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"
31 class MachineModuleInfo;
32 class MachineFunction;
33 class MachineConstantPoolValue;
35 /// SelectionDAG class - This is used to represent a portion of an LLVM function
36 /// in a low-level Data Dependence DAG representation suitable for instruction
37 /// selection. This DAG is constructed as the first step of instruction
38 /// selection in order to allow implementation of machine specific optimizations
39 /// and code simplifications.
41 /// The representation used by the SelectionDAG is a target-independent
42 /// representation, which has some similarities to the GCC RTL representation,
43 /// but is significantly more simple, powerful, and is a graph form instead of a
49 MachineModuleInfo *MMI;
51 /// Root - The root of the entire DAG. EntryNode - The starting token.
52 SDOperand Root, EntryNode;
54 /// AllNodes - A linked list of nodes in the current DAG.
55 ilist<SDNode> AllNodes;
57 /// CSEMap - This structure is used to memoize nodes, automatically performing
58 /// CSE with existing nodes with a duplicate is requested.
59 FoldingSet<SDNode> CSEMap;
62 SelectionDAG(TargetLowering &tli, MachineFunction &mf, MachineModuleInfo *mmi)
63 : TLI(tli), MF(mf), MMI(mmi) {
64 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
68 MachineFunction &getMachineFunction() const { return MF; }
69 const TargetMachine &getTarget() const;
70 TargetLowering &getTargetLoweringInfo() const { return TLI; }
71 MachineModuleInfo *getMachineModuleInfo() const { return MMI; }
73 /// viewGraph - Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
78 std::map<const SDNode *, std::string> NodeGraphAttrs;
81 /// clearGraphAttrs - Clear all previously defined node graph attributes.
82 /// Intended to be used from a debugging tool (eg. gdb).
83 void clearGraphAttrs();
85 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
87 void setGraphAttrs(const SDNode *N, const char *Attrs);
89 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
90 /// Used from getNodeAttributes.
91 const std::string getGraphAttrs(const SDNode *N) const;
93 /// setGraphColor - Convenience for setting node color attribute.
95 void setGraphColor(const SDNode *N, const char *Color);
97 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
98 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
99 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
100 typedef ilist<SDNode>::iterator allnodes_iterator;
101 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
102 allnodes_iterator allnodes_end() { return AllNodes.end(); }
104 /// getRoot - Return the root tag of the SelectionDAG.
106 const SDOperand &getRoot() const { return Root; }
108 /// getEntryNode - Return the token chain corresponding to the entry of the
110 const SDOperand &getEntryNode() const { return EntryNode; }
112 /// setRoot - Set the current root tag of the SelectionDAG.
114 const SDOperand &setRoot(SDOperand N) { return Root = N; }
116 /// Combine - This iterates over the nodes in the SelectionDAG, folding
117 /// certain types of nodes together, or eliminating superfluous nodes. When
118 /// the AfterLegalize argument is set to 'true', Combine takes care not to
119 /// generate any nodes that will be illegal on the target.
120 void Combine(bool AfterLegalize, AliasAnalysis &AA);
122 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
123 /// only uses types natively supported by the target.
125 /// Note that this is an involved process that may invalidate pointers into
127 void LegalizeTypes();
129 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
130 /// compatible with the target instruction selector, as indicated by the
131 /// TargetLowering object.
133 /// Note that this is an involved process that may invalidate pointers into
137 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
139 void RemoveDeadNodes();
141 /// DeleteNode - Remove the specified node from the system. This node must
142 /// have no referrers.
143 void DeleteNode(SDNode *N);
145 /// getVTList - Return an SDVTList that represents the list of values
147 SDVTList getVTList(MVT::ValueType VT);
148 SDVTList getVTList(MVT::ValueType VT1, MVT::ValueType VT2);
149 SDVTList getVTList(MVT::ValueType VT1, MVT::ValueType VT2,MVT::ValueType VT3);
150 SDVTList getVTList(const MVT::ValueType *VTs, unsigned NumVTs);
152 /// getNodeValueTypes - These are obsolete, use getVTList instead.
