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/DenseSet.h"
19 #include "llvm/ADT/SetVector.h"
20 #include "llvm/ADT/StringMap.h"
21 #include "llvm/ADT/ilist.h"
22 #include "llvm/CodeGen/DAGCombine.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/SelectionDAGNodes.h"
25 #include "llvm/Support/RecyclingAllocator.h"
26 #include "llvm/Target/TargetMachine.h"
35 class MachineConstantPoolValue;
36 class MachineFunction;
40 class TargetSelectionDAGInfo;
42 class SDVTListNode : public FoldingSetNode {
43 friend struct FoldingSetTrait<SDVTListNode>;
44 /// A reference to an Interned FoldingSetNodeID for this node.
45 /// The Allocator in SelectionDAG holds the data.
46 /// SDVTList contains all types which are frequently accessed in SelectionDAG.
47 /// The size of this list is not expected to be big so it won't introduce
49 FoldingSetNodeIDRef FastID;
52 /// The hash value for SDVTList is fixed, so cache it to avoid
56 SDVTListNode(const FoldingSetNodeIDRef ID, const EVT *VT, unsigned int Num) :
57 FastID(ID), VTs(VT), NumVTs(Num) {
58 HashValue = ID.ComputeHash();
60 SDVTList getSDVTList() {
61 SDVTList result = {VTs, NumVTs};
66 /// Specialize FoldingSetTrait for SDVTListNode
67 /// to avoid computing temp FoldingSetNodeID and hash value.
68 template<> struct FoldingSetTrait<SDVTListNode> : DefaultFoldingSetTrait<SDVTListNode> {
69 static void Profile(const SDVTListNode &X, FoldingSetNodeID& ID) {
72 static bool Equals(const SDVTListNode &X, const FoldingSetNodeID &ID,
73 unsigned IDHash, FoldingSetNodeID &TempID) {
74 if (X.HashValue != IDHash)
76 return ID == X.FastID;
78 static unsigned ComputeHash(const SDVTListNode &X, FoldingSetNodeID &TempID) {
83 template<> struct ilist_traits<SDNode> : public ilist_default_traits<SDNode> {
85 mutable ilist_half_node<SDNode> Sentinel;
87 SDNode *createSentinel() const {
88 return static_cast<SDNode*>(&Sentinel);
90 static void destroySentinel(SDNode *) {}
92 SDNode *provideInitialHead() const { return createSentinel(); }
93 SDNode *ensureHead(SDNode*) const { return createSentinel(); }
94 static void noteHead(SDNode*, SDNode*) {}
96 static void deleteNode(SDNode *) {
97 llvm_unreachable("ilist_traits<SDNode> shouldn't see a deleteNode call!");
100 static void createNode(const SDNode &);
103 /// Keeps track of dbg_value information through SDISel. We do
104 /// not build SDNodes for these so as not to perturb the generated code;
105 /// instead the info is kept off to the side in this structure. Each SDNode may
106 /// have one or more associated dbg_value entries. This information is kept in
108 /// Byval parameters are handled separately because they don't use alloca's,
109 /// which busts the normal mechanism. There is good reason for handling all
110 /// parameters separately: they may not have code generated for them, they
111 /// should always go at the beginning of the function regardless of other code
112 /// motion, and debug info for them is potentially useful even if the parameter
113 /// is unused. Right now only byval parameters are handled separately.
115 SmallVector<SDDbgValue*, 32> DbgValues;
116 SmallVector<SDDbgValue*, 32> ByvalParmDbgValues;
117 typedef DenseMap<const SDNode*, SmallVector<SDDbgValue*, 2> > DbgValMapType;
118 DbgValMapType DbgValMap;
120 void operator=(const SDDbgInfo&) = delete;
121 SDDbgInfo(const SDDbgInfo&) = delete;
125 void add(SDDbgValue *V, const SDNode *Node, bool isParameter) {
127 ByvalParmDbgValues.push_back(V);
128 } else DbgValues.push_back(V);
130 DbgValMap[Node].push_back(V);
133 /// \brief Invalidate all DbgValues attached to the node and remove
134 /// it from the Node-to-DbgValues map.
135 void erase(const SDNode *Node);
140 ByvalParmDbgValues.clear();
144 return DbgValues.empty() && ByvalParmDbgValues.empty();
147 ArrayRef<SDDbgValue*> getSDDbgValues(const SDNode *Node) {
148 DbgValMapType::iterator I = DbgValMap.find(Node);
149 if (I != DbgValMap.end())
151 return ArrayRef<SDDbgValue*>();
154 typedef SmallVectorImpl<SDDbgValue*>::iterator DbgIterator;
155 DbgIterator DbgBegin() { return DbgValues.begin(); }
156 DbgIterator DbgEnd() { return DbgValues.end(); }
157 DbgIterator ByvalParmDbgBegin() { return ByvalParmDbgValues.begin(); }
158 DbgIterator ByvalParmDbgEnd() { return ByvalParmDbgValues.end(); }
162 void checkForCycles(const SelectionDAG *DAG, bool force = false);
164 /// This is used to represent a portion of an LLVM function in a low-level
165 /// Data Dependence DAG representation suitable for instruction selection.
166 /// This DAG is constructed as the first step of instruction selection in order
167 /// to allow implementation of machine specific optimizations
168 /// and code simplifications.
170 /// The representation used by the SelectionDAG is a target-independent
171 /// representation, which has some similarities to the GCC RTL representation,
172 /// but is significantly more simple, powerful, and is a graph form instead of a
176 const TargetMachine &TM;
177 const TargetSelectionDAGInfo *TSI;
178 const TargetLowering *TLI;
180 LLVMContext *Context;
181 CodeGenOpt::Level OptLevel;
183 /// The starting token.
186 /// The root of the entire DAG.
189 /// A linked list of nodes in the current DAG.
190 ilist<SDNode> AllNodes;
192 /// The AllocatorType for allocating SDNodes. We use
193 /// pool allocation with recycling.
194 typedef RecyclingAllocator<BumpPtrAllocator, SDNode, sizeof(LargestSDNode),
195 AlignOf<MostAlignedSDNode>::Alignment>
198 /// Pool allocation for nodes.
199 NodeAllocatorType NodeAllocator;
201 /// This structure is used to memoize nodes, automatically performing
202 /// CSE with existing nodes when a duplicate is requested.
203 FoldingSet<SDNode> CSEMap;
205 /// Pool allocation for machine-opcode SDNode operands.
206 BumpPtrAllocator OperandAllocator;
208 /// Pool allocation for misc. objects that are created once per SelectionDAG.
209 BumpPtrAllocator Allocator;
211 /// Tracks dbg_value information through SDISel.
215 /// Clients of various APIs that cause global effects on
216 /// the DAG can optionally implement this interface. This allows the clients
217 /// to handle the various sorts of updates that happen.
219 /// A DAGUpdateListener automatically registers itself with DAG when it is
220 /// constructed, and removes itself when destroyed in RAII fashion.
