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/Target/TargetData.h"
19 #include "llvm/ADT/SetVector.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)) {
226 assert(false && "Unknown action!");
229 // The following calls must take care of *all* of the node's results,
230 // not just the illegal result they were passed (this includes results
231 // with a legal type). Results can be remapped using ReplaceValueWith,
232 // or their promoted/expanded/etc values registered in PromotedIntegers,
233 // ExpandedIntegers etc.
235 PromoteIntegerResult(N, i);
239 ExpandIntegerResult(N, i);
243 SoftenFloatResult(N, i);
247 ExpandFloatResult(N, i);
250 case ScalarizeVector:
251 ScalarizeVectorResult(N, i);
255 SplitVectorResult(N, i);
259 WidenVectorResult(N, i);
266 // Scan the operand list for the node, handling any nodes with operands that
269 unsigned NumOperands = N->getNumOperands();
270 bool NeedsReanalyzing = false;
272 for (i = 0; i != NumOperands; ++i) {
273 if (IgnoreNodeResults(N->getOperand(i).getNode()))
276 EVT OpVT = N->getOperand(i).getValueType();
277 switch (getTypeAction(OpVT)) {
279 assert(false && "Unknown action!");
282 // The following calls must either replace all of the node's results
283 // using ReplaceValueWith, and return "false"; or update the node's
284 // operands in place, and return "true".
286 NeedsReanalyzing = PromoteIntegerOperand(N, i);
290 NeedsReanalyzing = ExpandIntegerOperand(N, i);
294 NeedsReanalyzing = SoftenFloatOperand(N, i);
298 NeedsReanalyzing = ExpandFloatOperand(N, i);
301 case ScalarizeVector:
302 NeedsReanalyzing = ScalarizeVectorOperand(N, i);
306 NeedsReanalyzing = SplitVectorOperand(N, i);
310 NeedsReanalyzing = WidenVectorOperand(N, i);
317 // The sub-method updated N in place. Check to see if any operands are new,
318 // and if so, mark them. If the node needs revisiting, don't add all users
319 // to the worklist etc.
320 if (NeedsReanalyzing) {
321 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
322 N->setNodeId(NewNode);
323 // Recompute the NodeId and correct processed operands, adding the node to
324 // the worklist if ready.
325 SDNode *M = AnalyzeNewNode(N);
327 // The node didn't morph - nothing special to do, it will be revisited.
330 // The node morphed - this is equivalent to legalizing by replacing every
331 // value of N with the corresponding value of M. So do that now.
332 assert(N->getNumValues() == M->getNumValues() &&
333 "Node morphing changed the number of results!");
334 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
335 // Replacing the value takes care of remapping the new value.
336 ReplaceValueWith(SDValue(N, i), SDValue(M, i));
337 assert(N->getNodeId() == NewNode && "Unexpected node state!");
338 // The node continues to live on as part of the NewNode fungus that
339 // grows on top of the useful nodes. Nothing more needs to be done
340 // with it - move on to the next node.
344 if (i == NumOperands) {
345 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n");
350 // If we reach here, the node was processed, potentially creating new nodes.
351 // Mark it as processed and add its users to the worklist as appropriate.
352 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
353 N->setNodeId(Processed);
355 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
358 int NodeId = User->getNodeId();
360 // This node has two options: it can either be a new node or its Node ID
361 // may be a count of the number of operands it has that are not ready.
363 User->setNodeId(NodeId-1);
365 // If this was the last use it was waiting on, add it to the ready list.
366 if (NodeId-1 == ReadyToProcess)
367 Worklist.push_back(User);
371 // If this is an unreachable new node, then ignore it. If it ever becomes
372 // reachable by being used by a newly created node then it will be handled
373 // by AnalyzeNewNode.
374 if (NodeId == NewNode)
377 // Otherwise, this node is new: this is the first operand of it that
378 // became ready. Its new NodeId is the number of operands it has minus 1
379 // (as this node is now processed).
380 assert(NodeId == Unanalyzed && "Unknown node ID!");
381 User->setNodeId(User->getNumOperands() - 1);
383 // If the node only has a single operand, it is now ready.