153 const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT) {
154 return getVTList(VT).VTs;
156 const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1,
157 MVT::ValueType VT2) {
158 return getVTList(VT1, VT2).VTs;
160 const MVT::ValueType *getNodeValueTypes(MVT::ValueType VT1,MVT::ValueType VT2,
161 MVT::ValueType VT3) {
162 return getVTList(VT1, VT2, VT3).VTs;
164 const MVT::ValueType *getNodeValueTypes(std::vector<MVT::ValueType> &vtList) {
165 return getVTList(&vtList[0], (unsigned)vtList.size()).VTs;
169 //===--------------------------------------------------------------------===//
170 // Node creation methods.
172 SDOperand getString(const std::string &Val);
173 SDOperand getConstant(uint64_t Val, MVT::ValueType VT, bool isTarget = false);
174 SDOperand getConstant(const APInt &Val, MVT::ValueType VT, bool isTarget = false);
175 SDOperand getIntPtrConstant(uint64_t Val, bool isTarget = false);
176 SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT) {
177 return getConstant(Val, VT, true);
179 SDOperand getTargetConstant(const APInt &Val, MVT::ValueType VT) {
180 return getConstant(Val, VT, true);
182 SDOperand getConstantFP(double Val, MVT::ValueType VT, bool isTarget = false);
183 SDOperand getConstantFP(const APFloat& Val, MVT::ValueType VT,
184 bool isTarget = false);
185 SDOperand getTargetConstantFP(double Val, MVT::ValueType VT) {
186 return getConstantFP(Val, VT, true);
188 SDOperand getTargetConstantFP(const APFloat& Val, MVT::ValueType VT) {
189 return getConstantFP(Val, VT, true);
191 SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
192 int offset = 0, bool isTargetGA = false);
193 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT,
195 return getGlobalAddress(GV, VT, offset, true);
197 SDOperand getFrameIndex(int FI, MVT::ValueType VT, bool isTarget = false);
198 SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT) {
199 return getFrameIndex(FI, VT, true);
201 SDOperand getJumpTable(int JTI, MVT::ValueType VT, bool isTarget = false);
202 SDOperand getTargetJumpTable(int JTI, MVT::ValueType VT) {
203 return getJumpTable(JTI, VT, true);
205 SDOperand getConstantPool(Constant *C, MVT::ValueType VT,
206 unsigned Align = 0, int Offs = 0, bool isT=false);
207 SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT,
208 unsigned Align = 0, int Offset = 0) {
209 return getConstantPool(C, VT, Align, Offset, true);
211 SDOperand getConstantPool(MachineConstantPoolValue *C, MVT::ValueType VT,
212 unsigned Align = 0, int Offs = 0, bool isT=false);
213 SDOperand getTargetConstantPool(MachineConstantPoolValue *C,
214 MVT::ValueType VT, unsigned Align = 0,
216 return getConstantPool(C, VT, Align, Offset, true);
218 SDOperand getBasicBlock(MachineBasicBlock *MBB);
219 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
220 SDOperand getTargetExternalSymbol(const char *Sym, MVT::ValueType VT);
221 SDOperand getArgFlags(ISD::ArgFlagsTy Flags);
222 SDOperand getValueType(MVT::ValueType);
223 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
225 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
226 return getNode(ISD::CopyToReg, MVT::Other, Chain,
227 getRegister(Reg, N.getValueType()), N);
230 // This version of the getCopyToReg method takes an extra operand, which
231 // indicates that there is potentially an incoming flag value (if Flag is not
232 // null) and that there should be a flag result.
233 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
235 const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
236 SDOperand Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
237 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
240 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
241 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
243 const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
244 SDOperand Ops[] = { Chain, Reg, N, Flag };
245 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
248 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
249 const MVT::ValueType *VTs = getNodeValueTypes(VT, MVT::Other);
250 SDOperand Ops[] = { Chain, getRegister(Reg, VT) };
251 return getNode(ISD::CopyFromReg, VTs, 2, Ops, 2);
254 // This version of the getCopyFromReg method takes an extra operand, which
255 // indicates that there is potentially an incoming flag value (if Flag is not
256 // null) and that there should be a flag result.