221 struct DAGUpdateListener {
222 DAGUpdateListener *const Next;
225 explicit DAGUpdateListener(SelectionDAG &D)
226 : Next(D.UpdateListeners), DAG(D) {
227 DAG.UpdateListeners = this;
230 virtual ~DAGUpdateListener() {
231 assert(DAG.UpdateListeners == this &&
232 "DAGUpdateListeners must be destroyed in LIFO order");
233 DAG.UpdateListeners = Next;
236 /// The node N that was deleted and, if E is not null, an
237 /// equivalent node E that replaced it.
238 virtual void NodeDeleted(SDNode *N, SDNode *E);
240 /// The node N that was updated.
241 virtual void NodeUpdated(SDNode *N);
244 /// When true, additional steps are taken to
245 /// ensure that getConstant() and similar functions return DAG nodes that
246 /// have legal types. This is important after type legalization since
247 /// any illegally typed nodes generated after this point will not experience
248 /// type legalization.
249 bool NewNodesMustHaveLegalTypes;
252 /// DAGUpdateListener is a friend so it can manipulate the listener stack.
253 friend struct DAGUpdateListener;
255 /// Linked list of registered DAGUpdateListener instances.
256 /// This stack is maintained by DAGUpdateListener RAII.
257 DAGUpdateListener *UpdateListeners;
259 /// Implementation of setSubgraphColor.
260 /// Return whether we had to truncate the search.
261 bool setSubgraphColorHelper(SDNode *N, const char *Color,
262 DenseSet<SDNode *> &visited,
263 int level, bool &printed);
265 void operator=(const SelectionDAG&) = delete;
266 SelectionDAG(const SelectionDAG&) = delete;
269 explicit SelectionDAG(const TargetMachine &TM, llvm::CodeGenOpt::Level);
272 /// Prepare this SelectionDAG to process code in the given MachineFunction.
273 void init(MachineFunction &mf);
275 /// Clear state and free memory necessary to make this
276 /// SelectionDAG ready to process a new block.
279 MachineFunction &getMachineFunction() const { return *MF; }
280 const TargetMachine &getTarget() const { return TM; }
281 const TargetSubtargetInfo &getSubtarget() const { return MF->getSubtarget(); }
282 const TargetLowering &getTargetLoweringInfo() const { return *TLI; }
283 const TargetSelectionDAGInfo &getSelectionDAGInfo() const { return *TSI; }
284 LLVMContext *getContext() const {return Context; }
286 /// Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
287 void viewGraph(const std::string &Title);
291 std::map<const SDNode *, std::string> NodeGraphAttrs;
294 /// Clear all previously defined node graph attributes.
295 /// Intended to be used from a debugging tool (eg. gdb).
296 void clearGraphAttrs();
298 /// Set graph attributes for a node. (eg. "color=red".)
299 void setGraphAttrs(const SDNode *N, const char *Attrs);
301 /// Get graph attributes for a node. (eg. "color=red".)
302 /// Used from getNodeAttributes.
303 const std::string getGraphAttrs(const SDNode *N) const;
305 /// Convenience for setting node color attribute.
306 void setGraphColor(const SDNode *N, const char *Color);
308 /// Convenience for setting subgraph color attribute.
309 void setSubgraphColor(SDNode *N, const char *Color);
311 typedef ilist<SDNode>::const_iterator allnodes_const_iterator;
312 allnodes_const_iterator allnodes_begin() const { return AllNodes.begin(); }
313 allnodes_const_iterator allnodes_end() const { return AllNodes.end(); }
314 typedef ilist<SDNode>::iterator allnodes_iterator;
315 allnodes_iterator allnodes_begin() { return AllNodes.begin(); }
316 allnodes_iterator allnodes_end() { return AllNodes.end(); }
317 ilist<SDNode>::size_type allnodes_size() const {
318 return AllNodes.size();
321 /// Return the root tag of the SelectionDAG.
322 const SDValue &getRoot() const { return Root; }
324 /// Return the token chain corresponding to the entry of the function.
325 SDValue getEntryNode() const {
326 return SDValue(const_cast<SDNode *>(&EntryNode), 0);
329 /// Set the current root tag of the SelectionDAG.
331 const SDValue &setRoot(SDValue N) {
332 assert((!N.getNode() || N.getValueType() == MVT::Other) &&
333 "DAG root value is not a chain!");
335 checkForCycles(N.getNode(), this);
338 checkForCycles(this);
342 /// This iterates over the nodes in the SelectionDAG, folding
343 /// certain types of nodes together, or eliminating superfluous nodes. The
344 /// Level argument controls whether Combine is allowed to produce nodes and
345 /// types that are illegal on the target.
346 void Combine(CombineLevel Level, AliasAnalysis &AA,
347 CodeGenOpt::Level OptLevel);
349 /// This transforms the SelectionDAG into a SelectionDAG that
350 /// only uses types natively supported by the target.
351 /// Returns "true" if it made any changes.
353 /// Note that this is an involved process that may invalidate pointers into
355 bool LegalizeTypes();
357 /// This transforms the SelectionDAG into a SelectionDAG that is
358 /// compatible with the target instruction selector, as indicated by the
359 /// TargetLowering object.
361 /// Note that this is an involved process that may invalidate pointers into
365 /// \brief Transforms a SelectionDAG node and any operands to it into a node
366 /// that is compatible with the target instruction selector, as indicated by
367 /// the TargetLowering object.
369 /// \returns true if \c N is a valid, legal node after calling this.
371 /// This essentially runs a single recursive walk of the \c Legalize process
372 /// over the given node (and its operands). This can be used to incrementally
373 /// legalize the DAG. All of the nodes which are directly replaced,
374 /// potentially including N, are added to the output parameter \c
375 /// UpdatedNodes so that the delta to the DAG can be understood by the
378 /// When this returns false, N has been legalized in a way that make the
379 /// pointer passed in no longer valid. It may have even been deleted from the
380 /// DAG, and so it shouldn't be used further. When this returns true, the
381 /// N passed in is a legal node, and can be immediately processed as such.
382 /// This may still have done some work on the DAG, and will still populate
383 /// UpdatedNodes with any new nodes replacing those originally in the DAG.
384 bool LegalizeOp(SDNode *N, SmallSetVector<SDNode *, 16> &UpdatedNodes);
386 /// This transforms the SelectionDAG into a SelectionDAG
387 /// that only uses vector math operations supported by the target. This is
388 /// necessary as a separate step from Legalize because unrolling a vector
389 /// operation can introduce illegal types, which requires running
390 /// LegalizeTypes again.
392 /// This returns true if it made any changes; in that case, LegalizeTypes
393 /// is called again before Legalize.
395 /// Note that this is an involved process that may invalidate pointers into
397 bool LegalizeVectors();
399 /// This method deletes all unreachable nodes in the SelectionDAG.
400 void RemoveDeadNodes();
402 /// Remove the specified node from the system. This node must
403 /// have no referrers.
404 void DeleteNode(SDNode *N);
406 /// Return an SDVTList that represents the list of values specified.
407 SDVTList getVTList(EVT VT);
408 SDVTList getVTList(EVT VT1, EVT VT2);
409 SDVTList getVTList(EVT VT1, EVT VT2, EVT VT3);
410 SDVTList getVTList(EVT VT1, EVT VT2, EVT VT3, EVT VT4);
411 SDVTList getVTList(ArrayRef<EVT> VTs);
413 //===--------------------------------------------------------------------===//
414 // Node creation methods.
