1 //===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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/ADT/FoldingSet.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/ilist.h"
21 #include "llvm/CodeGen/SelectionDAGNodes.h"
32 class MachineModuleInfo;
33 class MachineFunction;
34 class MachineConstantPoolValue;
35 class FunctionLoweringInfo;
37 /// SelectionDAG class - This is used to represent a portion of an LLVM function
38 /// in a low-level Data Dependence DAG representation suitable for instruction
39 /// selection. This DAG is constructed as the first step of instruction
40 /// selection in order to allow implementation of machine specific optimizations
41 /// and code simplifications.
43 /// The representation used by the SelectionDAG is a target-independent
44 /// representation, which has some similarities to the GCC RTL representation,
45 /// but is significantly more simple, powerful, and is a graph form instead of a
51 FunctionLoweringInfo &FLI;
52 MachineModuleInfo *MMI;
54 /// Root - The root of the entire DAG. EntryNode - The starting token.
55 SDOperand Root, EntryNode;
57 /// AllNodes - A linked list of nodes in the current DAG.
58 ilist<SDNode> AllNodes;
60 /// CSEMap - This structure is used to memoize nodes, automatically performing
61 /// CSE with existing nodes with a duplicate is requested.
62 FoldingSet<SDNode> CSEMap;
65 SelectionDAG(TargetLowering &tli, MachineFunction &mf,
66 FunctionLoweringInfo &fli, MachineModuleInfo *mmi)
67 : TLI(tli), MF(mf), FLI(fli), MMI(mmi) {
68 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
72 MachineFunction &getMachineFunction() const { return MF; }
73 const TargetMachine &getTarget() const;
74 TargetLowering &getTargetLoweringInfo() const { return TLI; }
75 FunctionLoweringInfo &getFunctionLoweringInfo() const { return FLI; }
76 MachineModuleInfo *getMachineModuleInfo() const { return MMI; }
78 /// viewGraph - Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
83 std::map<const SDNode *, std::string> NodeGraphAttrs;
86 /// clearGraphAttrs - Clear all previously defined node graph attributes.
87 /// Intended to be used from a debugging tool (eg. gdb).
88 void clearGraphAttrs();
90 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
92 void setGraphAttrs(const SDNode *N, const char *Attrs);
94 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
95 /// Used from getNodeAttributes.
96 const std::string getGraphAttrs(const SDNode *N) const;
98 /// setGraphColor - Convenience for setting node color attribute.
100 void setGraphColor(const SDNode *N, const char *Color);
102 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
103 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
104 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
105 typedef ilist<SDNode>::iterator allnodes_iterator;
106 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
107 allnodes_iterator allnodes_end() { return AllNodes.end(); }
108 ilist<SDNode>::size_type allnodes_size() const { return AllNodes.size(); }
110 /// getRoot - Return the root tag of the SelectionDAG.
112 const SDOperand &getRoot() const { return Root; }
114 /// getEntryNode - Return the token chain corresponding to the entry of the
116 const SDOperand &getEntryNode() const { return EntryNode; }
118 /// setRoot - Set the current root tag of the SelectionDAG.
120 const SDOperand &setRoot(SDOperand N) { return Root = N; }
122 /// Combine - This iterates over the nodes in the SelectionDAG, folding
123 /// certain types of nodes together, or eliminating superfluous nodes. When
124 /// the AfterLegalize argument is set to 'true', Combine takes care not to
125 /// generate any nodes that will be illegal on the target.
126 void Combine(bool AfterLegalize, AliasAnalysis &AA);
128 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
129 /// only uses types natively supported by the target.
131 /// Note that this is an involved process that may invalidate pointers into
133 void LegalizeTypes();
135 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
136 /// compatible with the target instruction selector, as indicated by the
137 /// TargetLowering object.
139 /// Note that this is an involved process that may invalidate pointers into
143 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
145 void RemoveDeadNodes();
147 /// DeleteNode - Remove the specified node from the system. This node must
148 /// have no referrers.
149 void DeleteNode(SDNode *N);
151 /// getVTList - Return an SDVTList that represents the list of values
153 SDVTList getVTList(MVT VT);
154 SDVTList getVTList(MVT VT1, MVT VT2);
155 SDVTList getVTList(MVT VT1, MVT VT2, MVT VT3);
156 SDVTList getVTList(const MVT *VTs, unsigned NumVTs);
158 /// getNodeValueTypes - These are obsolete, use getVTList instead.
