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/ADT/SetVector.h"
18 #include "llvm/IR/CallingConv.h"
19 #include "llvm/IR/DataLayout.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/raw_ostream.h"
26 EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden);
28 /// PerformExpensiveChecks - Do extensive, expensive, sanity checking.
29 void DAGTypeLegalizer::PerformExpensiveChecks() {
30 // If a node is not processed, then none of its values should be mapped by any
31 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
33 // If a node is processed, then each value with an illegal type must be mapped
34 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
35 // Values with a legal type may be mapped by ReplacedValues, but not by any of
38 // Note that these invariants may not hold momentarily when processing a node:
39 // the node being processed may be put in a map before being marked Processed.
41 // Note that it is possible to have nodes marked NewNode in the DAG. This can
42 // occur in two ways. Firstly, a node may be created during legalization but
43 // never passed to the legalization core. This is usually due to the implicit
44 // folding that occurs when using the DAG.getNode operators. Secondly, a new
45 // node may be passed to the legalization core, but when analyzed may morph
46 // into a different node, leaving the original node as a NewNode in the DAG.
47 // A node may morph if one of its operands changes during analysis. Whether
48 // it actually morphs or not depends on whether, after updating its operands,
49 // it is equivalent to an existing node: if so, it morphs into that existing
50 // node (CSE). An operand can change during analysis if the operand is a new
51 // node that morphs, or it is a processed value that was mapped to some other
52 // value (as recorded in ReplacedValues) in which case the operand is turned
53 // into that other value. If a node morphs then the node it morphed into will
54 // be used instead of it for legalization, however the original node continues
55 // to live on in the DAG.
56 // The conclusion is that though there may be nodes marked NewNode in the DAG,
57 // all uses of such nodes are also marked NewNode: the result is a fungus of
58 // NewNodes growing on top of the useful nodes, and perhaps using them, but
61 // If a value is mapped by ReplacedValues, then it must have no uses, except
62 // by nodes marked NewNode (see above).
64 // The final node obtained by mapping by ReplacedValues is not marked NewNode.
65 // Note that ReplacedValues should be applied iteratively.
67 // Note that the ReplacedValues map may also map deleted nodes (by iterating
68 // over the DAG we never dereference deleted nodes). This means that it may
69 // also map nodes marked NewNode if the deallocated memory was reallocated as
70 // another node, and that new node was not seen by the LegalizeTypes machinery
71 // (for example because it was created but not used). In general, we cannot
72 // distinguish between new nodes and deleted nodes.
73 SmallVector<SDNode*, 16> NewNodes;
74 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
75 E = DAG.allnodes_end(); I != E; ++I) {
76 // Remember nodes marked NewNode - they are subject to extra checking below.
77 if (I->getNodeId() == NewNode)
78 NewNodes.push_back(I);
80 for (unsigned i = 0, e = I->getNumValues(); i != e; ++i) {
85 if (ReplacedValues.find(Res) != ReplacedValues.end()) {
87 // Check that remapped values are only used by nodes marked NewNode.
88 for (SDNode::use_iterator UI = I->use_begin(), UE = I->use_end();
90 if (UI.getUse().getResNo() == i)
91 assert(UI->getNodeId() == NewNode &&
92 "Remapped value has non-trivial use!");
94 // Check that the final result of applying ReplacedValues is not
96 SDValue NewVal = ReplacedValues[Res];
97 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(NewVal);
98 while (I != ReplacedValues.end()) {
100 I = ReplacedValues.find(NewVal);
102 assert(NewVal.getNode()->getNodeId() != NewNode &&
103 "ReplacedValues maps to a new node!");
105 if (PromotedIntegers.find(Res) != PromotedIntegers.end())
107 if (SoftenedFloats.find(Res) != SoftenedFloats.end())
109 if (ScalarizedVectors.find(Res) != ScalarizedVectors.end())
111 if (ExpandedIntegers.find(Res) != ExpandedIntegers.end())
113 if (ExpandedFloats.find(Res) != ExpandedFloats.end())
115 if (SplitVectors.find(Res) != SplitVectors.end())
117 if (WidenedVectors.find(Res) != WidenedVectors.end())
120 if (I->getNodeId() != Processed) {
121 // Since we allow ReplacedValues to map deleted nodes, it may map nodes
122 // marked NewNode too, since a deleted node may have been reallocated as
123 // another node that has not been seen by the LegalizeTypes machinery.