384 if (User->getNumOperands() == 1)
385 Worklist.push_back(User);
390 if (EnableExpensiveChecks)
392 PerformExpensiveChecks();
394 // If the root changed (e.g. it was a dead load) update the root.
395 DAG.setRoot(Dummy.getValue());
397 // Remove dead nodes. This is important to do for cleanliness but also before
398 // the checking loop below. Implicit folding by the DAG.getNode operators and
399 // node morphing can cause unreachable nodes to be around with their flags set
401 DAG.RemoveDeadNodes();
403 // In a debug build, scan all the nodes to make sure we found them all. This
404 // ensures that there are no cycles and that everything got processed.
406 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
407 E = DAG.allnodes_end(); I != E; ++I) {
410 // Check that all result types are legal.
411 if (!IgnoreNodeResults(I))
412 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i)
413 if (!isTypeLegal(I->getValueType(i))) {
414 dbgs() << "Result type " << i << " illegal!\n";
418 // Check that all operand types are legal.
419 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i)
420 if (!IgnoreNodeResults(I->getOperand(i).getNode()) &&
421 !isTypeLegal(I->getOperand(i).getValueType())) {
422 dbgs() << "Operand type " << i << " illegal!\n";
426 if (I->getNodeId() != Processed) {
427 if (I->getNodeId() == NewNode)
428 dbgs() << "New node not analyzed?\n";
429 else if (I->getNodeId() == Unanalyzed)
430 dbgs() << "Unanalyzed node not noticed?\n";
431 else if (I->getNodeId() > 0)
432 dbgs() << "Operand not processed?\n";
433 else if (I->getNodeId() == ReadyToProcess)
434 dbgs() << "Not added to worklist?\n";
439 I->dump(&DAG); dbgs() << "\n";
448 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially
449 /// new nodes. Correct any processed operands (this may change the node) and
450 /// calculate the NodeId. If the node itself changes to a processed node, it
451 /// is not remapped - the caller needs to take care of this.
452 /// Returns the potentially changed node.
453 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) {
454 // If this was an existing node that is already done, we're done.
455 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed)
458 // Remove any stale map entries.
461 // Okay, we know that this node is new. Recursively walk all of its operands
462 // to see if they are new also. The depth of this walk is bounded by the size
463 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry
464 // about revisiting of nodes.
466 // As we walk the operands, keep track of the number of nodes that are
467 // processed. If non-zero, this will become the new nodeid of this node.
468 // Operands may morph when they are analyzed. If so, the node will be
469 // updated after all operands have been analyzed. Since this is rare,
470 // the code tries to minimize overhead in the non-morphing case.
472 SmallVector<SDValue, 8> NewOps;
473 unsigned NumProcessed = 0;
474 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
475 SDValue OrigOp = N->getOperand(i);
478 AnalyzeNewValue(Op); // Op may morph.
480 if (Op.getNode()->getNodeId() == Processed)
483 if (!NewOps.empty()) {
484 // Some previous operand changed. Add this one to the list.
485 NewOps.push_back(Op);
486 } else if (Op != OrigOp) {
487 // This is the first operand to change - add all operands so far.
488 NewOps.insert(NewOps.end(), N->op_begin(), N->op_begin() + i);
489 NewOps.push_back(Op);
493 // Some operands changed - update the node.
494 if (!NewOps.empty()) {
495 SDNode *M = DAG.UpdateNodeOperands(SDValue(N, 0), &NewOps[0],
496 NewOps.size()).getNode();
498 // The node morphed into a different node. Normally for this to happen
499 // the original node would have to be marked NewNode. However this can
500 // in theory momentarily not be the case while ReplaceValueWith is doing
501 // its stuff. Mark the original node NewNode to help sanity checking.
502 N->setNodeId(NewNode);
503 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed)
504 // It morphed into a previously analyzed node - nothing more to do.
507 // It morphed into a different new node. Do the equivalent of passing
508 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need
509 // to remap the operands, since they are the same as the operands we
516 // Calculate the NodeId.
