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;
34 class FunctionLoweringInfo;
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 FunctionLoweringInfo &FLI;
51 MachineModuleInfo *MMI;
53 /// Root - The root of the entire DAG. EntryNode - The starting token.
54 SDOperand Root, EntryNode;
56 /// AllNodes - A linked list of nodes in the current DAG.
57 ilist<SDNode> AllNodes;
59 /// CSEMap - This structure is used to memoize nodes, automatically performing
60 /// CSE with existing nodes with a duplicate is requested.
61 FoldingSet<SDNode> CSEMap;
64 SelectionDAG(TargetLowering &tli, MachineFunction &mf,
65 FunctionLoweringInfo &fli, MachineModuleInfo *mmi)
66 : TLI(tli), MF(mf), FLI(fli), MMI(mmi) {
67 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
71 MachineFunction &getMachineFunction() const { return MF; }
72 const TargetMachine &getTarget() const;
73 TargetLowering &getTargetLoweringInfo() const { return TLI; }
74 FunctionLoweringInfo &getFunctionLoweringInfo() const { return FLI; }
75 MachineModuleInfo *getMachineModuleInfo() const { return MMI; }
77 /// viewGraph - Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
82 std::map<const SDNode *, std::string> NodeGraphAttrs;
85 /// clearGraphAttrs - Clear all previously defined node graph attributes.
86 /// Intended to be used from a debugging tool (eg. gdb).
87 void clearGraphAttrs();
89 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
91 void setGraphAttrs(const SDNode *N, const char *Attrs);
93 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
94 /// Used from getNodeAttributes.
95 const std::string getGraphAttrs(const SDNode *N) const;
97 /// setGraphColor - Convenience for setting node color attribute.
99 void setGraphColor(const SDNode *N, const char *Color);
101 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
102 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
103 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
104 typedef ilist<SDNode>::iterator allnodes_iterator;
105 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
106 allnodes_iterator allnodes_end() { return AllNodes.end(); }
107 ilist<SDNode>::size_type allnodes_size() const { return AllNodes.size(); }
109 /// getRoot - Return the root tag of the SelectionDAG.
111 const SDOperand &getRoot() const { return Root; }
113 /// getEntryNode - Return the token chain corresponding to the entry of the
115 const SDOperand &getEntryNode() const { return EntryNode; }
117 /// setRoot - Set the current root tag of the SelectionDAG.
119 const SDOperand &setRoot(SDOperand N) { return Root = N; }
121 /// Combine - This iterates over the nodes in the SelectionDAG, folding
122 /// certain types of nodes together, or eliminating superfluous nodes. When
123 /// the AfterLegalize argument is set to 'true', Combine takes care not to
124 /// generate any nodes that will be illegal on the target.
125 void Combine(bool AfterLegalize, AliasAnalysis &AA);
127 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
128 /// only uses types natively supported by the target.
130 /// Note that this is an involved process that may invalidate pointers into
132 void LegalizeTypes();
134 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
135 /// compatible with the target instruction selector, as indicated by the
136 /// TargetLowering object.
138 /// Note that this is an involved process that may invalidate pointers into
142 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
144 void RemoveDeadNodes();
146 /// DeleteNode - Remove the specified node from the system. This node must
147 /// have no referrers.
148 void DeleteNode(SDNode *N);
150 /// getVTList - Return an SDVTList that represents the list of values
152 SDVTList getVTList(MVT VT);
153 SDVTList getVTList(MVT VT1, MVT VT2);
154 SDVTList getVTList(MVT VT1, MVT VT2, MVT VT3);
155 SDVTList getVTList(const MVT *VTs, unsigned NumVTs);
157 /// getNodeValueTypes - These are obsolete, use getVTList instead.
158 const MVT *getNodeValueTypes(MVT VT) {
159 return getVTList(VT).VTs;
161 const MVT *getNodeValueTypes(MVT VT1, MVT VT2) {
162 return getVTList(VT1, VT2).VTs;
164 const MVT *getNodeValueTypes(MVT VT1, MVT VT2, MVT VT3) {
165 return getVTList(VT1, VT2, VT3).VTs;
167 const MVT *getNodeValueTypes(std::vector<MVT> &vtList) {
168 return getVTList(&vtList[0], (unsigned)vtList.size()).VTs;
172 //===--------------------------------------------------------------------===//
173 // Node creation methods.
