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/ilist.h"
19 #include "llvm/ADT/DenseSet.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/CodeGen/SelectionDAGNodes.h"
22 #include "llvm/Support/RecyclingAllocator.h"
23 #include "llvm/Target/TargetMachine.h"
32 class FunctionLoweringInfo;
33 class MachineConstantPoolValue;
34 class MachineFunction;
40 template<> struct ilist_traits<SDNode> : public ilist_default_traits<SDNode> {
42 mutable ilist_half_node<SDNode> Sentinel;
44 SDNode *createSentinel() const {
45 return static_cast<SDNode*>(&Sentinel);
47 static void destroySentinel(SDNode *) {}
49 SDNode *provideInitialHead() const { return createSentinel(); }
50 SDNode *ensureHead(SDNode*) const { return createSentinel(); }
51 static void noteHead(SDNode*, SDNode*) {}
53 static void deleteNode(SDNode *) {
54 assert(0 && "ilist_traits<SDNode> shouldn't see a deleteNode call!");
57 static void createNode(const SDNode &);
60 /// SDDbgInfo - Keeps track of dbg_value information through SDISel. We do
61 /// not build SDNodes for these so as not to perturb the generated code;
62 /// instead the info is kept off to the side in this structure. Each SDNode may
63 /// have one or more associated dbg_value entries. This information is kept in
65 /// Byval parameters are handled separately because they don't use alloca's,
66 /// which busts the normal mechanism. There is good reason for handling all
67 /// parameters separately: they may not have code generated for them, they
68 /// should always go at the beginning of the function regardless of other code
69 /// motion, and debug info for them is potentially useful even if the parameter
70 /// is unused. Right now only byval parameters are handled separately.
72 SmallVector<SDDbgValue*, 32> DbgValues;
73 SmallVector<SDDbgValue*, 32> ByvalParmDbgValues;
74 DenseMap<const SDNode*, SmallVector<SDDbgValue*, 2> > DbgValMap;
76 void operator=(const SDDbgInfo&); // Do not implement.
77 SDDbgInfo(const SDDbgInfo&); // Do not implement.
81 void add(SDDbgValue *V, const SDNode *Node, bool isParameter) {
83 ByvalParmDbgValues.push_back(V);
84 } else DbgValues.push_back(V);
86 DbgValMap[Node].push_back(V);
92 ByvalParmDbgValues.clear();
96 return DbgValues.empty() && ByvalParmDbgValues.empty();
99 SmallVector<SDDbgValue*,2> &getSDDbgValues(const SDNode *Node) {
100 return DbgValMap[Node];
103 typedef SmallVector<SDDbgValue*,32>::iterator DbgIterator;
104 DbgIterator DbgBegin() { return DbgValues.begin(); }
105 DbgIterator DbgEnd() { return DbgValues.end(); }
106 DbgIterator ByvalParmDbgBegin() { return ByvalParmDbgValues.begin(); }
107 DbgIterator ByvalParmDbgEnd() { return ByvalParmDbgValues.end(); }
111 Unrestricted, // Combine may create illegal operations and illegal types.
112 NoIllegalTypes, // Combine may create illegal operations but no illegal types.
113 NoIllegalOperations // Combine may only create legal operations and types.
117 void checkForCycles(const SDNode *N);
118 void checkForCycles(const SelectionDAG *DAG);
120 /// SelectionDAG class - This is used to represent a portion of an LLVM function
121 /// in a low-level Data Dependence DAG representation suitable for instruction
122 /// selection. This DAG is constructed as the first step of instruction
123 /// selection in order to allow implementation of machine specific optimizations
124 /// and code simplifications.
126 /// The representation used by the SelectionDAG is a target-independent
127 /// representation, which has some similarities to the GCC RTL representation,
128 /// but is significantly more simple, powerful, and is a graph form instead of a
132 const TargetMachine &TM;
133 const TargetLowering &TLI;
135 FunctionLoweringInfo &FLI;
136 LLVMContext *Context;
138 /// EntryNode - The starting token.
141 /// Root - The root of the entire DAG.
144 /// AllNodes - A linked list of nodes in the current DAG.
145 ilist<SDNode> AllNodes;
147 /// NodeAllocatorType - The AllocatorType for allocating SDNodes. We use
148 /// pool allocation with recycling.
149 typedef RecyclingAllocator<BumpPtrAllocator, SDNode, sizeof(LargestSDNode),
150 AlignOf<MostAlignedSDNode>::Alignment>
153 /// NodeAllocator - Pool allocation for nodes.
154 NodeAllocatorType NodeAllocator;
156 /// CSEMap - This structure is used to memoize nodes, automatically performing
157 /// CSE with existing nodes when a duplicate is requested.
158 FoldingSet<SDNode> CSEMap;
160 /// OperandAllocator - Pool allocation for machine-opcode SDNode operands.
161 BumpPtrAllocator OperandAllocator;
163 /// Allocator - Pool allocation for misc. objects that are created once per
165 BumpPtrAllocator Allocator;
167 /// SDNodeOrdering - The ordering of the SDNodes. It roughly corresponds to
168 /// the ordering of the original LLVM instructions.
169 SDNodeOrdering *Ordering;
171 /// DbgInfo - Tracks dbg_value information through SDISel.
174 /// VerifyNode - Sanity check the given node. Aborts if it is invalid.
175 void VerifyNode(SDNode *N);
177 /// setGraphColorHelper - Implementation of setSubgraphColor.
178 /// Return whether we had to truncate the search.
180 bool setSubgraphColorHelper(SDNode *N, const char *Color,
181 DenseSet<SDNode *> &visited,
182 int level, bool &printed);
184 void operator=(const SelectionDAG&); // Do not implement.
