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 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
237 SDOperand N5, SDOperand N6);
238 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
239 std::vector<SDOperand> &Children);
240 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
241 std::vector<SDOperand> &Ops);
243 /// getSetCC - Helper function to make it easier to build SetCC's if you just
244 /// have an ISD::CondCode instead of an SDOperand.
246 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
247 ISD::CondCode Cond) {
248 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
251 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
252 /// just have an ISD::CondCode instead of an SDOperand.
254 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
255 SDOperand True, SDOperand False, ISD::CondCode Cond) {
256 MVT::ValueType VT = True.getValueType();
257 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
260 /// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC
263 SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS,
264 SDOperand RHS, SDOperand True, SDOperand False) {
265 std::vector<SDOperand> Ops;
266 Ops.push_back(Chain);
267 Ops.push_back(CCNode);
271 Ops.push_back(False);
272 return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops);
275 /// getLoad - Loads are not normal binary operators: their result type is not
276 /// determined by their operands, and they produce a value AND a token chain.
278 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
280 SDOperand getVecLoad(unsigned Count, MVT::ValueType VT, SDOperand Chain,
281 SDOperand Ptr, SDOperand SV);
282 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
283 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
285 // getSrcValue - construct a node to track a Value* through the backend
286 SDOperand getSrcValue(const Value* I, int offset = 0);
289 /// SelectNodeTo - These are used for target selectors to *mutate* the
290 /// specified node to have the specified return type, Target opcode, and
291 /// operands. Note that target opcodes are stored as
292 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
293 /// of the resultant node is returned.
294 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
295 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
297 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
298 SDOperand Op1, SDOperand Op2);
299 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
300 SDOperand Op1, SDOperand Op2, SDOperand Op3);
301 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
302 SDOperand Op1, SDOperand Op2, SDOperand Op3,
304 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
305 SDOperand Op1, SDOperand Op2, SDOperand Op3,
306 SDOperand Op4, SDOperand Op5);
307 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
308 SDOperand Op1, SDOperand Op2, SDOperand Op3,
309 SDOperand Op4, SDOperand Op5, SDOperand Op6);
310 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
311 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,
315 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
316 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
317 SDOperand Op3, SDOperand Op4);
318 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
319 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
320 SDOperand Op3, SDOperand Op4, SDOperand Op5);
322 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT) {
323 return getNode(ISD::BUILTIN_OP_END+Opcode, VT);
325 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
327 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1);
329 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
330 SDOperand Op1, SDOperand Op2) {
331 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2);
333 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
334 SDOperand Op1, SDOperand Op2, SDOperand Op3) {
335 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3);
337 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
338 SDOperand Op1, SDOperand Op2, SDOperand Op3,
340 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4);
342 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
343 SDOperand Op1, SDOperand Op2, SDOperand Op3,
344 SDOperand Op4, SDOperand Op5) {
345 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5);
347 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
348 SDOperand Op1, SDOperand Op2, SDOperand Op3,
349 SDOperand Op4, SDOperand Op5, SDOperand Op6) {
350 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5, Op6);
352 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
353 std::vector<SDOperand> &Ops) {
354 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Ops);
356 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
357 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2) {
358 std::vector<MVT::ValueType> ResultTys;
359 ResultTys.push_back(VT1);
360 ResultTys.push_back(VT2);
361 std::vector<SDOperand> Ops;
364 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
366 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
367 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
369 std::vector<MVT::ValueType> ResultTys;
370 ResultTys.push_back(VT1);
371 ResultTys.push_back(VT2);
372 std::vector<SDOperand> Ops;
376 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
378 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
379 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
380 SDOperand Op3, SDOperand Op4) {
381 std::vector<MVT::ValueType> ResultTys;
382 ResultTys.push_back(VT1);
383 ResultTys.push_back(VT2);
384 std::vector<SDOperand> Ops;
389 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
391 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
392 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
393 SDOperand Op3, SDOperand Op4, SDOperand Op5) {
394 std::vector<MVT::ValueType> ResultTys;
395 ResultTys.push_back(VT1);
396 ResultTys.push_back(VT2);
397 std::vector<SDOperand> Ops;
403 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
405 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
406 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
407 SDOperand Op3, SDOperand Op4, SDOperand Op5,
409 std::vector<MVT::ValueType> ResultTys;
410 ResultTys.push_back(VT1);
411 ResultTys.push_back(VT2);
412 std::vector<SDOperand> Ops;
419 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
421 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
422 MVT::ValueType VT2, std::vector<SDOperand> &Ops) {
423 std::vector<MVT::ValueType> ResultTys;
424 ResultTys.push_back(VT1);
425 ResultTys.push_back(VT2);
426 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
429 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
430 /// This can cause recursive merging of nodes in the DAG. Use the first
431 /// version if 'From' is known to have a single result, use the second
432 /// if you have two nodes with identical results, use the third otherwise.