257 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
259 const MVT::ValueType *VTs = getNodeValueTypes(VT, MVT::Other, MVT::Flag);
260 SDOperand Ops[] = { Chain, getRegister(Reg, VT), Flag };
261 return getNode(ISD::CopyFromReg, VTs, 3, Ops, Flag.Val ? 3 : 2);
264 SDOperand getCondCode(ISD::CondCode Cond);
266 /// getZeroExtendInReg - Return the expression required to zero extend the Op
267 /// value assuming it was the smaller SrcTy value.
268 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
270 /// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
271 /// a flag result (to ensure it's not CSE'd).
272 SDOperand getCALLSEQ_START(SDOperand Chain, SDOperand Op) {
273 const MVT::ValueType *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
274 SDOperand Ops[] = { Chain, Op };
275 return getNode(ISD::CALLSEQ_START, VTs, 2, Ops, 2);
278 /// getCALLSEQ_END - Return a new CALLSEQ_END node, which always must have a
279 /// flag result (to ensure it's not CSE'd).
280 SDOperand getCALLSEQ_END(SDOperand Chain, SDOperand Op1, SDOperand Op2,
282 SDVTList NodeTys = getVTList(MVT::Other, MVT::Flag);
283 SmallVector<SDOperand, 4> Ops;
284 Ops.push_back(Chain);
287 Ops.push_back(InFlag);
288 return getNode(ISD::CALLSEQ_END, NodeTys, &Ops[0],
289 (unsigned)Ops.size() - (InFlag.Val == 0 ? 1 : 0));
292 /// getNode - Gets or creates the specified node.
294 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
295 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
296 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
297 SDOperand N1, SDOperand N2);
298 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
299 SDOperand N1, SDOperand N2, SDOperand N3);
300 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
301 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
302 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
303 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
305 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
306 SDOperandPtr Ops, unsigned NumOps);
307 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
308 SDOperandPtr Ops, unsigned NumOps);
309 SDOperand getNode(unsigned Opcode, const MVT::ValueType *VTs, unsigned NumVTs,
310 SDOperandPtr Ops, unsigned NumOps);
311 SDOperand getNode(unsigned Opcode, SDVTList VTs);
312 SDOperand getNode(unsigned Opcode, SDVTList VTs, SDOperand N);
313 SDOperand getNode(unsigned Opcode, SDVTList VTs,
314 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::ValueType 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::ValueType 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::ValueType 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, MVT::ValueType VT);
375 /// getAtomic - Gets a node for an atomic op, produces result and chain, takes
377 SDOperand getAtomic(unsigned Opcode, SDOperand Chain, SDOperand Ptr,
378 SDOperand Val, MVT::ValueType VT);
380 /// getLoad - Loads are not normal binary operators: their result type is not
381 /// determined by their operands, and they produce a value AND a token chain.
383 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
384 const Value *SV, int SVOffset, bool isVolatile=false,
385 unsigned Alignment=0);
386 SDOperand getExtLoad(ISD::LoadExtType ExtType, MVT::ValueType VT,
387 SDOperand Chain, SDOperand Ptr, const Value *SV,
388 int SVOffset, MVT::ValueType EVT, bool isVolatile=false,
389 unsigned Alignment=0);
390 SDOperand getIndexedLoad(SDOperand OrigLoad, SDOperand Base,
391 SDOperand Offset, ISD::MemIndexedMode AM);
392 SDOperand getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
393 MVT::ValueType VT, SDOperand Chain,
394 SDOperand Ptr, SDOperand Offset,
395 const Value *SV, int SVOffset, MVT::ValueType EVT,
396 bool isVolatile=false, unsigned Alignment=0);
398 /// getStore - Helper function to build ISD::STORE nodes.
400 SDOperand getStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
401 const Value *SV, int SVOffset, bool isVolatile=false,
402 unsigned Alignment=0);
403 SDOperand getTruncStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
404 const Value *SV, int SVOffset, MVT::ValueType TVT,
405 bool isVolatile=false, unsigned Alignment=0);
406 SDOperand getIndexedStore(SDOperand OrigStoe, SDOperand Base,
407 SDOperand Offset, ISD::MemIndexedMode AM);
409 // getSrcValue - Construct a node to track a Value* through the backend.
410 SDOperand getSrcValue(const Value *v);
412 // getMemOperand - Construct a node to track a memory reference
413 // through the backend.