185 SelectionDAG(const SelectionDAG&); // Do not implement.
188 SelectionDAG(const TargetMachine &TM, FunctionLoweringInfo &fli);
191 /// init - Prepare this SelectionDAG to process code in the given
194 void init(MachineFunction &mf);
196 /// clear - Clear state and free memory necessary to make this
197 /// SelectionDAG ready to process a new block.
201 MachineFunction &getMachineFunction() const { return *MF; }
202 const TargetMachine &getTarget() const { return TM; }
203 const TargetLowering &getTargetLoweringInfo() const { return TLI; }
204 FunctionLoweringInfo &getFunctionLoweringInfo() const { return FLI; }
205 LLVMContext *getContext() const {return Context; }
207 /// viewGraph - Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
209 void viewGraph(const std::string &Title);
213 std::map<const SDNode *, std::string> NodeGraphAttrs;
216 /// clearGraphAttrs - Clear all previously defined node graph attributes.
217 /// Intended to be used from a debugging tool (eg. gdb).
218 void clearGraphAttrs();
220 /// setGraphAttrs - Set graph attributes for a node. (eg. "color=red".)
222 void setGraphAttrs(const SDNode *N, const char *Attrs);
224 /// getGraphAttrs - Get graph attributes for a node. (eg. "color=red".)
225 /// Used from getNodeAttributes.
226 const std::string getGraphAttrs(const SDNode *N) const;
228 /// setGraphColor - Convenience for setting node color attribute.
230 void setGraphColor(const SDNode *N, const char *Color);
232 /// setGraphColor - Convenience for setting subgraph color attribute.
234 void setSubgraphColor(SDNode *N, const char *Color);
236 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
237 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
238 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
239 typedef ilist<SDNode>::iterator allnodes_iterator;
240 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
241 allnodes_iterator allnodes_end() { return AllNodes.end(); }
242 ilist<SDNode>::size_type allnodes_size() const {
243 return AllNodes.size();
246 /// getRoot - Return the root tag of the SelectionDAG.
248 const SDValue &getRoot() const { return Root; }
250 /// getEntryNode - Return the token chain corresponding to the entry of the
252 SDValue getEntryNode() const {
253 return SDValue(const_cast<SDNode *>(&EntryNode), 0);
256 /// setRoot - Set the current root tag of the SelectionDAG.
258 const SDValue &setRoot(SDValue N) {
259 assert((!N.getNode() || N.getValueType() == MVT::Other) &&
260 "DAG root value is not a chain!");
262 checkForCycles(N.getNode());
265 checkForCycles(this);
269 /// Combine - This iterates over the nodes in the SelectionDAG, folding
270 /// certain types of nodes together, or eliminating superfluous nodes. The
271 /// Level argument controls whether Combine is allowed to produce nodes and
272 /// types that are illegal on the target.
273 void Combine(CombineLevel Level, AliasAnalysis &AA,
274 CodeGenOpt::Level OptLevel);
276 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
277 /// only uses types natively supported by the target. Returns "true" if it
278 /// made any changes.
280 /// Note that this is an involved process that may invalidate pointers into
282 bool LegalizeTypes();
284 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
285 /// compatible with the target instruction selector, as indicated by the
286 /// TargetLowering object.
288 /// Note that this is an involved process that may invalidate pointers into
290 void Legalize(CodeGenOpt::Level OptLevel);
292 /// LegalizeVectors - This transforms the SelectionDAG into a SelectionDAG
293 /// that only uses vector math operations supported by the target. This is
294 /// necessary as a separate step from Legalize because unrolling a vector
295 /// operation can introduce illegal types, which requires running
296 /// LegalizeTypes again.
298 /// This returns true if it made any changes; in that case, LegalizeTypes
299 /// is called again before Legalize.
301 /// Note that this is an involved process that may invalidate pointers into
303 bool LegalizeVectors();
305 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
307 void RemoveDeadNodes();
309 /// DeleteNode - Remove the specified node from the system. This node must
310 /// have no referrers.
311 void DeleteNode(SDNode *N);
313 /// getVTList - Return an SDVTList that represents the list of values
315 SDVTList getVTList(EVT VT);
316 SDVTList getVTList(EVT VT1, EVT VT2);
317 SDVTList getVTList(EVT VT1, EVT VT2, EVT VT3);
318 SDVTList getVTList(EVT VT1, EVT VT2, EVT VT3, EVT VT4);
319 SDVTList getVTList(const EVT *VTs, unsigned NumVTs);
321 //===--------------------------------------------------------------------===//
322 // Node creation methods.