175 SDOperand getString(const std::string &Val);
176 SDOperand getConstant(uint64_t Val, MVT VT, bool isTarget = false);
177 SDOperand getConstant(const APInt &Val, MVT VT, bool isTarget = false);
178 SDOperand getIntPtrConstant(uint64_t Val, bool isTarget = false);
179 SDOperand getTargetConstant(uint64_t Val, MVT VT) {
180 return getConstant(Val, VT, true);
182 SDOperand getTargetConstant(const APInt &Val, MVT VT) {
183 return getConstant(Val, VT, true);
185 SDOperand getConstantFP(double Val, MVT VT, bool isTarget = false);
186 SDOperand getConstantFP(const APFloat& Val, MVT VT, bool isTarget = false);
187 SDOperand getTargetConstantFP(double Val, MVT VT) {
188 return getConstantFP(Val, VT, true);
190 SDOperand getTargetConstantFP(const APFloat& Val, MVT VT) {
191 return getConstantFP(Val, VT, true);
193 SDOperand getGlobalAddress(const GlobalValue *GV, MVT VT,
194 int offset = 0, bool isTargetGA = false);
195 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT VT,
197 return getGlobalAddress(GV, VT, offset, true);
199 SDOperand getFrameIndex(int FI, MVT VT, bool isTarget = false);
200 SDOperand getTargetFrameIndex(int FI, MVT VT) {
201 return getFrameIndex(FI, VT, true);
203 SDOperand getJumpTable(int JTI, MVT VT, bool isTarget = false);
204 SDOperand getTargetJumpTable(int JTI, MVT VT) {
205 return getJumpTable(JTI, VT, true);
207 SDOperand getConstantPool(Constant *C, MVT VT,
208 unsigned Align = 0, int Offs = 0, bool isT=false);
209 SDOperand getTargetConstantPool(Constant *C, MVT VT,
210 unsigned Align = 0, int Offset = 0) {
211 return getConstantPool(C, VT, Align, Offset, true);
213 SDOperand getConstantPool(MachineConstantPoolValue *C, MVT VT,
214 unsigned Align = 0, int Offs = 0, bool isT=false);
215 SDOperand getTargetConstantPool(MachineConstantPoolValue *C,
216 MVT VT, unsigned Align = 0,
218 return getConstantPool(C, VT, Align, Offset, true);
220 SDOperand getBasicBlock(MachineBasicBlock *MBB);
221 SDOperand getExternalSymbol(const char *Sym, MVT VT);
222 SDOperand getTargetExternalSymbol(const char *Sym, MVT VT);
223 SDOperand getArgFlags(ISD::ArgFlagsTy Flags);
224 SDOperand getValueType(MVT);
225 SDOperand getRegister(unsigned Reg, MVT VT);
227 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
228 return getNode(ISD::CopyToReg, MVT::Other, Chain,
229 getRegister(Reg, N.getValueType()), N);
232 // This version of the getCopyToReg method takes an extra operand, which
233 // indicates that there is potentially an incoming flag value (if Flag is not
234 // null) and that there should be a flag result.
235 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
237 const MVT *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
238 SDOperand Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
239 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
242 // Similar to last getCopyToReg() except parameter Reg is a SDOperand
243 SDOperand getCopyToReg(SDOperand Chain, SDOperand Reg, SDOperand N,
245 const MVT *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
246 SDOperand Ops[] = { Chain, Reg, N, Flag };
247 return getNode(ISD::CopyToReg, VTs, 2, Ops, Flag.Val ? 4 : 3);
250 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT VT) {
251 const MVT *VTs = getNodeValueTypes(VT, MVT::Other);
252 SDOperand Ops[] = { Chain, getRegister(Reg, VT) };
253 return getNode(ISD::CopyFromReg, VTs, 2, Ops, 2);
256 // This version of the getCopyFromReg method takes an extra operand, which
257 // indicates that there is potentially an incoming flag value (if Flag is not
258 // null) and that there should be a flag result.
