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/ADT/SetVector.h"
19 #include "llvm/Support/CommandLine.h"
20 #include "llvm/Target/TargetData.h"
24 EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden);
26 /// PerformExpensiveChecks - Do extensive, expensive, sanity checking.
27 void DAGTypeLegalizer::PerformExpensiveChecks() {
28 // If a node is not processed, then none of its values should be mapped by any
29 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
31 // If a node is processed, then each value with an illegal type must be mapped
32 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
33 // Values with a legal type may be mapped by ReplacedValues, but not by any of
36 // Note that these invariants may not hold momentarily when processing a node:
37 // the node being processed may be put in a map before being marked Processed.
39 // Note that it is possible to have nodes marked NewNode in the DAG. This can
40 // occur in two ways. Firstly, a node may be created during legalization but
41 // never passed to the legalization core. This is usually due to the implicit
42 // folding that occurs when using the DAG.getNode operators. Secondly, a new
43 // node may be passed to the legalization core, but when analyzed may morph
44 // into a different node, leaving the original node as a NewNode in the DAG.
45 // A node may morph if one of its operands changes during analysis. Whether
46 // it actually morphs or not depends on whether, after updating its operands,
47 // it is equivalent to an existing node: if so, it morphs into that existing
48 // node (CSE). An operand can change during analysis if the operand is a new
49 // node that morphs, or it is a processed value that was mapped to some other
50 // value (as recorded in ReplacedValues) in which case the operand is turned
51 // into that other value. If a node morphs then the node it morphed into will
52 // be used instead of it for legalization, however the original node continues
53 // to live on in the DAG.
54 // The conclusion is that though there may be nodes marked NewNode in the DAG,
55 // all uses of such nodes are also marked NewNode: the result is a fungus of
56 // NewNodes growing on top of the useful nodes, and perhaps using them, but
59 // If a value is mapped by ReplacedValues, then it must have no uses, except
60 // by nodes marked NewNode (see above).
62 // The final node obtained by mapping by ReplacedValues is not marked NewNode.
63 // Note that ReplacedValues should be applied iteratively.
65 // Note that the ReplacedValues map may also map deleted nodes. By iterating
66 // over the DAG we only consider non-deleted nodes.
67 SmallVector<SDNode*, 16> NewNodes;
68 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
69 E = DAG.allnodes_end(); I != E; ++I) {
70 // Remember nodes marked NewNode - they are subject to extra checking below.
71 if (I->getNodeId() == NewNode)
72 NewNodes.push_back(I);
74 for (unsigned i = 0, e = I->getNumValues(); i != e; ++i) {
79 if (ReplacedValues.find(Res) != ReplacedValues.end()) {
81 // Check that remapped values are only used by nodes marked NewNode.
82 for (SDNode::use_iterator UI = I->use_begin(), UE = I->use_end();
84 if (UI.getUse().getResNo() == i)
85 assert(UI->getNodeId() == NewNode &&
86 "Remapped value has non-trivial use!");
88 // Check that the final result of applying ReplacedValues is not
90 SDValue NewVal = ReplacedValues[Res];
91 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(NewVal);
92 while (I != ReplacedValues.end()) {
94 I = ReplacedValues.find(NewVal);
96 assert(NewVal.getNode()->getNodeId() != NewNode &&
97 "ReplacedValues maps to a new node!");
99 if (PromotedIntegers.find(Res) != PromotedIntegers.end())
101 if (SoftenedFloats.find(Res) != SoftenedFloats.end())
103 if (ScalarizedVectors.find(Res) != ScalarizedVectors.end())
105 if (ExpandedIntegers.find(Res) != ExpandedIntegers.end())
107 if (ExpandedFloats.find(Res) != ExpandedFloats.end())
109 if (SplitVectors.find(Res) != SplitVectors.end())
111 if (WidenedVectors.find(Res) != WidenedVectors.end())
114 if (I->getNodeId() != Processed) {
116 cerr << "Unprocessed value in a map!";
119 } else if (isTypeLegal(Res.getValueType())) {
121 cerr << "Value with legal type was transformed!";
126 cerr << "Processed value not in any map!";
128 } else if (Mapped & (Mapped - 1)) {
129 cerr << "Value in multiple maps!";
136 cerr << " ReplacedValues";
138 cerr << " PromotedIntegers";
140 cerr << " SoftenedFloats";
142 cerr << " ScalarizedVectors";
144 cerr << " ExpandedIntegers";
146 cerr << " ExpandedFloats";
148 cerr << " SplitVectors";
150 cerr << " WidenedVectors";
157 // Checked that NewNodes are only used by other NewNodes.
