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/ilist.h"
20 #include "llvm/CodeGen/SelectionDAGNodes.h"
32 class MachineModuleInfo;
33 class MachineFunction;
34 class MachineConstantPoolValue;
36 /// SelectionDAG class - This is used to represent a portion of an LLVM function
37 /// in a low-level Data Dependence DAG representation suitable for instruction
38 /// selection. This DAG is constructed as the first step of instruction
39 /// selection in order to allow implementation of machine specific optimizations
40 /// and code simplifications.
42 /// The representation used by the SelectionDAG is a target-independent
43 /// representation, which has some similarities to the GCC RTL representation,
44 /// but is significantly more simple, powerful, and is a graph form instead of a
50 MachineModuleInfo *MMI;
52 /// Root - The root of the entire DAG. EntryNode - The starting token.
53 SDOperand Root, EntryNode;
55 /// AllNodes - A linked list of nodes in the current DAG.
56 ilist<SDNode> AllNodes;
58 /// CSEMap - This structure is used to memoize nodes, automatically performing
59 /// CSE with existing nodes with a duplicate is requested.
60 FoldingSet<SDNode> CSEMap;
63 SelectionDAG(TargetLowering &tli, MachineFunction &mf, MachineModuleInfo *mmi)
64 : TLI(tli), MF(mf), MMI(mmi) {
65 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
69 MachineFunction &getMachineFunction() const { return MF; }
70 const TargetMachine &getTarget() const;
71 TargetLowering &getTargetLoweringInfo() const { return TLI; }
72 MachineModuleInfo *getMachineModuleInfo() const { return MMI; }
74 /// viewGraph - Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
79 std::map<const SDNode *, std::string> NodeGraphAttrs;
82 /// clearGraphAttrs - Clear all previously defined node graph attributes.
83 /// Intended to be used from a debugging tool (eg. gdb).
84 void clearGraphAttrs();
86 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
88 void setGraphAttrs(const SDNode *N, const char *Attrs);
90 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
91 /// Used from getNodeAttributes.
92 const std::string getGraphAttrs(const SDNode *N) const;
94 /// setGraphColor - Convenience for setting node color attribute.
96 void setGraphColor(const SDNode *N, const char *Color);
98 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
99 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
100 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
101 typedef ilist<SDNode>::iterator allnodes_iterator;
102 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
103 allnodes_iterator allnodes_end() { return AllNodes.end(); }
105 /// getRoot - Return the root tag of the SelectionDAG.
107 const SDOperand &getRoot() const { return Root; }
109 /// getEntryNode - Return the token chain corresponding to the entry of the
111 const SDOperand &getEntryNode() const { return EntryNode; }
113 /// setRoot - Set the current root tag of the SelectionDAG.
115 const SDOperand &setRoot(SDOperand N) { return Root = N; }
117 /// Combine - This iterates over the nodes in the SelectionDAG, folding
118 /// certain types of nodes together, or eliminating superfluous nodes. When
119 /// the AfterLegalize argument is set to 'true', Combine takes care not to
120 /// generate any nodes that will be illegal on the target.
121 void Combine(bool AfterLegalize, AliasAnalysis &AA);
123 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
124 /// only uses types natively supported by the target.
126 /// Note that this is an involved process that may invalidate pointers into
128 void LegalizeTypes();
130 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
131 /// compatible with the target instruction selector, as indicated by the
132 /// TargetLowering object.
134 /// Note that this is an involved process that may invalidate pointers into
138 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
140 void RemoveDeadNodes();
142 /// DeleteNode - Remove the specified node from the system. This node must
143 /// have no referrers.
144 void DeleteNode(SDNode *N);
146 /// getVTList - Return an SDVTList that represents the list of values
148 SDVTList getVTList(MVT::ValueType VT);
149 SDVTList getVTList(MVT::ValueType VT1, MVT::ValueType VT2);
150 SDVTList getVTList(MVT::ValueType VT1, MVT::ValueType VT2,MVT::ValueType VT3);
151 SDVTList getVTList(const MVT::ValueType *VTs, unsigned NumVTs);
153 /// getNodeValueTypes - These are obsolete, use getVTList instead.
154 const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT) {
155 return getVTList(VT).VTs;
157 const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1,
158 MVT::ValueType VT2) {
159 return getVTList(VT1, VT2).VTs;
161 const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1,MVT::ValueType VT2,
162 MVT::ValueType VT3) {
163 return getVTList(VT1, VT2, VT3).VTs;
165 const MVT::ValueType *getNodeValueTypes(std::vector<MVT::ValueType> &vtList) {
166 return getVTList(&vtList[0], (unsigned)vtList.size()).VTs;
170 //===--------------------------------------------------------------------===//
171 // Node creation methods.