324 SDValue getConstant(uint64_t Val, EVT VT, bool isTarget = false);
325 SDValue getConstant(const APInt &Val, EVT VT, bool isTarget = false);
326 SDValue getConstant(const ConstantInt &Val, EVT VT, bool isTarget = false);
327 SDValue getIntPtrConstant(uint64_t Val, bool isTarget = false);
328 SDValue getTargetConstant(uint64_t Val, EVT VT) {
329 return getConstant(Val, VT, true);
331 SDValue getTargetConstant(const APInt &Val, EVT VT) {
332 return getConstant(Val, VT, true);
334 SDValue getTargetConstant(const ConstantInt &Val, EVT VT) {
335 return getConstant(Val, VT, true);
337 SDValue getConstantFP(double Val, EVT VT, bool isTarget = false);
338 SDValue getConstantFP(const APFloat& Val, EVT VT, bool isTarget = false);
339 SDValue getConstantFP(const ConstantFP &CF, EVT VT, bool isTarget = false);
340 SDValue getTargetConstantFP(double Val, EVT VT) {
341 return getConstantFP(Val, VT, true);
343 SDValue getTargetConstantFP(const APFloat& Val, EVT VT) {
344 return getConstantFP(Val, VT, true);
346 SDValue getTargetConstantFP(const ConstantFP &Val, EVT VT) {
347 return getConstantFP(Val, VT, true);
349 SDValue getGlobalAddress(const GlobalValue *GV, EVT VT,
350 int64_t offset = 0, bool isTargetGA = false,
351 unsigned char TargetFlags = 0);
352 SDValue getTargetGlobalAddress(const GlobalValue *GV, EVT VT,
354 unsigned char TargetFlags = 0) {
355 return getGlobalAddress(GV, VT, offset, true, TargetFlags);
357 SDValue getFrameIndex(int FI, EVT VT, bool isTarget = false);
358 SDValue getTargetFrameIndex(int FI, EVT VT) {
359 return getFrameIndex(FI, VT, true);
361 SDValue getJumpTable(int JTI, EVT VT, bool isTarget = false,
362 unsigned char TargetFlags = 0);
363 SDValue getTargetJumpTable(int JTI, EVT VT, unsigned char TargetFlags = 0) {
364 return getJumpTable(JTI, VT, true, TargetFlags);
366 SDValue getConstantPool(const Constant *C, EVT VT,
367 unsigned Align = 0, int Offs = 0, bool isT=false,
368 unsigned char TargetFlags = 0);
369 SDValue getTargetConstantPool(const Constant *C, EVT VT,
370 unsigned Align = 0, int Offset = 0,
371 unsigned char TargetFlags = 0) {
372 return getConstantPool(C, VT, Align, Offset, true, TargetFlags);
374 SDValue getConstantPool(MachineConstantPoolValue *C, EVT VT,
375 unsigned Align = 0, int Offs = 0, bool isT=false,
376 unsigned char TargetFlags = 0);
377 SDValue getTargetConstantPool(MachineConstantPoolValue *C,
378 EVT VT, unsigned Align = 0,
379 int Offset = 0, unsigned char TargetFlags=0) {
380 return getConstantPool(C, VT, Align, Offset, true, TargetFlags);
382 // When generating a branch to a BB, we don't in general know enough
383 // to provide debug info for the BB at that time, so keep this one around.
384 SDValue getBasicBlock(MachineBasicBlock *MBB);
385 SDValue getBasicBlock(MachineBasicBlock *MBB, DebugLoc dl);
386 SDValue getExternalSymbol(const char *Sym, EVT VT);
387 SDValue getExternalSymbol(const char *Sym, DebugLoc dl, EVT VT);
388 SDValue getTargetExternalSymbol(const char *Sym, EVT VT,
389 unsigned char TargetFlags = 0);
390 SDValue getValueType(EVT);
391 SDValue getRegister(unsigned Reg, EVT VT);
392 SDValue getEHLabel(DebugLoc dl, SDValue Root, MCSymbol *Label);
393 SDValue getBlockAddress(const BlockAddress *BA, EVT VT,
394 bool isTarget = false, unsigned char TargetFlags = 0);
396 SDValue getCopyToReg(SDValue Chain, DebugLoc dl, unsigned Reg, SDValue N) {
397 return getNode(ISD::CopyToReg, dl, MVT::Other, Chain,
398 getRegister(Reg, N.getValueType()), N);
401 // This version of the getCopyToReg method takes an extra operand, which
402 // indicates that there is potentially an incoming flag value (if Flag is not
403 // null) and that there should be a flag result.
404 SDValue getCopyToReg(SDValue Chain, DebugLoc dl, unsigned Reg, SDValue N,
406 SDVTList VTs = getVTList(MVT::Other, MVT::Flag);
407 SDValue Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Flag };
408 return getNode(ISD::CopyToReg, dl, VTs, Ops, Flag.getNode() ? 4 : 3);
411 // Similar to last getCopyToReg() except parameter Reg is a SDValue
412 SDValue getCopyToReg(SDValue Chain, DebugLoc dl, SDValue Reg, SDValue N,
414 SDVTList VTs = getVTList(MVT::Other, MVT::Flag);
415 SDValue Ops[] = { Chain, Reg, N, Flag };
416 return getNode(ISD::CopyToReg, dl, VTs, Ops, Flag.getNode() ? 4 : 3);
419 SDValue getCopyFromReg(SDValue Chain, DebugLoc dl, unsigned Reg, EVT VT) {
420 SDVTList VTs = getVTList(VT, MVT::Other);
421 SDValue Ops[] = { Chain, getRegister(Reg, VT) };
422 return getNode(ISD::CopyFromReg, dl, VTs, Ops, 2);
425 // This version of the getCopyFromReg method takes an extra operand, which
426 // indicates that there is potentially an incoming flag value (if Flag is not
427 // null) and that there should be a flag result.
428 SDValue getCopyFromReg(SDValue Chain, DebugLoc dl, unsigned Reg, EVT VT,
430 SDVTList VTs = getVTList(VT, MVT::Other, MVT::Flag);
431 SDValue Ops[] = { Chain, getRegister(Reg, VT), Flag };
432 return getNode(ISD::CopyFromReg, dl, VTs, Ops, Flag.getNode() ? 3 : 2);
435 SDValue getCondCode(ISD::CondCode Cond);
437 /// Returns the ConvertRndSat Note: Avoid using this node because it may
438 /// disappear in the future and most targets don't support it.