124 if ((I->getNodeId() == NewNode && Mapped > 1) ||
125 (I->getNodeId() != NewNode && Mapped != 0)) {
126 dbgs() << "Unprocessed value in a map!";
129 } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(I)) {
131 dbgs() << "Value with legal type was transformed!";
136 dbgs() << "Processed value not in any map!";
138 } else if (Mapped & (Mapped - 1)) {
139 dbgs() << "Value in multiple maps!";
146 dbgs() << " ReplacedValues";
148 dbgs() << " PromotedIntegers";
150 dbgs() << " SoftenedFloats";
152 dbgs() << " ScalarizedVectors";
154 dbgs() << " ExpandedIntegers";
156 dbgs() << " ExpandedFloats";
158 dbgs() << " SplitVectors";
160 dbgs() << " WidenedVectors";
167 // Checked that NewNodes are only used by other NewNodes.
168 for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) {
169 SDNode *N = NewNodes[i];
170 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
172 assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!");
176 /// run - This is the main entry point for the type legalizer. This does a
177 /// top-down traversal of the dag, legalizing types as it goes. Returns "true"
178 /// if it made any changes.
179 bool DAGTypeLegalizer::run() {
180 bool Changed = false;
182 // Create a dummy node (which is not added to allnodes), that adds a reference
183 // to the root node, preventing it from being deleted, and tracking any
184 // changes of the root.
185 HandleSDNode Dummy(DAG.getRoot());
186 Dummy.setNodeId(Unanalyzed);
188 // The root of the dag may dangle to deleted nodes until the type legalizer is
189 // done. Set it to null to avoid confusion.
190 DAG.setRoot(SDValue());
192 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess'
193 // (and remembering them) if they are leaves and assigning 'Unanalyzed' if
195 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
196 E = DAG.allnodes_end(); I != E; ++I) {
197 if (I->getNumOperands() == 0) {
198 I->setNodeId(ReadyToProcess);
199 Worklist.push_back(I);
201 I->setNodeId(Unanalyzed);
205 // Now that we have a set of nodes to process, handle them all.
206 while (!Worklist.empty()) {
208 if (EnableExpensiveChecks)
210 PerformExpensiveChecks();
212 SDNode *N = Worklist.back();
214 assert(N->getNodeId() == ReadyToProcess &&
215 "Node should be ready if on worklist!");
217 if (IgnoreNodeResults(N))
220 // Scan the values produced by the node, checking to see if any result
221 // types are illegal.
222 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) {
223 EVT ResultVT = N->getValueType(i);
224 switch (getTypeAction(ResultVT)) {
225 case TargetLowering::TypeLegal:
227 // The following calls must take care of *all* of the node's results,
228 // not just the illegal result they were passed (this includes results
229 // with a legal type). Results can be remapped using ReplaceValueWith,
230 // or their promoted/expanded/etc values registered in PromotedIntegers,
231 // ExpandedIntegers etc.
232 case TargetLowering::TypePromoteInteger:
233 PromoteIntegerResult(N, i);
236 case TargetLowering::TypeExpandInteger:
237 ExpandIntegerResult(N, i);
240 case TargetLowering::TypeSoftenFloat:
241 SoftenFloatResult(N, i);
244 case TargetLowering::TypeExpandFloat:
245 ExpandFloatResult(N, i);
248 case TargetLowering::TypeScalarizeVector:
249 ScalarizeVectorResult(N, i);
252 case TargetLowering::TypeSplitVector:
253 SplitVectorResult(N, i);
256 case TargetLowering::TypeWidenVector:
257 WidenVectorResult(N, i);
264 // Scan the operand list for the node, handling any nodes with operands that
267 unsigned NumOperands = N->getNumOperands();
268 bool NeedsReanalyzing = false;
270 for (i = 0; i != NumOperands; ++i) {
271 if (IgnoreNodeResults(N->getOperand(i).getNode()))
274 EVT OpVT = N->getOperand(i).getValueType();
275 switch (getTypeAction(OpVT)) {
276 case TargetLowering::TypeLegal:
278 // The following calls must either replace all of the node's results
279 // using ReplaceValueWith, and return "false"; or update the node's
280 // operands in place, and return "true".