173 SDOperand getString(const std::string &Val);
174 SDOperand getConstant(uint64_t Val, MVT::ValueType VT, bool isTarget = false);
175 SDOperand getConstant(const APInt &Val, MVT::ValueType VT, bool isTarget = false);
176 SDOperand getIntPtrConstant(uint64_t Val, bool isTarget = false);
177 SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT) {
178 return getConstant(Val, VT, true);
180 SDOperand getTargetConstant(const APInt &Val, MVT::ValueType VT) {
181 return getConstant(Val, VT, true);
183 SDOperand getConstantFP(double Val, MVT::ValueType VT, bool isTarget = false);
184 SDOperand getConstantFP(const APFloat& Val, MVT::ValueType VT,
185 bool isTarget = false);
186 SDOperand getTargetConstantFP(double Val, MVT::ValueType VT) {
187 return getConstantFP(Val, VT, true);
189 SDOperand getTargetConstantFP(const APFloat& Val, MVT::ValueType VT) {
190 return getConstantFP(Val, VT, true);
192 SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
193 int offset = 0, bool isTargetGA = false);
194 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
196 return getGlobalAddress(GV, VT, offset, true);
198 SDOperand getFrameIndex(int FI, MVT::ValueType VT, bool isTarget = false);
199 SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT) {
200 return getFrameIndex(FI, VT, true);
202 SDOperand getJumpTable(int JTI, MVT::ValueType VT, bool isTarget = false);
203 SDOperand getTargetJumpTable(int JTI, MVT::ValueType VT) {
204 return getJumpTable(JTI, VT, true);
206 SDOperand getConstantPool(Constant *C, MVT::ValueType VT,
207 unsigned Align = 0, int Offs = 0, bool isT=false);
208 SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT,
209 unsigned Align = 0, int Offset = 0) {
210 return getConstantPool(C, VT, Align, Offset, true);
212 SDOperand getConstantPool(MachineConstantPoolValue *C, MVT::ValueType VT,
213 unsigned Align = 0, int Offs = 0, bool isT=false);
214 SDOperand getTargetConstantPool(MachineConstantPoolValue *C,
215 MVT::ValueType VT, unsigned Align = 0,
217 return getConstantPool(C, VT, Align, Offset, true);
219 SDOperand getBasicBlock(MachineBasicBlock *MBB);
220 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
221 SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
222 SDOperand getArgFlags(ISD::ArgFlagsTy Flags);
223 SDOperand getValueType(MVT::ValueType);
224 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
226 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
227 return getNode(ISD::CopyToReg, MVT::Other, Chain,
228 getRegister(Reg, N.getValueType()), N);
231 // This version of the getCopyToReg method takes an extra operand, which
232 // indicates that there is potentially an incoming flag value (if Flag is not
233 // null) and that there should be a flag result.
234 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
236 const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
237 SDOperand Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
238 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
241 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
242 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
244 const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
245 SDOperand Ops[] = { Chain, Reg, N, Flag };
246 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
249 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
250 const MVT::ValueType *VTs = getNodeValueTypes(VT, MVT::Other);
251 SDOperand Ops[] = { Chain, getRegister(Reg, VT) };
252 return getNode(ISD::CopyFromReg, VTs, 2, Ops, 2);
255 // This version of the getCopyFromReg method takes an extra operand, which
256 // indicates that there is potentially an incoming flag value (if Flag is not
257 // null) and that there should be a flag result.
258 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
260 const MVT::ValueType *VTs = getNodeValueTypes(VT, MVT::Other, MVT::Flag);
261 SDOperand Ops[] = { Chain, getRegister(Reg, VT), Flag };
262 return getNode(ISD::CopyFromReg, VTs, 3, Ops, Flag.Val ? 3 : 2);
265 SDOperand getCondCode(ISD::CondCode Cond);
267 /// getZeroExtendInReg - Return the expression required to zero extend the Op
268 /// value assuming it was the smaller SrcTy value.
269 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
271 /// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
272 /// a flag result (to ensure it's not CSE'd).
273 SDOperand getCALLSEQ_START(SDOperand Chain, SDOperand Op) {
274 const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
275 SDOperand Ops[] = { Chain, Op };
276 return getNode(ISD::CALLSEQ_START, VTs, 2, Ops, 2);
279 /// getCALLSEQ_END - Return a new CALLSEQ_END node, which always must have a
280 /// flag result (to ensure it's not CSE'd).