439 SDValue getConvertRndSat(EVT VT, DebugLoc dl, SDValue Val, SDValue DTy,
441 SDValue Rnd, SDValue Sat, ISD::CvtCode Code);
443 /// getVectorShuffle - Return an ISD::VECTOR_SHUFFLE node. The number of
444 /// elements in VT, which must be a vector type, must match the number of
445 /// mask elements NumElts. A integer mask element equal to -1 is treated as
447 SDValue getVectorShuffle(EVT VT, DebugLoc dl, SDValue N1, SDValue N2,
448 const int *MaskElts);
450 /// getSExtOrTrunc - Convert Op, which must be of integer type, to the
451 /// integer type VT, by either sign-extending or truncating it.
452 SDValue getSExtOrTrunc(SDValue Op, DebugLoc DL, EVT VT);
454 /// getZExtOrTrunc - Convert Op, which must be of integer type, to the
455 /// integer type VT, by either zero-extending or truncating it.
456 SDValue getZExtOrTrunc(SDValue Op, DebugLoc DL, EVT VT);
458 /// getZeroExtendInReg - Return the expression required to zero extend the Op
459 /// value assuming it was the smaller SrcTy value.
460 SDValue getZeroExtendInReg(SDValue Op, DebugLoc DL, EVT SrcTy);
462 /// getNOT - Create a bitwise NOT operation as (XOR Val, -1).
463 SDValue getNOT(DebugLoc DL, SDValue Val, EVT VT);
465 /// getCALLSEQ_START - Return a new CALLSEQ_START node, which always must have
466 /// a flag result (to ensure it's not CSE'd). CALLSEQ_START does not have a
468 SDValue getCALLSEQ_START(SDValue Chain, SDValue Op) {
469 SDVTList VTs = getVTList(MVT::Other, MVT::Flag);
470 SDValue Ops[] = { Chain, Op };
471 return getNode(ISD::CALLSEQ_START, DebugLoc(), VTs, Ops, 2);
474 /// getCALLSEQ_END - Return a new CALLSEQ_END node, which always must have a
475 /// flag result (to ensure it's not CSE'd). CALLSEQ_END does not have
476 /// a useful DebugLoc.
477 SDValue getCALLSEQ_END(SDValue Chain, SDValue Op1, SDValue Op2,
479 SDVTList NodeTys = getVTList(MVT::Other, MVT::Flag);
480 SmallVector<SDValue, 4> Ops;
481 Ops.push_back(Chain);
484 Ops.push_back(InFlag);
485 return getNode(ISD::CALLSEQ_END, DebugLoc(), NodeTys, &Ops[0],
486 (unsigned)Ops.size() - (InFlag.getNode() == 0 ? 1 : 0));
489 /// getUNDEF - Return an UNDEF node. UNDEF does not have a useful DebugLoc.
490 SDValue getUNDEF(EVT VT) {
491 return getNode(ISD::UNDEF, DebugLoc(), VT);
494 /// getGLOBAL_OFFSET_TABLE - Return a GLOBAL_OFFSET_TABLE node. This does
495 /// not have a useful DebugLoc.
496 SDValue getGLOBAL_OFFSET_TABLE(EVT VT) {
497 return getNode(ISD::GLOBAL_OFFSET_TABLE, DebugLoc(), VT);
500 /// getNode - Gets or creates the specified node.
502 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT);
503 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT, SDValue N);
504 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT, SDValue N1, SDValue N2);
505 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT,
506 SDValue N1, SDValue N2, SDValue N3);
507 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT,
508 SDValue N1, SDValue N2, SDValue N3, SDValue N4);
509 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT,
510 SDValue N1, SDValue N2, SDValue N3, SDValue N4,
512 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT,
513 const SDUse *Ops, unsigned NumOps);
514 SDValue getNode(unsigned Opcode, DebugLoc DL, EVT VT,
515 const SDValue *Ops, unsigned NumOps);
516 SDValue getNode(unsigned Opcode, DebugLoc DL,
517 const std::vector<EVT> &ResultTys,
518 const SDValue *Ops, unsigned NumOps);
519 SDValue getNode(unsigned Opcode, DebugLoc DL, const EVT *VTs, unsigned NumVTs,
520 const SDValue *Ops, unsigned NumOps);
521 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs,
522 const SDValue *Ops, unsigned NumOps);
523 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs);
524 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs, SDValue N);
525 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs,
526 SDValue N1, SDValue N2);
527 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs,
528 SDValue N1, SDValue N2, SDValue N3);
529 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs,
530 SDValue N1, SDValue N2, SDValue N3, SDValue N4);
531 SDValue getNode(unsigned Opcode, DebugLoc DL, SDVTList VTs,
532 SDValue N1, SDValue N2, SDValue N3, SDValue N4,
535 /// getStackArgumentTokenFactor - Compute a TokenFactor to force all
536 /// the incoming stack arguments to be loaded from the stack. This is
537 /// used in tail call lowering to protect stack arguments from being
539 SDValue getStackArgumentTokenFactor(SDValue Chain);
541 SDValue getMemcpy(SDValue Chain, DebugLoc dl, SDValue Dst, SDValue Src,
542 SDValue Size, unsigned Align, bool isVol, bool AlwaysInline,
543 const Value *DstSV, uint64_t DstSVOff,
544 const Value *SrcSV, uint64_t SrcSVOff);
546 SDValue getMemmove(SDValue Chain, DebugLoc dl, SDValue Dst, SDValue Src,
547 SDValue Size, unsigned Align, bool isVol,
548 const Value *DstSV, uint64_t DstOSVff,
549 const Value *SrcSV, uint64_t SrcSVOff);
551 SDValue getMemset(SDValue Chain, DebugLoc dl, SDValue Dst, SDValue Src,
552 SDValue Size, unsigned Align, bool isVol,
553 const Value *DstSV, uint64_t DstSVOff);
555 /// getSetCC - Helper function to make it easier to build SetCC's if you just
556 /// have an ISD::CondCode instead of an SDValue.
