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 MachineDebugInfo;
29 class MachineFunction;
31 /// SelectionDAG class - This is used to represent a portion of an LLVM function
32 /// in a low-level Data Dependence DAG representation suitable for instruction
33 /// selection. This DAG is constructed as the first step of instruction
34 /// selection in order to allow implementation of machine specific optimizations
35 /// and code simplifications.
37 /// The representation used by the SelectionDAG is a target-independent
38 /// representation, which has some similarities to the GCC RTL representation,
39 /// but is significantly more simple, powerful, and is a graph form instead of a
47 // Root - The root of the entire DAG. EntryNode - The starting token.
48 SDOperand Root, EntryNode;
50 // AllNodes - A linked list of nodes in the current DAG.
51 ilist<SDNode> AllNodes;
53 // ValueNodes - track SrcValue nodes
54 std::map<std::pair<const Value*, int>, SDNode*> ValueNodes;
57 SelectionDAG(TargetLowering &tli, MachineFunction &mf, MachineDebugInfo *di)
58 : TLI(tli), MF(mf), DI(di) {
59 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
63 MachineFunction &getMachineFunction() const { return MF; }
64 const TargetMachine &getTarget() const;
65 TargetLowering &getTargetLoweringInfo() const { return TLI; }
66 MachineDebugInfo *getMachineDebugInfo() const { return DI; }
68 /// viewGraph - Pop up a ghostview window with the DAG rendered using 'dot'.
73 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
74 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
75 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
76 typedef ilist<SDNode>::iterator allnodes_iterator;
77 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
78 allnodes_iterator allnodes_end() { return AllNodes.end(); }
80 /// getRoot - Return the root tag of the SelectionDAG.
82 const SDOperand &getRoot() const { return Root; }
84 /// getEntryNode - Return the token chain corresponding to the entry of the
86 const SDOperand &getEntryNode() const { return EntryNode; }
88 /// setRoot - Set the current root tag of the SelectionDAG.
90 const SDOperand &setRoot(SDOperand N) { return Root = N; }
92 /// Combine - This iterates over the nodes in the SelectionDAG, folding
93 /// certain types of nodes together, or eliminating superfluous nodes. When
94 /// the AfterLegalize argument is set to 'true', Combine takes care not to
95 /// generate any nodes that will be illegal on the target.
96 void Combine(bool AfterLegalize);
98 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
99 /// compatible with the target instruction selector, as indicated by the
100 /// TargetLowering object.
102 /// Note that this is an involved process that may invalidate pointers into
106 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
107 /// SelectionDAG, including nodes (like loads) that have uses of their token
108 /// chain but no other uses and no side effect. If a node is passed in as an
109 /// argument, it is used as the seed for node deletion.
110 void RemoveDeadNodes(SDNode *N = 0);
112 SDOperand getString(const std::string &Val);
113 SDOperand getConstant(uint64_t Val, MVT::ValueType VT);
114 SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT);
115 SDOperand getConstantFP(double Val, MVT::ValueType VT);
116 SDOperand getTargetConstantFP(double Val, MVT::ValueType VT);
117 SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
119 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
121 SDOperand getFrameIndex(int FI, MVT::ValueType VT);
122 SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT);
123 SDOperand getConstantPool(Constant *C, MVT::ValueType VT,
124 unsigned Alignment=0);
125 SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT,
126 unsigned Alignment=0);
127 SDOperand getBasicBlock(MachineBasicBlock *MBB);
128 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
129 SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
130 SDOperand getValueType(MVT::ValueType);
131 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
133 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
134 return getNode(ISD::CopyToReg, MVT::Other, Chain,
135 getRegister(Reg, N.getValueType()), N);
138 // This version of the getCopyToReg method takes an extra operand, which
139 // indicates that there is potentially an incoming flag value (if Flag is not
140 // null) and that there should be a flag result.