281 SDOperand getCALLSEQ_END(SDOperand Chain, SDOperand Op1, SDOperand Op2,
283 SDVTList NodeTys = getVTList(MVT::Other, MVT::Flag);
284 SmallVector<SDOperand, 4> Ops;
285 Ops.push_back(Chain);
288 Ops.push_back(InFlag);
289 return getNode(ISD::CALLSEQ_END, NodeTys, &Ops[0],
290 (unsigned)Ops.size() - (InFlag.Val == 0 ? 1 : 0));
293 /// getNode - Gets or creates the specified node.
295 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
296 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
297 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
298 SDOperand N1, SDOperand N2);
299 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
300 SDOperand N1, SDOperand N2, SDOperand N3);
301 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
302 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
303 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
304 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
306 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
307 SDOperandPtr Ops, unsigned NumOps);
308 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
309 SDOperandPtr Ops, unsigned NumOps);
310 SDOperand getNode(unsigned Opcode, const MVT::ValueType *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,
315 SDOperand N1, SDOperand N2);
316 SDOperand getNode(unsigned Opcode, SDVTList VTs,
317 SDOperand N1, SDOperand N2, SDOperand N3);
318 SDOperand getNode(unsigned Opcode, SDVTList VTs,
319 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
320 SDOperand getNode(unsigned Opcode, SDVTList VTs,
321 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
323 SDOperand getNode(unsigned Opcode, SDVTList VTs,
324 SDOperandPtr Ops, unsigned NumOps);
326 SDOperand getMemcpy(SDOperand Chain, SDOperand Dst, SDOperand Src,
327 SDOperand Size, unsigned Align,
329 const Value *DstSV, uint64_t DstSVOff,
330 const Value *SrcSV, uint64_t SrcSVOff);
332 SDOperand getMemmove(SDOperand Chain, SDOperand Dst, SDOperand Src,
333 SDOperand Size, unsigned Align,
334 const Value *DstSV, uint64_t DstOSVff,
335 const Value *SrcSV, uint64_t SrcSVOff);
337 SDOperand getMemset(SDOperand Chain, SDOperand Dst, SDOperand Src,
338 SDOperand Size, unsigned Align,
339 const Value *DstSV, uint64_t DstSVOff);
341 /// getSetCC - Helper function to make it easier to build SetCC's if you just
342 /// have an ISD::CondCode instead of an SDOperand.
344 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
345 ISD::CondCode Cond) {
346 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
349 /// getVSetCC - Helper function to make it easier to build VSetCC's nodes
350 /// if you just have an ISD::CondCode instead of an SDOperand.
352 SDOperand getVSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
353 ISD::CondCode Cond) {
354 return getNode(ISD::VSETCC, VT, LHS, RHS, getCondCode(Cond));
357 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
358 /// just have an ISD::CondCode instead of an SDOperand.
360 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
361 SDOperand True, SDOperand False, ISD::CondCode Cond) {
362 return getNode(ISD::SELECT_CC, True.getValueType(), LHS, RHS, True, False,
366 /// getVAArg - VAArg produces a result and token chain, and takes a pointer
367 /// and a source value as input.
368 SDOperand getVAArg(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
371 /// getAtomic - Gets a node for an atomic op, produces result and chain, takes
373 SDOperand getAtomic(unsigned Opcode, SDOperand Chain, SDOperand Ptr,
374 SDOperand Cmp, SDOperand Swp, MVT::ValueType VT);
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, MVT::ValueType VT);
381 /// getLoad - Loads are not normal binary operators: their result type is not
382 /// determined by their operands, and they produce a value AND a token chain.
384 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
385 const Value *SV, int SVOffset, bool isVolatile=false,
386 unsigned Alignment=0);
387 SDOperand getExtLoad(ISD::LoadExtType ExtType, MVT::ValueType VT,
388 SDOperand Chain, SDOperand Ptr, const Value *SV,
389 int SVOffset, MVT::ValueType EVT, bool isVolatile=false,
390 unsigned Alignment=0);
391 SDOperand getIndexedLoad(SDOperand OrigLoad, SDOperand Base,
392 SDOperand Offset, ISD::MemIndexedMode AM);
393 SDOperand getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
394 MVT::ValueType VT, SDOperand Chain,
395 SDOperand Ptr, SDOperand Offset,
396 const Value *SV, int SVOffset, MVT::ValueType EVT,
397 bool isVolatile=false, unsigned Alignment=0);
399 /// getStore - Helper function to build ISD::STORE nodes.
