1 //===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- 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 SelectionDAG class, and transitively defines the
11 // SDNode class and subclasses.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_SELECTIONDAG_H
16 #define LLVM_CODEGEN_SELECTIONDAG_H
18 #include "llvm/CodeGen/SelectionDAGNodes.h"
19 #include "llvm/ADT/ilist"
28 class MachineFunction;
30 /// SelectionDAG class - This is used to represent a portion of an LLVM function
31 /// in a low-level Data Dependence DAG representation suitable for instruction
32 /// selection. This DAG is constructed as the first step of instruction
33 /// selection in order to allow implementation of machine specific optimizations
34 /// and code simplifications.
36 /// The representation used by the SelectionDAG is a target-independent
37 /// representation, which has some similarities to the GCC RTL representation,
38 /// but is significantly more simple, powerful, and is a graph form instead of a
45 // Root - The root of the entire DAG. EntryNode - The starting token.
46 SDOperand Root, EntryNode;
48 // AllNodes - A linked list of nodes in the current DAG.
49 ilist<SDNode> AllNodes;
51 // ValueNodes - track SrcValue nodes
52 std::map<std::pair<const Value*, int>, SDNode*> ValueNodes;
55 SelectionDAG(TargetLowering &tli, MachineFunction &mf) : TLI(tli), MF(mf) {
56 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
60 MachineFunction &getMachineFunction() const { return MF; }
61 const TargetMachine &getTarget() const;
62 TargetLowering &getTargetLoweringInfo() const { return TLI; }
64 /// viewGraph - Pop up a ghostview window with the DAG rendered using 'dot'.
69 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
70 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
71 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
72 typedef ilist<SDNode>::iterator allnodes_iterator;
73 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
74 allnodes_iterator allnodes_end() { return AllNodes.end(); }
76 /// getRoot - Return the root tag of the SelectionDAG.
78 const SDOperand &getRoot() const { return Root; }
80 /// getEntryNode - Return the token chain corresponding to the entry of the
82 const SDOperand &getEntryNode() const { return EntryNode; }
84 /// setRoot - Set the current root tag of the SelectionDAG.
86 const SDOperand &setRoot(SDOperand N) { return Root = N; }
88 /// Combine - This iterates over the nodes in the SelectionDAG, folding
89 /// certain types of nodes together, or eliminating superfluous nodes. When
90 /// the AfterLegalize argument is set to 'true', Combine takes care not to
91 /// generate any nodes that will be illegal on the target.
92 void Combine(bool AfterLegalize);
94 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
95 /// compatible with the target instruction selector, as indicated by the
96 /// TargetLowering object.
98 /// Note that this is an involved process that may invalidate pointers into
102 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
103 /// SelectionDAG, including nodes (like loads) that have uses of their token
104 /// chain but no other uses and no side effect. If a node is passed in as an
105 /// argument, it is used as the seed for node deletion.
106 void RemoveDeadNodes(SDNode *N = 0);
108 SDOperand getString(const std::string &Val);
109 SDOperand getConstant(uint64_t Val, MVT::ValueType VT);
110 SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT);
111 SDOperand getConstantFP(double Val, MVT::ValueType VT);
112 SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
114 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
116 SDOperand getFrameIndex(int FI, MVT::ValueType VT);
117 SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT);
118 SDOperand getConstantPool(Constant *C, MVT::ValueType VT);
119 SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT);
120 SDOperand getBasicBlock(MachineBasicBlock *MBB);
121 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
122 SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
123 SDOperand getValueType(MVT::ValueType);
124 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
126 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
127 return getNode(ISD::CopyToReg, MVT::Other, Chain,
128 getRegister(Reg, N.getValueType()), N);
131 // This version of the getCopyToReg method takes an extra operand, which
132 // indicates that there is potentially an incoming flag value (if Flag is not
133 // null) and that there should be a flag result.
134 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
136 std::vector<MVT::ValueType> VTs;
137 VTs.push_back(MVT::Other);
138 VTs.push_back(MVT::Flag);
139 std::vector<SDOperand> Ops;
140 Ops.push_back(Chain);
141 Ops.push_back(getRegister(Reg, N.getValueType()));
143 if (Flag.Val) Ops.push_back(Flag);
144 return getNode(ISD::CopyToReg, VTs, Ops);
147 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
148 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
150 std::vector<MVT::ValueType> VTs;
151 VTs.push_back(MVT::Other);
152 VTs.push_back(MVT::Flag);
153 std::vector<SDOperand> Ops;
154 Ops.push_back(Chain);
157 if (Flag.Val) Ops.push_back(Flag);
158 return getNode(ISD::CopyToReg, VTs, Ops);
161 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
162 std::vector<MVT::ValueType> ResultTys;
163 ResultTys.push_back(VT);
164 ResultTys.push_back(MVT::Other);
165 std::vector<SDOperand> Ops;
166 Ops.push_back(Chain);
167 Ops.push_back(getRegister(Reg, VT));
168 return getNode(ISD::CopyFromReg, ResultTys, Ops);
171 // This version of the getCopyFromReg method takes an extra operand, which
172 // indicates that there is potentially an incoming flag value (if Flag is not
173 // null) and that there should be a flag result.