259 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT VT,
261 const MVT *VTs = getNodeValueTypes(VT, MVT::Other, MVT::Flag);
262 SDOperand Ops[] = { Chain, getRegister(Reg, VT), Flag };
263 return getNode(ISD::CopyFromReg, VTs, 3, Ops, Flag.Val ? 3 : 2);
266 SDOperand getCondCode(ISD::CondCode Cond);
268 /// getZeroExtendInReg - Return the expression required to zero extend the Op
269 /// value assuming it was the smaller SrcTy value.
270 SDOperand getZeroExtendInReg(SDOperand Op, MVT SrcTy);
272 /// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
273 /// a flag result (to ensure it's not CSE'd).
274 SDOperand getCALLSEQ_START(SDOperand Chain, SDOperand Op) {
275 const MVT *VTs = getNodeValueTypes(MVT::Other, MVT::Flag);
276 SDOperand Ops[] = { Chain, Op };
277 return getNode(ISD::CALLSEQ_START, VTs, 2, Ops, 2);
280 /// getCALLSEQ_END - Return a new CALLSEQ_END node, which always must have a
281 /// flag result (to ensure it's not CSE'd).
282 SDOperand getCALLSEQ_END(SDOperand Chain, SDOperand Op1, SDOperand Op2,
284 SDVTList NodeTys = getVTList(MVT::Other, MVT::Flag);
285 SmallVector<SDOperand, 4> Ops;
286 Ops.push_back(Chain);
289 Ops.push_back(InFlag);
290 return getNode(ISD::CALLSEQ_END, NodeTys, &Ops[0],
291 (unsigned)Ops.size() - (InFlag.Val == 0 ? 1 : 0));
294 /// getNode - Gets or creates the specified node.
296 SDOperand getNode(unsigned Opcode, MVT VT);
297 SDOperand getNode(unsigned Opcode, MVT VT, SDOperand N);
298 SDOperand getNode(unsigned Opcode, MVT VT, SDOperand N1, SDOperand N2);
299 SDOperand getNode(unsigned Opcode, MVT VT,
300 SDOperand N1, SDOperand N2, SDOperand N3);
301 SDOperand getNode(unsigned Opcode, MVT VT,
302 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
303 SDOperand getNode(unsigned Opcode, MVT VT,
304 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
306 SDOperand getNode(unsigned Opcode, MVT VT, SDOperandPtr Ops, unsigned NumOps);
307 SDOperand getNode(unsigned Opcode, std::vector<MVT> &ResultTys,
308 SDOperandPtr Ops, unsigned NumOps);
309 SDOperand getNode(unsigned Opcode, const MVT *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, SDOperand N1, SDOperand N2);
314 SDOperand getNode(unsigned Opcode, SDVTList VTs,
315 SDOperand N1, SDOperand N2, SDOperand N3);
316 SDOperand getNode(unsigned Opcode, SDVTList VTs,
317 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
318 SDOperand getNode(unsigned Opcode, SDVTList VTs,
319 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
321 SDOperand getNode(unsigned Opcode, SDVTList VTs,
322 SDOperandPtr Ops, unsigned NumOps);
324 SDOperand getMemcpy(SDOperand Chain, SDOperand Dst, SDOperand Src,
325 SDOperand Size, unsigned Align,
327 const Value *DstSV, uint64_t DstSVOff,
328 const Value *SrcSV, uint64_t SrcSVOff);
330 SDOperand getMemmove(SDOperand Chain, SDOperand Dst, SDOperand Src,
331 SDOperand Size, unsigned Align,
332 const Value *DstSV, uint64_t DstOSVff,
333 const Value *SrcSV, uint64_t SrcSVOff);
335 SDOperand getMemset(SDOperand Chain, SDOperand Dst, SDOperand Src,
336 SDOperand Size, unsigned Align,
337 const Value *DstSV, uint64_t DstSVOff);
339 /// getSetCC - Helper function to make it easier to build SetCC's if you just
340 /// have an ISD::CondCode instead of an SDOperand.
342 SDOperand getSetCC(MVT VT, SDOperand LHS, SDOperand RHS,
343 ISD::CondCode Cond) {
344 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
347 /// getVSetCC - Helper function to make it easier to build VSetCC's nodes
348 /// if you just have an ISD::CondCode instead of an SDOperand.