558 SDValue getSetCC(DebugLoc DL, EVT VT, SDValue LHS, SDValue RHS,
559 ISD::CondCode Cond) {
560 return getNode(ISD::SETCC, DL, VT, LHS, RHS, getCondCode(Cond));
563 /// getVSetCC - Helper function to make it easier to build VSetCC's nodes
564 /// if you just have an ISD::CondCode instead of an SDValue.
566 SDValue getVSetCC(DebugLoc DL, EVT VT, SDValue LHS, SDValue RHS,
567 ISD::CondCode Cond) {
568 return getNode(ISD::VSETCC, DL, VT, LHS, RHS, getCondCode(Cond));
571 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
572 /// just have an ISD::CondCode instead of an SDValue.
574 SDValue getSelectCC(DebugLoc DL, SDValue LHS, SDValue RHS,
575 SDValue True, SDValue False, ISD::CondCode Cond) {
576 return getNode(ISD::SELECT_CC, DL, True.getValueType(),
577 LHS, RHS, True, False, getCondCode(Cond));
580 /// getVAArg - VAArg produces a result and token chain, and takes a pointer
581 /// and a source value as input.
582 SDValue getVAArg(EVT VT, DebugLoc dl, SDValue Chain, SDValue Ptr,
585 /// getAtomic - Gets a node for an atomic op, produces result and chain and
587 SDValue getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT, SDValue Chain,
588 SDValue Ptr, SDValue Cmp, SDValue Swp, const Value* PtrVal,
589 unsigned Alignment=0);
590 SDValue getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT, SDValue Chain,
591 SDValue Ptr, SDValue Cmp, SDValue Swp,
592 MachineMemOperand *MMO);
594 /// getAtomic - Gets a node for an atomic op, produces result and chain and
595 /// takes 2 operands.
596 SDValue getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT, SDValue Chain,
597 SDValue Ptr, SDValue Val, const Value* PtrVal,
598 unsigned Alignment = 0);
599 SDValue getAtomic(unsigned Opcode, DebugLoc dl, EVT MemVT, SDValue Chain,
600 SDValue Ptr, SDValue Val,
601 MachineMemOperand *MMO);
603 /// getMemIntrinsicNode - Creates a MemIntrinsicNode that may produce a
604 /// result and takes a list of operands. Opcode may be INTRINSIC_VOID,
605 /// INTRINSIC_W_CHAIN, or a target-specific opcode with a value not
606 /// less than FIRST_TARGET_MEMORY_OPCODE.
607 SDValue getMemIntrinsicNode(unsigned Opcode, DebugLoc dl,
608 const EVT *VTs, unsigned NumVTs,
609 const SDValue *Ops, unsigned NumOps,
610 EVT MemVT, const Value *srcValue, int SVOff,
611 unsigned Align = 0, bool Vol = false,
612 bool ReadMem = true, bool WriteMem = true);
614 SDValue getMemIntrinsicNode(unsigned Opcode, DebugLoc dl, SDVTList VTList,
615 const SDValue *Ops, unsigned NumOps,
616 EVT MemVT, const Value *srcValue, int SVOff,
617 unsigned Align = 0, bool Vol = false,
618 bool ReadMem = true, bool WriteMem = true);
620 SDValue getMemIntrinsicNode(unsigned Opcode, DebugLoc dl, SDVTList VTList,
621 const SDValue *Ops, unsigned NumOps,
622 EVT MemVT, MachineMemOperand *MMO);
624 /// getMergeValues - Create a MERGE_VALUES node from the given operands.
625 SDValue getMergeValues(const SDValue *Ops, unsigned NumOps, DebugLoc dl);
627 /// getLoad - Loads are not normal binary operators: their result type is not
628 /// determined by their operands, and they produce a value AND a token chain.
630 SDValue getLoad(EVT VT, DebugLoc dl, SDValue Chain, SDValue Ptr,
631 const Value *SV, int SVOffset, bool isVolatile,
632 bool isNonTemporal, unsigned Alignment);
633 SDValue getExtLoad(ISD::LoadExtType ExtType, DebugLoc dl, EVT VT,
634 SDValue Chain, SDValue Ptr, const Value *SV,
635 int SVOffset, EVT MemVT, bool isVolatile,
636 bool isNonTemporal, unsigned Alignment);
637 SDValue getIndexedLoad(SDValue OrigLoad, DebugLoc dl, SDValue Base,
638 SDValue Offset, ISD::MemIndexedMode AM);
639 SDValue getLoad(ISD::MemIndexedMode AM, DebugLoc dl, ISD::LoadExtType ExtType,
640 EVT VT, SDValue Chain, SDValue Ptr, SDValue Offset,
641 const Value *SV, int SVOffset, EVT MemVT,
642 bool isVolatile, bool isNonTemporal, unsigned Alignment);
643 SDValue getLoad(ISD::MemIndexedMode AM, DebugLoc dl, ISD::LoadExtType ExtType,
644 EVT VT, SDValue Chain, SDValue Ptr, SDValue Offset,
645 EVT MemVT, MachineMemOperand *MMO);
647 /// getStore - Helper function to build ISD::STORE nodes.