416 SDValue getConstant(uint64_t Val, SDLoc DL, EVT VT, bool isTarget = false,
417 bool isOpaque = false);
418 SDValue getConstant(const APInt &Val, SDLoc DL, EVT VT, bool isTarget = false,
419 bool isOpaque = false);
420 SDValue getConstant(const ConstantInt &Val, SDLoc DL, EVT VT,
421 bool isTarget = false, bool isOpaque = false);
422 SDValue getIntPtrConstant(uint64_t Val, SDLoc DL, bool isTarget = false);
423 SDValue getTargetConstant(uint64_t Val, SDLoc DL, EVT VT,
424 bool isOpaque = false) {
425 return getConstant(Val, DL, VT, true, isOpaque);
427 SDValue getTargetConstant(const APInt &Val, SDLoc DL, EVT VT,
428 bool isOpaque = false) {
429 return getConstant(Val, DL, VT, true, isOpaque);
431 SDValue getTargetConstant(const ConstantInt &Val, SDLoc DL, EVT VT,
432 bool isOpaque = false) {
433 return getConstant(Val, DL, VT, true, isOpaque);
435 // The forms below that take a double should only be used for simple
436 // constants that can be exactly represented in VT. No checks are made.
437 SDValue getConstantFP(double Val, SDLoc DL, EVT VT, bool isTarget = false);
438 SDValue getConstantFP(const APFloat& Val, SDLoc DL, EVT VT,
439 bool isTarget = false);
440 SDValue getConstantFP(const ConstantFP &CF, SDLoc DL, EVT VT,
441 bool isTarget = false);
442 SDValue getTargetConstantFP(double Val, SDLoc DL, EVT VT) {
443 return getConstantFP(Val, DL, VT, true);
445 SDValue getTargetConstantFP(const APFloat& Val, SDLoc DL, EVT VT) {
446 return getConstantFP(Val, DL, VT, true);
448 SDValue getTargetConstantFP(const ConstantFP &Val, SDLoc DL, EVT VT) {
449 return getConstantFP(Val, DL, VT, true);
451 SDValue getGlobalAddress(const GlobalValue *GV, SDLoc DL, EVT VT,
452 int64_t offset = 0, bool isTargetGA = false,
453 unsigned char TargetFlags = 0);
454 SDValue getTargetGlobalAddress(const GlobalValue *GV, SDLoc DL, EVT VT,
456 unsigned char TargetFlags = 0) {
457 return getGlobalAddress(GV, DL, VT, offset, true, TargetFlags);
459 SDValue getFrameIndex(int FI, EVT VT, bool isTarget = false);
460 SDValue getTargetFrameIndex(int FI, EVT VT) {
461 return getFrameIndex(FI, VT, true);
463 SDValue getJumpTable(int JTI, EVT VT, bool isTarget = false,
464 unsigned char TargetFlags = 0);
465 SDValue getTargetJumpTable(int JTI, EVT VT, unsigned char TargetFlags = 0) {
466 return getJumpTable(JTI, VT, true, TargetFlags);
468 SDValue getConstantPool(const Constant *C, EVT VT,
469 unsigned Align = 0, int Offs = 0, bool isT=false,
470 unsigned char TargetFlags = 0);
471 SDValue getTargetConstantPool(const Constant *C, EVT VT,
472 unsigned Align = 0, int Offset = 0,
473 unsigned char TargetFlags = 0) {
474 return getConstantPool(C, VT, Align, Offset, true, TargetFlags);
476 SDValue getConstantPool(MachineConstantPoolValue *C, EVT VT,
477 unsigned Align = 0, int Offs = 0, bool isT=false,
478 unsigned char TargetFlags = 0);
479 SDValue getTargetConstantPool(MachineConstantPoolValue *C,
480 EVT VT, unsigned Align = 0,
481 int Offset = 0, unsigned char TargetFlags=0) {
482 return getConstantPool(C, VT, Align, Offset, true, TargetFlags);
484 SDValue getTargetIndex(int Index, EVT VT, int64_t Offset = 0,
485 unsigned char TargetFlags = 0);
486 // When generating a branch to a BB, we don't in general know enough
487 // to provide debug info for the BB at that time, so keep this one around.
488 SDValue getBasicBlock(MachineBasicBlock *MBB);
489 SDValue getBasicBlock(MachineBasicBlock *MBB, SDLoc dl);
490 SDValue getExternalSymbol(const char *Sym, EVT VT);
491 SDValue getExternalSymbol(const char *Sym, SDLoc dl, EVT VT);
492 SDValue getTargetExternalSymbol(const char *Sym, EVT VT,
493 unsigned char TargetFlags = 0);
494 SDValue getValueType(EVT);
495 SDValue getRegister(unsigned Reg, EVT VT);
496 SDValue getRegisterMask(const uint32_t *RegMask);
497 SDValue getEHLabel(SDLoc dl, SDValue Root, MCSymbol *Label);
498 SDValue getBlockAddress(const BlockAddress *BA, EVT VT,
499 int64_t Offset = 0, bool isTarget = false,
500 unsigned char TargetFlags = 0);
501 SDValue getTargetBlockAddress(const BlockAddress *BA, EVT VT,
503 unsigned char TargetFlags = 0) {
504 return getBlockAddress(BA, VT, Offset, true, TargetFlags);
507 SDValue getCopyToReg(SDValue Chain, SDLoc dl, unsigned Reg, SDValue N) {
508 return getNode(ISD::CopyToReg, dl, MVT::Other, Chain,
509 getRegister(Reg, N.getValueType()), N);
512 // This version of the getCopyToReg method takes an extra operand, which
513 // indicates that there is potentially an incoming glue value (if Glue is not
514 // null) and that there should be a glue result.
515 SDValue getCopyToReg(SDValue Chain, SDLoc dl, unsigned Reg, SDValue N,
517 SDVTList VTs = getVTList(MVT::Other, MVT::Glue);
518 SDValue Ops[] = { Chain, getRegister(Reg, N.getValueType()), N, Glue };
519 return getNode(ISD::CopyToReg, dl, VTs,
520 ArrayRef<SDValue>(Ops, Glue.getNode() ? 4 : 3));
523 // Similar to last getCopyToReg() except parameter Reg is a SDValue
524 SDValue getCopyToReg(SDValue Chain, SDLoc dl, SDValue Reg, SDValue N,
526 SDVTList VTs = getVTList(MVT::Other, MVT::Glue);
527 SDValue Ops[] = { Chain, Reg, N, Glue };
528 return getNode(ISD::CopyToReg, dl, VTs,
529 ArrayRef<SDValue>(Ops, Glue.getNode() ? 4 : 3));
532 SDValue getCopyFromReg(SDValue Chain, SDLoc dl, unsigned Reg, EVT VT) {
533 SDVTList VTs = getVTList(VT, MVT::Other);
534 SDValue Ops[] = { Chain, getRegister(Reg, VT) };
535 return getNode(ISD::CopyFromReg, dl, VTs, Ops);
538 // This version of the getCopyFromReg method takes an extra operand, which
539 // indicates that there is potentially an incoming glue value (if Glue is not
540 // null) and that there should be a glue result.