281 case TargetLowering::TypePromoteInteger:
282 NeedsReanalyzing = PromoteIntegerOperand(N, i);
285 case TargetLowering::TypeExpandInteger:
286 NeedsReanalyzing = ExpandIntegerOperand(N, i);
289 case TargetLowering::TypeSoftenFloat:
290 NeedsReanalyzing = SoftenFloatOperand(N, i);
293 case TargetLowering::TypeExpandFloat:
294 NeedsReanalyzing = ExpandFloatOperand(N, i);
297 case TargetLowering::TypeScalarizeVector:
298 NeedsReanalyzing = ScalarizeVectorOperand(N, i);
301 case TargetLowering::TypeSplitVector:
302 NeedsReanalyzing = SplitVectorOperand(N, i);
305 case TargetLowering::TypeWidenVector:
306 NeedsReanalyzing = WidenVectorOperand(N, i);
313 // The sub-method updated N in place. Check to see if any operands are new,
314 // and if so, mark them. If the node needs revisiting, don't add all users
315 // to the worklist etc.
316 if (NeedsReanalyzing) {
317 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
318 N->setNodeId(NewNode);
319 // Recompute the NodeId and correct processed operands, adding the node to
320 // the worklist if ready.
321 SDNode *M = AnalyzeNewNode(N);
323 // The node didn't morph - nothing special to do, it will be revisited.
326 // The node morphed - this is equivalent to legalizing by replacing every
327 // value of N with the corresponding value of M. So do that now.
328 assert(N->getNumValues() == M->getNumValues() &&
329 "Node morphing changed the number of results!");
330 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
331 // Replacing the value takes care of remapping the new value.
332 ReplaceValueWith(SDValue(N, i), SDValue(M, i));
333 assert(N->getNodeId() == NewNode && "Unexpected node state!");
334 // The node continues to live on as part of the NewNode fungus that
335 // grows on top of the useful nodes. Nothing more needs to be done
336 // with it - move on to the next node.
340 if (i == NumOperands) {
341 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n");
346 // If we reach here, the node was processed, potentially creating new nodes.
347 // Mark it as processed and add its users to the worklist as appropriate.
348 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
349 N->setNodeId(Processed);
351 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
354 int NodeId = User->getNodeId();
356 // This node has two options: it can either be a new node or its Node ID
357 // may be a count of the number of operands it has that are not ready.
359 User->setNodeId(NodeId-1);
361 // If this was the last use it was waiting on, add it to the ready list.
362 if (NodeId-1 == ReadyToProcess)
363 Worklist.push_back(User);
367 // If this is an unreachable new node, then ignore it. If it ever becomes
368 // reachable by being used by a newly created node then it will be handled
369 // by AnalyzeNewNode.
370 if (NodeId == NewNode)
373 // Otherwise, this node is new: this is the first operand of it that
374 // became ready. Its new NodeId is the number of operands it has minus 1
375 // (as this node is now processed).
376 assert(NodeId == Unanalyzed && "Unknown node ID!");
377 User->setNodeId(User->getNumOperands() - 1);
379 // If the node only has a single operand, it is now ready.
380 if (User->getNumOperands() == 1)
381 Worklist.push_back(User);
386 if (EnableExpensiveChecks)
388 PerformExpensiveChecks();
390 // If the root changed (e.g. it was a dead load) update the root.
391 DAG.setRoot(Dummy.getValue());
393 // Remove dead nodes. This is important to do for cleanliness but also before
394 // the checking loop below. Implicit folding by the DAG.getNode operators and
395 // node morphing can cause unreachable nodes to be around with their flags set
397 DAG.RemoveDeadNodes();
399 // In a debug build, scan all the nodes to make sure we found them all. This
400 // ensures that there are no cycles and that everything got processed.
402 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
403 E = DAG.allnodes_end(); I != E; ++I) {
406 // Check that all result types are legal.
407 if (!IgnoreNodeResults(I))
408 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i)
409 if (!isTypeLegal(I->getValueType(i))) {
410 dbgs() << "Result type " << i << " illegal!\n";
414 // Check that all operand types are legal.