414 SDOperand getMemOperand(const MachineMemOperand &MO);
416 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
417 /// specified operands. If the resultant node already exists in the DAG,
418 /// this does not modify the specified node, instead it returns the node that
419 /// already exists. If the resultant node does not exist in the DAG, the
420 /// input node is returned. As a degenerate case, if you specify the same
421 /// input operands as the node already has, the input node is returned.
422 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
423 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
424 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
426 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
427 SDOperand Op3, SDOperand Op4);
428 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
429 SDOperand Op3, SDOperand Op4, SDOperand Op5);
430 SDOperand UpdateNodeOperands(SDOperand N, SDOperandPtr Ops, unsigned NumOps);
432 /// SelectNodeTo - These are used for target selectors to *mutate* the
433 /// specified node to have the specified return type, Target opcode, and
434 /// operands. Note that target opcodes are stored as
435 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
436 /// of the resultant node is returned.
437 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
438 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
440 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
441 SDOperand Op1, SDOperand Op2);
442 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
443 SDOperand Op1, SDOperand Op2, SDOperand Op3);
444 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
445 SDOperandPtr Ops, unsigned NumOps);
446 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
447 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
448 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
449 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
453 /// getTargetNode - These are used for target selectors to create a new node
454 /// with specified return type(s), target opcode, and operands.
456 /// Note that getTargetNode returns the resultant node. If there is already a
457 /// node of the specified opcode and operands, it returns that node instead of
459 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT);
460 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
462 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
463 SDOperand Op1, SDOperand Op2);
464 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
465 SDOperand Op1, SDOperand Op2, SDOperand Op3);
466 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT,
467 SDOperandPtr Ops, unsigned NumOps);
468 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
470 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
471 MVT::ValueType VT2, SDOperand Op1);
472 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
473 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
474 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
475 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
477 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
479 SDOperandPtr Ops, unsigned NumOps);
480 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
481 MVT::ValueType VT2, MVT::ValueType VT3,
482 SDOperand Op1, SDOperand Op2);
483 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
484 MVT::ValueType VT2, MVT::ValueType VT3,
485 SDOperand Op1, SDOperand Op2, SDOperand Op3);
486 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
487 MVT::ValueType VT2, MVT::ValueType VT3,
488 SDOperandPtr Ops, unsigned NumOps);
489 SDNode *getTargetNode(unsigned Opcode, MVT::ValueType VT1,
490 MVT::ValueType VT2, MVT::ValueType VT3,
492 SDOperandPtr Ops, unsigned NumOps);
493 SDNode *getTargetNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
494 SDOperandPtr Ops, unsigned NumOps);
496 /// getNodeIfExists - Get the specified node if it's already available, or
497 /// else return NULL.
498 SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTs,
499 SDOperandPtr Ops, unsigned NumOps);
501 /// DAGUpdateListener - Clients of various APIs that cause global effects on
502 /// the DAG can optionally implement this interface. This allows the clients
503 /// to handle the various sorts of updates that happen.
504 class DAGUpdateListener {
506 virtual ~DAGUpdateListener();
507 virtual void NodeDeleted(SDNode *N) = 0;
508 virtual void NodeUpdated(SDNode *N) = 0;
511 /// RemoveDeadNode - Remove the specified node from the system. If any of its
512 /// operands then becomes dead, remove them as well. Inform UpdateListener
513 /// for each node deleted.
514 void RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener = 0);
516 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
517 /// This can cause recursive merging of nodes in the DAG. Use the first
518 /// version if 'From' is known to have a single result, use the second
519 /// if you have two nodes with identical results, use the third otherwise.
521 /// These methods all take an optional UpdateListener, which (if not null) is
522 /// informed about nodes that are deleted and modified due to recursive
523 /// changes in the dag.
525 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
526 DAGUpdateListener *UpdateListener = 0);
527 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
528 DAGUpdateListener *UpdateListener = 0);
529 void ReplaceAllUsesWith(SDNode *From, SDOperandPtr To,
530 DAGUpdateListener *UpdateListener = 0);
532 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
533 /// uses of other values produced by From.Val alone.
534 void ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
535 DAGUpdateListener *UpdateListener = 0);
537 /// AssignNodeIds - Assign a unique node id for each node in the DAG based on
538 /// their allnodes order. It returns the maximum id.