141 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
143 std::vector<MVT::ValueType> VTs;
144 VTs.push_back(MVT::Other);
145 VTs.push_back(MVT::Flag);
146 std::vector<SDOperand> Ops;
147 Ops.push_back(Chain);
148 Ops.push_back(getRegister(Reg, N.getValueType()));
150 if (Flag.Val) Ops.push_back(Flag);
151 return getNode(ISD::CopyToReg, VTs, Ops);
154 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
155 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
157 std::vector<MVT::ValueType> VTs;
158 VTs.push_back(MVT::Other);
159 VTs.push_back(MVT::Flag);
160 std::vector<SDOperand> Ops;
161 Ops.push_back(Chain);
164 if (Flag.Val) Ops.push_back(Flag);
165 return getNode(ISD::CopyToReg, VTs, Ops);
168 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
169 std::vector<MVT::ValueType> ResultTys;
170 ResultTys.push_back(VT);
171 ResultTys.push_back(MVT::Other);
172 std::vector<SDOperand> Ops;
173 Ops.push_back(Chain);
174 Ops.push_back(getRegister(Reg, VT));
175 return getNode(ISD::CopyFromReg, ResultTys, Ops);
178 // This version of the getCopyFromReg method takes an extra operand, which
179 // indicates that there is potentially an incoming flag value (if Flag is not
180 // null) and that there should be a flag result.
181 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
183 std::vector<MVT::ValueType> ResultTys;
184 ResultTys.push_back(VT);
185 ResultTys.push_back(MVT::Other);
186 ResultTys.push_back(MVT::Flag);
187 std::vector<SDOperand> Ops;
188 Ops.push_back(Chain);
189 Ops.push_back(getRegister(Reg, VT));
190 if (Flag.Val) Ops.push_back(Flag);
191 return getNode(ISD::CopyFromReg, ResultTys, Ops);
194 SDOperand getCondCode(ISD::CondCode Cond);
196 /// getZeroExtendInReg - Return the expression required to zero extend the Op
197 /// value assuming it was the smaller SrcTy value.
198 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
200 /// getNode - Gets or creates the specified node.
202 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
203 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
204 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
205 SDOperand N1, SDOperand N2);
206 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
207 SDOperand N1, SDOperand N2, SDOperand N3);
208 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
209 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
210 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
211 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
213 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
214 std::vector<SDOperand> &Children);
215 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
216 std::vector<SDOperand> &Ops);
218 /// getSetCC - Helper function to make it easier to build SetCC's if you just
219 /// have an ISD::CondCode instead of an SDOperand.
221 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
222 ISD::CondCode Cond) {
223 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
226 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
227 /// just have an ISD::CondCode instead of an SDOperand.
229 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
230 SDOperand True, SDOperand False, ISD::CondCode Cond) {
231 MVT::ValueType VT = True.getValueType();
232 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
235 /// getVAArg - VAArg produces a result and token chain, and takes a pointer
236 /// and a source value as input.
237 SDOperand getVAArg(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
240 /// getLoad - Loads are not normal binary operators: their result type is not
241 /// determined by their operands, and they produce a value AND a token chain.
243 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
245 SDOperand getVecLoad(unsigned Count, MVT::ValueType VT, SDOperand Chain,
246 SDOperand Ptr, SDOperand SV);
247 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
248 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
250 // getSrcValue - construct a node to track a Value* through the backend
251 SDOperand getSrcValue(const Value* I, int offset = 0);
253 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
254 /// specified operands. If the resultant node already exists in the DAG,
255 /// this does not modify the specified node, instead it returns the node that
256 /// already exists. If the resultant node does not exist in the DAG, the
257 /// input node is returned. As a degenerate case, if you specify the same
258 /// input operands as the node already has, the input node is returned.