517 N->setNodeId(N->getNumOperands() - NumProcessed);
518 if (N->getNodeId() == ReadyToProcess)
519 Worklist.push_back(N);
524 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed.
525 /// If the node changes to a processed node, then remap it.
526 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) {
527 Val.setNode(AnalyzeNewNode(Val.getNode()));
528 if (Val.getNode()->getNodeId() == Processed)
529 // We were passed a processed node, or it morphed into one - remap it.
533 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it.
534 /// This can occur when a node is deleted then reallocated as a new node -
535 /// the mapping in ReplacedValues applies to the deleted node, not the new
537 /// The only map that can have a deleted node as a source is ReplacedValues.
538 /// Other maps can have deleted nodes as targets, but since their looked-up
539 /// values are always immediately remapped using RemapValue, resulting in a
540 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue
541 /// always performs correct mappings. In order to keep the mapping correct,
542 /// ExpungeNode should be called on any new nodes *before* adding them as
543 /// either source or target to ReplacedValues (which typically means calling
544 /// Expunge when a new node is first seen, since it may no longer be marked
545 /// NewNode by the time it is added to ReplacedValues).
546 void DAGTypeLegalizer::ExpungeNode(SDNode *N) {
547 if (N->getNodeId() != NewNode)
550 // If N is not remapped by ReplacedValues then there is nothing to do.
552 for (i = 0, e = N->getNumValues(); i != e; ++i)
553 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end())
559 // Remove N from all maps - this is expensive but rare.
561 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(),
562 E = PromotedIntegers.end(); I != E; ++I) {
563 assert(I->first.getNode() != N);
564 RemapValue(I->second);
567 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(),
568 E = SoftenedFloats.end(); I != E; ++I) {
569 assert(I->first.getNode() != N);
570 RemapValue(I->second);
573 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(),
574 E = ScalarizedVectors.end(); I != E; ++I) {
575 assert(I->first.getNode() != N);
576 RemapValue(I->second);
579 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(),
580 E = WidenedVectors.end(); I != E; ++I) {
581 assert(I->first.getNode() != N);
582 RemapValue(I->second);
585 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
586 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){
587 assert(I->first.getNode() != N);
588 RemapValue(I->second.first);
589 RemapValue(I->second.second);
592 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
593 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) {
594 assert(I->first.getNode() != N);
595 RemapValue(I->second.first);
596 RemapValue(I->second.second);
599 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
600 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) {
601 assert(I->first.getNode() != N);
602 RemapValue(I->second.first);
603 RemapValue(I->second.second);
606 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(),
607 E = ReplacedValues.end(); I != E; ++I)
608 RemapValue(I->second);
610 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
611 ReplacedValues.erase(SDValue(N, i));
614 /// RemapValue - If the specified value was already legalized to another value,
615 /// replace it by that value.
616 void DAGTypeLegalizer::RemapValue(SDValue &N) {
617 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N);
618 if (I != ReplacedValues.end()) {
619 // Use path compression to speed up future lookups if values get multiply
620 // replaced with other values.
621 RemapValue(I->second);
623 assert(N.getNode()->getNodeId() != NewNode && "Mapped to new node!");
628 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for
629 /// updates to nodes and recomputes their ready state.
630 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener {
631 DAGTypeLegalizer &DTL;
632 SmallSetVector<SDNode*, 16> &NodesToAnalyze;
634 explicit NodeUpdateListener(DAGTypeLegalizer &dtl,
635 SmallSetVector<SDNode*, 16> &nta)
636 : DTL(dtl), NodesToAnalyze(nta) {}
638 virtual void NodeDeleted(SDNode *N, SDNode *E) {
639 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
640 N->getNodeId() != DAGTypeLegalizer::Processed &&
641 "Invalid node ID for RAUW deletion!");
642 // It is possible, though rare, for the deleted node N to occur as a
643 // target in a map, so note the replacement N -> E in ReplacedValues.
644 assert(E && "Node not replaced?");
645 DTL.NoteDeletion(N, E);
647 // In theory the deleted node could also have been scheduled for analysis.