415 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i)
416 if (!IgnoreNodeResults(I->getOperand(i).getNode()) &&
417 !isTypeLegal(I->getOperand(i).getValueType())) {
418 dbgs() << "Operand type " << i << " illegal!\n";
422 if (I->getNodeId() != Processed) {
423 if (I->getNodeId() == NewNode)
424 dbgs() << "New node not analyzed?\n";
425 else if (I->getNodeId() == Unanalyzed)
426 dbgs() << "Unanalyzed node not noticed?\n";
427 else if (I->getNodeId() > 0)
428 dbgs() << "Operand not processed?\n";
429 else if (I->getNodeId() == ReadyToProcess)
430 dbgs() << "Not added to worklist?\n";
435 I->dump(&DAG); dbgs() << "\n";
444 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially
445 /// new nodes. Correct any processed operands (this may change the node) and
446 /// calculate the NodeId. If the node itself changes to a processed node, it
447 /// is not remapped - the caller needs to take care of this.
448 /// Returns the potentially changed node.
449 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) {
450 // If this was an existing node that is already done, we're done.
451 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed)
454 // Remove any stale map entries.
457 // Okay, we know that this node is new. Recursively walk all of its operands
458 // to see if they are new also. The depth of this walk is bounded by the size
459 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry
460 // about revisiting of nodes.
462 // As we walk the operands, keep track of the number of nodes that are
463 // processed. If non-zero, this will become the new nodeid of this node.
464 // Operands may morph when they are analyzed. If so, the node will be
465 // updated after all operands have been analyzed. Since this is rare,
466 // the code tries to minimize overhead in the non-morphing case.
468 SmallVector<SDValue, 8> NewOps;
469 unsigned NumProcessed = 0;
470 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
471 SDValue OrigOp = N->getOperand(i);
474 AnalyzeNewValue(Op); // Op may morph.
476 if (Op.getNode()->getNodeId() == Processed)
479 if (!NewOps.empty()) {
480 // Some previous operand changed. Add this one to the list.
481 NewOps.push_back(Op);
482 } else if (Op != OrigOp) {
483 // This is the first operand to change - add all operands so far.
484 NewOps.append(N->op_begin(), N->op_begin() + i);
485 NewOps.push_back(Op);
489 // Some operands changed - update the node.
490 if (!NewOps.empty()) {
491 SDNode *M = DAG.UpdateNodeOperands(N, &NewOps[0], NewOps.size());
493 // The node morphed into a different node. Normally for this to happen
494 // the original node would have to be marked NewNode. However this can
495 // in theory momentarily not be the case while ReplaceValueWith is doing
496 // its stuff. Mark the original node NewNode to help sanity checking.
497 N->setNodeId(NewNode);
498 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed)
499 // It morphed into a previously analyzed node - nothing more to do.
502 // It morphed into a different new node. Do the equivalent of passing
503 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need
504 // to remap the operands, since they are the same as the operands we
511 // Calculate the NodeId.
512 N->setNodeId(N->getNumOperands() - NumProcessed);
513 if (N->getNodeId() == ReadyToProcess)
514 Worklist.push_back(N);
519 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed.
520 /// If the node changes to a processed node, then remap it.
521 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) {
522 Val.setNode(AnalyzeNewNode(Val.getNode()));
523 if (Val.getNode()->getNodeId() == Processed)
524 // We were passed a processed node, or it morphed into one - remap it.
528 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it.
529 /// This can occur when a node is deleted then reallocated as a new node -
530 /// the mapping in ReplacedValues applies to the deleted node, not the new
532 /// The only map that can have a deleted node as a source is ReplacedValues.
533 /// Other maps can have deleted nodes as targets, but since their looked-up
534 /// values are always immediately remapped using RemapValue, resulting in a
535 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue
536 /// always performs correct mappings. In order to keep the mapping correct,
537 /// ExpungeNode should be called on any new nodes *before* adding them as
538 /// either source or target to ReplacedValues (which typically means calling
539 /// Expunge when a new node is first seen, since it may no longer be marked
540 /// NewNode by the time it is added to ReplacedValues).
541 void DAGTypeLegalizer::ExpungeNode(SDNode *N) {
542 if (N->getNodeId() != NewNode)
545 // If N is not remapped by ReplacedValues then there is nothing to do.
547 for (i = 0, e = N->getNumValues(); i != e; ++i)
548 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end())
554 // Remove N from all maps - this is expensive but rare.