259 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
260 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
261 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
263 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
264 SDOperand Op3, SDOperand Op4);
265 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
266 SDOperand Op3, SDOperand Op4, SDOperand Op5);
267 SDOperand UpdateNodeOperands(SDOperand N, const std::vector<SDOperand> &Op);
269 /// SelectNodeTo - These are used for target selectors to *mutate* the
270 /// specified node to have the specified return type, Target opcode, and
271 /// operands. Note that target opcodes are stored as
272 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
273 /// of the resultant node is returned.
274 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
275 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
277 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
278 SDOperand Op1, SDOperand Op2);
279 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
280 SDOperand Op1, SDOperand Op2, SDOperand Op3);
281 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
282 SDOperand Op1, SDOperand Op2, SDOperand Op3,
284 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
285 SDOperand Op1, SDOperand Op2, SDOperand Op3,
286 SDOperand Op4, SDOperand Op5);
287 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
288 SDOperand Op1, SDOperand Op2, SDOperand Op3,
289 SDOperand Op4, SDOperand Op5, SDOperand Op6);
290 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
291 SDOperand Op1, SDOperand Op2, SDOperand Op3,
292 SDOperand Op4, SDOperand Op5, SDOperand Op6,
294 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
295 SDOperand Op1, SDOperand Op2, SDOperand Op3,
296 SDOperand Op4, SDOperand Op5, SDOperand Op6,
297 SDOperand Op7, SDOperand Op8);
298 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
299 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
300 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
301 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
303 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
304 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
305 SDOperand Op3, SDOperand Op4);
306 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
307 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
308 SDOperand Op3, SDOperand Op4, SDOperand Op5);
310 /// getTargetNode - These are used for target selectors to create a new node
311 /// with specified return type(s), target opcode, and operands.
313 /// Note that getTargetNode returns the resultant node. If there is already a
314 /// node of the specified opcode and operands, it returns that node instead of
316 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT);
317 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
319 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
320 SDOperand Op1, SDOperand Op2);
321 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
322 SDOperand Op1, SDOperand Op2, SDOperand Op3);
323 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
324 SDOperand Op1, SDOperand Op2, SDOperand Op3,
326 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
327 SDOperand Op1, SDOperand Op2, SDOperand Op3,
328 SDOperand Op4, SDOperand Op5);
329 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
330 SDOperand Op1, SDOperand Op2, SDOperand Op3,
331 SDOperand Op4, SDOperand Op5, SDOperand Op6);
332 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
333 SDOperand Op1, SDOperand Op2, SDOperand Op3,
334 SDOperand Op4, SDOperand Op5, SDOperand Op6,
336 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
337 SDOperand Op1, SDOperand Op2, SDOperand Op3,
338 SDOperand Op4, SDOperand Op5, SDOperand Op6,
339 SDOperand Op7, SDOperand Op8);
340 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
341 std::vector<SDOperand> &Ops);
342 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
343 MVT::ValueType VT2, SDOperand Op1);
344 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
345 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
346 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
347 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
349 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
350 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
351 SDOperand Op3, SDOperand Op4);
352 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
353 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
354 SDOperand Op3, SDOperand Op4, SDOperand Op5);
355 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
356 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
357 SDOperand Op3, SDOperand Op4, SDOperand Op5,
359 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
360 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
361 SDOperand Op3, SDOperand Op4, SDOperand Op5,
362 SDOperand Op6, SDOperand Op7);
363 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
364 MVT::ValueType VT2, MVT::ValueType VT3,
365 SDOperand Op1, SDOperand Op2);
366 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
367 MVT::ValueType VT2, MVT::ValueType VT3,
368 SDOperand Op1, SDOperand Op2,
369 SDOperand Op3, SDOperand Op4, SDOperand Op5);
370 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
371 MVT::ValueType VT2, MVT::ValueType VT3,
372 SDOperand Op1, SDOperand Op2,
373 SDOperand Op3, SDOperand Op4, SDOperand Op5,
375 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
376 MVT::ValueType VT2, MVT::ValueType VT3,
377 SDOperand Op1, SDOperand Op2,
378 SDOperand Op3, SDOperand Op4, SDOperand Op5,
379 SDOperand Op6, SDOperand Op7);
380 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
381 MVT::ValueType VT2, std::vector<SDOperand> &Ops);
383 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
384 /// This can cause recursive merging of nodes in the DAG. Use the first
385 /// version if 'From' is known to have a single result, use the second
386 /// if you have two nodes with identical results, use the third otherwise.
