1 //===-- LegalizeTypes.cpp - Common code for DAG type legalizer ------------===//
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 implements the SelectionDAG::LegalizeTypes method. It transforms
11 // an arbitrary well-formed SelectionDAG to only consist of legal types. This
12 // is common code shared among the LegalizeTypes*.cpp files.
14 //===----------------------------------------------------------------------===//
16 #include "LegalizeTypes.h"
17 #include "llvm/CallingConv.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/Target/TargetData.h"
22 /// run - This is the main entry point for the type legalizer. This does a
23 /// top-down traversal of the dag, legalizing types as it goes. Returns "true"
24 /// if it made any changes.
25 bool DAGTypeLegalizer::run() {
28 // Create a dummy node (which is not added to allnodes), that adds a reference
29 // to the root node, preventing it from being deleted, and tracking any
30 // changes of the root.
31 HandleSDNode Dummy(DAG.getRoot());
33 // The root of the dag may dangle to deleted nodes until the type legalizer is
34 // done. Set it to null to avoid confusion.
35 DAG.setRoot(SDValue());
37 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess'
38 // (and remembering them) if they are leaves and assigning 'NewNode' if
40 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
41 E = DAG.allnodes_end(); I != E; ++I) {
42 if (I->getNumOperands() == 0) {
43 I->setNodeId(ReadyToProcess);
44 Worklist.push_back(I);
46 I->setNodeId(NewNode);
50 // Now that we have a set of nodes to process, handle them all.
51 while (!Worklist.empty()) {
52 SDNode *N = Worklist.back();
54 assert(N->getNodeId() == ReadyToProcess &&
55 "Node should be ready if on worklist!");
57 if (IgnoreNodeResults(N))
60 // Scan the values produced by the node, checking to see if any result
62 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) {
63 MVT ResultVT = N->getValueType(i);
64 switch (getTypeAction(ResultVT)) {
66 assert(false && "Unknown action!");
70 PromoteIntegerResult(N, i);
74 ExpandIntegerResult(N, i);
78 SoftenFloatResult(N, i);
82 ExpandFloatResult(N, i);
86 ScalarizeVectorResult(N, i);
90 SplitVectorResult(N, i);
97 // Scan the operand list for the node, handling any nodes with operands that
100 unsigned NumOperands = N->getNumOperands();
101 bool NeedsRevisit = false;
103 for (i = 0; i != NumOperands; ++i) {
104 if (IgnoreNodeResults(N->getOperand(i).getNode()))
107 MVT OpVT = N->getOperand(i).getValueType();
108 switch (getTypeAction(OpVT)) {
110 assert(false && "Unknown action!");
114 NeedsRevisit = PromoteIntegerOperand(N, i);
118 NeedsRevisit = ExpandIntegerOperand(N, i);
122 NeedsRevisit = SoftenFloatOperand(N, i);
126 NeedsRevisit = ExpandFloatOperand(N, i);
129 case ScalarizeVector:
130 NeedsRevisit = ScalarizeVectorOperand(N, i);
134 NeedsRevisit = SplitVectorOperand(N, i);
141 // If the node needs revisiting, don't add all users to the worklist etc.
145 if (i == NumOperands) {
146 DEBUG(cerr << "Legally typed node: "; N->dump(&DAG); cerr << "\n");
151 // If we reach here, the node was processed, potentially creating new nodes.
152 // Mark it as processed and add its users to the worklist as appropriate.
153 N->setNodeId(Processed);
155 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
158 int NodeId = User->getNodeId();
159 assert(NodeId != ReadyToProcess && NodeId != Processed &&
160 "Invalid node id for user of unprocessed node!");
162 // This node has two options: it can either be a new node or its Node ID
163 // may be a count of the number of operands it has that are not ready.
165 User->setNodeId(NodeId-1);
167 // If this was the last use it was waiting on, add it to the ready list.
168 if (NodeId-1 == ReadyToProcess)
169 Worklist.push_back(User);
173 // Otherwise, this node is new: this is the first operand of it that
174 // became ready. Its new NodeId is the number of operands it has minus 1
175 // (as this node is now processed).
176 assert(NodeId == NewNode && "Unknown node ID!");
177 User->setNodeId(User->getNumOperands()-1);
179 // If the node only has a single operand, it is now ready.
180 if (User->getNumOperands() == 1)
181 Worklist.push_back(User);
185 // If the root changed (e.g. it was a dead load, update the root).