350 SDOperand getVSetCC(MVT VT, SDOperand LHS, SDOperand RHS,
351 ISD::CondCode Cond) {
352 return getNode(ISD::VSETCC, VT, LHS, RHS, getCondCode(Cond));
355 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
356 /// just have an ISD::CondCode instead of an SDOperand.
358 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
359 SDOperand True, SDOperand False, ISD::CondCode Cond) {
360 return getNode(ISD::SELECT_CC, True.getValueType(), LHS, RHS, True, False,
364 /// getVAArg - VAArg produces a result and token chain, and takes a pointer
365 /// and a source value as input.
366 SDOperand getVAArg(MVT VT, SDOperand Chain, SDOperand Ptr,
369 /// getAtomic - Gets a node for an atomic op, produces result and chain, takes
371 SDOperand getAtomic(unsigned Opcode, SDOperand Chain, SDOperand Ptr,
372 SDOperand Cmp, SDOperand Swp, MVT VT);
374 /// getAtomic - Gets a node for an atomic op, produces result and chain, takes
376 SDOperand getAtomic(unsigned Opcode, SDOperand Chain, SDOperand Ptr,
377 SDOperand Val, MVT VT);
379 /// getLoad - Loads are not normal binary operators: their result type is not
380 /// determined by their operands, and they produce a value AND a token chain.
382 SDOperand getLoad(MVT VT, SDOperand Chain, SDOperand Ptr,
383 const Value *SV, int SVOffset, bool isVolatile=false,
384 unsigned Alignment=0);
385 SDOperand getExtLoad(ISD::LoadExtType ExtType, MVT VT,
386 SDOperand Chain, SDOperand Ptr, const Value *SV,
387 int SVOffset, MVT EVT, bool isVolatile=false,
388 unsigned Alignment=0);
389 SDOperand getIndexedLoad(SDOperand OrigLoad, SDOperand Base,
390 SDOperand Offset, ISD::MemIndexedMode AM);
391 SDOperand getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
392 MVT VT, SDOperand Chain,
393 SDOperand Ptr, SDOperand Offset,
394 const Value *SV, int SVOffset, MVT EVT,
395 bool isVolatile=false, unsigned Alignment=0);
397 /// getStore - Helper function to build ISD::STORE nodes.
399 SDOperand getStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
400 const Value *SV, int SVOffset, bool isVolatile=false,
401 unsigned Alignment=0);
402 SDOperand getTruncStore(SDOperand Chain, SDOperand Val, SDOperand Ptr,
403 const Value *SV, int SVOffset, MVT TVT,
404 bool isVolatile=false, unsigned Alignment=0);
405 SDOperand getIndexedStore(SDOperand OrigStoe, SDOperand Base,
406 SDOperand Offset, ISD::MemIndexedMode AM);
408 // getSrcValue - Construct a node to track a Value* through the backend.
409 SDOperand getSrcValue(const Value *v);
411 // getMemOperand - Construct a node to track a memory reference
412 // through the backend.
413 SDOperand getMemOperand(const MachineMemOperand &MO);
415 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
416 /// specified operands. If the resultant node already exists in the DAG,
417 /// this does not modify the specified node, instead it returns the node that
418 /// already exists. If the resultant node does not exist in the DAG, the
419 /// input node is returned. As a degenerate case, if you specify the same
420 /// input operands as the node already has, the input node is returned.
421 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op);
422 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2);
423 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
425 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
426 SDOperand Op3, SDOperand Op4);
427 SDOperand UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
428 SDOperand Op3, SDOperand Op4, SDOperand Op5);
429 SDOperand UpdateNodeOperands(SDOperand N, SDOperandPtr Ops, unsigned NumOps);
431 /// SelectNodeTo - These are used for target selectors to *mutate* the
432 /// specified node to have the specified return type, Target opcode, and
433 /// operands. Note that target opcodes are stored as
434 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field. The 0th value
435 /// of the resultant node is returned.