649 SDValue getStore(SDValue Chain, DebugLoc dl, SDValue Val, SDValue Ptr,
650 const Value *SV, int SVOffset, bool isVolatile,
651 bool isNonTemporal, unsigned Alignment);
652 SDValue getStore(SDValue Chain, DebugLoc dl, SDValue Val, SDValue Ptr,
653 MachineMemOperand *MMO);
654 SDValue getTruncStore(SDValue Chain, DebugLoc dl, SDValue Val, SDValue Ptr,
655 const Value *SV, int SVOffset, EVT TVT,
656 bool isNonTemporal, bool isVolatile,
658 SDValue getTruncStore(SDValue Chain, DebugLoc dl, SDValue Val, SDValue Ptr,
659 EVT TVT, MachineMemOperand *MMO);
660 SDValue getIndexedStore(SDValue OrigStoe, DebugLoc dl, SDValue Base,
661 SDValue Offset, ISD::MemIndexedMode AM);
663 /// getSrcValue - Construct a node to track a Value* through the backend.
664 SDValue getSrcValue(const Value *v);
666 /// getMDNode - Return an MDNodeSDNode which holds an MDNode.
667 SDValue getMDNode(const MDNode *MD);
669 /// getShiftAmountOperand - Return the specified value casted to
670 /// the target's desired shift amount type.
671 SDValue getShiftAmountOperand(SDValue Op);
673 /// UpdateNodeOperands - *Mutate* the specified node in-place to have the
674 /// specified operands. If the resultant node already exists in the DAG,
675 /// this does not modify the specified node, instead it returns the node that
676 /// already exists. If the resultant node does not exist in the DAG, the
677 /// input node is returned. As a degenerate case, if you specify the same
678 /// input operands as the node already has, the input node is returned.
679 SDValue UpdateNodeOperands(SDValue N, SDValue Op);
680 SDValue UpdateNodeOperands(SDValue N, SDValue Op1, SDValue Op2);
681 SDValue UpdateNodeOperands(SDValue N, SDValue Op1, SDValue Op2,
683 SDValue UpdateNodeOperands(SDValue N, SDValue Op1, SDValue Op2,
684 SDValue Op3, SDValue Op4);
685 SDValue UpdateNodeOperands(SDValue N, SDValue Op1, SDValue Op2,
686 SDValue Op3, SDValue Op4, SDValue Op5);
687 SDValue UpdateNodeOperands(SDValue N,
688 const SDValue *Ops, unsigned NumOps);
690 /// SelectNodeTo - These are used for target selectors to *mutate* the
691 /// specified node to have the specified return type, Target opcode, and
692 /// operands. Note that target opcodes are stored as
693 /// ~TargetOpcode in the node opcode field. The resultant node is returned.
694 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT);
695 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT, SDValue Op1);
696 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT,
697 SDValue Op1, SDValue Op2);
698 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT,
699 SDValue Op1, SDValue Op2, SDValue Op3);
700 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT,
701 const SDValue *Ops, unsigned NumOps);
702 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1, EVT VT2);
703 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
704 EVT VT2, const SDValue *Ops, unsigned NumOps);
705 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
706 EVT VT2, EVT VT3, const SDValue *Ops, unsigned NumOps);
707 SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT1,
708 EVT VT2, EVT VT3, EVT VT4, const SDValue *Ops,
710 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
711 EVT VT2, SDValue Op1);
712 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
713 EVT VT2, SDValue Op1, SDValue Op2);
714 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
715 EVT VT2, SDValue Op1, SDValue Op2, SDValue Op3);
716 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
717 EVT VT2, EVT VT3, SDValue Op1, SDValue Op2, SDValue Op3);
718 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, SDVTList VTs,
719 const SDValue *Ops, unsigned NumOps);
721 /// MorphNodeTo - This *mutates* the specified node to have the specified
722 /// return type, opcode, and operands.
723 SDNode *MorphNodeTo(SDNode *N, unsigned Opc, SDVTList VTs,
724 const SDValue *Ops, unsigned NumOps);
726 /// getMachineNode - These are used for target selectors to create a new node
727 /// with specified return type(s), MachineInstr opcode, and operands.
729 /// Note that getMachineNode returns the resultant node. If there is already
730 /// a node of the specified opcode and operands, it returns that node instead
731 /// of the current one.
732 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT);
733 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
735 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
736 SDValue Op1, SDValue Op2);
737 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
738 SDValue Op1, SDValue Op2, SDValue Op3);
739 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT,
740 const SDValue *Ops, unsigned NumOps);
741 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2);
742 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2,
744 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
745 EVT VT2, SDValue Op1, SDValue Op2);
746 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1,
747 EVT VT2, SDValue Op1, SDValue Op2, SDValue Op3);
748 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2,
749 const SDValue *Ops, unsigned NumOps);
750 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2,
751 EVT VT3, SDValue Op1, SDValue Op2);
752 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2,
753 EVT VT3, SDValue Op1, SDValue Op2, SDValue Op3);
754 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2,
755 EVT VT3, const SDValue *Ops, unsigned NumOps);
756 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2,
757 EVT VT3, EVT VT4, const SDValue *Ops, unsigned NumOps);
758 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl,
759 const std::vector<EVT> &ResultTys, const SDValue *Ops,
761 MachineSDNode *getMachineNode(unsigned Opcode, DebugLoc dl, SDVTList VTs,
762 const SDValue *Ops, unsigned NumOps);
764 /// getTargetExtractSubreg - A convenience function for creating
765 /// TargetInstrInfo::EXTRACT_SUBREG nodes.
766 SDValue getTargetExtractSubreg(int SRIdx, DebugLoc DL, EVT VT,
769 /// getTargetInsertSubreg - A convenience function for creating
770 /// TargetInstrInfo::INSERT_SUBREG nodes.
771 SDValue getTargetInsertSubreg(int SRIdx, DebugLoc DL, EVT VT,
772 SDValue Operand, SDValue Subreg);
774 /// getNodeIfExists - Get the specified node if it's already available, or
775 /// else return NULL.
776 SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTs,
777 const SDValue *Ops, unsigned NumOps);
779 /// getDbgValue - Creates a SDDbgValue node.