648 // So remove it from the set of nodes which will be analyzed.
649 NodesToAnalyze.remove(N);
651 // In general nothing needs to be done for E, since it didn't change but
652 // only gained new uses. However N -> E was just added to ReplacedValues,
653 // and the result of a ReplacedValues mapping is not allowed to be marked
654 // NewNode. So if E is marked NewNode, then it needs to be analyzed.
655 if (E->getNodeId() == DAGTypeLegalizer::NewNode)
656 NodesToAnalyze.insert(E);
659 virtual void NodeUpdated(SDNode *N) {
660 // Node updates can mean pretty much anything. It is possible that an
661 // operand was set to something already processed (f.e.) in which case
662 // this node could become ready. Recompute its flags.
663 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
664 N->getNodeId() != DAGTypeLegalizer::Processed &&
665 "Invalid node ID for RAUW deletion!");
666 N->setNodeId(DAGTypeLegalizer::NewNode);
667 NodesToAnalyze.insert(N);
673 /// ReplaceValueWith - The specified value was legalized to the specified other
674 /// value. Update the DAG and NodeIds replacing any uses of From to use To
676 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) {
677 assert(From.getNode() != To.getNode() && "Potential legalization loop!");
679 // If expansion produced new nodes, make sure they are properly marked.
680 ExpungeNode(From.getNode());
681 AnalyzeNewValue(To); // Expunges To.
683 // Anything that used the old node should now use the new one. Note that this
684 // can potentially cause recursive merging.
685 SmallSetVector<SDNode*, 16> NodesToAnalyze;
686 NodeUpdateListener NUL(*this, NodesToAnalyze);
687 DAG.ReplaceAllUsesOfValueWith(From, To, &NUL);
689 // The old node may still be present in a map like ExpandedIntegers or
690 // PromotedIntegers. Inform maps about the replacement.
691 ReplacedValues[From] = To;
693 // Process the list of nodes that need to be reanalyzed.
694 while (!NodesToAnalyze.empty()) {
695 SDNode *N = NodesToAnalyze.back();
696 NodesToAnalyze.pop_back();
697 if (N->getNodeId() != DAGTypeLegalizer::NewNode)
698 // The node was analyzed while reanalyzing an earlier node - it is safe to
699 // skip. Note that this is not a morphing node - otherwise it would still
700 // be marked NewNode.
703 // Analyze the node's operands and recalculate the node ID.
704 SDNode *M = AnalyzeNewNode(N);
706 // The node morphed into a different node. Make everyone use the new node
708 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!");
709 assert(N->getNumValues() == M->getNumValues() &&
710 "Node morphing changed the number of results!");
711 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
712 SDValue OldVal(N, i);
713 SDValue NewVal(M, i);
714 if (M->getNodeId() == Processed)
716 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal, &NUL);
718 // The original node continues to exist in the DAG, marked NewNode.
723 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
724 assert(Result.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
725 "Invalid type for promoted integer");
726 AnalyzeNewValue(Result);
728 SDValue &OpEntry = PromotedIntegers[Op];
729 assert(OpEntry.getNode() == 0 && "Node is already promoted!");
733 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
734 assert(Result.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
735 "Invalid type for softened float");
736 AnalyzeNewValue(Result);
738 SDValue &OpEntry = SoftenedFloats[Op];
739 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!");
743 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
744 assert(Result.getValueType() == Op.getValueType().getVectorElementType() &&
745 "Invalid type for scalarized vector");
746 AnalyzeNewValue(Result);
748 SDValue &OpEntry = ScalarizedVectors[Op];
749 assert(OpEntry.getNode() == 0 && "Node is already scalarized!");
753 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
755 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
756 RemapValue(Entry.first);
757 RemapValue(Entry.second);
758 assert(Entry.first.getNode() && "Operand isn't expanded");
763 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
765 assert(Lo.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
766 Hi.getValueType() == Lo.getValueType() &&
767 "Invalid type for expanded integer");
768 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
772 // Remember that this is the result of the node.