436 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT);
437 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT, SDOperand Op1);
438 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT,
439 SDOperand Op1, SDOperand Op2);
440 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT,
441 SDOperand Op1, SDOperand Op2, SDOperand Op3);
442 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT,
443 SDOperandPtr Ops, unsigned NumOps);
444 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT1,
445 MVT VT2, SDOperand Op1, SDOperand Op2);
446 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT VT1,
447 MVT VT2, SDOperand Op1, SDOperand Op2, SDOperand Op3);
450 /// getTargetNode - These are used for target selectors to create a new node
451 /// with specified return type(s), target opcode, and operands.
453 /// Note that getTargetNode returns the resultant node. If there is already a
454 /// node of the specified opcode and operands, it returns that node instead of
456 SDNode *getTargetNode(unsigned Opcode, MVT VT);
457 SDNode *getTargetNode(unsigned Opcode, MVT VT, SDOperand Op1);
458 SDNode *getTargetNode(unsigned Opcode, MVT VT, SDOperand Op1, SDOperand Op2);
459 SDNode *getTargetNode(unsigned Opcode, MVT VT,
460 SDOperand Op1, SDOperand Op2, SDOperand Op3);
461 SDNode *getTargetNode(unsigned Opcode, MVT VT,
462 SDOperandPtr Ops, unsigned NumOps);
463 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2);
464 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, SDOperand Op1);
465 SDNode *getTargetNode(unsigned Opcode, MVT VT1,
466 MVT VT2, SDOperand Op1, SDOperand Op2);
467 SDNode *getTargetNode(unsigned Opcode, MVT VT1,
468 MVT VT2, SDOperand Op1, SDOperand Op2, SDOperand Op3);
469 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2,
470 SDOperandPtr Ops, unsigned NumOps);
471 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3,
472 SDOperand Op1, SDOperand Op2);
473 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3,
474 SDOperand Op1, SDOperand Op2, SDOperand Op3);
475 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3,
476 SDOperandPtr Ops, unsigned NumOps);
477 SDNode *getTargetNode(unsigned Opcode, MVT VT1, MVT VT2, MVT VT3, MVT VT4,
478 SDOperandPtr Ops, unsigned NumOps);
479 SDNode *getTargetNode(unsigned Opcode, std::vector<MVT> &ResultTys,
480 SDOperandPtr Ops, unsigned NumOps);
482 /// getNodeIfExists - Get the specified node if it's already available, or
483 /// else return NULL.
484 SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTs,
485 SDOperandPtr Ops, unsigned NumOps);
487 /// DAGUpdateListener - Clients of various APIs that cause global effects on
488 /// the DAG can optionally implement this interface. This allows the clients
489 /// to handle the various sorts of updates that happen.
490 class DAGUpdateListener {
492 virtual ~DAGUpdateListener();
494 /// NodeDeleted - The node N that was deleted and, if E is not null, an
495 /// equivalent node E that replaced it.
496 virtual void NodeDeleted(SDNode *N, SDNode *E) = 0;
498 /// NodeUpdated - The node N that was updated.
499 virtual void NodeUpdated(SDNode *N) = 0;
502 /// RemoveDeadNode - Remove the specified node from the system. If any of its
503 /// operands then becomes dead, remove them as well. Inform UpdateListener
504 /// for each node deleted.
505 void RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener = 0);
507 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
508 /// This can cause recursive merging of nodes in the DAG. Use the first
509 /// version if 'From' is known to have a single result, use the second
510 /// if you have two nodes with identical results, use the third otherwise.
512 /// These methods all take an optional UpdateListener, which (if not null) is
513 /// informed about nodes that are deleted and modified due to recursive
514 /// changes in the dag.
516 void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
517 DAGUpdateListener *UpdateListener = 0);
518 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
519 DAGUpdateListener *UpdateListener = 0);
520 void ReplaceAllUsesWith(SDNode *From, SDOperandPtr To,
521 DAGUpdateListener *UpdateListener = 0);
523 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
524 /// uses of other values produced by From.Val alone.
525 void ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
526 DAGUpdateListener *UpdateListener = 0);
528 /// AssignNodeIds - Assign a unique node id for each node in the DAG based on
529 /// their allnodes order. It returns the maximum id.
