(GA);
559 GlobalValue *getGlobal() const { return TheGlobal; }
561 static bool classof(const GlobalAddressSDNode *) { return true; }
562 static bool classof(const SDNode *N) {
563 return N->getOpcode() == ISD::GlobalAddress;
568 class FrameIndexSDNode : public SDNode {
571 friend class SelectionDAG;
572 FrameIndexSDNode(int fi, MVT::ValueType VT)
573 : SDNode(ISD::FrameIndex, VT), FI(fi) {}
576 int getIndex() const { return FI; }
578 static bool classof(const FrameIndexSDNode *) { return true; }
579 static bool classof(const SDNode *N) {
580 return N->getOpcode() == ISD::FrameIndex;
584 class ConstantPoolSDNode : public SDNode {
587 friend class SelectionDAG;
588 ConstantPoolSDNode(unsigned cpi, MVT::ValueType VT)
589 : SDNode(ISD::ConstantPool, VT), CPI(cpi) {}
592 unsigned getIndex() const { return CPI; }
594 static bool classof(const ConstantPoolSDNode *) { return true; }
595 static bool classof(const SDNode *N) {
596 return N->getOpcode() == ISD::ConstantPool;
600 class BasicBlockSDNode : public SDNode {
601 MachineBasicBlock *MBB;
603 friend class SelectionDAG;
604 BasicBlockSDNode(MachineBasicBlock *mbb)
605 : SDNode(ISD::BasicBlock, MVT::Other), MBB(mbb) {}
608 MachineBasicBlock *getBasicBlock() const { return MBB; }
610 static bool classof(const BasicBlockSDNode *) { return true; }
611 static bool classof(const SDNode *N) {
612 return N->getOpcode() == ISD::BasicBlock;
617 class RegSDNode : public SDNode {
620 friend class SelectionDAG;
621 RegSDNode(SDOperand Chain, SDOperand Src, unsigned reg)
622 : SDNode(ISD::CopyToReg, Chain, Src), Reg(reg) {
623 setValueTypes(MVT::Other); // Just a token chain.
625 RegSDNode(unsigned Opc, unsigned reg, MVT::ValueType VT)
626 : SDNode(Opc, VT), Reg(reg) {
630 unsigned getReg() const { return Reg; }
632 static bool classof(const RegSDNode *) { return true; }
633 static bool classof(const SDNode *N) {
634 return N->getOpcode() == ISD::CopyToReg ||
635 N->getOpcode() == ISD::CopyFromReg ||
636 N->getOpcode() == ISD::ImplicitDef;
640 class ExternalSymbolSDNode : public SDNode {
643 friend class SelectionDAG;
644 ExternalSymbolSDNode(const char *Sym, MVT::ValueType VT)
645 : SDNode(ISD::ExternalSymbol, VT), Symbol(Sym) {
649 const char *getSymbol() const { return Symbol; }
651 static bool classof(const ExternalSymbolSDNode *) { return true; }
652 static bool classof(const SDNode *N) {
653 return N->getOpcode() == ISD::ExternalSymbol;
657 class SetCCSDNode : public SDNode {
658 ISD::CondCode Condition;
660 friend class SelectionDAG;
661 SetCCSDNode(ISD::CondCode Cond, SDOperand LHS, SDOperand RHS)
662 : SDNode(ISD::SETCC, LHS, RHS), Condition(Cond) {
663 setValueTypes(MVT::i1);
667 ISD::CondCode getCondition() const { return Condition; }
669 static bool classof(const SetCCSDNode *) { return true; }
670 static bool classof(const SDNode *N) {
671 return N->getOpcode() == ISD::SETCC;
676 class SDNodeIterator : public forward_iterator<SDNode, ptrdiff_t> {
680 SDNodeIterator(SDNode *N, unsigned Op) : Node(N), Operand(Op) {}
682 bool operator==(const SDNodeIterator& x) const {
683 return Operand == x.Operand;
685 bool operator!=(const SDNodeIterator& x) const { return !operator==(x); }
687 const SDNodeIterator &operator=(const SDNodeIterator &I) {
688 assert(I.Node == Node && "Cannot assign iterators to two different nodes!");
693 pointer operator*() const {
694 return Node->getOperand(Operand).Val;
696 pointer operator->() const { return operator*(); }
698 SDNodeIterator& operator++() { // Preincrement
702 SDNodeIterator operator++(int) { // Postincrement
703 SDNodeIterator tmp = *this; ++*this; return tmp;
706 static SDNodeIterator begin(SDNode *N) { return SDNodeIterator(N, 0); }
707 static SDNodeIterator end (SDNode *N) {
708 return SDNodeIterator(N, N->getNumOperands());
711 unsigned getOperand() const { return Operand; }
712 const SDNode *getNode() const { return Node; }
715 template <> struct GraphTraits<SDNode*> {
716 typedef SDNode NodeType;
717 typedef SDNodeIterator ChildIteratorType;
718 static inline NodeType *getEntryNode(SDNode *N) { return N; }
719 static inline ChildIteratorType child_begin(NodeType *N) {
720 return SDNodeIterator::begin(N);
722 static inline ChildIteratorType child_end(NodeType *N) {
723 return SDNodeIterator::end(N);
730 } // end llvm namespace