781 SDDbgValue *getDbgValue(MDNode *MDPtr, SDNode *N, unsigned R, uint64_t Off,
782 DebugLoc DL, unsigned O);
783 SDDbgValue *getDbgValue(MDNode *MDPtr, const Value *C, uint64_t Off,
784 DebugLoc DL, unsigned O);
785 SDDbgValue *getDbgValue(MDNode *MDPtr, unsigned FI, uint64_t Off,
786 DebugLoc DL, unsigned O);
788 /// DAGUpdateListener - Clients of various APIs that cause global effects on
789 /// the DAG can optionally implement this interface. This allows the clients
790 /// to handle the various sorts of updates that happen.
791 class DAGUpdateListener {
793 virtual ~DAGUpdateListener();
795 /// NodeDeleted - The node N that was deleted and, if E is not null, an
796 /// equivalent node E that replaced it.
797 virtual void NodeDeleted(SDNode *N, SDNode *E) = 0;
799 /// NodeUpdated - The node N that was updated.
800 virtual void NodeUpdated(SDNode *N) = 0;
803 /// RemoveDeadNode - Remove the specified node from the system. If any of its
804 /// operands then becomes dead, remove them as well. Inform UpdateListener
805 /// for each node deleted.
806 void RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener = 0);
808 /// RemoveDeadNodes - This method deletes the unreachable nodes in the
809 /// given list, and any nodes that become unreachable as a result.
810 void RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes,
811 DAGUpdateListener *UpdateListener = 0);
813 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
814 /// This can cause recursive merging of nodes in the DAG. Use the first
815 /// version if 'From' is known to have a single result, use the second
816 /// if you have two nodes with identical results (or if 'To' has a superset
817 /// of the results of 'From'), use the third otherwise.
819 /// These methods all take an optional UpdateListener, which (if not null) is
820 /// informed about nodes that are deleted and modified due to recursive
821 /// changes in the dag.
823 /// These functions only replace all existing uses. It's possible that as
824 /// these replacements are being performed, CSE may cause the From node
825 /// to be given new uses. These new uses of From are left in place, and
826 /// not automatically transfered to To.
828 void ReplaceAllUsesWith(SDValue From, SDValue Op,
829 DAGUpdateListener *UpdateListener = 0);
830 void ReplaceAllUsesWith(SDNode *From, SDNode *To,
831 DAGUpdateListener *UpdateListener = 0);
832 void ReplaceAllUsesWith(SDNode *From, const SDValue *To,
833 DAGUpdateListener *UpdateListener = 0);
835 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
836 /// uses of other values produced by From.Val alone.
837 void ReplaceAllUsesOfValueWith(SDValue From, SDValue To,
838 DAGUpdateListener *UpdateListener = 0);
840 /// ReplaceAllUsesOfValuesWith - Like ReplaceAllUsesOfValueWith, but
841 /// for multiple values at once. This correctly handles the case where
842 /// there is an overlap between the From values and the To values.
843 void ReplaceAllUsesOfValuesWith(const SDValue *From, const SDValue *To,
845 DAGUpdateListener *UpdateListener = 0);
847 /// AssignTopologicalOrder - Topological-sort the AllNodes list and a
848 /// assign a unique node id for each node in the DAG based on their
849 /// topological order. Returns the number of nodes.
850 unsigned AssignTopologicalOrder();
852 /// RepositionNode - Move node N in the AllNodes list to be immediately
853 /// before the given iterator Position. This may be used to update the
854 /// topological ordering when the list of nodes is modified.
855 void RepositionNode(allnodes_iterator Position, SDNode *N) {
856 AllNodes.insert(Position, AllNodes.remove(N));
859 /// isCommutativeBinOp - Returns true if the opcode is a commutative binary
861 static bool isCommutativeBinOp(unsigned Opcode) {
862 // FIXME: This should get its info from the td file, so that we can include
879 case ISD::ADDE: return true;
880 default: return false;
884 /// AssignOrdering - Assign an order to the SDNode.
885 void AssignOrdering(const SDNode *SD, unsigned Order);
887 /// GetOrdering - Get the order for the SDNode.
888 unsigned GetOrdering(const SDNode *SD) const;
890 /// AddDbgValue - Add a dbg_value SDNode. If SD is non-null that means the
891 /// value is produced by SD.
892 void AddDbgValue(SDDbgValue *DB, SDNode *SD, bool isParameter);
894 /// GetDbgValues - Get the debug values which reference the given SDNode.
895 SmallVector<SDDbgValue*,2> &GetDbgValues(const SDNode* SD) {
896 return DbgInfo->getSDDbgValues(SD);
899 /// hasDebugValues - Return true if there are any SDDbgValue nodes associated
900 /// with this SelectionDAG.
901 bool hasDebugValues() const { return !DbgInfo->empty(); }
903 SDDbgInfo::DbgIterator DbgBegin() { return DbgInfo->DbgBegin(); }
904 SDDbgInfo::DbgIterator DbgEnd() { return DbgInfo->DbgEnd(); }
905 SDDbgInfo::DbgIterator ByvalParmDbgBegin() {
906 return DbgInfo->ByvalParmDbgBegin();
908 SDDbgInfo::DbgIterator ByvalParmDbgEnd() {
909 return DbgInfo->ByvalParmDbgEnd();
914 /// CreateStackTemporary - Create a stack temporary, suitable for holding the
915 /// specified value type. If minAlign is specified, the slot size will have
916 /// at least that alignment.
917 SDValue CreateStackTemporary(EVT VT, unsigned minAlign = 1);
919 /// CreateStackTemporary - Create a stack temporary suitable for holding
920 /// either of the specified value types.