541 SDValue getCopyFromReg(SDValue Chain, SDLoc dl, unsigned Reg, EVT VT,
543 SDVTList VTs = getVTList(VT, MVT::Other, MVT::Glue);
544 SDValue Ops[] = { Chain, getRegister(Reg, VT), Glue };
545 return getNode(ISD::CopyFromReg, dl, VTs,
546 ArrayRef<SDValue>(Ops, Glue.getNode() ? 3 : 2));
549 SDValue getCondCode(ISD::CondCode Cond);
551 /// Returns the ConvertRndSat Note: Avoid using this node because it may
552 /// disappear in the future and most targets don't support it.
553 SDValue getConvertRndSat(EVT VT, SDLoc dl, SDValue Val, SDValue DTy,
555 SDValue Rnd, SDValue Sat, ISD::CvtCode Code);
557 /// Return an ISD::VECTOR_SHUFFLE node. The number of elements in VT,
558 /// which must be a vector type, must match the number of mask elements
559 /// NumElts. An integer mask element equal to -1 is treated as undefined.
560 SDValue getVectorShuffle(EVT VT, SDLoc dl, SDValue N1, SDValue N2,
561 const int *MaskElts);
562 SDValue getVectorShuffle(EVT VT, SDLoc dl, SDValue N1, SDValue N2,
563 ArrayRef<int> MaskElts) {
564 assert(VT.getVectorNumElements() == MaskElts.size() &&
565 "Must have the same number of vector elements as mask elements!");
566 return getVectorShuffle(VT, dl, N1, N2, MaskElts.data());
569 /// \brief Returns an ISD::VECTOR_SHUFFLE node semantically equivalent to
570 /// the shuffle node in input but with swapped operands.
572 /// Example: shuffle A, B, <0,5,2,7> -> shuffle B, A, <4,1,6,3>
573 SDValue getCommutedVectorShuffle(const ShuffleVectorSDNode &SV);
575 /// Convert Op, which must be of integer type, to the
576 /// integer type VT, by either any-extending or truncating it.
577 SDValue getAnyExtOrTrunc(SDValue Op, SDLoc DL, EVT VT);
579 /// Convert Op, which must be of integer type, to the
580 /// integer type VT, by either sign-extending or truncating it.
581 SDValue getSExtOrTrunc(SDValue Op, SDLoc DL, EVT VT);
583 /// Convert Op, which must be of integer type, to the
584 /// integer type VT, by either zero-extending or truncating it.
585 SDValue getZExtOrTrunc(SDValue Op, SDLoc DL, EVT VT);
587 /// Return the expression required to zero extend the Op
588 /// value assuming it was the smaller SrcTy value.
589 SDValue getZeroExtendInReg(SDValue Op, SDLoc DL, EVT SrcTy);
591 /// Return an operation which will any-extend the low lanes of the operand
592 /// into the specified vector type. For example,
593 /// this can convert a v16i8 into a v4i32 by any-extending the low four
594 /// lanes of the operand from i8 to i32.
595 SDValue getAnyExtendVectorInReg(SDValue Op, SDLoc DL, EVT VT);
597 /// Return an operation which will sign extend the low lanes of the operand
598 /// into the specified vector type. For example,
599 /// this can convert a v16i8 into a v4i32 by sign extending the low four
600 /// lanes of the operand from i8 to i32.
601 SDValue getSignExtendVectorInReg(SDValue Op, SDLoc DL, EVT VT);
603 /// Return an operation which will zero extend the low lanes of the operand
604 /// into the specified vector type. For example,
605 /// this can convert a v16i8 into a v4i32 by zero extending the low four
606 /// lanes of the operand from i8 to i32.
607 SDValue getZeroExtendVectorInReg(SDValue Op, SDLoc DL, EVT VT);
609 /// Convert Op, which must be of integer type, to the integer type VT,
610 /// by using an extension appropriate for the target's
611 /// BooleanContent for type OpVT or truncating it.
612 SDValue getBoolExtOrTrunc(SDValue Op, SDLoc SL, EVT VT, EVT OpVT);
614 /// Create a bitwise NOT operation as (XOR Val, -1).
615 SDValue getNOT(SDLoc DL, SDValue Val, EVT VT);
617 /// \brief Create a logical NOT operation as (XOR Val, BooleanOne).
618 SDValue getLogicalNOT(SDLoc DL, SDValue Val, EVT VT);
620 /// Return a new CALLSEQ_START node, which always must have a glue result
621 /// (to ensure it's not CSE'd). CALLSEQ_START does not have a useful SDLoc.
622 SDValue getCALLSEQ_START(SDValue Chain, SDValue Op, SDLoc DL) {
623 SDVTList VTs = getVTList(MVT::Other, MVT::Glue);
624 SDValue Ops[] = { Chain, Op };
625 return getNode(ISD::CALLSEQ_START, DL, VTs, Ops);
628 /// Return a new CALLSEQ_END node, which always must have a
629 /// glue result (to ensure it's not CSE'd).
630 /// CALLSEQ_END does not have a useful SDLoc.
631 SDValue getCALLSEQ_END(SDValue Chain, SDValue Op1, SDValue Op2,
632 SDValue InGlue, SDLoc DL) {
633 SDVTList NodeTys = getVTList(MVT::Other, MVT::Glue);
634 SmallVector<SDValue, 4> Ops;
635 Ops.push_back(Chain);
638 if (InGlue.getNode())
639 Ops.push_back(InGlue);
640 return getNode(ISD::CALLSEQ_END, DL, NodeTys, Ops);
643 /// Return an UNDEF node. UNDEF does not have a useful SDLoc.
644 SDValue getUNDEF(EVT VT) {
645 return getNode(ISD::UNDEF, SDLoc(), VT);
648 /// Return a GLOBAL_OFFSET_TABLE node. This does not have a useful SDLoc.
649 SDValue getGLOBAL_OFFSET_TABLE(EVT VT) {
650 return getNode(ISD::GLOBAL_OFFSET_TABLE, SDLoc(), VT);
653 /// Gets or creates the specified node.
655 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT,
656 ArrayRef<SDUse> Ops);
657 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT,
658 ArrayRef<SDValue> Ops);
659 SDValue getNode(unsigned Opcode, SDLoc DL, ArrayRef<EVT> ResultTys,
660 ArrayRef<SDValue> Ops);
661 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs,
662 ArrayRef<SDValue> Ops);
664 // Specialize based on number of operands.
665 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT);
666 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT, SDValue N);
667 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT, SDValue N1, SDValue N2,
668 const SDNodeFlags *Flags = nullptr);
669 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT, SDValue N1, SDValue N2,
671 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT, SDValue N1, SDValue N2,
672 SDValue N3, SDValue N4);
673 SDValue getNode(unsigned Opcode, SDLoc DL, EVT VT, SDValue N1, SDValue N2,
674 SDValue N3, SDValue N4, SDValue N5);
676 // Specialize again based on number of operands for nodes with a VTList
677 // rather than a single VT.