158 for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) {
159 SDNode *N = NewNodes[i];
160 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
162 assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!");
166 /// run - This is the main entry point for the type legalizer. This does a
167 /// top-down traversal of the dag, legalizing types as it goes. Returns "true"
168 /// if it made any changes.
169 bool DAGTypeLegalizer::run() {
170 bool Changed = false;
172 // Create a dummy node (which is not added to allnodes), that adds a reference
173 // to the root node, preventing it from being deleted, and tracking any
174 // changes of the root.
175 HandleSDNode Dummy(DAG.getRoot());
176 Dummy.setNodeId(Unanalyzed);
178 // The root of the dag may dangle to deleted nodes until the type legalizer is
179 // done. Set it to null to avoid confusion.
180 DAG.setRoot(SDValue());
182 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess'
183 // (and remembering them) if they are leaves and assigning 'Unanalyzed' if
185 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
186 E = DAG.allnodes_end(); I != E; ++I) {
187 if (I->getNumOperands() == 0) {
188 I->setNodeId(ReadyToProcess);
189 Worklist.push_back(I);
191 I->setNodeId(Unanalyzed);
195 // Now that we have a set of nodes to process, handle them all.
196 while (!Worklist.empty()) {
198 if (EnableExpensiveChecks)
200 PerformExpensiveChecks();
202 SDNode *N = Worklist.back();
204 assert(N->getNodeId() == ReadyToProcess &&
205 "Node should be ready if on worklist!");
207 if (IgnoreNodeResults(N))
210 // Scan the values produced by the node, checking to see if any result
211 // types are illegal.
212 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) {
213 MVT ResultVT = N->getValueType(i);
214 switch (getTypeAction(ResultVT)) {
216 assert(false && "Unknown action!");
219 // The following calls must take care of *all* of the node's results,
220 // not just the illegal result they were passed (this includes results
221 // with a legal type). Results can be remapped using ReplaceValueWith,
222 // or their promoted/expanded/etc values registered in PromotedIntegers,
223 // ExpandedIntegers etc.
225 PromoteIntegerResult(N, i);
229 ExpandIntegerResult(N, i);
233 SoftenFloatResult(N, i);
237 ExpandFloatResult(N, i);
240 case ScalarizeVector:
241 ScalarizeVectorResult(N, i);
245 SplitVectorResult(N, i);
249 WidenVectorResult(N, i);
256 // Scan the operand list for the node, handling any nodes with operands that
259 unsigned NumOperands = N->getNumOperands();
260 bool NeedsReanalyzing = false;
262 for (i = 0; i != NumOperands; ++i) {
263 if (IgnoreNodeResults(N->getOperand(i).getNode()))
266 MVT OpVT = N->getOperand(i).getValueType();
267 switch (getTypeAction(OpVT)) {
269 assert(false && "Unknown action!");
272 // The following calls must either replace all of the node's results
273 // using ReplaceValueWith, and return "false"; or update the node's
274 // operands in place, and return "true".