159 const MVT *getNodeValueTypes(MVT VT) {
160 return getVTList(VT).VTs;
162 const MVT *getNodeValueTypes(MVT VT1, MVT VT2) {
163 return getVTList(VT1, VT2).VTs;
165 const MVT *getNodeValueTypes(MVT VT1, MVT VT2, MVT VT3) {
166 return getVTList(VT1, VT2, VT3).VTs;
168 const MVT *getNodeValueTypes(std::vector<MVT> &vtList) {
169 return getVTList(&vtList[0], (unsigned)vtList.size()).VTs;
173 //===--------------------------------------------------------------------===//
174 // Node creation methods.
176 SDOperand getString(const std::string &Val);
177 SDOperand getConstant(uint64_t Val, MVT VT, bool isTarget = false);
178 SDOperand getConstant(const APInt &Val, MVT VT, bool isTarget = false);
179 SDOperand getIntPtrConstant(uint64_t Val, bool isTarget = false);
180 SDOperand getTargetConstant(uint64_t Val, MVT VT) {
181 return getConstant(Val, VT, true);
183 SDOperand getTargetConstant(const APInt &Val, MVT VT) {
184 return getConstant(Val, VT, true);
186 SDOperand getConstantFP(double Val, MVT VT, bool isTarget = false);
187 SDOperand getConstantFP(const APFloat& Val, MVT VT, bool isTarget = false);
188 SDOperand getTargetConstantFP(double Val, MVT VT) {
189 return getConstantFP(Val, VT, true);
191 SDOperand getTargetConstantFP(const APFloat& Val, MVT VT) {
192 return getConstantFP(Val, VT, true);
194 SDOperand getGlobalAddress(const GlobalValue *GV, MVT VT,
195 int offset = 0, bool isTargetGA = false);
196 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT VT,
198 return getGlobalAddress(GV, VT, offset, true);
200 SDOperand getFrameIndex(int FI, MVT VT, bool isTarget = false);
201 SDOperand getTargetFrameIndex(int FI, MVT VT) {
202 return getFrameIndex(FI, VT, true);
204 SDOperand getJumpTable(int JTI, MVT VT, bool isTarget = false);
205 SDOperand getTargetJumpTable(int JTI, MVT VT) {
206 return getJumpTable(JTI, VT, true);
208 SDOperand getConstantPool(Constant *C, MVT VT,
209 unsigned Align = 0, int Offs = 0, bool isT=false);
210 SDOperand getTargetConstantPool(Constant *C, MVT VT,
211 unsigned Align = 0, int Offset = 0) {
212 return getConstantPool(C, VT, Align, Offset, true);
214 SDOperand getConstantPool(MachineConstantPoolValue *C, MVT VT,
215 unsigned Align = 0, int Offs = 0, bool isT=false);
216 SDOperand getTargetConstantPool(MachineConstantPoolValue *C,
217 MVT VT, unsigned Align = 0,
219 return getConstantPool(C, VT, Align, Offset, true);
221 SDOperand getBasicBlock(MachineBasicBlock *MBB);
222 SDOperand getExternalSymbol(const char *Sym, MVT VT);
223 SDOperand getTargetExternalSymbol(const char *Sym, MVT VT);
224 SDOperand getArgFlags(ISD::ArgFlagsTy Flags);
225 SDOperand getValueType(MVT);
226 SDOperand getRegister(unsigned Reg, MVT VT);
228 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
229 return getNode(ISD::CopyToReg, MVT::Other, Chain,
230 getRegister(Reg, N.getValueType()), N);
233 // This version of the getCopyToReg method takes an extra operand, which
234 // indicates that there is potentially an incoming flag value (if Flag is not
235 // null) and that there should be a flag result.
236 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
238 const MVT *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
239 SDOperand Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
240 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
243 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
244 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
246 const MVT *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
247 SDOperand Ops[] = { Chain, Reg, N, Flag };
248 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
251 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT VT) {
252 const MVT *VTs = getNodeValueTypes(VT, MVT::Other);
253 SDOperand Ops[] = { Chain, getRegister(Reg, VT) };
254 return getNode(ISD::CopyFromReg, VTs, 2, Ops, 2);
257 // This version of the getCopyFromReg method takes an extra operand, which
258 // indicates that there is potentially an incoming flag value (if Flag is not
259 // null) and that there should be a flag result.