678 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs);
679 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs, SDValue N);
680 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs, SDValue N1,
682 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs, SDValue N1,
683 SDValue N2, SDValue N3);
684 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs, SDValue N1,
685 SDValue N2, SDValue N3, SDValue N4);
686 SDValue getNode(unsigned Opcode, SDLoc DL, SDVTList VTs, SDValue N1,
687 SDValue N2, SDValue N3, SDValue N4, SDValue N5);
689 /// Compute a TokenFactor to force all the incoming stack arguments to be
690 /// loaded from the stack. This is used in tail call lowering to protect
691 /// stack arguments from being clobbered.
692 SDValue getStackArgumentTokenFactor(SDValue Chain);
694 SDValue getMemcpy(SDValue Chain, SDLoc dl, SDValue Dst, SDValue Src,
695 SDValue Size, unsigned Align, bool isVol, bool AlwaysInline,
696 bool isTailCall, MachinePointerInfo DstPtrInfo,
697 MachinePointerInfo SrcPtrInfo);
699 SDValue getMemmove(SDValue Chain, SDLoc dl, SDValue Dst, SDValue Src,
700 SDValue Size, unsigned Align, bool isVol, bool isTailCall,
701 MachinePointerInfo DstPtrInfo,
702 MachinePointerInfo SrcPtrInfo);
704 SDValue getMemset(SDValue Chain, SDLoc dl, SDValue Dst, SDValue Src,
705 SDValue Size, unsigned Align, bool isVol, bool isTailCall,
706 MachinePointerInfo DstPtrInfo);
708 /// Helper function to make it easier to build SetCC's if you just
709 /// have an ISD::CondCode instead of an SDValue.
711 SDValue getSetCC(SDLoc DL, EVT VT, SDValue LHS, SDValue RHS,
712 ISD::CondCode Cond) {
713 assert(LHS.getValueType().isVector() == RHS.getValueType().isVector() &&
714 "Cannot compare scalars to vectors");
715 assert(LHS.getValueType().isVector() == VT.isVector() &&
716 "Cannot compare scalars to vectors");
717 assert(Cond != ISD::SETCC_INVALID &&
718 "Cannot create a setCC of an invalid node.");
719 return getNode(ISD::SETCC, DL, VT, LHS, RHS, getCondCode(Cond));
722 /// Helper function to make it easier to build Select's if you just
723 /// have operands and don't want to check for vector.
724 SDValue getSelect(SDLoc DL, EVT VT, SDValue Cond,
725 SDValue LHS, SDValue RHS) {
726 assert(LHS.getValueType() == RHS.getValueType() &&
727 "Cannot use select on differing types");
728 assert(VT.isVector() == LHS.getValueType().isVector() &&
729 "Cannot mix vectors and scalars");
730 return getNode(Cond.getValueType().isVector() ? ISD::VSELECT : ISD::SELECT, DL, VT,
734 /// Helper function to make it easier to build SelectCC's if you
735 /// just have an ISD::CondCode instead of an SDValue.
737 SDValue getSelectCC(SDLoc DL, SDValue LHS, SDValue RHS,
738 SDValue True, SDValue False, ISD::CondCode Cond) {
739 return getNode(ISD::SELECT_CC, DL, True.getValueType(),
740 LHS, RHS, True, False, getCondCode(Cond));
743 /// VAArg produces a result and token chain, and takes a pointer
744 /// and a source value as input.
745 SDValue getVAArg(EVT VT, SDLoc dl, SDValue Chain, SDValue Ptr,
746 SDValue SV, unsigned Align);
748 /// Gets a node for an atomic cmpxchg op. There are two
749 /// valid Opcodes. ISD::ATOMIC_CMO_SWAP produces the value loaded and a
750 /// chain result. ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS produces the value loaded,
751 /// a success flag (initially i1), and a chain.
752 SDValue getAtomicCmpSwap(unsigned Opcode, SDLoc dl, EVT MemVT, SDVTList VTs,
753 SDValue Chain, SDValue Ptr, SDValue Cmp, SDValue Swp,
754 MachinePointerInfo PtrInfo, unsigned Alignment,
755 AtomicOrdering SuccessOrdering,
756 AtomicOrdering FailureOrdering,
757 SynchronizationScope SynchScope);
758 SDValue getAtomicCmpSwap(unsigned Opcode, SDLoc dl, EVT MemVT, SDVTList VTs,
759 SDValue Chain, SDValue Ptr, SDValue Cmp, SDValue Swp,
760 MachineMemOperand *MMO,
761 AtomicOrdering SuccessOrdering,
762 AtomicOrdering FailureOrdering,
763 SynchronizationScope SynchScope);
765 /// Gets a node for an atomic op, produces result (if relevant)
766 /// and chain and takes 2 operands.
767 SDValue getAtomic(unsigned Opcode, SDLoc dl, EVT MemVT, SDValue Chain,
768 SDValue Ptr, SDValue Val, const Value *PtrVal,
769 unsigned Alignment, AtomicOrdering Ordering,
770 SynchronizationScope SynchScope);
771 SDValue getAtomic(unsigned Opcode, SDLoc dl, EVT MemVT, SDValue Chain,
772 SDValue Ptr, SDValue Val, MachineMemOperand *MMO,
773 AtomicOrdering Ordering,
774 SynchronizationScope SynchScope);
776 /// Gets a node for an atomic op, produces result and chain and
778 SDValue getAtomic(unsigned Opcode, SDLoc dl, EVT MemVT, EVT VT,
779 SDValue Chain, SDValue Ptr, MachineMemOperand *MMO,
780 AtomicOrdering Ordering,
781 SynchronizationScope SynchScope);
783 /// Gets a node for an atomic op, produces result and chain and takes N
785 SDValue getAtomic(unsigned Opcode, SDLoc dl, EVT MemVT, SDVTList VTList,
786 ArrayRef<SDValue> Ops, MachineMemOperand *MMO,
787 AtomicOrdering SuccessOrdering,
788 AtomicOrdering FailureOrdering,
789 SynchronizationScope SynchScope);
790 SDValue getAtomic(unsigned Opcode, SDLoc dl, EVT MemVT, SDVTList VTList,
791 ArrayRef<SDValue> Ops, MachineMemOperand *MMO,
792 AtomicOrdering Ordering, SynchronizationScope SynchScope);
794 /// Creates a MemIntrinsicNode that may produce a
795 /// result and takes a list of operands. Opcode may be INTRINSIC_VOID,
796 /// INTRINSIC_W_CHAIN, or a target-specific opcode with a value not
797 /// less than FIRST_TARGET_MEMORY_OPCODE.
798 SDValue getMemIntrinsicNode(unsigned Opcode, SDLoc dl, SDVTList VTList,
799 ArrayRef<SDValue> Ops,
800 EVT MemVT, MachinePointerInfo PtrInfo,
801 unsigned Align = 0, bool Vol = false,
802 bool ReadMem = true, bool WriteMem = true,
805 SDValue getMemIntrinsicNode(unsigned Opcode, SDLoc dl, SDVTList VTList,
806 ArrayRef<SDValue> Ops,
807 EVT MemVT, MachineMemOperand *MMO);
809 /// Create a MERGE_VALUES node from the given operands.