556 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(),
557 E = PromotedIntegers.end(); I != E; ++I) {
558 assert(I->first.getNode() != N);
559 RemapValue(I->second);
562 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(),
563 E = SoftenedFloats.end(); I != E; ++I) {
564 assert(I->first.getNode() != N);
565 RemapValue(I->second);
568 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(),
569 E = ScalarizedVectors.end(); I != E; ++I) {
570 assert(I->first.getNode() != N);
571 RemapValue(I->second);
574 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(),
575 E = WidenedVectors.end(); I != E; ++I) {
576 assert(I->first.getNode() != N);
577 RemapValue(I->second);
580 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
581 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){
582 assert(I->first.getNode() != N);
583 RemapValue(I->second.first);
584 RemapValue(I->second.second);
587 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
588 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) {
589 assert(I->first.getNode() != N);
590 RemapValue(I->second.first);
591 RemapValue(I->second.second);
594 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
595 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) {
596 assert(I->first.getNode() != N);
597 RemapValue(I->second.first);
598 RemapValue(I->second.second);
601 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(),
602 E = ReplacedValues.end(); I != E; ++I)
603 RemapValue(I->second);
605 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
606 ReplacedValues.erase(SDValue(N, i));
609 /// RemapValue - If the specified value was already legalized to another value,
610 /// replace it by that value.
611 void DAGTypeLegalizer::RemapValue(SDValue &N) {
612 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N);
613 if (I != ReplacedValues.end()) {
614 // Use path compression to speed up future lookups if values get multiply
615 // replaced with other values.
616 RemapValue(I->second);
618 assert(N.getNode()->getNodeId() != NewNode && "Mapped to new node!");
623 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for
624 /// updates to nodes and recomputes their ready state.
625 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener {
626 DAGTypeLegalizer &DTL;
627 SmallSetVector<SDNode*, 16> &NodesToAnalyze;
629 explicit NodeUpdateListener(DAGTypeLegalizer &dtl,
630 SmallSetVector<SDNode*, 16> &nta)
631 : SelectionDAG::DAGUpdateListener(dtl.getDAG()),
632 DTL(dtl), NodesToAnalyze(nta) {}
634 virtual void NodeDeleted(SDNode *N, SDNode *E) {
635 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
636 N->getNodeId() != DAGTypeLegalizer::Processed &&
637 "Invalid node ID for RAUW deletion!");
638 // It is possible, though rare, for the deleted node N to occur as a
639 // target in a map, so note the replacement N -> E in ReplacedValues.
640 assert(E && "Node not replaced?");
641 DTL.NoteDeletion(N, E);
643 // In theory the deleted node could also have been scheduled for analysis.
644 // So remove it from the set of nodes which will be analyzed.
645 NodesToAnalyze.remove(N);
647 // In general nothing needs to be done for E, since it didn't change but
648 // only gained new uses. However N -> E was just added to ReplacedValues,
649 // and the result of a ReplacedValues mapping is not allowed to be marked
650 // NewNode. So if E is marked NewNode, then it needs to be analyzed.
651 if (E->getNodeId() == DAGTypeLegalizer::NewNode)
652 NodesToAnalyze.insert(E);
655 virtual void NodeUpdated(SDNode *N) {
656 // Node updates can mean pretty much anything. It is possible that an
657 // operand was set to something already processed (f.e.) in which case
658 // this node could become ready. Recompute its flags.
659 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
660 N->getNodeId() != DAGTypeLegalizer::Processed &&
661 "Invalid node ID for RAUW deletion!");
662 N->setNodeId(DAGTypeLegalizer::NewNode);
663 NodesToAnalyze.insert(N);
669 /// ReplaceValueWith - The specified value was legalized to the specified other
670 /// value. Update the DAG and NodeIds replacing any uses of From to use To
672 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) {
673 assert(From.getNode() != To.getNode() && "Potential legalization loop!");
675 // If expansion produced new nodes, make sure they are properly marked.
676 ExpungeNode(From.getNode());
677 AnalyzeNewValue(To); // Expunges To.
679 // Anything that used the old node should now use the new one. Note that this
680 // can potentially cause recursive merging.