186 DAG.setRoot(Dummy.getValue());
190 // Remove dead nodes. This is important to do for cleanliness but also before
191 // the checking loop below. Implicit folding by the DAG.getNode operators can
192 // cause unreachable nodes to be around with their flags set to new.
193 DAG.RemoveDeadNodes();
195 // In a debug build, scan all the nodes to make sure we found them all. This
196 // ensures that there are no cycles and that everything got processed.
198 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
199 E = DAG.allnodes_end(); I != E; ++I) {
202 // Check that all result types are legal.
203 if (!IgnoreNodeResults(I))
204 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i)
205 if (!isTypeLegal(I->getValueType(i))) {
206 cerr << "Result type " << i << " illegal!\n";
210 // Check that all operand types are legal.
211 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i)
212 if (!IgnoreNodeResults(I->getOperand(i).getNode()) &&
213 !isTypeLegal(I->getOperand(i).getValueType())) {
214 cerr << "Operand type " << i << " illegal!\n";
218 if (I->getNodeId() != Processed) {
219 if (I->getNodeId() == NewNode)
220 cerr << "New node not 'noticed'?\n";
221 else if (I->getNodeId() > 0)
222 cerr << "Operand not processed?\n";
223 else if (I->getNodeId() == ReadyToProcess)
224 cerr << "Not added to worklist?\n";
229 I->dump(&DAG); cerr << "\n";
238 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially
239 /// new nodes. Correct any processed operands (this may change the node) and
240 /// calculate the NodeId. If the node itself changes to a processed node, it
241 /// is not remapped - the caller needs to take care of this.
242 /// Returns the potentially changed node.
243 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) {
244 // If this was an existing node that is already done, we're done.
245 if (N->getNodeId() != NewNode)
248 // Remove any stale map entries.
251 // Okay, we know that this node is new. Recursively walk all of its operands
252 // to see if they are new also. The depth of this walk is bounded by the size
253 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry
254 // about revisiting of nodes.
256 // As we walk the operands, keep track of the number of nodes that are
257 // processed. If non-zero, this will become the new nodeid of this node.
258 // Already processed operands may need to be remapped to the node that
259 // replaced them, which can result in our node changing. Since remapping
260 // is rare, the code tries to minimize overhead in the non-remapping case.
262 SmallVector<SDValue, 8> NewOps;
263 unsigned NumProcessed = 0;
264 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
265 SDValue OrigOp = N->getOperand(i);
268 if (Op.getNode()->getNodeId() == Processed)
270 else if (Op.getNode()->getNodeId() == NewNode)
273 if (Op.getNode()->getNodeId() == Processed)
276 if (!NewOps.empty()) {
277 // Some previous operand changed. Add this one to the list.
278 NewOps.push_back(Op);
279 } else if (Op != OrigOp) {
280 // This is the first operand to change - add all operands so far.
281 for (unsigned j = 0; j < i; ++j)
282 NewOps.push_back(N->getOperand(j));
283 NewOps.push_back(Op);
287 // Some operands changed - update the node.
288 if (!NewOps.empty()) {
289 SDNode *M = DAG.UpdateNodeOperands(SDValue(N, 0), &NewOps[0],
290 NewOps.size()).getNode();
292 if (M->getNodeId() != NewNode)
293 // It morphed into a previously analyzed node - nothing more to do.
296 // It morphed into a different new node. Do the equivalent of passing
297 // it to AnalyzeNewNode: expunge it and calculate the NodeId.
303 // Calculate the NodeId.
304 N->setNodeId(N->getNumOperands()-NumProcessed);
305 if (N->getNodeId() == ReadyToProcess)
306 Worklist.push_back(N);
311 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed.
312 /// If the node changes to a processed node, then remap it.
313 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) {
314 SDNode *N(Val.getNode());
315 // If this was an existing node that is already done, avoid remapping it.
316 if (N->getNodeId() != NewNode)
318 SDNode *M(AnalyzeNewNode(N));
321 if (M->getNodeId() == Processed)
322 // It morphed into an already processed node - remap it.
328 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for
329 /// updates to nodes and recomputes their ready state.
330 class VISIBILITY_HIDDEN NodeUpdateListener :
331 public SelectionDAG::DAGUpdateListener {
332 DAGTypeLegalizer &DTL;
334 explicit NodeUpdateListener(DAGTypeLegalizer &dtl) : DTL(dtl) {}
336 virtual void NodeDeleted(SDNode *N, SDNode *E) {
337 assert(N->getNodeId() != DAGTypeLegalizer::Processed &&
338 N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
339 "RAUW deleted processed node!");
340 // It is possible, though rare, for the deleted node N to occur as a
341 // target in a map, so note the replacement N -> E in ReplacedValues.