276 NeedsReanalyzing = PromoteIntegerOperand(N, i);
280 NeedsReanalyzing = ExpandIntegerOperand(N, i);
284 NeedsReanalyzing = SoftenFloatOperand(N, i);
288 NeedsReanalyzing = ExpandFloatOperand(N, i);
291 case ScalarizeVector:
292 NeedsReanalyzing = ScalarizeVectorOperand(N, i);
296 NeedsReanalyzing = SplitVectorOperand(N, i);
300 NeedsReanalyzing = WidenVectorOperand(N, i);
307 // The sub-method updated N in place. Check to see if any operands are new,
308 // and if so, mark them. If the node needs revisiting, don't add all users
309 // to the worklist etc.
310 if (NeedsReanalyzing) {
311 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
312 N->setNodeId(NewNode);
313 // Recompute the NodeId and correct processed operands, adding the node to
314 // the worklist if ready.
315 SDNode *M = AnalyzeNewNode(N);
317 // The node didn't morph - nothing special to do, it will be revisited.
320 // The node morphed - this is equivalent to legalizing by replacing every
321 // value of N with the corresponding value of M. So do that now. However
322 // there is no need to remember the replacement - morphing will make sure
323 // it is never used non-trivially.
324 assert(N->getNumValues() == M->getNumValues() &&
325 "Node morphing changed the number of results!");
326 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
327 // Replacing the value takes care of remapping the new value. Do the
328 // replacement without recording it in ReplacedValues. This does not
329 // expunge From but that is fine - it is not really a new node.
330 ReplaceValueWithHelper(SDValue(N, i), SDValue(M, i));
331 assert(N->getNodeId() == NewNode && "Unexpected node state!");
332 // The node continues to live on as part of the NewNode fungus that
333 // grows on top of the useful nodes. Nothing more needs to be done
334 // with it - move on to the next node.
338 if (i == NumOperands) {
339 DEBUG(cerr << "Legally typed node: "; N->dump(&DAG); cerr << "\n");
344 // If we reach here, the node was processed, potentially creating new nodes.
345 // Mark it as processed and add its users to the worklist as appropriate.
346 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
347 N->setNodeId(Processed);
349 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
352 int NodeId = User->getNodeId();
354 // This node has two options: it can either be a new node or its Node ID
355 // may be a count of the number of operands it has that are not ready.
357 User->setNodeId(NodeId-1);
359 // If this was the last use it was waiting on, add it to the ready list.
360 if (NodeId-1 == ReadyToProcess)
361 Worklist.push_back(User);
365 // If this is an unreachable new node, then ignore it. If it ever becomes
366 // reachable by being used by a newly created node then it will be handled
367 // by AnalyzeNewNode.
368 if (NodeId == NewNode)
371 // Otherwise, this node is new: this is the first operand of it that
372 // became ready. Its new NodeId is the number of operands it has minus 1
373 // (as this node is now processed).
374 assert(NodeId == Unanalyzed && "Unknown node ID!");
375 User->setNodeId(User->getNumOperands() - 1);
377 // If the node only has a single operand, it is now ready.
378 if (User->getNumOperands() == 1)
379 Worklist.push_back(User);
384 if (EnableExpensiveChecks)
386 PerformExpensiveChecks();
388 // If the root changed (e.g. it was a dead load) update the root.
389 DAG.setRoot(Dummy.getValue());
391 // Remove dead nodes. This is important to do for cleanliness but also before
392 // the checking loop below. Implicit folding by the DAG.getNode operators and
393 // node morphing can cause unreachable nodes to be around with their flags set
395 DAG.RemoveDeadNodes();
397 // In a debug build, scan all the nodes to make sure we found them all. This
398 // ensures that there are no cycles and that everything got processed.
400 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
401 E = DAG.allnodes_end(); I != E; ++I) {
404 // Check that all result types are legal.
405 if (!IgnoreNodeResults(I))
406 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i)
407 if (!isTypeLegal(I->getValueType(i))) {
408 cerr << "Result type " << i << " illegal!\n";
412 // Check that all operand types are legal.