260 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT VT,
262 const MVT *VTs = getNodeValueTypes(VT, MVT::Other, MVT::Flag);
263 SDOperand Ops[] = { Chain, getRegister(Reg, VT), Flag };
264 return getNode(ISD::CopyFromReg, VTs, 3, Ops, Flag.Val ? 3 : 2);
267 SDOperand getCondCode(ISD::CondCode Cond);
269 /// getZeroExtendInReg - Return the expression required to zero extend the Op
270 /// value assuming it was the smaller SrcTy value.
271 SDOperand getZeroExtendInReg(SDOperand Op, MVT SrcTy);
273 /// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
274 /// a flag result (to ensure it's not CSE'd).
275 SDOperand getCALLSEQ_START(SDOperand Chain, SDOperand Op) {
276 const MVT *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
277 SDOperand Ops[] = { Chain, Op };
278 return getNode(ISD::CALLSEQ_START, VTs, 2, Ops, 2);
281 /// getCALLSEQ_END - Return a new CALLSEQ_END node, which always must have a
282 /// flag result (to ensure it's not CSE'd).
283 SDOperand getCALLSEQ_END(SDOperand Chain, SDOperand Op1, SDOperand Op2,
285 SDVTList NodeTys = getVTList(MVT::Other, MVT::Flag);
286 SmallVector<SDOperand, 4> Ops;
287 Ops.push_back(Chain);
290 Ops.push_back(InFlag);
291 return getNode(ISD::CALLSEQ_END, NodeTys, &Ops[0],
292 (unsigned)Ops.size() - (InFlag.Val == 0 ? 1 : 0));
295 /// getNode - Gets or creates the specified node.
297 SDOperand getNode(unsigned Opcode, MVT VT);
298 SDOperand getNode(unsigned Opcode, MVT VT, SDOperand N);
299 SDOperand getNode(unsigned Opcode, MVT VT, SDOperand N1, SDOperand N2);
300 SDOperand getNode(unsigned Opcode, MVT VT,
301 SDOperand N1, SDOperand N2, SDOperand N3);
302 SDOperand getNode(unsigned Opcode, MVT VT,
303 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
304 SDOperand getNode(unsigned Opcode, MVT VT,
305 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
307 SDOperand getNode(unsigned Opcode, MVT VT, SDOperandPtr Ops, unsigned NumOps);
308 SDOperand getNode(unsigned Opcode, std::vector<MVT> &ResultTys,
309 SDOperandPtr Ops, unsigned NumOps);
310 SDOperand getNode(unsigned Opcode, const MVT *VTs, unsigned NumVTs,
311 SDOperandPtr Ops, unsigned NumOps);
312 SDOperand getNode(unsigned Opcode, SDVTList VTs);
313 SDOperand getNode(unsigned Opcode, SDVTList VTs, SDOperand N);
314 SDOperand getNode(unsigned Opcode, SDVTList VTs, SDOperand N1, SDOperand N2);
315 SDOperand getNode(unsigned Opcode, SDVTList VTs,
316 SDOperand N1, SDOperand N2, SDOperand N3);
317 SDOperand getNode(unsigned Opcode, SDVTList VTs,
318 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
319 SDOperand getNode(unsigned Opcode, SDVTList VTs,
320 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
322 SDOperand getNode(unsigned Opcode, SDVTList VTs,
323 SDOperandPtr Ops, unsigned NumOps);
325 SDOperand getMemcpy(SDOperand Chain, SDOperand Dst, SDOperand Src,
326 SDOperand Size, unsigned Align,
328 const Value *DstSV, uint64_t DstSVOff,
329 const Value *SrcSV, uint64_t SrcSVOff);
331 SDOperand getMemmove(SDOperand Chain, SDOperand Dst, SDOperand Src,
332 SDOperand Size, unsigned Align,
333 const Value *DstSV, uint64_t DstOSVff,
334 const Value *SrcSV, uint64_t SrcSVOff);
336 SDOperand getMemset(SDOperand Chain, SDOperand Dst, SDOperand Src,
337 SDOperand Size, unsigned Align,
338 const Value *DstSV, uint64_t DstSVOff);
340 /// getSetCC - Helper function to make it easier to build SetCC's if you just
341 /// have an ISD::CondCode instead of an SDOperand.