539 unsigned AssignNodeIds();
541 /// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
542 /// based on their topological order. It returns the maximum id and a vector
543 /// of the SDNodes* in assigned order by reference.
544 unsigned AssignTopologicalOrder(std::vector<SDNode*> &TopOrder);
546 /// isCommutativeBinOp - Returns true if the opcode is a commutative binary
548 static bool isCommutativeBinOp(unsigned Opcode) {
549 // FIXME: This should get its info from the td file, so that we can include
564 case ISD::ADDE: return true;
565 default: return false;
571 /// CreateStackTemporary - Create a stack temporary, suitable for holding the
572 /// specified value type.
573 SDOperand CreateStackTemporary(MVT::ValueType VT);
575 /// FoldSetCC - Constant fold a setcc to true or false.
576 SDOperand FoldSetCC(MVT::ValueType VT, SDOperand N1,
577 SDOperand N2, ISD::CondCode Cond);
579 /// SignBitIsZero - Return true if the sign bit of Op is known to be zero. We
580 /// use this predicate to simplify operations downstream.
581 bool SignBitIsZero(SDOperand Op, unsigned Depth = 0) const;
583 /// MaskedValueIsZero - Return true if 'Op & Mask' is known to be zero. We
584 /// use this predicate to simplify operations downstream. Op and Mask are
585 /// known to be the same type.
586 bool MaskedValueIsZero(SDOperand Op, const APInt &Mask, unsigned Depth = 0)
589 /// ComputeMaskedBits - Determine which of the bits specified in Mask are
590 /// known to be either zero or one and return them in the KnownZero/KnownOne
591 /// bitsets. This code only analyzes bits in Mask, in order to short-circuit
592 /// processing. Targets can implement the computeMaskedBitsForTargetNode
593 /// method in the TargetLowering class to allow target nodes to be understood.
594 void ComputeMaskedBits(SDOperand Op, const APInt &Mask, APInt &KnownZero,
595 APInt &KnownOne, unsigned Depth = 0) const;
597 /// ComputeNumSignBits - Return the number of times the sign bit of the
598 /// register is replicated into the other bits. We know that at least 1 bit
599 /// is always equal to the sign bit (itself), but other cases can give us
600 /// information. For example, immediately after an "SRA X, 2", we know that
601 /// the top 3 bits are all equal to each other, so we return 3. Targets can
602 /// implement the ComputeNumSignBitsForTarget method in the TargetLowering
603 /// class to allow target nodes to be understood.
604 unsigned ComputeNumSignBits(SDOperand Op, unsigned Depth = 0) const;
606 /// isVerifiedDebugInfoDesc - Returns true if the specified SDOperand has
607 /// been verified as a debug information descriptor.
608 bool isVerifiedDebugInfoDesc(SDOperand Op) const;
610 /// getShuffleScalarElt - Returns the scalar element that will make up the ith
611 /// element of the result of the vector shuffle.
612 SDOperand getShuffleScalarElt(const SDNode *N, unsigned Idx);
615 void RemoveNodeFromCSEMaps(SDNode *N);
616 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
617 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op, void *&InsertPos);
618 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2,
620 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperandPtr Ops, unsigned NumOps,
623 void DeleteNodeNotInCSEMaps(SDNode *N);
625 // List of non-single value types.
626 std::list<std::vector<MVT::ValueType> > VTList;
628 // Maps to auto-CSE operations.
629 std::vector<CondCodeSDNode*> CondCodeNodes;
631 std::vector<SDNode*> ValueTypeNodes;
632 std::map<MVT::ValueType, SDNode*> ExtendedValueTypeNodes;
633 std::map<std::string, SDNode*> ExternalSymbols;
634 std::map<std::string, SDNode*> TargetExternalSymbols;
635 std::map<std::string, StringSDNode*> StringNodes;
638 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
639 typedef SelectionDAG::allnodes_iterator nodes_iterator;
640 static nodes_iterator nodes_begin(SelectionDAG *G) {
641 return G->allnodes_begin();
643 static nodes_iterator nodes_end(SelectionDAG *G) {
644 return G->allnodes_end();
648 } // end namespace llvm