530 unsigned AssignNodeIds();
532 /// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
533 /// based on their topological order. It returns the maximum id and a vector
534 /// of the SDNodes* in assigned order by reference.
535 unsigned AssignTopologicalOrder(std::vector<SDNode*> &TopOrder);
537 /// isCommutativeBinOp - Returns true if the opcode is a commutative binary
539 static bool isCommutativeBinOp(unsigned Opcode) {
540 // FIXME: This should get its info from the td file, so that we can include
555 case ISD::ADDE: return true;
556 default: return false;
562 /// CreateStackTemporary - Create a stack temporary, suitable for holding the
563 /// specified value type.
564 SDOperand CreateStackTemporary(MVT VT);
566 /// FoldSetCC - Constant fold a setcc to true or false.
567 SDOperand FoldSetCC(MVT VT, SDOperand N1,
568 SDOperand N2, ISD::CondCode Cond);
570 /// SignBitIsZero - Return true if the sign bit of Op is known to be zero. We
571 /// use this predicate to simplify operations downstream.
572 bool SignBitIsZero(SDOperand Op, unsigned Depth = 0) const;
574 /// MaskedValueIsZero - Return true if 'Op & Mask' is known to be zero. We
575 /// use this predicate to simplify operations downstream. Op and Mask are
576 /// known to be the same type.
577 bool MaskedValueIsZero(SDOperand Op, const APInt &Mask, unsigned Depth = 0)
580 /// ComputeMaskedBits - Determine which of the bits specified in Mask are
581 /// known to be either zero or one and return them in the KnownZero/KnownOne
582 /// bitsets. This code only analyzes bits in Mask, in order to short-circuit
583 /// processing. Targets can implement the computeMaskedBitsForTargetNode
584 /// method in the TargetLowering class to allow target nodes to be understood.
585 void ComputeMaskedBits(SDOperand Op, const APInt &Mask, APInt &KnownZero,
586 APInt &KnownOne, unsigned Depth = 0) const;
588 /// ComputeNumSignBits - Return the number of times the sign bit of the
589 /// register is replicated into the other bits. We know that at least 1 bit
590 /// is always equal to the sign bit (itself), but other cases can give us
591 /// information. For example, immediately after an "SRA X, 2", we know that
592 /// the top 3 bits are all equal to each other, so we return 3. Targets can
593 /// implement the ComputeNumSignBitsForTarget method in the TargetLowering
594 /// class to allow target nodes to be understood.
595 unsigned ComputeNumSignBits(SDOperand Op, unsigned Depth = 0) const;
597 /// isVerifiedDebugInfoDesc - Returns true if the specified SDOperand has
598 /// been verified as a debug information descriptor.
599 bool isVerifiedDebugInfoDesc(SDOperand Op) const;
601 /// getShuffleScalarElt - Returns the scalar element that will make up the ith
602 /// element of the result of the vector shuffle.
603 SDOperand getShuffleScalarElt(const SDNode *N, unsigned Idx);
606 void RemoveNodeFromCSEMaps(SDNode *N);
607 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
608 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op, void *&InsertPos);
609 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperand Op1, SDOperand Op2,
611 SDNode *FindModifiedNodeSlot(SDNode *N, SDOperandPtr Ops, unsigned NumOps,
614 void DeleteNodeNotInCSEMaps(SDNode *N);
616 // List of non-single value types.
617 std::list<std::vector<MVT> > VTList;
619 // Maps to auto-CSE operations.
620 std::vector<CondCodeSDNode*> CondCodeNodes;
622 std::vector<SDNode*> ValueTypeNodes;
623 std::map<MVT, SDNode*, MVT::compareRawBits> ExtendedValueTypeNodes;
624 std::map<std::string, SDNode*> ExternalSymbols;
625 std::map<std::string, SDNode*> TargetExternalSymbols;
626 std::map<std::string, StringSDNode*> StringNodes;
629 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
630 typedef SelectionDAG::allnodes_iterator nodes_iterator;
631 static nodes_iterator nodes_begin(SelectionDAG *G) {
632 return G->allnodes_begin();
634 static nodes_iterator nodes_end(SelectionDAG *G) {
635 return G->allnodes_end();
639 } // end namespace llvm