681 SmallSetVector<SDNode*, 16> NodesToAnalyze;
682 NodeUpdateListener NUL(*this, NodesToAnalyze);
684 DAG.ReplaceAllUsesOfValueWith(From, To);
686 // The old node may still be present in a map like ExpandedIntegers or
687 // PromotedIntegers. Inform maps about the replacement.
688 ReplacedValues[From] = To;
690 // Process the list of nodes that need to be reanalyzed.
691 while (!NodesToAnalyze.empty()) {
692 SDNode *N = NodesToAnalyze.back();
693 NodesToAnalyze.pop_back();
694 if (N->getNodeId() != DAGTypeLegalizer::NewNode)
695 // The node was analyzed while reanalyzing an earlier node - it is safe
696 // to skip. Note that this is not a morphing node - otherwise it would
697 // still be marked NewNode.
700 // Analyze the node's operands and recalculate the node ID.
701 SDNode *M = AnalyzeNewNode(N);
703 // The node morphed into a different node. Make everyone use the new
705 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!");
706 assert(N->getNumValues() == M->getNumValues() &&
707 "Node morphing changed the number of results!");
708 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
709 SDValue OldVal(N, i);
710 SDValue NewVal(M, i);
711 if (M->getNodeId() == Processed)
713 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal);
714 // OldVal may be a target of the ReplacedValues map which was marked
715 // NewNode to force reanalysis because it was updated. Ensure that
716 // anything that ReplacedValues mapped to OldVal will now be mapped
717 // all the way to NewVal.
718 ReplacedValues[OldVal] = NewVal;
720 // The original node continues to exist in the DAG, marked NewNode.
723 // When recursively update nodes with new nodes, it is possible to have
724 // new uses of From due to CSE. If this happens, replace the new uses of
726 } while (!From.use_empty());
729 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
730 assert(Result.getValueType() ==
731 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
732 "Invalid type for promoted integer");
733 AnalyzeNewValue(Result);
735 SDValue &OpEntry = PromotedIntegers[Op];
736 assert(OpEntry.getNode() == 0 && "Node is already promoted!");
740 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
741 assert(Result.getValueType() ==
742 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
743 "Invalid type for softened float");
744 AnalyzeNewValue(Result);
746 SDValue &OpEntry = SoftenedFloats[Op];
747 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!");
751 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
752 // Note that in some cases vector operation operands may be greater than
753 // the vector element type. For example BUILD_VECTOR of type <1 x i1> with
754 // a constant i8 operand.
755 assert(Result.getValueType().getSizeInBits() >=
756 Op.getValueType().getVectorElementType().getSizeInBits() &&
757 "Invalid type for scalarized vector");
758 AnalyzeNewValue(Result);
760 SDValue &OpEntry = ScalarizedVectors[Op];
761 assert(OpEntry.getNode() == 0 && "Node is already scalarized!");
765 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
767 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
768 RemapValue(Entry.first);
769 RemapValue(Entry.second);
770 assert(Entry.first.getNode() && "Operand isn't expanded");
775 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
777 assert(Lo.getValueType() ==
778 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
779 Hi.getValueType() == Lo.getValueType() &&
780 "Invalid type for expanded integer");
781 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
785 // Remember that this is the result of the node.
786 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
787 assert(Entry.first.getNode() == 0 && "Node already expanded");
792 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
794 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
795 RemapValue(Entry.first);
796 RemapValue(Entry.second);
797 assert(Entry.first.getNode() && "Operand isn't expanded");
802 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
804 assert(Lo.getValueType() ==
805 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
806 Hi.getValueType() == Lo.getValueType() &&
807 "Invalid type for expanded float");
808 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
812 // Remember that this is the result of the node.
813 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
814 assert(Entry.first.getNode() == 0 && "Node already expanded");
819 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
821 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
822 RemapValue(Entry.first);
823 RemapValue(Entry.second);
824 assert(Entry.first.getNode() && "Operand isn't split");
829 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
831 assert(Lo.getValueType().getVectorElementType() ==
832 Op.getValueType().getVectorElementType() &&
833 2*Lo.getValueType().getVectorNumElements() ==
834 Op.getValueType().getVectorNumElements() &&
835 Hi.getValueType() == Lo.getValueType() &&
836 "Invalid type for split vector");
837 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
841 // Remember that this is the result of the node.
