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/CodeGen/SelectionDAGCSEMap.h"
20 #include "llvm/ADT/ilist"
30 class MachineDebugInfo;
31 class MachineFunction;
33 /// SelectionDAG class - This is used to represent a portion of an LLVM function
34 /// in a low-level Data Dependence DAG representation suitable for instruction
35 /// selection. This DAG is constructed as the first step of instruction
36 /// selection in order to allow implementation of machine specific optimizations
37 /// and code simplifications.
39 /// The representation used by the SelectionDAG is a target-independent
40 /// representation, which has some similarities to the GCC RTL representation,
41 /// but is significantly more simple, powerful, and is a graph form instead of a
49 // Root - The root of the entire DAG. EntryNode - The starting token.
50 SDOperand Root, EntryNode;
52 // AllNodes - A linked list of nodes in the current DAG.
53 ilist<SDNode> AllNodes;
55 // ValueNodes - track SrcValue nodes
56 std::map<std::pair<const Value*, int>, SDNode*> ValueNodes;
59 SelectionDAG(TargetLowering &tli, MachineFunction &mf, MachineDebugInfo *di)
60 : TLI(tli), MF(mf), DI(di) {
61 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
65 MachineFunction &getMachineFunction() const { return MF; }
66 const TargetMachine &getTarget() const;
67 TargetLowering &getTargetLoweringInfo() const { return TLI; }
68 MachineDebugInfo *getMachineDebugInfo() const { return DI; }
70 /// viewGraph - Pop up a ghostview window with the DAG rendered using 'dot'.
75 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
76 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
77 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
78 typedef ilist<SDNode>::iterator allnodes_iterator;
79 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
80 allnodes_iterator allnodes_end() { return AllNodes.end(); }
82 /// getRoot - Return the root tag of the SelectionDAG.
84 const SDOperand &getRoot() const { return Root; }
86 /// getEntryNode - Return the token chain corresponding to the entry of the
88 const SDOperand &getEntryNode() const { return EntryNode; }
90 /// setRoot - Set the current root tag of the SelectionDAG.
92 const SDOperand &setRoot(SDOperand N) { return Root = N; }
94 /// Combine - This iterates over the nodes in the SelectionDAG, folding
95 /// certain types of nodes together, or eliminating superfluous nodes. When
96 /// the AfterLegalize argument is set to 'true', Combine takes care not to
97 /// generate any nodes that will be illegal on the target.
98 void Combine(bool AfterLegalize);
100 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
101 /// compatible with the target instruction selector, as indicated by the
102 /// TargetLowering object.
104 /// Note that this is an involved process that may invalidate pointers into
108 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
110 void RemoveDeadNodes();
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 getJumpTable(int JTI, MVT::ValueType VT);
124 SDOperand getTargetJumpTable(int JTI, MVT::ValueType VT);
125 SDOperand getConstantPool(Constant *C, MVT::ValueType VT,
126 unsigned Alignment=0, int offset = 0);
127 SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT,
128 unsigned Alignment=0, int offset = 0);
129 SDOperand getBasicBlock(MachineBasicBlock *MBB);
130 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
131 SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
132 SDOperand getValueType(MVT::ValueType);
133 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
135 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
136 return getNode(ISD::CopyToReg, MVT::Other, Chain,
137 getRegister(Reg, N.getValueType()), N);
140 // This version of the getCopyToReg method takes an extra operand, which
141 // indicates that there is potentially an incoming flag value (if Flag is not
142 // null) and that there should be a flag result.
143 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
145 std::vector<MVT::ValueType> VTs;
146 VTs.push_back(MVT::Other);
147 VTs.push_back(MVT::Flag);
148 SDOperand Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
149 return getNode(ISD::CopyToReg, VTs, Ops, Flag.Val ? 4 : 3);
152 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
153 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
155 std::vector<MVT::ValueType> VTs;
156 VTs.push_back(MVT::Other);
157 VTs.push_back(MVT::Flag);
158 SDOperand Ops[] = { Chain, Reg, N, Flag };
159 return getNode(ISD::CopyToReg, VTs, Ops, Flag.Val ? 4 : 3);
162 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
163 std::vector<MVT::ValueType> ResultTys;
164 ResultTys.push_back(VT);
165 ResultTys.push_back(MVT::Other);
166 SDOperand Ops[] = { Chain, getRegister(Reg, VT) };
167 return getNode(ISD::CopyFromReg, ResultTys, Ops, 2);
170 // This version of the getCopyFromReg method takes an extra operand, which
171 // indicates that there is potentially an incoming flag value (if Flag is not
172 // null) and that there should be a flag result.
173 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
175 std::vector<MVT::ValueType> ResultTys;
176 ResultTys.push_back(VT);
177 ResultTys.push_back(MVT::Other);
178 ResultTys.push_back(MVT::Flag);
179 SDOperand Ops[] = { Chain, getRegister(Reg, VT), Flag };
180 return getNode(ISD::CopyFromReg, ResultTys, Ops, Flag.Val ? 3 : 2);
183 SDOperand getCondCode(ISD::CondCode Cond);
185 /// getZeroExtendInReg - Return the expression required to zero extend the Op
186 /// value assuming it was the smaller SrcTy value.