343 SDOperand getSetCC(MVT VT, SDOperand LHS, SDOperand RHS,
344 ISD::CondCode Cond) {
345 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
348 /// getVSetCC - Helper function to make it easier to build VSetCC's nodes
349 /// if you just have an ISD::CondCode instead of an SDOperand.
351 SDOperand getVSetCC(MVT VT, SDOperand LHS, SDOperand RHS,
352 ISD::CondCode Cond) {
353 return getNode(ISD::VSETCC, VT, LHS, RHS, getCondCode(Cond));
356 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
357 /// just have an ISD::CondCode instead of an SDOperand.
359 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
360 SDOperand True, SDOperand False, ISD::CondCode Cond) {
361 return getNode(ISD::SELECT_CC, True.getValueType(), LHS, RHS, True, False,
365 /// getVAArg - VAArg produces a result and token chain, and takes a pointer
366 /// and a source value as input.
367 SDOperand getVAArg(MVT VT, SDOperand Chain, SDOperand Ptr,
370 /// getAtomic - Gets a node for an atomic op, produces result and chain, takes
372 SDOperand getAtomic(unsigned Opcode, SDOperand Chain, SDOperand Ptr,
373 SDOperand Cmp, SDOperand Swp, const Value* PtrVal,
374 unsigned Alignment=0);
376 /// getAtomic - Gets a node for an atomic op, produces result and chain, takes
378 SDOperand getAtomic(unsigned Opcode, SDOperand Chain, SDOperand Ptr,
379 SDOperand Val, const Value* PtrVal,
380 unsigned Alignment = 0);
382 /// getMergeValues - Create a MERGE_VALUES node from the given types and ops.
383 /// Allowed to return something different (and simpler) if Simplify is true.
384 SDOperand getMergeValues(SDVTList VTs, SDOperandPtr Ops, unsigned NumOps,
385 bool Simplify = true) {
386 if (Simplify && NumOps == 1)
388 return getNode(ISD::MERGE_VALUES, VTs, Ops, NumOps);
391 /// getLoad - Loads are not normal binary operators: their result type is not
392 /// determined by their operands, and they produce a value AND a token chain.
394 SDOperand getLoad(MVT VT, SDOperand Chain, SDOperand Ptr,
395 const Value *SV, int SVOffset, bool isVolatile=false,
396 unsigned Alignment=0);
397 SDOperand getExtLoad(ISD::LoadExtType ExtType, MVT VT,
398 SDOperand Chain, SDOperand Ptr, const Value *SV,
399 int SVOffset, MVT EVT, bool isVolatile=false,
400 unsigned Alignment=0);
401 SDOperand getIndexedLoad(SDOperand OrigLoad, SDOperand Base,
402 SDOperand Offset, ISD::MemIndexedMode AM);
403 SDOperand getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
404 MVT VT, SDOperand Chain,
405 SDOperand Ptr, SDOperand Offset,
406 const Value *SV, int SVOffset, MVT EVT,
407 bool isVolatile=false, unsigned Alignment=0);
409 /// getStore - Helper function to build ISD::STORE nodes.
411 SDOperand getStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
412 const Value *SV, int SVOffset, bool isVolatile=false,
413 unsigned Alignment=0);
414 SDOperand getTruncStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
415 const Value *SV, int SVOffset, MVT TVT,
416 bool isVolatile=false, unsigned Alignment=0);
417 SDOperand getIndexedStore(SDOperand OrigStoe, SDOperand Base,
418 SDOperand Offset, ISD::MemIndexedMode AM);
420 // getSrcValue - Construct a node to track a Value* through the backend.
421 SDOperand getSrcValue(const Value *v);
423 // getMemOperand - Construct a node to track a memory reference
424 // through the backend.
425 SDOperand getMemOperand(const MachineMemOperand &MO);
427 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
428 /// specified operands. If the resultant node already exists in the DAG,
429 /// this does not modify the specified node, instead it returns the node that
430 /// already exists. If the resultant node does not exist in the DAG, the
431 /// input node is returned. As a degenerate case, if you specify the same
432 /// input operands as the node already has, the input node is returned.