810 SDValue getMergeValues(ArrayRef<SDValue> Ops, SDLoc dl);
812 /// Loads are not normal binary operators: their result type is not
813 /// determined by their operands, and they produce a value AND a token chain.
815 SDValue getLoad(EVT VT, SDLoc dl, SDValue Chain, SDValue Ptr,
816 MachinePointerInfo PtrInfo, bool isVolatile,
817 bool isNonTemporal, bool isInvariant, unsigned Alignment,
818 const AAMDNodes &AAInfo = AAMDNodes(),
819 const MDNode *Ranges = nullptr);
820 SDValue getLoad(EVT VT, SDLoc dl, SDValue Chain, SDValue Ptr,
821 MachineMemOperand *MMO);
822 SDValue getExtLoad(ISD::LoadExtType ExtType, SDLoc dl, EVT VT,
823 SDValue Chain, SDValue Ptr, MachinePointerInfo PtrInfo,
824 EVT MemVT, bool isVolatile,
825 bool isNonTemporal, bool isInvariant, unsigned Alignment,
826 const AAMDNodes &AAInfo = AAMDNodes());
827 SDValue getExtLoad(ISD::LoadExtType ExtType, SDLoc dl, EVT VT,
828 SDValue Chain, SDValue Ptr, EVT MemVT,
829 MachineMemOperand *MMO);
830 SDValue getIndexedLoad(SDValue OrigLoad, SDLoc dl, SDValue Base,
831 SDValue Offset, ISD::MemIndexedMode AM);
832 SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
834 SDValue Chain, SDValue Ptr, SDValue Offset,
835 MachinePointerInfo PtrInfo, EVT MemVT,
836 bool isVolatile, bool isNonTemporal, bool isInvariant,
837 unsigned Alignment, const AAMDNodes &AAInfo = AAMDNodes(),
838 const MDNode *Ranges = nullptr);
839 SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
841 SDValue Chain, SDValue Ptr, SDValue Offset,
842 EVT MemVT, MachineMemOperand *MMO);
844 /// Helper function to build ISD::STORE nodes.
845 SDValue getStore(SDValue Chain, SDLoc dl, SDValue Val, SDValue Ptr,
846 MachinePointerInfo PtrInfo, bool isVolatile,
847 bool isNonTemporal, unsigned Alignment,
848 const AAMDNodes &AAInfo = AAMDNodes());
849 SDValue getStore(SDValue Chain, SDLoc dl, SDValue Val, SDValue Ptr,
850 MachineMemOperand *MMO);
851 SDValue getTruncStore(SDValue Chain, SDLoc dl, SDValue Val, SDValue Ptr,
852 MachinePointerInfo PtrInfo, EVT TVT,
853 bool isNonTemporal, bool isVolatile,
855 const AAMDNodes &AAInfo = AAMDNodes());
856 SDValue getTruncStore(SDValue Chain, SDLoc dl, SDValue Val, SDValue Ptr,
857 EVT TVT, MachineMemOperand *MMO);
858 SDValue getIndexedStore(SDValue OrigStoe, SDLoc dl, SDValue Base,
859 SDValue Offset, ISD::MemIndexedMode AM);
861 SDValue getMaskedLoad(EVT VT, SDLoc dl, SDValue Chain, SDValue Ptr,
862 SDValue Mask, SDValue Src0, EVT MemVT,
863 MachineMemOperand *MMO, ISD::LoadExtType);
864 SDValue getMaskedStore(SDValue Chain, SDLoc dl, SDValue Val,
865 SDValue Ptr, SDValue Mask, EVT MemVT,
866 MachineMemOperand *MMO, bool IsTrunc);
867 SDValue getMaskedGather(SDVTList VTs, EVT VT, SDLoc dl,
868 ArrayRef<SDValue> Ops, MachineMemOperand *MMO);
869 SDValue getMaskedScatter(SDVTList VTs, EVT VT, SDLoc dl,
870 ArrayRef<SDValue> Ops, MachineMemOperand *MMO);
871 /// Construct a node to track a Value* through the backend.
872 SDValue getSrcValue(const Value *v);
874 /// Return an MDNodeSDNode which holds an MDNode.
875 SDValue getMDNode(const MDNode *MD);
877 /// Return an AddrSpaceCastSDNode.
878 SDValue getAddrSpaceCast(SDLoc dl, EVT VT, SDValue Ptr,
879 unsigned SrcAS, unsigned DestAS);
881 /// Return the specified value casted to
882 /// the target's desired shift amount type.
883 SDValue getShiftAmountOperand(EVT LHSTy, SDValue Op);
885 /// *Mutate* the specified node in-place to have the
886 /// specified operands. If the resultant node already exists in the DAG,
887 /// this does not modify the specified node, instead it returns the node that
888 /// already exists. If the resultant node does not exist in the DAG, the
889 /// input node is returned. As a degenerate case, if you specify the same
890 /// input operands as the node already has, the input node is returned.
891 SDNode *UpdateNodeOperands(SDNode *N, SDValue Op);
892 SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2);
893 SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2,
895 SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2,
896 SDValue Op3, SDValue Op4);
897 SDNode *UpdateNodeOperands(SDNode *N, SDValue Op1, SDValue Op2,
898 SDValue Op3, SDValue Op4, SDValue Op5);
899 SDNode *UpdateNodeOperands(SDNode *N, ArrayRef<SDValue> Ops);
901 /// These are used for target selectors to *mutate* the
902 /// specified node to have the specified return type, Target opcode, and
903 /// operands. Note that target opcodes are stored as
904 /// ~TargetOpcode in the node opcode field. The resultant node is returned.
905 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT);
906 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT, SDValue Op1);
907 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT,
908 SDValue Op1, SDValue Op2);
909 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT,
910 SDValue Op1, SDValue Op2, SDValue Op3);
911 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT,
912 ArrayRef<SDValue> Ops);
913 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1, EVT VT2);
914 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
915 EVT VT2, ArrayRef<SDValue> Ops);
916 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
917 EVT VT2, EVT VT3, ArrayRef<SDValue> Ops);
918 SDNode *SelectNodeTo(SDNode *N, unsigned MachineOpc, EVT VT1,
919 EVT VT2, EVT VT3, EVT VT4, ArrayRef<SDValue> Ops);
920 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
921 EVT VT2, SDValue Op1);
922 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
923 EVT VT2, SDValue Op1, SDValue Op2);
924 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
925 EVT VT2, SDValue Op1, SDValue Op2, SDValue Op3);
926 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, EVT VT1,
927 EVT VT2, EVT VT3, SDValue Op1, SDValue Op2, SDValue Op3);
928 SDNode *SelectNodeTo(SDNode *N, unsigned TargetOpc, SDVTList VTs,
929 ArrayRef<SDValue> Ops);
931 /// This *mutates* the specified node to have the specified
932 /// return type, opcode, and operands.
933 SDNode *MorphNodeTo(SDNode *N, unsigned Opc, SDVTList VTs,
934 ArrayRef<SDValue> Ops);
936 /// These are used for target selectors to create a new node
937 /// with specified return type(s), MachineInstr opcode, and operands.
939 /// Note that getMachineNode returns the resultant node. If there is already
940 /// a node of the specified opcode and operands, it returns that node instead
941 /// of the current one.