342 assert(E && "Node not replaced?");
343 DTL.NoteDeletion(N, E);
346 virtual void NodeUpdated(SDNode *N) {
347 // Node updates can mean pretty much anything. It is possible that an
348 // operand was set to something already processed (f.e.) in which case
349 // this node could become ready. Recompute its flags.
350 assert(N->getNodeId() != DAGTypeLegalizer::Processed &&
351 N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
352 "RAUW updated processed node!");
353 DTL.ReanalyzeNode(N);
359 /// ReplaceValueWith - The specified value was legalized to the specified other
360 /// value. If they are different, update the DAG and NodeIds replacing any uses
361 /// of From to use To instead.
362 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) {
363 if (From == To) return;
365 // If expansion produced new nodes, make sure they are properly marked.
366 ExpungeNode(From.getNode());
367 AnalyzeNewValue(To); // Expunges To.
369 // Anything that used the old node should now use the new one. Note that this
370 // can potentially cause recursive merging.
371 NodeUpdateListener NUL(*this);
372 DAG.ReplaceAllUsesOfValueWith(From, To, &NUL);
374 // The old node may still be present in a map like ExpandedIntegers or
375 // PromotedIntegers. Inform maps about the replacement.
376 ReplacedValues[From] = To;
379 /// ReplaceNodeWith - Replace uses of the 'from' node's results with the 'to'
380 /// node's results. The from and to node must define identical result types.
381 void DAGTypeLegalizer::ReplaceNodeWith(SDNode *From, SDNode *To) {
382 if (From == To) return;
384 // If expansion produced new nodes, make sure they are properly marked.
387 To = AnalyzeNewNode(To); // Expunges To.
388 // If To morphed into an already processed node, its values may need
389 // remapping. This is done below.
391 assert(From->getNumValues() == To->getNumValues() &&
392 "Node results don't match");
394 // Anything that used the old node should now use the new one. Note that this
395 // can potentially cause recursive merging.
396 NodeUpdateListener NUL(*this);
397 for (unsigned i = 0, e = From->getNumValues(); i != e; ++i) {
398 SDValue FromVal(From, i);
399 SDValue ToVal(To, i);
401 // AnalyzeNewNode may have morphed a new node into a processed node. Remap
403 if (To->getNodeId() == Processed)
406 assert(FromVal.getValueType() == ToVal.getValueType() &&
407 "Node results don't match!");
409 // Make anything that used the old value use the new value.
410 DAG.ReplaceAllUsesOfValueWith(FromVal, ToVal, &NUL);
412 // The old node may still be present in a map like ExpandedIntegers or
413 // PromotedIntegers. Inform maps about the replacement.
414 ReplacedValues[FromVal] = ToVal;
418 /// RemapValue - If the specified value was already legalized to another value,
419 /// replace it by that value.
420 void DAGTypeLegalizer::RemapValue(SDValue &N) {
421 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N);
422 if (I != ReplacedValues.end()) {
423 // Use path compression to speed up future lookups if values get multiply
424 // replaced with other values.
425 RemapValue(I->second);
428 assert(N.getNode()->getNodeId() != NewNode && "Mapped to unanalyzed node!");
431 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it.
432 /// This can occur when a node is deleted then reallocated as a new node -
433 /// the mapping in ReplacedValues applies to the deleted node, not the new
435 /// The only map that can have a deleted node as a source is ReplacedValues.
436 /// Other maps can have deleted nodes as targets, but since their looked-up
437 /// values are always immediately remapped using RemapValue, resulting in a
438 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue
439 /// always performs correct mappings. In order to keep the mapping correct,
440 /// ExpungeNode should be called on any new nodes *before* adding them as
441 /// either source or target to ReplacedValues (which typically means calling
442 /// Expunge when a new node is first seen, since it may no longer be marked
443 /// NewNode by the time it is added to ReplacedValues).
444 void DAGTypeLegalizer::ExpungeNode(SDNode *N) {
445 if (N->getNodeId() != NewNode)
448 // If N is not remapped by ReplacedValues then there is nothing to do.
450 for (i = 0, e = N->getNumValues(); i != e; ++i)
451 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end())
457 // Remove N from all maps - this is expensive but rare.