842 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
843 assert(Entry.first.getNode() == 0 && "Node already split");
848 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
849 assert(Result.getValueType() ==
850 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
851 "Invalid type for widened vector");
852 AnalyzeNewValue(Result);
854 SDValue &OpEntry = WidenedVectors[Op];
855 assert(OpEntry.getNode() == 0 && "Node already widened!");
860 //===----------------------------------------------------------------------===//
862 //===----------------------------------------------------------------------===//
864 /// BitConvertToInteger - Convert to an integer of the same size.
865 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) {
866 unsigned BitWidth = Op.getValueType().getSizeInBits();
867 return DAG.getNode(ISD::BITCAST, Op.getDebugLoc(),
868 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op);
871 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the
873 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) {
874 assert(Op.getValueType().isVector() && "Only applies to vectors!");
875 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits();
876 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth);
877 unsigned NumElts = Op.getValueType().getVectorNumElements();
878 return DAG.getNode(ISD::BITCAST, Op.getDebugLoc(),
879 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op);
882 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op,
884 DebugLoc dl = Op.getDebugLoc();
885 // Create the stack frame object. Make sure it is aligned for both
886 // the source and destination types.
887 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT);
888 // Emit a store to the stack slot.
889 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr,
890 MachinePointerInfo(), false, false, 0);
891 // Result is a load from the stack slot.
892 return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(),
893 false, false, false, 0);
896 /// CustomLowerNode - Replace the node's results with custom code provided
897 /// by the target and return "true", or do nothing and return "false".
898 /// The last parameter is FALSE if we are dealing with a node with legal
899 /// result types and illegal operand. The second parameter denotes the type of
900 /// illegal OperandNo in that case.
901 /// The last parameter being TRUE means we are dealing with a
902 /// node with illegal result types. The second parameter denotes the type of
903 /// illegal ResNo in that case.
904 bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) {
905 // See if the target wants to custom lower this node.
906 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
909 SmallVector<SDValue, 8> Results;
911 TLI.ReplaceNodeResults(N, Results, DAG);
913 TLI.LowerOperationWrapper(N, Results, DAG);
916 // The target didn't want to custom lower it after all.
919 // Make everything that once used N's values now use those in Results instead.
920 assert(Results.size() == N->getNumValues() &&
921 "Custom lowering returned the wrong number of results!");
922 for (unsigned i = 0, e = Results.size(); i != e; ++i)
923 ReplaceValueWith(SDValue(N, i), Results[i]);
928 /// CustomWidenLowerNode - Widen the node's results with custom code provided
929 /// by the target and return "true", or do nothing and return "false".
930 bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) {
931 // See if the target wants to custom lower this node.
932 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
935 SmallVector<SDValue, 8> Results;
936 TLI.ReplaceNodeResults(N, Results, DAG);
939 // The target didn't want to custom widen lower its result after all.
942 // Update the widening map.
943 assert(Results.size() == N->getNumValues() &&
944 "Custom lowering returned the wrong number of results!");
945 for (unsigned i = 0, e = Results.size(); i != e; ++i)
946 SetWidenedVector(SDValue(N, i), Results[i]);
950 SDValue DAGTypeLegalizer::DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo) {
951 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
953 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
954 return SDValue(N->getOperand(ResNo));
957 /// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type
958 /// which is split into two not necessarily identical pieces.
959 void DAGTypeLegalizer::GetSplitDestVTs(EVT InVT, EVT &LoVT, EVT &HiVT) {
960 // Currently all types are split in half.
961 if (!InVT.isVector()) {
962 LoVT = HiVT = TLI.getTypeToTransformTo(*DAG.getContext(), InVT);
964 unsigned NumElements = InVT.getVectorNumElements();
965 assert(!(NumElements & 1) && "Splitting vector, but not in half!");
966 LoVT = HiVT = EVT::getVectorVT(*DAG.getContext(),
967 InVT.getVectorElementType(), NumElements/2);
971 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and
972 /// high parts of the given value.
973 void DAGTypeLegalizer::GetPairElements(SDValue Pair,
974 SDValue &Lo, SDValue &Hi) {
975 DebugLoc dl = Pair.getDebugLoc();
976 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType());
977 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
978 DAG.getIntPtrConstant(0));
979 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
980 DAG.getIntPtrConstant(1));
983 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT,
985 DebugLoc dl = Index.getDebugLoc();
986 // Make sure the index type is big enough to compute in.