942 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT);
943 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT,
945 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT,
946 SDValue Op1, SDValue Op2);
947 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT,
948 SDValue Op1, SDValue Op2, SDValue Op3);
949 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT,
950 ArrayRef<SDValue> Ops);
951 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2);
952 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
954 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
955 SDValue Op1, SDValue Op2);
956 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
957 SDValue Op1, SDValue Op2, SDValue Op3);
958 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
959 ArrayRef<SDValue> Ops);
960 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
961 EVT VT3, SDValue Op1, SDValue Op2);
962 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
963 EVT VT3, SDValue Op1, SDValue Op2,
965 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
966 EVT VT3, ArrayRef<SDValue> Ops);
967 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, EVT VT1, EVT VT2,
968 EVT VT3, EVT VT4, ArrayRef<SDValue> Ops);
969 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl,
970 ArrayRef<EVT> ResultTys,
971 ArrayRef<SDValue> Ops);
972 MachineSDNode *getMachineNode(unsigned Opcode, SDLoc dl, SDVTList VTs,
973 ArrayRef<SDValue> Ops);
975 /// A convenience function for creating TargetInstrInfo::EXTRACT_SUBREG nodes.
976 SDValue getTargetExtractSubreg(int SRIdx, SDLoc DL, EVT VT,
979 /// A convenience function for creating TargetInstrInfo::INSERT_SUBREG nodes.
980 SDValue getTargetInsertSubreg(int SRIdx, SDLoc DL, EVT VT,
981 SDValue Operand, SDValue Subreg);
983 /// Get the specified node if it's already available, or else return NULL.
984 SDNode *getNodeIfExists(unsigned Opcode, SDVTList VTs, ArrayRef<SDValue> Ops,
985 const SDNodeFlags *Flags = nullptr);
987 /// Creates a SDDbgValue node.
988 SDDbgValue *getDbgValue(MDNode *Var, MDNode *Expr, SDNode *N, unsigned R,
989 bool IsIndirect, uint64_t Off, DebugLoc DL,
993 SDDbgValue *getConstantDbgValue(MDNode *Var, MDNode *Expr, const Value *C,
994 uint64_t Off, DebugLoc DL, unsigned O);
997 SDDbgValue *getFrameIndexDbgValue(MDNode *Var, MDNode *Expr, unsigned FI,
998 uint64_t Off, DebugLoc DL, unsigned O);
1000 /// Remove the specified node from the system. If any of its
1001 /// operands then becomes dead, remove them as well. Inform UpdateListener
1002 /// for each node deleted.
1003 void RemoveDeadNode(SDNode *N);
1005 /// This method deletes the unreachable nodes in the
1006 /// given list, and any nodes that become unreachable as a result.
1007 void RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes);
1009 /// Modify anything using 'From' to use 'To' instead.
1010 /// This can cause recursive merging of nodes in the DAG. Use the first
1011 /// version if 'From' is known to have a single result, use the second
1012 /// if you have two nodes with identical results (or if 'To' has a superset
1013 /// of the results of 'From'), use the third otherwise.
1015 /// These methods all take an optional UpdateListener, which (if not null) is
1016 /// informed about nodes that are deleted and modified due to recursive
1017 /// changes in the dag.
1019 /// These functions only replace all existing uses. It's possible that as
1020 /// these replacements are being performed, CSE may cause the From node
1021 /// to be given new uses. These new uses of From are left in place, and
1022 /// not automatically transferred to To.
1024 void ReplaceAllUsesWith(SDValue From, SDValue Op);
1025 void ReplaceAllUsesWith(SDNode *From, SDNode *To);
1026 void ReplaceAllUsesWith(SDNode *From, const SDValue *To);
1028 /// Replace any uses of From with To, leaving
1029 /// uses of other values produced by From.Val alone.
1030 void ReplaceAllUsesOfValueWith(SDValue From, SDValue To);
1032 /// Like ReplaceAllUsesOfValueWith, but for multiple values at once.
1033 /// This correctly handles the case where
1034 /// there is an overlap between the From values and the To values.
1035 void ReplaceAllUsesOfValuesWith(const SDValue *From, const SDValue *To,
1038 /// Topological-sort the AllNodes list and a
1039 /// assign a unique node id for each node in the DAG based on their
1040 /// topological order. Returns the number of nodes.
1041 unsigned AssignTopologicalOrder();
1043 /// Move node N in the AllNodes list to be immediately
1044 /// before the given iterator Position. This may be used to update the
1045 /// topological ordering when the list of nodes is modified.
1046 void RepositionNode(allnodes_iterator Position, SDNode *N) {
1047 AllNodes.insert(Position, AllNodes.remove(N));
1050 /// Returns true if the opcode is a commutative binary operation.
1051 static bool isCommutativeBinOp(unsigned Opcode) {
1052 // FIXME: This should get its info from the td file, so that we can include
1059 case ISD::SMUL_LOHI:
1060 case ISD::UMUL_LOHI:
1073 default: return false;
1077 /// Returns an APFloat semantics tag appropriate for the given type. If VT is
1078 /// a vector type, the element semantics are returned.
1079 static const fltSemantics &EVTToAPFloatSemantics(EVT VT) {
1080 switch (VT.getScalarType().getSimpleVT().SimpleTy) {
1081 default: llvm_unreachable("Unknown FP format");
1082 case MVT::f16: return APFloat::IEEEhalf;
1083 case MVT::f32: return APFloat::IEEEsingle;
1084 case MVT::f64: return APFloat::IEEEdouble;
1085 case MVT::f80: return APFloat::x87DoubleExtended;
1086 case MVT::f128: return APFloat::IEEEquad;
1087 case MVT::ppcf128: return APFloat::PPCDoubleDouble;
1091 /// Add a dbg_value SDNode. If SD is non-null that means the
1092 /// value is produced by SD.
1093 void AddDbgValue(SDDbgValue *DB, SDNode *SD, bool isParameter);
1095 /// Get the debug values which reference the given SDNode.
1096 ArrayRef<SDDbgValue*> GetDbgValues(const SDNode* SD) {
1097 return DbgInfo->getSDDbgValues(SD);
1100 /// Transfer SDDbgValues.
1101 void TransferDbgValues(SDValue From, SDValue To);
1103 /// Return true if there are any SDDbgValue nodes associated
1104 /// with this SelectionDAG.
1105 bool hasDebugValues() const { return !DbgInfo->empty(); }
1107 SDDbgInfo::DbgIterator DbgBegin() { return DbgInfo->DbgBegin(); }
1108 SDDbgInfo::DbgIterator DbgEnd() { return DbgInfo->DbgEnd(); }
1109 SDDbgInfo::DbgIterator ByvalParmDbgBegin() {
1110 return DbgInfo->ByvalParmDbgBegin();
1112 SDDbgInfo::DbgIterator ByvalParmDbgEnd() {
1113 return DbgInfo->ByvalParmDbgEnd();
1118 /// Create a stack temporary, suitable for holding the
1119 /// specified value type. If minAlign is specified, the slot size will have
1120 /// at least that alignment.
1121 SDValue CreateStackTemporary(EVT VT, unsigned minAlign = 1);
1123 /// Create a stack temporary suitable for holding
1124 /// either of the specified value types.