773 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
774 assert(Entry.first.getNode() == 0 && "Node already expanded");
779 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
781 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
782 RemapValue(Entry.first);
783 RemapValue(Entry.second);
784 assert(Entry.first.getNode() && "Operand isn't expanded");
789 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
791 assert(Lo.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
792 Hi.getValueType() == Lo.getValueType() &&
793 "Invalid type for expanded float");
794 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
798 // Remember that this is the result of the node.
799 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
800 assert(Entry.first.getNode() == 0 && "Node already expanded");
805 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
807 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
808 RemapValue(Entry.first);
809 RemapValue(Entry.second);
810 assert(Entry.first.getNode() && "Operand isn't split");
815 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
817 assert(Lo.getValueType().getVectorElementType() ==
818 Op.getValueType().getVectorElementType() &&
819 2*Lo.getValueType().getVectorNumElements() ==
820 Op.getValueType().getVectorNumElements() &&
821 Hi.getValueType() == Lo.getValueType() &&
822 "Invalid type for split vector");
823 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
827 // Remember that this is the result of the node.
828 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
829 assert(Entry.first.getNode() == 0 && "Node already split");
834 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
835 assert(Result.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
836 "Invalid type for widened vector");
837 AnalyzeNewValue(Result);
839 SDValue &OpEntry = WidenedVectors[Op];
840 assert(OpEntry.getNode() == 0 && "Node already widened!");
845 //===----------------------------------------------------------------------===//
847 //===----------------------------------------------------------------------===//
849 /// BitConvertToInteger - Convert to an integer of the same size.
850 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) {
851 unsigned BitWidth = Op.getValueType().getSizeInBits();
852 return DAG.getNode(ISD::BIT_CONVERT, Op.getDebugLoc(),
853 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op);
856 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the
858 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) {
859 assert(Op.getValueType().isVector() && "Only applies to vectors!");
860 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits();
861 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth);
862 unsigned NumElts = Op.getValueType().getVectorNumElements();
863 return DAG.getNode(ISD::BIT_CONVERT, Op.getDebugLoc(),
864 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op);
867 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op,
869 DebugLoc dl = Op.getDebugLoc();
870 // Create the stack frame object. Make sure it is aligned for both
871 // the source and destination types.
872 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT);
873 // Emit a store to the stack slot.
874 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr, NULL, 0,
876 // Result is a load from the stack slot.
877 return DAG.getLoad(DestVT, dl, Store, StackPtr, NULL, 0, false, false, 0);
880 /// CustomLowerNode - Replace the node's results with custom code provided
881 /// by the target and return "true", or do nothing and return "false".
882 /// The last parameter is FALSE if we are dealing with a node with legal
883 /// result types and illegal operand. The second parameter denotes the type of
884 /// illegal OperandNo in that case.
885 /// The last parameter being TRUE means we are dealing with a
886 /// node with illegal result types. The second parameter denotes the type of
887 /// illegal ResNo in that case.
888 bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) {
889 // See if the target wants to custom lower this node.
890 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
893 SmallVector<SDValue, 8> Results;
895 TLI.ReplaceNodeResults(N, Results, DAG);
897 TLI.LowerOperationWrapper(N, Results, DAG);
900 // The target didn't want to custom lower it after all.
903 // Make everything that once used N's values now use those in Results instead.
904 assert(Results.size() == N->getNumValues() &&
905 "Custom lowering returned the wrong number of results!");
906 for (unsigned i = 0, e = Results.size(); i != e; ++i)
907 ReplaceValueWith(SDValue(N, i), Results[i]);
912 /// CustomWidenLowerNode - Widen the node's results with custom code provided
913 /// by the target and return "true", or do nothing and return "false".
914 bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) {
915 // See if the target wants to custom lower this node.
916 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
919 SmallVector<SDValue, 8> Results;
920 TLI.ReplaceNodeResults(N, Results, DAG);
923 // The target didn't want to custom widen lower its result after all.
926 // Update the widening map.
927 assert(Results.size() == N->getNumValues() &&
928 "Custom lowering returned the wrong number of results!");
929 for (unsigned i = 0, e = Results.size(); i != e; ++i)
930 SetWidenedVector(SDValue(N, i), Results[i]);
934 /// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type
935 /// which is split into two not necessarily identical pieces.