413 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i)
414 if (!IgnoreNodeResults(I->getOperand(i).getNode()) &&
415 !isTypeLegal(I->getOperand(i).getValueType())) {
416 cerr << "Operand type " << i << " illegal!\n";
420 if (I->getNodeId() != Processed) {
421 if (I->getNodeId() == NewNode)
422 cerr << "New node not analyzed?\n";
423 else if (I->getNodeId() == Unanalyzed)
424 cerr << "Unanalyzed node not noticed?\n";
425 else if (I->getNodeId() > 0)
426 cerr << "Operand not processed?\n";
427 else if (I->getNodeId() == ReadyToProcess)
428 cerr << "Not added to worklist?\n";
433 I->dump(&DAG); cerr << "\n";
442 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially
443 /// new nodes. Correct any processed operands (this may change the node) and
444 /// calculate the NodeId. If the node itself changes to a processed node, it
445 /// is not remapped - the caller needs to take care of this.
446 /// Returns the potentially changed node.
447 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) {
448 // If this was an existing node that is already done, we're done.
449 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed)
452 // Remove any stale map entries.
455 // Okay, we know that this node is new. Recursively walk all of its operands
456 // to see if they are new also. The depth of this walk is bounded by the size
457 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry
458 // about revisiting of nodes.
460 // As we walk the operands, keep track of the number of nodes that are
461 // processed. If non-zero, this will become the new nodeid of this node.
462 // Operands may morph when they are analyzed. If so, the node will be
463 // updated after all operands have been analyzed. Since this is rare,
464 // the code tries to minimize overhead in the non-morphing case.
466 SmallVector<SDValue, 8> NewOps;
467 unsigned NumProcessed = 0;
468 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
469 SDValue OrigOp = N->getOperand(i);
472 AnalyzeNewValue(Op); // Op may morph.
474 if (Op.getNode()->getNodeId() == Processed)
477 if (!NewOps.empty()) {
478 // Some previous operand changed. Add this one to the list.
479 NewOps.push_back(Op);
480 } else if (Op != OrigOp) {
481 // This is the first operand to change - add all operands so far.
482 for (unsigned j = 0; j < i; ++j)
483 NewOps.push_back(N->getOperand(j));
484 NewOps.push_back(Op);
488 // Some operands changed - update the node.
489 if (!NewOps.empty()) {
490 SDNode *M = DAG.UpdateNodeOperands(SDValue(N, 0), &NewOps[0],
491 NewOps.size()).getNode();
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 VISIBILITY_HIDDEN NodeUpdateListener :
626 public SelectionDAG::DAGUpdateListener {
627 DAGTypeLegalizer &DTL;
628 SmallSetVector<SDNode*, 16> &NodesToAnalyze;
630 explicit NodeUpdateListener(DAGTypeLegalizer &dtl,
631 SmallSetVector<SDNode*, 16> &nta)
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 /// ReplaceValueWithHelper - Internal helper for ReplaceValueWith. Updates the
670 /// DAG causing any uses of From to use To instead, but without expunging From
671 /// or recording the replacement in ReplacedValues. Do not call directly unless
672 /// you really know what you are doing!
673 void DAGTypeLegalizer::ReplaceValueWithHelper(SDValue From, SDValue To) {
674 assert(From.getNode() != To.getNode() && "Potential legalization loop!");
676 // If expansion produced new nodes, make sure they are properly marked.
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);
683 DAG.ReplaceAllUsesOfValueWith(From, To, &NUL);
685 // Process the list of nodes that need to be reanalyzed.
686 while (!NodesToAnalyze.empty()) {
687 SDNode *N = NodesToAnalyze.back();
688 NodesToAnalyze.pop_back();
689 if (N->getNodeId() != DAGTypeLegalizer::NewNode)
690 // The node was analyzed while reanalyzing an earlier node - it is safe to
691 // skip. Note that this is not a morphing node - otherwise it would still
692 // be marked NewNode.