187 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
189 /// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
190 /// a flag result (to ensure it's not CSE'd).
191 SDOperand getCALLSEQ_START(SDOperand Chain, SDOperand Op) {
192 std::vector<MVT::ValueType> ResultTys;
193 ResultTys.push_back(MVT::Other);
194 ResultTys.push_back(MVT::Flag);
195 SDOperand Ops[] = { Chain, Op };
196 return getNode(ISD::CALLSEQ_START, ResultTys, Ops, 2);
199 /// getNode - Gets or creates the specified node.
201 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
202 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
203 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
204 SDOperand N1, SDOperand N2);
205 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
206 SDOperand N1, SDOperand N2, SDOperand N3);
207 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
208 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
209 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
210 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
212 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
213 const SDOperand *Ops, unsigned NumOps);
214 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
215 const SDOperand *Ops, unsigned NumOps);
217 /// getSetCC - Helper function to make it easier to build SetCC's if you just
218 /// have an ISD::CondCode instead of an SDOperand.
220 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
221 ISD::CondCode Cond) {
222 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
225 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
226 /// just have an ISD::CondCode instead of an SDOperand.
228 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
229 SDOperand True, SDOperand False, ISD::CondCode Cond) {
230 MVT::ValueType VT = True.getValueType();
231 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
234 /// getVAArg - VAArg produces a result and token chain, and takes a pointer
235 /// and a source value as input.
236 SDOperand getVAArg(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
239 /// getLoad - Loads are not normal binary operators: their result type is not
240 /// determined by their operands, and they produce a value AND a token chain.
242 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
244 SDOperand getVecLoad(unsigned Count, MVT::ValueType VT, SDOperand Chain,
245 SDOperand Ptr, SDOperand SV);
246 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
247 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
249 // getSrcValue - construct a node to track a Value* through the backend
250 SDOperand getSrcValue(const Value* I, int offset = 0);
252 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
253 /// specified operands. If the resultant node already exists in the DAG,
254 /// this does not modify the specified node, instead it returns the node that
255 /// already exists. If the resultant node does not exist in the DAG, the
256 /// input node is returned. As a degenerate case, if you specify the same
257 /// input operands as the node already has, the input node is returned.
258 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
259 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
260 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
262 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
263 SDOperand Op3, SDOperand Op4);
264 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
265 SDOperand Op3, SDOperand Op4, SDOperand Op5);
266 SDOperand UpdateNodeOperands(SDOperand N, SDOperand *Ops, unsigned NumOps);
268 /// SelectNodeTo - These are used for target selectors to *mutate* the
269 /// specified node to have the specified return type, Target opcode, and
270 /// operands. Note that target opcodes are stored as
271 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
272 /// of the resultant node is returned.
273 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
274 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
276 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
277 SDOperand Op1, SDOperand Op2);
278 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
279 SDOperand Op1, SDOperand Op2, SDOperand Op3);
280 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
281 SDOperand Op1, SDOperand Op2, SDOperand Op3,
283 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
284 SDOperand Op1, SDOperand Op2, SDOperand Op3,
285 SDOperand Op4, SDOperand Op5);
286 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
287 SDOperand Op1, SDOperand Op2, SDOperand Op3,
288 SDOperand Op4, SDOperand Op5, SDOperand Op6);
289 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
290 SDOperand Op1, SDOperand Op2, SDOperand Op3,
291 SDOperand Op4, SDOperand Op5, SDOperand Op6,
293 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
294 SDOperand Op1, SDOperand Op2, SDOperand Op3,
295 SDOperand Op4, SDOperand Op5, SDOperand Op6,
296 SDOperand Op7, SDOperand Op8);
297 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
298 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
299 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
300 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
302 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
303 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
304 SDOperand Op3, SDOperand Op4);
305 SDOperand SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
306 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
307 SDOperand Op3, SDOperand Op4, SDOperand Op5);
309 /// getTargetNode - These are used for target selectors to create a new node
310 /// with specified return type(s), target opcode, and operands.