388 /// These methods all take an optional vector, which (if not null) is
389 /// populated with any nodes that are deleted from the SelectionDAG, due to
390 /// new equivalences that are discovered.
392 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
393 std::vector<SDNode*> *Deleted = 0);
394 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
395 std::vector<SDNode*> *Deleted = 0);
396 void ReplaceAllUsesWith(SDNode *From, const std::vector<SDOperand> &To,
397 std::vector<SDNode*> *Deleted = 0);
400 /// DeleteNode - Remove the specified node from the system. This node must
401 /// have no referrers.
402 void DeleteNode(SDNode *N);
407 void RemoveNodeFromCSEMaps(SDNode *N);
408 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
409 SDNode **FindModifiedNodeSlot(SDNode *N, SDOperand Op);
410 SDNode **FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2);
411 SDNode **FindModifiedNodeSlot(SDNode *N, const std::vector<SDOperand> &Ops);
413 void DestroyDeadNode(SDNode *N);
414 void DeleteNodeNotInCSEMaps(SDNode *N);
415 void setNodeValueTypes(SDNode *N, std::vector<MVT::ValueType> &RetVals);
416 void setNodeValueTypes(SDNode *N, MVT::ValueType VT1, MVT::ValueType VT2);
419 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
420 /// and cc. If unable to simplify it, return a null SDOperand.
421 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
422 SDOperand N2, ISD::CondCode Cond);
424 // List of non-single value types.
425 std::list<std::vector<MVT::ValueType> > VTList;
427 // Maps to auto-CSE operations.
428 std::map<std::pair<unsigned, MVT::ValueType>, SDNode *> NullaryOps;
429 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
431 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
434 std::map<std::pair<unsigned, MVT::ValueType>, RegisterSDNode*> RegNodes;
435 std::vector<CondCodeSDNode*> CondCodeNodes;
437 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
440 std::map<std::pair<const GlobalValue*, int>, SDNode*> GlobalValues;
441 std::map<std::pair<const GlobalValue*, int>, SDNode*> TargetGlobalValues;
442 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
443 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
444 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
445 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstantFPs;
446 std::map<int, SDNode*> FrameIndices, TargetFrameIndices;
447 std::map<std::pair<Constant *, unsigned>, SDNode*> ConstantPoolIndices;
448 std::map<std::pair<Constant *, unsigned>, SDNode*> TargetConstantPoolIndices;
449 std::map<MachineBasicBlock *, SDNode*> BBNodes;
450 std::vector<SDNode*> ValueTypeNodes;
451 std::map<std::string, SDNode*> ExternalSymbols;
452 std::map<std::string, SDNode*> TargetExternalSymbols;
453 std::map<std::string, StringSDNode*> StringNodes;
454 std::map<std::pair<unsigned,
455 std::pair<MVT::ValueType, std::vector<SDOperand> > >,
456 SDNode*> OneResultNodes;
457 std::map<std::pair<unsigned,
458 std::pair<std::vector<MVT::ValueType>,
459 std::vector<SDOperand> > >,
460 SDNode*> ArbitraryNodes;
463 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
464 typedef SelectionDAG::allnodes_iterator nodes_iterator;
465 static nodes_iterator nodes_begin(SelectionDAG *G) {
466 return G->allnodes_begin();
468 static nodes_iterator nodes_end(SelectionDAG *G) {
469 return G->allnodes_end();
473 } // end namespace llvm