695 // Analyze the node's operands and recalculate the node ID.
696 SDNode *M = AnalyzeNewNode(N);
698 // The node morphed into a different node. Make everyone use the new node
700 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!");
701 assert(N->getNumValues() == M->getNumValues() &&
702 "Node morphing changed the number of results!");
703 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
704 SDValue OldVal(N, i);
705 SDValue NewVal(M, i);
706 if (M->getNodeId() == Processed)
708 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal, &NUL);
710 // The original node continues to exist in the DAG, marked NewNode.
715 /// ReplaceValueWith - The specified value was legalized to the specified other
716 /// value. Update the DAG and NodeIds replacing any uses of From to use To
718 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) {
719 assert(From.getNode()->getNodeId() == ReadyToProcess &&
720 "Only the node being processed may be remapped!");
722 // If expansion produced new nodes, make sure they are properly marked.
723 ExpungeNode(From.getNode());
724 AnalyzeNewValue(To); // Expunges To.
726 // The old node may still be present in a map like ExpandedIntegers or
727 // PromotedIntegers. Inform maps about the replacement.
728 ReplacedValues[From] = To;
730 // Do the replacement.
731 ReplaceValueWithHelper(From, To);
734 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
735 AnalyzeNewValue(Result);
737 SDValue &OpEntry = PromotedIntegers[Op];
738 assert(OpEntry.getNode() == 0 && "Node is already promoted!");
742 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
743 AnalyzeNewValue(Result);
745 SDValue &OpEntry = SoftenedFloats[Op];
746 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!");
750 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
751 AnalyzeNewValue(Result);
753 SDValue &OpEntry = ScalarizedVectors[Op];
754 assert(OpEntry.getNode() == 0 && "Node is already scalarized!");
758 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
760 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
761 RemapValue(Entry.first);
762 RemapValue(Entry.second);
763 assert(Entry.first.getNode() && "Operand isn't expanded");
768 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
770 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
774 // Remember that this is the result of the node.
775 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
776 assert(Entry.first.getNode() == 0 && "Node already expanded");
781 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
783 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
784 RemapValue(Entry.first);
785 RemapValue(Entry.second);
786 assert(Entry.first.getNode() && "Operand isn't expanded");
791 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
793 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
797 // Remember that this is the result of the node.
798 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
799 assert(Entry.first.getNode() == 0 && "Node already expanded");
804 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
806 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
807 RemapValue(Entry.first);
808 RemapValue(Entry.second);
809 assert(Entry.first.getNode() && "Operand isn't split");
814 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
816 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
820 // Remember that this is the result of the node.
821 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
822 assert(Entry.first.getNode() == 0 && "Node already split");
827 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
828 AnalyzeNewValue(Result);
830 SDValue &OpEntry = WidenedVectors[Op];
831 assert(OpEntry.getNode() == 0 && "Node already widened!");
836 //===----------------------------------------------------------------------===//
838 //===----------------------------------------------------------------------===//
840 /// BitConvertToInteger - Convert to an integer of the same size.
841 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) {
842 unsigned BitWidth = Op.getValueType().getSizeInBits();
843 return DAG.getNode(ISD::BIT_CONVERT, Op.getDebugLoc(),
844 MVT::getIntegerVT(BitWidth), Op);
847 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the
849 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) {
850 assert(Op.getValueType().isVector() && "Only applies to vectors!");
851 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits();
852 MVT EltNVT = MVT::getIntegerVT(EltWidth);
853 unsigned NumElts = Op.getValueType().getVectorNumElements();
854 return DAG.getNode(ISD::BIT_CONVERT, Op.getDebugLoc(),
855 MVT::getVectorVT(EltNVT, NumElts), Op);
858 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op,
860 DebugLoc dl = Op.getDebugLoc();
861 // Create the stack frame object. Make sure it is aligned for both
862 // the source and destination types.
863 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT);
864 // Emit a store to the stack slot.