312 /// Note that getTargetNode returns the resultant node. If there is already a
313 /// node of the specified opcode and operands, it returns that node instead of
315 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT);
316 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
318 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
319 SDOperand Op1, SDOperand Op2);
320 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
321 SDOperand Op1, SDOperand Op2, SDOperand Op3);
322 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
323 SDOperand Op1, SDOperand Op2, SDOperand Op3,
325 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
326 SDOperand Op1, SDOperand Op2, SDOperand Op3,
327 SDOperand Op4, SDOperand Op5);
328 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
329 SDOperand Op1, SDOperand Op2, SDOperand Op3,
330 SDOperand Op4, SDOperand Op5, SDOperand Op6);
331 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
332 SDOperand Op1, SDOperand Op2, SDOperand Op3,
333 SDOperand Op4, SDOperand Op5, SDOperand Op6,
335 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
336 SDOperand Op1, SDOperand Op2, SDOperand Op3,
337 SDOperand Op4, SDOperand Op5, SDOperand Op6,
338 SDOperand Op7, SDOperand Op8);
339 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
340 const SDOperand *Ops, unsigned NumOps);
341 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
342 MVT::ValueType VT2, SDOperand Op1);
343 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
344 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
345 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
346 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
348 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
349 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
350 SDOperand Op3, SDOperand Op4);
351 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
352 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
353 SDOperand Op3, SDOperand Op4, SDOperand Op5);
354 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
355 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
356 SDOperand Op3, SDOperand Op4, SDOperand Op5,
358 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
359 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
360 SDOperand Op3, SDOperand Op4, SDOperand Op5,
361 SDOperand Op6, SDOperand Op7);
362 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
363 MVT::ValueType VT2, MVT::ValueType VT3,
364 SDOperand Op1, SDOperand Op2);
365 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
366 MVT::ValueType VT2, MVT::ValueType VT3,
367 SDOperand Op1, SDOperand Op2,
368 SDOperand Op3, SDOperand Op4, SDOperand Op5);
369 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
370 MVT::ValueType VT2, MVT::ValueType VT3,
371 SDOperand Op1, SDOperand Op2,
372 SDOperand Op3, SDOperand Op4, SDOperand Op5,
374 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
375 MVT::ValueType VT2, MVT::ValueType VT3,
376 SDOperand Op1, SDOperand Op2,
377 SDOperand Op3, SDOperand Op4, SDOperand Op5,
378 SDOperand Op6, SDOperand Op7);
379 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
381 const SDOperand *Ops, unsigned NumOps);
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 SDOperand *To,
397 std::vector<SDNode*> *Deleted = 0);
399 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
400 /// uses of other values produced by From.Val alone. The Deleted vector is
401 /// handled the same was as for ReplaceAllUsesWith, but it is required for
403 void ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
404 std::vector<SDNode*> &Deleted);
406 /// DeleteNode - Remove the specified node from the system. This node must
407 /// have no referrers.
408 void DeleteNode(SDNode *N);
410 /// AssignNodeIds - Assign a unique node id for each node in the DAG based on
411 /// their allnodes order. It returns the maximum id.
412 unsigned AssignNodeIds();
414 /// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
415 /// based on their topological order. It returns the maximum id and a vector
416 /// of the SDNodes* in assigned order by reference.
417 unsigned AssignTopologicalOrder(std::vector<SDNode*> &TopOrder);
421 /// InsertISelMapEntry - A helper function to insert a key / element pair
422 /// into a SDOperand to SDOperand map. This is added to avoid the map
423 /// insertion operator from being inlined.
424 static void InsertISelMapEntry(std::map<SDOperand, SDOperand> &Map,
425 SDNode *Key, unsigned KeyResNo,
426 SDNode *Element, unsigned ElementResNo);
429 void RemoveNodeFromCSEMaps(SDNode *N);
430 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
431 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op, void *&InsertPos);
432 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2,
434 SDNode *FindModifiedNodeSlot(SDNode *N, const SDOperand *Ops, unsigned NumOps,
437 void DeleteNodeNotInCSEMaps(SDNode *N);
438 MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1);
439 MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1, MVT::ValueType VT2);
440 MVT::ValueType *getNodeValueTypes(std::vector<MVT::ValueType> &RetVals);
443 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
444 /// and cc. If unable to simplify it, return a null SDOperand.
445 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
446 SDOperand N2, ISD::CondCode Cond);
448 // List of non-single value types.
449 std::list<std::vector<MVT::ValueType> > VTList;
451 // Maps to auto-CSE operations.
452 std::map<std::pair<unsigned, MVT::ValueType>, RegisterSDNode*> RegNodes;
453 std::vector<CondCodeSDNode*> CondCodeNodes;
455 std::map<std::pair<const GlobalValue*, int>, SDNode*> GlobalValues;
456 std::map<std::pair<const GlobalValue*, int>, SDNode*> TargetGlobalValues;
457 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
458 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
459 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
460 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstantFPs;
461 std::map<int, SDNode*> FrameIndices, TargetFrameIndices, JumpTableIndices,
462 TargetJumpTableIndices;
463 std::map<std::pair<Constant *,
464 std::pair<int, unsigned> >, SDNode*> ConstantPoolIndices;
465 std::map<std::pair<Constant *,
466 std::pair<int, unsigned> >, SDNode*> TargetConstantPoolIndices;
467 std::map<MachineBasicBlock *, SDNode*> BBNodes;
468 std::vector<SDNode*> ValueTypeNodes;
469 std::map<std::string, SDNode*> ExternalSymbols;
470 std::map<std::string, SDNode*> TargetExternalSymbols;
471 std::map<std::string, StringSDNode*> StringNodes;
472 SelectionDAGCSEMap CSEMap;
475 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
476 typedef SelectionDAG::allnodes_iterator nodes_iterator;
477 static nodes_iterator nodes_begin(SelectionDAG *G) {
478 return G->allnodes_begin();
480 static nodes_iterator nodes_end(SelectionDAG *G) {
481 return G->allnodes_end();
485 } // end namespace llvm