1125 SDValue CreateStackTemporary(EVT VT1, EVT VT2);
1127 SDValue FoldConstantArithmetic(unsigned Opcode, SDLoc DL, EVT VT,
1128 SDNode *Cst1, SDNode *Cst2);
1130 /// Constant fold a setcc to true or false.
1131 SDValue FoldSetCC(EVT VT, SDValue N1,
1132 SDValue N2, ISD::CondCode Cond, SDLoc dl);
1134 /// Return true if the sign bit of Op is known to be zero.
1135 /// We use this predicate to simplify operations downstream.
1136 bool SignBitIsZero(SDValue Op, unsigned Depth = 0) const;
1138 /// Return true if 'Op & Mask' is known to be zero. We
1139 /// use this predicate to simplify operations downstream. Op and Mask are
1140 /// known to be the same type.
1141 bool MaskedValueIsZero(SDValue Op, const APInt &Mask, unsigned Depth = 0)
1144 /// Determine which bits of Op are known to be either zero or one and return
1145 /// them in the KnownZero/KnownOne bitsets. Targets can implement the
1146 /// computeKnownBitsForTargetNode method in the TargetLowering class to allow
1147 /// target nodes to be understood.
1148 void computeKnownBits(SDValue Op, APInt &KnownZero, APInt &KnownOne,
1149 unsigned Depth = 0) const;
1151 /// Return the number of times the sign bit of the
1152 /// register is replicated into the other bits. We know that at least 1 bit
1153 /// is always equal to the sign bit (itself), but other cases can give us
1154 /// information. For example, immediately after an "SRA X, 2", we know that
1155 /// the top 3 bits are all equal to each other, so we return 3. Targets can
1156 /// implement the ComputeNumSignBitsForTarget method in the TargetLowering
1157 /// class to allow target nodes to be understood.
1158 unsigned ComputeNumSignBits(SDValue Op, unsigned Depth = 0) const;
1160 /// Return true if the specified operand is an
1161 /// ISD::ADD with a ConstantSDNode on the right-hand side, or if it is an
1162 /// ISD::OR with a ConstantSDNode that is guaranteed to have the same
1163 /// semantics as an ADD. This handles the equivalence:
1164 /// X|Cst == X+Cst iff X&Cst = 0.
1165 bool isBaseWithConstantOffset(SDValue Op) const;
1167 /// Test whether the given SDValue is known to never be NaN.
1168 bool isKnownNeverNaN(SDValue Op) const;
1170 /// Test whether the given SDValue is known to never be
1171 /// positive or negative Zero.
1172 bool isKnownNeverZero(SDValue Op) const;
1174 /// Test whether two SDValues are known to compare equal. This
1175 /// is true if they are the same value, or if one is negative zero and the
1176 /// other positive zero.
1177 bool isEqualTo(SDValue A, SDValue B) const;
1179 /// Utility function used by legalize and lowering to
1180 /// "unroll" a vector operation by splitting out the scalars and operating
1181 /// on each element individually. If the ResNE is 0, fully unroll the vector
1182 /// op. If ResNE is less than the width of the vector op, unroll up to ResNE.
1183 /// If the ResNE is greater than the width of the vector op, unroll the
1184 /// vector op and fill the end of the resulting vector with UNDEFS.
1185 SDValue UnrollVectorOp(SDNode *N, unsigned ResNE = 0);
1187 /// Return true if LD is loading 'Bytes' bytes from a location that is 'Dist'
1188 /// units away from the location that the 'Base' load is loading from.
1189 bool isConsecutiveLoad(LoadSDNode *LD, LoadSDNode *Base,
1190 unsigned Bytes, int Dist) const;
1192 /// Infer alignment of a load / store address. Return 0 if
1193 /// it cannot be inferred.
1194 unsigned InferPtrAlignment(SDValue Ptr) const;
1196 /// Compute the VTs needed for the low/hi parts of a type
1197 /// which is split (or expanded) into two not necessarily identical pieces.
1198 std::pair<EVT, EVT> GetSplitDestVTs(const EVT &VT) const;
1200 /// Split the vector with EXTRACT_SUBVECTOR using the provides
1201 /// VTs and return the low/high part.
1202 std::pair<SDValue, SDValue> SplitVector(const SDValue &N, const SDLoc &DL,
1203 const EVT &LoVT, const EVT &HiVT);
1205 /// Split the vector with EXTRACT_SUBVECTOR and return the low/high part.
1206 std::pair<SDValue, SDValue> SplitVector(const SDValue &N, const SDLoc &DL) {
1208 std::tie(LoVT, HiVT) = GetSplitDestVTs(N.getValueType());
1209 return SplitVector(N, DL, LoVT, HiVT);
1212 /// Split the node's operand with EXTRACT_SUBVECTOR and
1213 /// return the low/high part.
1214 std::pair<SDValue, SDValue> SplitVectorOperand(const SDNode *N, unsigned OpNo)
1216 return SplitVector(N->getOperand(OpNo), SDLoc(N));
1219 /// Append the extracted elements from Start to Count out of the vector Op
1220 /// in Args. If Count is 0, all of the elements will be extracted.
1221 void ExtractVectorElements(SDValue Op, SmallVectorImpl<SDValue> &Args,
1222 unsigned Start = 0, unsigned Count = 0);
1224 unsigned getEVTAlignment(EVT MemoryVT) const;
1227 void InsertNode(SDNode *N);
1228 bool RemoveNodeFromCSEMaps(SDNode *N);
1229 void AddModifiedNodeToCSEMaps(SDNode *N);
1230 SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op, void *&InsertPos);
1231 SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op1, SDValue Op2,
1233 SDNode *FindModifiedNodeSlot(SDNode *N, ArrayRef<SDValue> Ops,
1235 SDNode *UpdadeSDLocOnMergedSDNode(SDNode *N, SDLoc loc);
1237 void DeleteNodeNotInCSEMaps(SDNode *N);
1238 void DeallocateNode(SDNode *N);
1240 void allnodes_clear();
1242 BinarySDNode *GetBinarySDNode(unsigned Opcode, SDLoc DL, SDVTList VTs,
1243 SDValue N1, SDValue N2,
1244 const SDNodeFlags *Flags = nullptr);
1246 /// List of non-single value types.
1247 FoldingSet<SDVTListNode> VTListMap;
1249 /// Maps to auto-CSE operations.
1250 std::vector<CondCodeSDNode*> CondCodeNodes;
1252 std::vector<SDNode*> ValueTypeNodes;
1253 std::map<EVT, SDNode*, EVT::compareRawBits> ExtendedValueTypeNodes;
1254 StringMap<SDNode*> ExternalSymbols;
1256 std::map<std::pair<std::string, unsigned char>,SDNode*> TargetExternalSymbols;
1259 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
1260 typedef SelectionDAG::allnodes_iterator nodes_iterator;
1261 static nodes_iterator nodes_begin(SelectionDAG *G) {
1262 return G->allnodes_begin();
1264 static nodes_iterator nodes_end(SelectionDAG *G) {
1265 return G->allnodes_end();
1269 } // end namespace llvm