865 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr, NULL, 0);
866 // Result is a load from the stack slot.
867 return DAG.getLoad(DestVT, dl, Store, StackPtr, NULL, 0);
870 /// CustomLowerResults - Replace the node's results with custom code provided
871 /// by the target and return "true", or do nothing and return "false".
872 /// The last parameter is FALSE if we are dealing with a node with legal
873 /// result types and illegal operand. The second parameter denotes the type of
874 /// illegal OperandNo in that case.
875 /// The last parameter being TRUE means we are dealing with a
876 /// node with illegal result types. The second parameter denotes the type of
877 /// illegal ResNo in that case.
878 bool DAGTypeLegalizer::CustomLowerResults(SDNode *N, MVT VT,
879 bool LegalizeResult) {
880 // See if the target wants to custom lower this node.
881 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
884 SmallVector<SDValue, 8> Results;
886 TLI.ReplaceNodeResults(N, Results, DAG);
888 TLI.LowerOperationWrapper(N, Results, DAG);
891 // The target didn't want to custom lower it after all.
894 // Make everything that once used N's values now use those in Results instead.
895 assert(Results.size() == N->getNumValues() &&
896 "Custom lowering returned the wrong number of results!");
897 for (unsigned i = 0, e = Results.size(); i != e; ++i)
898 ReplaceValueWith(SDValue(N, i), Results[i]);
902 /// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type
903 /// which is split into two not necessarily identical pieces.
904 void DAGTypeLegalizer::GetSplitDestVTs(MVT InVT, MVT &LoVT, MVT &HiVT) {
905 if (!InVT.isVector()) {
906 LoVT = HiVT = TLI.getTypeToTransformTo(InVT);
908 MVT NewEltVT = InVT.getVectorElementType();
909 unsigned NumElements = InVT.getVectorNumElements();
910 if ((NumElements & (NumElements-1)) == 0) { // Simple power of two vector.
912 LoVT = HiVT = MVT::getVectorVT(NewEltVT, NumElements);
913 } else { // Non-power-of-two vectors.
914 unsigned NewNumElts_Lo = 1 << Log2_32(NumElements);
915 unsigned NewNumElts_Hi = NumElements - NewNumElts_Lo;
916 LoVT = MVT::getVectorVT(NewEltVT, NewNumElts_Lo);
917 HiVT = MVT::getVectorVT(NewEltVT, NewNumElts_Hi);
922 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and
923 /// high parts of the given value.
924 void DAGTypeLegalizer::GetPairElements(SDValue Pair,
925 SDValue &Lo, SDValue &Hi) {
926 DebugLoc dl = Pair.getDebugLoc();
927 MVT NVT = TLI.getTypeToTransformTo(Pair.getValueType());
928 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
929 DAG.getIntPtrConstant(0));
930 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
931 DAG.getIntPtrConstant(1));
934 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, MVT EltVT,
936 DebugLoc dl = Index.getDebugLoc();
937 // Make sure the index type is big enough to compute in.
938 if (Index.getValueType().bitsGT(TLI.getPointerTy()))
939 Index = DAG.getNode(ISD::TRUNCATE, dl, TLI.getPointerTy(), Index);
941 Index = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Index);
943 // Calculate the element offset and add it to the pointer.
944 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size.
946 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
947 DAG.getConstant(EltSize, Index.getValueType()));
948 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr);
951 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
952 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) {
953 // Arbitrarily use dlHi for result DebugLoc
954 DebugLoc dlHi = Hi.getDebugLoc();
955 DebugLoc dlLo = Lo.getDebugLoc();
956 MVT LVT = Lo.getValueType();
957 MVT HVT = Hi.getValueType();
958 MVT NVT = MVT::getIntegerVT(LVT.getSizeInBits() + HVT.getSizeInBits());
960 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo);
961 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi);
962 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi,
963 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy()));
964 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi);
967 /// LibCallify - Convert the node into a libcall with the same prototype.