433 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
434 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
435 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
437 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
438 SDOperand Op3, SDOperand Op4);
439 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
440 SDOperand Op3, SDOperand Op4, SDOperand Op5);
441 SDOperand UpdateNodeOperands(SDOperand N, SDOperandPtr Ops, unsigned NumOps);
443 /// SelectNodeTo - These are used for target selectors to *mutate* the
444 /// specified node to have the specified return type, Target opcode, and
445 /// operands. Note that target opcodes are stored as
446 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
447 /// of the resultant node is returned.
448 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT);
449 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT, SDOperand Op1);
450 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT,
451 SDOperand Op1, SDOperand Op2);
452 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT,
453 SDOperand Op1, SDOperand Op2, SDOperand Op3);
454 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT,
455 SDOperandPtr Ops, unsigned NumOps);
456 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT1,
457 MVT VT2, SDOperand Op1, SDOperand Op2);
458 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT1,
459 MVT VT2, SDOperand Op1, SDOperand Op2, SDOperand Op3);
462 /// getTargetNode - These are used for target selectors to create a new node
463 /// with specified return type(s), target opcode, and operands.
465 /// Note that getTargetNode returns the resultant node. If there is already a
466 /// node of the specified opcode and operands, it returns that node instead of
468 SDNode *getTargetNode(unsigned Opcode, MVT VT);
469 SDNode *getTargetNode(unsigned Opcode, MVT VT, SDOperand Op1);
470 SDNode *getTargetNode(unsigned Opcode, MVT VT, SDOperand Op1, SDOperand Op2);
471 SDNode *getTargetNode(unsigned Opcode, MVT VT,
472 SDOperand Op1, SDOperand Op2, SDOperand Op3);
473 SDNode *getTargetNode(unsigned Opcode, MVT VT,
474 SDOperandPtr Ops, unsigned NumOps);
475 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2);
476 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, SDOperand Op1);
477 SDNode *getTargetNode(unsigned Opcode, MVT VT1,
478 MVT VT2, SDOperand Op1, SDOperand Op2);
479 SDNode *getTargetNode(unsigned Opcode, MVT VT1,
480 MVT VT2, SDOperand Op1, SDOperand Op2, SDOperand Op3);
481 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2,
482 SDOperandPtr Ops, unsigned NumOps);
483 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3,
484 SDOperand Op1, SDOperand Op2);
485 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3,
486 SDOperand Op1, SDOperand Op2, SDOperand Op3);
487 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3,
488 SDOperandPtr Ops, unsigned NumOps);
489 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3, MVT VT4,
490 SDOperandPtr Ops, unsigned NumOps);
491 SDNode *getTargetNode(unsigned Opcode, std::vector<MVT> &ResultTys,
492 SDOperandPtr Ops, unsigned NumOps);
494 /// getNodeIfExists - Get the specified node if it's already available, or
495 /// else return NULL.
496 SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTs,
497 SDOperandPtr Ops, unsigned NumOps);
499 /// DAGUpdateListener - Clients of various APIs that cause global effects on
500 /// the DAG can optionally implement this interface. This allows the clients
501 /// to handle the various sorts of updates that happen.
502 class DAGUpdateListener {
504 virtual ~DAGUpdateListener();
506 /// NodeDeleted - The node N that was deleted and, if E is not null, an
507 /// equivalent node E that replaced it.
508 virtual void NodeDeleted(SDNode *N, SDNode *E) = 0;
510 /// NodeUpdated - The node N that was updated.
511 virtual void NodeUpdated(SDNode *N) = 0;
514 /// RemoveDeadNode - Remove the specified node from the system. If any of its
515 /// operands then becomes dead, remove them as well. Inform UpdateListener
516 /// for each node deleted.
517 void RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener = 0);
519 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
520 /// This can cause recursive merging of nodes in the DAG. Use the first
521 /// version if 'From' is known to have a single result, use the second
522 /// if you have two nodes with identical results, use the third otherwise.
524 /// These methods all take an optional UpdateListener, which (if not null) is
525 /// informed about nodes that are deleted and modified due to recursive
526 /// changes in the dag.
528 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
529 DAGUpdateListener *UpdateListener = 0);
530 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
531 DAGUpdateListener *UpdateListener = 0);
532 void ReplaceAllUsesWith(SDNode *From, SDOperandPtr To,
533 DAGUpdateListener *UpdateListener = 0);
535 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
536 /// uses of other values produced by From.Val alone.