459 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(),
460 E = PromotedIntegers.end(); I != E; ++I) {
461 assert(I->first.getNode() != N);
462 RemapValue(I->second);
465 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(),
466 E = SoftenedFloats.end(); I != E; ++I) {
467 assert(I->first.getNode() != N);
468 RemapValue(I->second);
471 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(),
472 E = ScalarizedVectors.end(); I != E; ++I) {
473 assert(I->first.getNode() != N);
474 RemapValue(I->second);
477 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
478 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){
479 assert(I->first.getNode() != N);
480 RemapValue(I->second.first);
481 RemapValue(I->second.second);
484 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
485 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) {
486 assert(I->first.getNode() != N);
487 RemapValue(I->second.first);
488 RemapValue(I->second.second);
491 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
492 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) {
493 assert(I->first.getNode() != N);
494 RemapValue(I->second.first);
495 RemapValue(I->second.second);
498 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(),
499 E = ReplacedValues.end(); I != E; ++I)
500 RemapValue(I->second);
502 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
503 ReplacedValues.erase(SDValue(N, i));
506 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
507 AnalyzeNewValue(Result);
509 SDValue &OpEntry = PromotedIntegers[Op];
510 assert(OpEntry.getNode() == 0 && "Node is already promoted!");
514 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
515 AnalyzeNewValue(Result);
517 SDValue &OpEntry = SoftenedFloats[Op];
518 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!");
522 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
523 AnalyzeNewValue(Result);
525 SDValue &OpEntry = ScalarizedVectors[Op];
526 assert(OpEntry.getNode() == 0 && "Node is already scalarized!");
530 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
532 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
533 RemapValue(Entry.first);
534 RemapValue(Entry.second);
535 assert(Entry.first.getNode() && "Operand isn't expanded");
540 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
542 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
546 // Remember that this is the result of the node.
547 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
548 assert(Entry.first.getNode() == 0 && "Node already expanded");
553 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
555 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
556 RemapValue(Entry.first);
557 RemapValue(Entry.second);
558 assert(Entry.first.getNode() && "Operand isn't expanded");
563 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
565 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
569 // Remember that this is the result of the node.
570 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
571 assert(Entry.first.getNode() == 0 && "Node already expanded");
576 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
578 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
579 RemapValue(Entry.first);
580 RemapValue(Entry.second);
581 assert(Entry.first.getNode() && "Operand isn't split");
586 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
588 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
592 // Remember that this is the result of the node.
593 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
594 assert(Entry.first.getNode() == 0 && "Node already split");
600 //===----------------------------------------------------------------------===//
602 //===----------------------------------------------------------------------===//
604 /// BitConvertToInteger - Convert to an integer of the same size.
605 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) {
606 unsigned BitWidth = Op.getValueType().getSizeInBits();
607 return DAG.getNode(ISD::BIT_CONVERT, MVT::getIntegerVT(BitWidth), Op);
610 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op,
612 // Create the stack frame object. Make sure it is aligned for both
613 // the source and destination types.
615 TLI.getTargetData()->getPrefTypeAlignment(Op.getValueType().getTypeForMVT());
616 SDValue FIPtr = DAG.CreateStackTemporary(DestVT, SrcAlign);
618 // Emit a store to the stack slot.
619 SDValue Store = DAG.getStore(DAG.getEntryNode(), Op, FIPtr, NULL, 0);
620 // Result is a load from the stack slot.
621 return DAG.getLoad(DestVT, Store, FIPtr, NULL, 0);
624 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
625 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) {
626 MVT LVT = Lo.getValueType();
627 MVT HVT = Hi.getValueType();
628 MVT NVT = MVT::getIntegerVT(LVT.getSizeInBits() + HVT.getSizeInBits());
630 Lo = DAG.getNode(ISD::ZERO_EXTEND, NVT, Lo);
631 Hi = DAG.getNode(ISD::ANY_EXTEND, NVT, Hi);
632 Hi = DAG.getNode(ISD::SHL, NVT, Hi, DAG.getConstant(LVT.getSizeInBits(),
633 TLI.getShiftAmountTy()));
634 return DAG.getNode(ISD::OR, NVT, Lo, Hi);
637 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT
639 void DAGTypeLegalizer::SplitInteger(SDValue Op,
641 SDValue &Lo, SDValue &Hi) {
642 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() ==
643 Op.getValueType().getSizeInBits() && "Invalid integer splitting!");
644 Lo = DAG.getNode(ISD::TRUNCATE, LoVT, Op);
645 Hi = DAG.getNode(ISD::SRL, Op.getValueType(), Op,
646 DAG.getConstant(LoVT.getSizeInBits(),
647 TLI.getShiftAmountTy()));
648 Hi = DAG.getNode(ISD::TRUNCATE, HiVT, Hi);
651 /// SplitInteger - Return the lower and upper halves of Op's bits in a value
652 /// type half the size of Op's.