174 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
176 std::vector<MVT::ValueType> ResultTys;
177 ResultTys.push_back(VT);
178 ResultTys.push_back(MVT::Other);
179 ResultTys.push_back(MVT::Flag);
180 std::vector<SDOperand> Ops;
181 Ops.push_back(Chain);
182 Ops.push_back(getRegister(Reg, VT));
183 if (Flag.Val) Ops.push_back(Flag);
184 return getNode(ISD::CopyFromReg, ResultTys, Ops);
187 SDOperand getImplicitDef(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
188 return getNode(ISD::ImplicitDef, MVT::Other, Chain, getRegister(Reg, VT));
191 /// getCall - Note that this destroys the vector of RetVals passed in.
193 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
194 SDOperand Callee, bool isTailCall = false) {
195 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, Chain,
197 setNodeValueTypes(NN, RetVals);
198 AllNodes.push_back(NN);
202 /// getCall - This is identical to the one above, and should be used for calls
203 /// where arguments are passed in physical registers. This destroys the
204 /// RetVals and ArgsInRegs vectors.
205 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
206 SDOperand Callee, std::vector<SDOperand> &ArgsInRegs,
207 bool isTailCall = false) {
208 ArgsInRegs.insert(ArgsInRegs.begin(), Callee);
209 ArgsInRegs.insert(ArgsInRegs.begin(), Chain);
210 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, ArgsInRegs);
211 setNodeValueTypes(NN, RetVals);
212 AllNodes.push_back(NN);
216 SDOperand getCondCode(ISD::CondCode Cond);
218 /// getZeroExtendInReg - Return the expression required to zero extend the Op
219 /// value assuming it was the smaller SrcTy value.
220 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
222 /// getNode - Gets or creates the specified node.
224 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
225 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
226 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
227 SDOperand N1, SDOperand N2);
228 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
229 SDOperand N1, SDOperand N2, SDOperand N3);
230 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
231 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
232 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
233 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
235 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
236 std::vector<SDOperand> &Children);
237 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
238 std::vector<SDOperand> &Ops);
240 /// getSetCC - Helper function to make it easier to build SetCC's if you just
241 /// have an ISD::CondCode instead of an SDOperand.
243 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
244 ISD::CondCode Cond) {
245 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
248 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
249 /// just have an ISD::CondCode instead of an SDOperand.
251 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
252 SDOperand True, SDOperand False, ISD::CondCode Cond) {
253 MVT::ValueType VT = True.getValueType();
254 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
257 /// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC
260 SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS,
261 SDOperand RHS, SDOperand True, SDOperand False) {
262 std::vector<SDOperand> Ops;
263 Ops.push_back(Chain);
264 Ops.push_back(CCNode);
268 Ops.push_back(False);
269 return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops);
272 /// getLoad - Loads are not normal binary operators: their result type is not
273 /// determined by their operands, and they produce a value AND a token chain.
275 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
277 SDOperand getVecLoad(unsigned Count, MVT::ValueType VT, SDOperand Chain,
278 SDOperand Ptr, SDOperand SV);
279 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
280 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
282 // getSrcValue - construct a node to track a Value* through the backend
283 SDOperand getSrcValue(const Value* I, int offset = 0);
286 /// SelectNodeTo - These are used for target selectors to *mutate* the
287 /// specified node to have the specified return type, Target opcode, and
288 /// operands. Note that target opcodes are stored as
289 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
290 /// of the resultant node is returned.