537 void ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
538 DAGUpdateListener *UpdateListener = 0);
540 /// AssignNodeIds - Assign a unique node id for each node in the DAG based on
541 /// their allnodes order. It returns the maximum id.
542 unsigned AssignNodeIds();
544 /// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
545 /// based on their topological order. It returns the maximum id and a vector
546 /// of the SDNodes* in assigned order by reference.
547 unsigned AssignTopologicalOrder(std::vector<SDNode*> &TopOrder);
549 /// isCommutativeBinOp - Returns true if the opcode is a commutative binary
551 static bool isCommutativeBinOp(unsigned Opcode) {
552 // FIXME: This should get its info from the td file, so that we can include
567 case ISD::ADDE: return true;
568 default: return false;
574 /// CreateStackTemporary - Create a stack temporary, suitable for holding the
575 /// specified value type.
576 SDOperand CreateStackTemporary(MVT VT);
578 /// FoldSetCC - Constant fold a setcc to true or false.
579 SDOperand FoldSetCC(MVT VT, SDOperand N1,
580 SDOperand N2, ISD::CondCode Cond);
582 /// SignBitIsZero - Return true if the sign bit of Op is known to be zero. We
583 /// use this predicate to simplify operations downstream.
584 bool SignBitIsZero(SDOperand Op, unsigned Depth = 0) const;
586 /// MaskedValueIsZero - Return true if 'Op & Mask' is known to be zero. We
587 /// use this predicate to simplify operations downstream. Op and Mask are
588 /// known to be the same type.
589 bool MaskedValueIsZero(SDOperand Op, const APInt &Mask, unsigned Depth = 0)
592 /// ComputeMaskedBits - Determine which of the bits specified in Mask are
593 /// known to be either zero or one and return them in the KnownZero/KnownOne
594 /// bitsets. This code only analyzes bits in Mask, in order to short-circuit
595 /// processing. Targets can implement the computeMaskedBitsForTargetNode
596 /// method in the TargetLowering class to allow target nodes to be understood.
597 void ComputeMaskedBits(SDOperand Op, const APInt &Mask, APInt &KnownZero,
598 APInt &KnownOne, unsigned Depth = 0) const;
600 /// ComputeNumSignBits - Return the number of times the sign bit of the
601 /// register is replicated into the other bits. We know that at least 1 bit
602 /// is always equal to the sign bit (itself), but other cases can give us
603 /// information. For example, immediately after an "SRA X, 2", we know that
604 /// the top 3 bits are all equal to each other, so we return 3. Targets can
605 /// implement the ComputeNumSignBitsForTarget method in the TargetLowering
606 /// class to allow target nodes to be understood.
607 unsigned ComputeNumSignBits(SDOperand Op, unsigned Depth = 0) const;
609 /// isVerifiedDebugInfoDesc - Returns true if the specified SDOperand has
610 /// been verified as a debug information descriptor.
611 bool isVerifiedDebugInfoDesc(SDOperand Op) const;
613 /// getShuffleScalarElt - Returns the scalar element that will make up the ith
614 /// element of the result of the vector shuffle.
615 SDOperand getShuffleScalarElt(const SDNode *N, unsigned Idx);
618 void RemoveNodeFromCSEMaps(SDNode *N);
619 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
620 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op, void *&InsertPos);
621 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2,
623 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperandPtr Ops, unsigned NumOps,
626 void DeleteNodeNotInCSEMaps(SDNode *N);
628 // List of non-single value types.
629 std::list<std::vector<MVT> > VTList;
631 // Maps to auto-CSE operations.
632 std::vector<CondCodeSDNode*> CondCodeNodes;
634 std::vector<SDNode*> ValueTypeNodes;
635 std::map<MVT, SDNode*, MVT::compareRawBits> ExtendedValueTypeNodes;
636 StringMap<SDNode*> ExternalSymbols;
637 StringMap<SDNode*> TargetExternalSymbols;
638 StringMap<StringSDNode*> StringNodes;
641 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
642 typedef SelectionDAG::allnodes_iterator nodes_iterator;
643 static nodes_iterator nodes_begin(SelectionDAG *G) {
644 return G->allnodes_begin();
646 static nodes_iterator nodes_end(SelectionDAG *G) {
647 return G->allnodes_end();
651 } // end namespace llvm