401 SDOperand getStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
402 const Value *SV, int SVOffset, bool isVolatile=false,
403 unsigned Alignment=0);
404 SDOperand getTruncStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
405 const Value *SV, int SVOffset, MVT::ValueType TVT,
406 bool isVolatile=false, unsigned Alignment=0);
407 SDOperand getIndexedStore(SDOperand OrigStoe, SDOperand Base,
408 SDOperand Offset, ISD::MemIndexedMode AM);
410 // getSrcValue - Construct a node to track a Value* through the backend.
411 SDOperand getSrcValue(const Value *v);
413 // getMemOperand - Construct a node to track a memory reference
414 // through the backend.
415 SDOperand getMemOperand(const MachineMemOperand &MO);
417 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
418 /// specified operands. If the resultant node already exists in the DAG,
419 /// this does not modify the specified node, instead it returns the node that
420 /// already exists. If the resultant node does not exist in the DAG, the
421 /// input node is returned. As a degenerate case, if you specify the same
422 /// input operands as the node already has, the input node is returned.
423 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
424 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
425 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
427 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
428 SDOperand Op3, SDOperand Op4);
429 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
430 SDOperand Op3, SDOperand Op4, SDOperand Op5);
431 SDOperand UpdateNodeOperands(SDOperand N, SDOperandPtr Ops, unsigned NumOps);
433 /// SelectNodeTo - These are used for target selectors to *mutate* the
434 /// specified node to have the specified return type, Target opcode, and
435 /// operands. Note that target opcodes are stored as
436 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
437 /// of the resultant node is returned.
438 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
439 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
441 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
442 SDOperand Op1, SDOperand Op2);
443 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
444 SDOperand Op1, SDOperand Op2, SDOperand Op3);
445 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
446 SDOperandPtr Ops, unsigned NumOps);
447 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
448 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
449 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
450 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
454 /// getTargetNode - These are used for target selectors to create a new node
455 /// with specified return type(s), target opcode, and operands.
457 /// Note that getTargetNode returns the resultant node. If there is already a
458 /// node of the specified opcode and operands, it returns that node instead of
460 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT);
461 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
463 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
464 SDOperand Op1, SDOperand Op2);
465 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
466 SDOperand Op1, SDOperand Op2, SDOperand Op3);
467 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
468 SDOperandPtr Ops, unsigned NumOps);
469 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
471 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
472 MVT::ValueType VT2, SDOperand Op1);
473 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
474 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
475 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
476 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
478 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
480 SDOperandPtr Ops, unsigned NumOps);
481 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
482 MVT::ValueType VT2, MVT::ValueType VT3,
483 SDOperand Op1, SDOperand Op2);
484 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
485 MVT::ValueType VT2, MVT::ValueType VT3,
486 SDOperand Op1, SDOperand Op2, SDOperand Op3);
487 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
488 MVT::ValueType VT2, MVT::ValueType VT3,
489 SDOperandPtr Ops, unsigned NumOps);
490 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
491 MVT::ValueType VT2, MVT::ValueType VT3,
493 SDOperandPtr Ops, unsigned NumOps);
494 SDNode *getTargetNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
495 SDOperandPtr Ops, unsigned NumOps);
497 /// getNodeIfExists - Get the specified node if it's already available, or
498 /// else return NULL.
499 SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTs,
500 SDOperandPtr Ops, unsigned NumOps);
502 /// DAGUpdateListener - Clients of various APIs that cause global effects on
503 /// the DAG can optionally implement this interface. This allows the clients
504 /// to handle the various sorts of updates that happen.
505 class DAGUpdateListener {
507 virtual ~DAGUpdateListener();
508 virtual void NodeDeleted(SDNode *N) = 0;
509 virtual void NodeUpdated(SDNode *N) = 0;
512 /// RemoveDeadNode - Remove the specified node from the system. If any of its
513 /// operands then becomes dead, remove them as well. Inform UpdateListener
514 /// for each node deleted.
515 void RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener = 0);
517 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
518 /// This can cause recursive merging of nodes in the DAG. Use the first
519 /// version if 'From' is known to have a single result, use the second
520 /// if you have two nodes with identical results, use the third otherwise.
522 /// These methods all take an optional UpdateListener, which (if not null) is
523 /// informed about nodes that are deleted and modified due to recursive
524 /// changes in the dag.