987 if (Index.getValueType().bitsGT(TLI.getPointerTy()))
988 Index = DAG.getNode(ISD::TRUNCATE, dl, TLI.getPointerTy(), Index);
990 Index = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Index);
992 // Calculate the element offset and add it to the pointer.
993 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size.
995 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
996 DAG.getConstant(EltSize, Index.getValueType()));
997 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr);
1000 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
1001 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) {
1002 // Arbitrarily use dlHi for result DebugLoc
1003 DebugLoc dlHi = Hi.getDebugLoc();
1004 DebugLoc dlLo = Lo.getDebugLoc();
1005 EVT LVT = Lo.getValueType();
1006 EVT HVT = Hi.getValueType();
1007 EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
1008 LVT.getSizeInBits() + HVT.getSizeInBits());
1010 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo);
1011 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi);
1012 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi,
1013 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy()));
1014 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi);
1017 /// LibCallify - Convert the node into a libcall with the same prototype.
1018 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N,
1020 unsigned NumOps = N->getNumOperands();
1021 DebugLoc dl = N->getDebugLoc();
1023 return TLI.makeLibCall(DAG, LC, N->getValueType(0), 0, 0, isSigned, dl);
1024 } else if (NumOps == 1) {
1025 SDValue Op = N->getOperand(0);
1026 return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Op, 1, isSigned, dl);
1027 } else if (NumOps == 2) {
1028 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) };
1029 return TLI.makeLibCall(DAG, LC, N->getValueType(0), Ops, 2, isSigned, dl);
1031 SmallVector<SDValue, 8> Ops(NumOps);
1032 for (unsigned i = 0; i < NumOps; ++i)
1033 Ops[i] = N->getOperand(i);
1035 return TLI.makeLibCall(DAG, LC, N->getValueType(0),
1036 &Ops[0], NumOps, isSigned, dl);
1039 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to
1040 // ExpandLibCall except that the first operand is the in-chain.
1041 std::pair<SDValue, SDValue>
1042 DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC,
1045 SDValue InChain = Node->getOperand(0);
1047 TargetLowering::ArgListTy Args;
1048 TargetLowering::ArgListEntry Entry;
1049 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
1050 EVT ArgVT = Node->getOperand(i).getValueType();
1051 Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1052 Entry.Node = Node->getOperand(i);
1054 Entry.isSExt = isSigned;
1055 Entry.isZExt = !isSigned;
1056 Args.push_back(Entry);
1058 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1059 TLI.getPointerTy());
1061 Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
1063 CallLoweringInfo CLI(InChain, RetTy, isSigned, !isSigned, false, false,
1064 0, TLI.getLibcallCallingConv(LC), /*isTailCall=*/false,
1065 /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
1066 Callee, Args, DAG, Node->getDebugLoc());
1067 std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
1072 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean
1073 /// of the given type. A target boolean is an integer value, not necessarily of
1074 /// type i1, the bits of which conform to getBooleanContents.
1075 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT VT) {
1076 DebugLoc dl = Bool.getDebugLoc();
1077 ISD::NodeType ExtendCode =
1078 TargetLowering::getExtendForContent(TLI.getBooleanContents(VT.isVector()));
1079 return DAG.getNode(ExtendCode, dl, VT, Bool);
1082 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT
1084 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1086 SDValue &Lo, SDValue &Hi) {
1087 DebugLoc dl = Op.getDebugLoc();
1088 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() ==
1089 Op.getValueType().getSizeInBits() && "Invalid integer splitting!");
1090 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op);
1091 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op,
1092 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy()));
1093 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi);
1096 /// SplitInteger - Return the lower and upper halves of Op's bits in a value
1097 /// type half the size of Op's.
1098 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1099 SDValue &Lo, SDValue &Hi) {
1100 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(),
1101 Op.getValueType().getSizeInBits()/2);
1102 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi);
1106 //===----------------------------------------------------------------------===//
1108 //===----------------------------------------------------------------------===//
1110 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
1111 /// only uses types natively supported by the target. Returns "true" if it made
1114 /// Note that this is an involved process that may invalidate pointers into
1116 bool SelectionDAG::LegalizeTypes() {
1117 return DAGTypeLegalizer(*this).run();