968 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N,
970 unsigned NumOps = N->getNumOperands();
971 DebugLoc dl = N->getDebugLoc();
973 return MakeLibCall(LC, N->getValueType(0), 0, 0, isSigned, dl);
974 } else if (NumOps == 1) {
975 SDValue Op = N->getOperand(0);
976 return MakeLibCall(LC, N->getValueType(0), &Op, 1, isSigned, dl);
977 } else if (NumOps == 2) {
978 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) };
979 return MakeLibCall(LC, N->getValueType(0), Ops, 2, isSigned, dl);
981 SmallVector<SDValue, 8> Ops(NumOps);
982 for (unsigned i = 0; i < NumOps; ++i)
983 Ops[i] = N->getOperand(i);
985 return MakeLibCall(LC, N->getValueType(0), &Ops[0], NumOps, isSigned, dl);
988 /// MakeLibCall - Generate a libcall taking the given operands as arguments and
989 /// returning a result of type RetVT.
990 SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, MVT RetVT,
991 const SDValue *Ops, unsigned NumOps,
992 bool isSigned, DebugLoc dl) {
993 TargetLowering::ArgListTy Args;
994 Args.reserve(NumOps);
996 TargetLowering::ArgListEntry Entry;
997 for (unsigned i = 0; i != NumOps; ++i) {
999 Entry.Ty = Entry.Node.getValueType().getTypeForMVT();
1000 Entry.isSExt = isSigned;
1001 Entry.isZExt = !isSigned;
1002 Args.push_back(Entry);
1004 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1005 TLI.getPointerTy());
1007 const Type *RetTy = RetVT.getTypeForMVT();
1008 std::pair<SDValue,SDValue> CallInfo =
1009 TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
1010 false, CallingConv::C, false, Callee, Args, DAG, dl);
1011 return CallInfo.first;
1014 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean
1015 /// of the given type. A target boolean is an integer value, not necessarily of
1016 /// type i1, the bits of which conform to getBooleanContents.
1017 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, MVT VT) {
1018 DebugLoc dl = Bool.getDebugLoc();
1019 ISD::NodeType ExtendCode;
1020 switch (TLI.getBooleanContents()) {
1022 assert(false && "Unknown BooleanContent!");
1023 case TargetLowering::UndefinedBooleanContent:
1024 // Extend to VT by adding rubbish bits.
1025 ExtendCode = ISD::ANY_EXTEND;
1027 case TargetLowering::ZeroOrOneBooleanContent:
1028 // Extend to VT by adding zero bits.
1029 ExtendCode = ISD::ZERO_EXTEND;
1031 case TargetLowering::ZeroOrNegativeOneBooleanContent: {
1032 // Extend to VT by copying the sign bit.
1033 ExtendCode = ISD::SIGN_EXTEND;
1037 return DAG.getNode(ExtendCode, dl, VT, Bool);
1040 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT
1042 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1044 SDValue &Lo, SDValue &Hi) {
1045 DebugLoc dl = Op.getDebugLoc();
1046 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() ==
1047 Op.getValueType().getSizeInBits() && "Invalid integer splitting!");
1048 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op);
1049 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op,
1050 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy()));
1051 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi);
1054 /// SplitInteger - Return the lower and upper halves of Op's bits in a value
1055 /// type half the size of Op's.
1056 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1057 SDValue &Lo, SDValue &Hi) {
1058 MVT HalfVT = MVT::getIntegerVT(Op.getValueType().getSizeInBits()/2);
1059 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi);
1063 //===----------------------------------------------------------------------===//
1065 //===----------------------------------------------------------------------===//
1067 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
1068 /// only uses types natively supported by the target. Returns "true" if it made
1071 /// Note that this is an involved process that may invalidate pointers into
1073 bool SelectionDAG::LegalizeTypes() {
1074 return DAGTypeLegalizer(*this).run();