653 void DAGTypeLegalizer::SplitInteger(SDValue Op,
654 SDValue &Lo, SDValue &Hi) {
655 MVT HalfVT = MVT::getIntegerVT(Op.getValueType().getSizeInBits()/2);
656 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi);
659 /// MakeLibCall - Generate a libcall taking the given operands as arguments and
660 /// returning a result of type RetVT.
661 SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, MVT RetVT,
662 const SDValue *Ops, unsigned NumOps,
664 TargetLowering::ArgListTy Args;
665 Args.reserve(NumOps);
667 TargetLowering::ArgListEntry Entry;
668 for (unsigned i = 0; i != NumOps; ++i) {
670 Entry.Ty = Entry.Node.getValueType().getTypeForMVT();
671 Entry.isSExt = isSigned;
672 Entry.isZExt = !isSigned;
673 Args.push_back(Entry);
675 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
678 const Type *RetTy = RetVT.getTypeForMVT();
679 std::pair<SDValue,SDValue> CallInfo =
680 TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
681 false, CallingConv::C, false, Callee, Args, DAG);
682 return CallInfo.first;
685 /// LibCallify - Convert the node into a libcall with the same prototype.
686 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N,
688 unsigned NumOps = N->getNumOperands();
690 return MakeLibCall(LC, N->getValueType(0), 0, 0, isSigned);
691 } else if (NumOps == 1) {
692 SDValue Op = N->getOperand(0);
693 return MakeLibCall(LC, N->getValueType(0), &Op, 1, isSigned);
694 } else if (NumOps == 2) {
695 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) };
696 return MakeLibCall(LC, N->getValueType(0), Ops, 2, isSigned);
698 SmallVector<SDValue, 8> Ops(NumOps);
699 for (unsigned i = 0; i < NumOps; ++i)
700 Ops[i] = N->getOperand(i);
702 return MakeLibCall(LC, N->getValueType(0), &Ops[0], NumOps, isSigned);
705 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, MVT EltVT,
707 // Make sure the index type is big enough to compute in.
708 if (Index.getValueType().bitsGT(TLI.getPointerTy()))
709 Index = DAG.getNode(ISD::TRUNCATE, TLI.getPointerTy(), Index);
711 Index = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), Index);
713 // Calculate the element offset and add it to the pointer.
714 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size.
716 Index = DAG.getNode(ISD::MUL, Index.getValueType(), Index,
717 DAG.getConstant(EltSize, Index.getValueType()));
718 return DAG.getNode(ISD::ADD, Index.getValueType(), Index, VecPtr);
721 /// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type
722 /// which is split into two not necessarily identical pieces.
723 void DAGTypeLegalizer::GetSplitDestVTs(MVT InVT, MVT &LoVT, MVT &HiVT) {
724 if (!InVT.isVector()) {
725 LoVT = HiVT = TLI.getTypeToTransformTo(InVT);
727 MVT NewEltVT = InVT.getVectorElementType();
728 unsigned NumElements = InVT.getVectorNumElements();
729 if ((NumElements & (NumElements-1)) == 0) { // Simple power of two vector.
731 LoVT = HiVT = MVT::getVectorVT(NewEltVT, NumElements);
732 } else { // Non-power-of-two vectors.
733 unsigned NewNumElts_Lo = 1 << Log2_32(NumElements);
734 unsigned NewNumElts_Hi = NumElements - NewNumElts_Lo;
735 LoVT = MVT::getVectorVT(NewEltVT, NewNumElts_Lo);
736 HiVT = MVT::getVectorVT(NewEltVT, NewNumElts_Hi);
742 //===----------------------------------------------------------------------===//
744 //===----------------------------------------------------------------------===//
746 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
747 /// only uses types natively supported by the target. Returns "true" if it made
750 /// Note that this is an involved process that may invalidate pointers into
752 bool SelectionDAG::LegalizeTypes() {
753 return DAGTypeLegalizer(*this).run();