291 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
292 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
294 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
295 SDOperand Op1, SDOperand Op2);
296 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
297 SDOperand Op1, SDOperand Op2, SDOperand Op3);
298 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
299 SDOperand Op1, SDOperand Op2, SDOperand Op3,
301 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
302 SDOperand Op1, SDOperand Op2, SDOperand Op3,
303 SDOperand Op4, SDOperand Op5);
304 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
305 SDOperand Op1, SDOperand Op2, SDOperand Op3,
306 SDOperand Op4, SDOperand Op5, SDOperand Op6);
307 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
308 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
309 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
310 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
312 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
313 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
314 SDOperand Op3, SDOperand Op4);
315 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
316 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
317 SDOperand Op3, SDOperand Op4, SDOperand Op5);
319 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT) {
320 return getNode(ISD::BUILTIN_OP_END+Opcode, VT);
322 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
324 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1);
326 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
327 SDOperand Op1, SDOperand Op2) {
328 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2);
330 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
331 SDOperand Op1, SDOperand Op2, SDOperand Op3) {
332 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3);
334 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
335 SDOperand Op1, SDOperand Op2, SDOperand Op3,
337 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4);
339 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
340 SDOperand Op1, SDOperand Op2, SDOperand Op3,
341 SDOperand Op4, SDOperand Op5) {
342 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5);
344 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
345 std::vector<SDOperand> &Ops) {
346 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Ops);
348 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
349 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2) {
350 std::vector<MVT::ValueType> ResultTys;
351 ResultTys.push_back(VT1);
352 ResultTys.push_back(VT2);
353 std::vector<SDOperand> Ops;
356 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
358 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
359 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
361 std::vector<MVT::ValueType> ResultTys;
362 ResultTys.push_back(VT1);
363 ResultTys.push_back(VT2);
364 std::vector<SDOperand> Ops;
368 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
370 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
371 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
372 SDOperand Op3, SDOperand Op4) {
373 std::vector<MVT::ValueType> ResultTys;
374 ResultTys.push_back(VT1);
375 ResultTys.push_back(VT2);
376 std::vector<SDOperand> Ops;
381 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
383 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
384 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
385 SDOperand Op3, SDOperand Op4, SDOperand Op5) {
386 std::vector<MVT::ValueType> ResultTys;
387 ResultTys.push_back(VT1);
388 ResultTys.push_back(VT2);
389 std::vector<SDOperand> Ops;
395 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
397 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
398 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
399 SDOperand Op3, SDOperand Op4, SDOperand Op5,
401 std::vector<MVT::ValueType> ResultTys;
402 ResultTys.push_back(VT1);
403 ResultTys.push_back(VT2);
404 std::vector<SDOperand> Ops;
411 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
413 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
414 MVT::ValueType VT2, std::vector<SDOperand> &Ops) {
415 std::vector<MVT::ValueType> ResultTys;
416 ResultTys.push_back(VT1);
417 ResultTys.push_back(VT2);
418 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
421 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
422 /// This can cause recursive merging of nodes in the DAG. Use the first
423 /// version if 'From' is known to have a single result, use the second
424 /// if you have two nodes with identical results, use the third otherwise.
426 /// These methods all take an optional vector, which (if not null) is
427 /// populated with any nodes that are deleted from the SelectionDAG, due to
428 /// new equivalences that are discovered.
430 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
431 std::vector<SDNode*> *Deleted = 0);
432 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
433 std::vector<SDNode*> *Deleted = 0);
434 void ReplaceAllUsesWith(SDNode *From, const std::vector<SDOperand> &To,
435 std::vector<SDNode*> *Deleted = 0);
438 /// DeleteNode - Remove the specified node from the system. This node must
439 /// have no referrers.
440 void DeleteNode(SDNode *N);
445 void RemoveNodeFromCSEMaps(SDNode *N);
446 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
447 void DestroyDeadNode(SDNode *N);
448 void DeleteNodeNotInCSEMaps(SDNode *N);
449 void setNodeValueTypes(SDNode *N, std::vector<MVT::ValueType> &RetVals);
450 void setNodeValueTypes(SDNode *N, MVT::ValueType VT1, MVT::ValueType VT2);
453 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
454 /// and cc. If unable to simplify it, return a null SDOperand.
455 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
456 SDOperand N2, ISD::CondCode Cond);
458 // List of non-single value types.
459 std::list<std::vector<MVT::ValueType> > VTList;
461 // Maps to auto-CSE operations.
462 std::map<std::pair<unsigned, MVT::ValueType>, SDNode *> NullaryOps;
463 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
465 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
468 std::map<std::pair<unsigned, MVT::ValueType>, RegisterSDNode*> RegNodes;
469 std::vector<CondCodeSDNode*> CondCodeNodes;
471 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
474 std::map<std::pair<const GlobalValue*, int>, SDNode*> GlobalValues;
475 std::map<std::pair<const GlobalValue*, int>, SDNode*> TargetGlobalValues;
476 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
477 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
478 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
479 std::map<int, SDNode*> FrameIndices, TargetFrameIndices;
480 std::map<Constant *, SDNode*> ConstantPoolIndices;
481 std::map<Constant *, SDNode*> TargetConstantPoolIndices;
482 std::map<MachineBasicBlock *, SDNode*> BBNodes;
483 std::vector<SDNode*> ValueTypeNodes;
484 std::map<std::string, SDNode*> ExternalSymbols;
485 std::map<std::string, SDNode*> TargetExternalSymbols;
486 std::map<std::string, StringSDNode*> StringNodes;
487 std::map<std::pair<unsigned,
488 std::pair<MVT::ValueType, std::vector<SDOperand> > >,
489 SDNode*> OneResultNodes;
490 std::map<std::pair<unsigned,
491 std::pair<std::vector<MVT::ValueType>,
492 std::vector<SDOperand> > >,
493 SDNode*> ArbitraryNodes;
496 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
497 typedef SelectionDAG::allnodes_iterator nodes_iterator;
498 static nodes_iterator nodes_begin(SelectionDAG *G) {
499 return G->allnodes_begin();
501 static nodes_iterator nodes_end(SelectionDAG *G) {
502 return G->allnodes_end();
506 } // end namespace llvm