526 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
527 DAGUpdateListener *UpdateListener = 0);
528 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
529 DAGUpdateListener *UpdateListener = 0);
530 void ReplaceAllUsesWith(SDNode *From, SDOperandPtr To,
531 DAGUpdateListener *UpdateListener = 0);
533 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
534 /// uses of other values produced by From.Val alone.
535 void ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
536 DAGUpdateListener *UpdateListener = 0);
538 /// AssignNodeIds - Assign a unique node id for each node in the DAG based on
539 /// their allnodes order. It returns the maximum id.
540 unsigned AssignNodeIds();
542 /// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
543 /// based on their topological order. It returns the maximum id and a vector
544 /// of the SDNodes* in assigned order by reference.
545 unsigned AssignTopologicalOrder(std::vector<SDNode*> &TopOrder);
547 /// isCommutativeBinOp - Returns true if the opcode is a commutative binary
549 static bool isCommutativeBinOp(unsigned Opcode) {
550 // FIXME: This should get its info from the td file, so that we can include
565 case ISD::ADDE: return true;
566 default: return false;
572 /// CreateStackTemporary - Create a stack temporary, suitable for holding the
573 /// specified value type.
574 SDOperand CreateStackTemporary(MVT::ValueType VT);
576 /// FoldSetCC - Constant fold a setcc to true or false.
577 SDOperand FoldSetCC(MVT::ValueType VT, SDOperand N1,
578 SDOperand N2, ISD::CondCode Cond);
580 /// SignBitIsZero - Return true if the sign bit of Op is known to be zero. We
581 /// use this predicate to simplify operations downstream.
582 bool SignBitIsZero(SDOperand Op, unsigned Depth = 0) const;
584 /// MaskedValueIsZero - Return true if 'Op & Mask' is known to be zero. We
585 /// use this predicate to simplify operations downstream. Op and Mask are
586 /// known to be the same type.
587 bool MaskedValueIsZero(SDOperand Op, const APInt &Mask, unsigned Depth = 0)
590 /// ComputeMaskedBits - Determine which of the bits specified in Mask are
591 /// known to be either zero or one and return them in the KnownZero/KnownOne
592 /// bitsets. This code only analyzes bits in Mask, in order to short-circuit
593 /// processing. Targets can implement the computeMaskedBitsForTargetNode
594 /// method in the TargetLowering class to allow target nodes to be understood.
595 void ComputeMaskedBits(SDOperand Op, const APInt &Mask, APInt &KnownZero,
596 APInt &KnownOne, unsigned Depth = 0) const;
598 /// ComputeNumSignBits - Return the number of times the sign bit of the
599 /// register is replicated into the other bits. We know that at least 1 bit
600 /// is always equal to the sign bit (itself), but other cases can give us
601 /// information. For example, immediately after an "SRA X, 2", we know that
602 /// the top 3 bits are all equal to each other, so we return 3. Targets can
603 /// implement the ComputeNumSignBitsForTarget method in the TargetLowering
604 /// class to allow target nodes to be understood.
605 unsigned ComputeNumSignBits(SDOperand Op, unsigned Depth = 0) const;
607 /// isVerifiedDebugInfoDesc - Returns true if the specified SDOperand has
608 /// been verified as a debug information descriptor.
609 bool isVerifiedDebugInfoDesc(SDOperand Op) const;
611 /// getShuffleScalarElt - Returns the scalar element that will make up the ith
612 /// element of the result of the vector shuffle.
613 SDOperand getShuffleScalarElt(const SDNode *N, unsigned Idx);
616 void RemoveNodeFromCSEMaps(SDNode *N);
617 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
618 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op, void *&InsertPos);
619 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2,
621 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperandPtr Ops, unsigned NumOps,
624 void DeleteNodeNotInCSEMaps(SDNode *N);
626 // List of non-single value types.
627 std::list<std::vector<MVT::ValueType> > VTList;
629 // Maps to auto-CSE operations.
630 std::vector<CondCodeSDNode*> CondCodeNodes;
632 std::vector<SDNode*> ValueTypeNodes;
633 std::map<MVT::ValueType, SDNode*> ExtendedValueTypeNodes;
634 std::map<std::string, SDNode*> ExternalSymbols;
635 std::map<std::string, SDNode*> TargetExternalSymbols;
636 std::map<std::string, StringSDNode*> StringNodes;
639 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
640 typedef SelectionDAG::allnodes_iterator nodes_iterator;
641 static nodes_iterator nodes_begin(SelectionDAG *G) {
642 return G->allnodes_begin();
644 static nodes_iterator nodes_end(SelectionDAG *G) {
645 return G->allnodes_end();
649 } // end namespace llvm