921 SDValue CreateStackTemporary(EVT VT1, EVT VT2);
923 /// FoldConstantArithmetic -
924 SDValue FoldConstantArithmetic(unsigned Opcode,
926 ConstantSDNode *Cst1,
927 ConstantSDNode *Cst2);
929 /// FoldSetCC - Constant fold a setcc to true or false.
930 SDValue FoldSetCC(EVT VT, SDValue N1,
931 SDValue N2, ISD::CondCode Cond, DebugLoc dl);
933 /// SignBitIsZero - Return true if the sign bit of Op is known to be zero. We
934 /// use this predicate to simplify operations downstream.
935 bool SignBitIsZero(SDValue Op, unsigned Depth = 0) const;
937 /// MaskedValueIsZero - Return true if 'Op & Mask' is known to be zero. We
938 /// use this predicate to simplify operations downstream. Op and Mask are
939 /// known to be the same type.
940 bool MaskedValueIsZero(SDValue Op, const APInt &Mask, unsigned Depth = 0)
943 /// ComputeMaskedBits - Determine which of the bits specified in Mask are
944 /// known to be either zero or one and return them in the KnownZero/KnownOne
945 /// bitsets. This code only analyzes bits in Mask, in order to short-circuit
946 /// processing. Targets can implement the computeMaskedBitsForTargetNode
947 /// method in the TargetLowering class to allow target nodes to be understood.
948 void ComputeMaskedBits(SDValue Op, const APInt &Mask, APInt &KnownZero,
949 APInt &KnownOne, unsigned Depth = 0) const;
951 /// ComputeNumSignBits - Return the number of times the sign bit of the
952 /// register is replicated into the other bits. We know that at least 1 bit
953 /// is always equal to the sign bit (itself), but other cases can give us
954 /// information. For example, immediately after an "SRA X, 2", we know that
955 /// the top 3 bits are all equal to each other, so we return 3. Targets can
956 /// implement the ComputeNumSignBitsForTarget method in the TargetLowering
957 /// class to allow target nodes to be understood.
958 unsigned ComputeNumSignBits(SDValue Op, unsigned Depth = 0) const;
960 /// isKnownNeverNan - Test whether the given SDValue is known to never be NaN.
961 bool isKnownNeverNaN(SDValue Op) const;
963 /// isKnownNeverZero - Test whether the given SDValue is known to never be
964 /// positive or negative Zero.
965 bool isKnownNeverZero(SDValue Op) const;
967 /// isEqualTo - Test whether two SDValues are known to compare equal. This
968 /// is true if they are the same value, or if one is negative zero and the
969 /// other positive zero.
970 bool isEqualTo(SDValue A, SDValue B) const;
972 /// isVerifiedDebugInfoDesc - Returns true if the specified SDValue has
973 /// been verified as a debug information descriptor.
974 bool isVerifiedDebugInfoDesc(SDValue Op) const;
976 /// getShuffleScalarElt - Returns the scalar element that will make up the ith
977 /// element of the result of the vector shuffle.
978 SDValue getShuffleScalarElt(const ShuffleVectorSDNode *N, unsigned Idx);
980 /// UnrollVectorOp - Utility function used by legalize and lowering to
981 /// "unroll" a vector operation by splitting out the scalars and operating
982 /// on each element individually. If the ResNE is 0, fully unroll the vector
983 /// op. If ResNE is less than the width of the vector op, unroll up to ResNE.
984 /// If the ResNE is greater than the width of the vector op, unroll the
985 /// vector op and fill the end of the resulting vector with UNDEFS.
986 SDValue UnrollVectorOp(SDNode *N, unsigned ResNE = 0);
988 /// isConsecutiveLoad - Return true if LD is loading 'Bytes' bytes from a
989 /// location that is 'Dist' units away from the location that the 'Base' load
991 bool isConsecutiveLoad(LoadSDNode *LD, LoadSDNode *Base,
992 unsigned Bytes, int Dist) const;
994 /// InferPtrAlignment - Infer alignment of a load / store address. Return 0 if
995 /// it cannot be inferred.
996 unsigned InferPtrAlignment(SDValue Ptr) const;
999 bool RemoveNodeFromCSEMaps(SDNode *N);
1000 void AddModifiedNodeToCSEMaps(SDNode *N, DAGUpdateListener *UpdateListener);
1001 SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op, void *&InsertPos);
1002 SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op1, SDValue Op2,
1004 SDNode *FindModifiedNodeSlot(SDNode *N, const SDValue *Ops, unsigned NumOps,
1007 void DeleteNodeNotInCSEMaps(SDNode *N);
1008 void DeallocateNode(SDNode *N);
1010 unsigned getEVTAlignment(EVT MemoryVT) const;
1012 void allnodes_clear();
1014 /// VTList - List of non-single value types.
1015 std::vector<SDVTList> VTList;
1017 /// CondCodeNodes - Maps to auto-CSE operations.
1018 std::vector<CondCodeSDNode*> CondCodeNodes;
1020 std::vector<SDNode*> ValueTypeNodes;
1021 std::map<EVT, SDNode*, EVT::compareRawBits> ExtendedValueTypeNodes;
1022 StringMap<SDNode*> ExternalSymbols;
1024 std::map<std::pair<std::string, unsigned char>,SDNode*> TargetExternalSymbols;
1027 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
1028 typedef SelectionDAG::allnodes_iterator nodes_iterator;
1029 static nodes_iterator nodes_begin(SelectionDAG *G) {
1030 return G->allnodes_begin();
1032 static nodes_iterator nodes_end(SelectionDAG *G) {
1033 return G->allnodes_end();
1037 } // end namespace llvm