434 /// These methods all take an optional vector, which (if not null) is
435 /// populated with any nodes that are deleted from the SelectionDAG, due to
436 /// new equivalences that are discovered.
438 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
439 std::vector<SDNode*> *Deleted = 0);
440 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
441 std::vector<SDNode*> *Deleted = 0);
442 void ReplaceAllUsesWith(SDNode *From, const std::vector<SDOperand> &To,
443 std::vector<SDNode*> *Deleted = 0);
446 /// DeleteNode - Remove the specified node from the system. This node must
447 /// have no referrers.
448 void DeleteNode(SDNode *N);
453 void RemoveNodeFromCSEMaps(SDNode *N);
454 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
455 void DestroyDeadNode(SDNode *N);
456 void DeleteNodeNotInCSEMaps(SDNode *N);
457 void setNodeValueTypes(SDNode *N, std::vector<MVT::ValueType> &RetVals);
458 void setNodeValueTypes(SDNode *N, MVT::ValueType VT1, MVT::ValueType VT2);
461 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
462 /// and cc. If unable to simplify it, return a null SDOperand.
463 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
464 SDOperand N2, ISD::CondCode Cond);
466 // List of non-single value types.
467 std::list<std::vector<MVT::ValueType> > VTList;
469 // Maps to auto-CSE operations.
470 std::map<std::pair<unsigned, MVT::ValueType>, SDNode *> NullaryOps;
471 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
473 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
476 std::map<std::pair<unsigned, MVT::ValueType>, RegisterSDNode*> RegNodes;
477 std::vector<CondCodeSDNode*> CondCodeNodes;
479 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
482 std::map<std::pair<const GlobalValue*, int>, SDNode*> GlobalValues;
483 std::map<std::pair<const GlobalValue*, int>, SDNode*> TargetGlobalValues;
484 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
485 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
486 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
487 std::map<int, SDNode*> FrameIndices, TargetFrameIndices;
488 std::map<Constant *, SDNode*> ConstantPoolIndices;
489 std::map<Constant *, SDNode*> TargetConstantPoolIndices;
490 std::map<MachineBasicBlock *, SDNode*> BBNodes;
491 std::vector<SDNode*> ValueTypeNodes;
492 std::map<std::string, SDNode*> ExternalSymbols;
493 std::map<std::string, SDNode*> TargetExternalSymbols;
494 std::map<std::string, StringSDNode*> StringNodes;
495 std::map<std::pair<unsigned,
496 std::pair<MVT::ValueType, std::vector<SDOperand> > >,
497 SDNode*> OneResultNodes;
498 std::map<std::pair<unsigned,
499 std::pair<std::vector<MVT::ValueType>,
500 std::vector<SDOperand> > >,
501 SDNode*> ArbitraryNodes;
504 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
505 typedef SelectionDAG::allnodes_iterator nodes_iterator;
506 static nodes_iterator nodes_begin(SelectionDAG *G) {
507 return G->allnodes_begin();
509 static nodes_iterator nodes_end(SelectionDAG *G) {
510 return G->allnodes_end();
514 } // end namespace llvm