936 void DAGTypeLegalizer::GetSplitDestVTs(EVT InVT, EVT &LoVT, EVT &HiVT) {
937 // Currently all types are split in half.
938 if (!InVT.isVector()) {
939 LoVT = HiVT = TLI.getTypeToTransformTo(*DAG.getContext(), InVT);
941 unsigned NumElements = InVT.getVectorNumElements();
942 assert(!(NumElements & 1) && "Splitting vector, but not in half!");
943 LoVT = HiVT = EVT::getVectorVT(*DAG.getContext(), InVT.getVectorElementType(), NumElements/2);
947 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and
948 /// high parts of the given value.
949 void DAGTypeLegalizer::GetPairElements(SDValue Pair,
950 SDValue &Lo, SDValue &Hi) {
951 DebugLoc dl = Pair.getDebugLoc();
952 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType());
953 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
954 DAG.getIntPtrConstant(0));
955 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
956 DAG.getIntPtrConstant(1));
959 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT,
961 DebugLoc dl = Index.getDebugLoc();
962 // Make sure the index type is big enough to compute in.
963 if (Index.getValueType().bitsGT(TLI.getPointerTy()))
964 Index = DAG.getNode(ISD::TRUNCATE, dl, TLI.getPointerTy(), Index);
966 Index = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Index);
968 // Calculate the element offset and add it to the pointer.
969 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size.
971 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
972 DAG.getConstant(EltSize, Index.getValueType()));
973 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr);
976 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
977 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) {
978 // Arbitrarily use dlHi for result DebugLoc
979 DebugLoc dlHi = Hi.getDebugLoc();
980 DebugLoc dlLo = Lo.getDebugLoc();
981 EVT LVT = Lo.getValueType();
982 EVT HVT = Hi.getValueType();
983 EVT NVT = EVT::getIntegerVT(*DAG.getContext(), LVT.getSizeInBits() + HVT.getSizeInBits());
985 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo);
986 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi);
987 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi,
988 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy()));
989 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi);
992 /// LibCallify - Convert the node into a libcall with the same prototype.
993 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N,
995 unsigned NumOps = N->getNumOperands();
996 DebugLoc dl = N->getDebugLoc();
998 return MakeLibCall(LC, N->getValueType(0), 0, 0, isSigned, dl);
999 } else if (NumOps == 1) {
1000 SDValue Op = N->getOperand(0);
1001 return MakeLibCall(LC, N->getValueType(0), &Op, 1, isSigned, dl);
1002 } else if (NumOps == 2) {
1003 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) };
1004 return MakeLibCall(LC, N->getValueType(0), Ops, 2, isSigned, dl);
1006 SmallVector<SDValue, 8> Ops(NumOps);
1007 for (unsigned i = 0; i < NumOps; ++i)
1008 Ops[i] = N->getOperand(i);
1010 return MakeLibCall(LC, N->getValueType(0), &Ops[0], NumOps, isSigned, dl);
1013 /// MakeLibCall - Generate a libcall taking the given operands as arguments and
1014 /// returning a result of type RetVT.
1015 SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, EVT RetVT,
1016 const SDValue *Ops, unsigned NumOps,
1017 bool isSigned, DebugLoc dl) {
1018 TargetLowering::ArgListTy Args;
1019 Args.reserve(NumOps);
1021 TargetLowering::ArgListEntry Entry;
1022 for (unsigned i = 0; i != NumOps; ++i) {
1023 Entry.Node = Ops[i];
1024 Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
1025 Entry.isSExt = isSigned;
1026 Entry.isZExt = !isSigned;
1027 Args.push_back(Entry);
1029 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1030 TLI.getPointerTy());
1032 const Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
1033 std::pair<SDValue,SDValue> CallInfo =
1034 TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
1035 false, 0, TLI.getLibcallCallingConv(LC), false,
1036 /*isReturnValueUsed=*/true,
1037 Callee, Args, DAG, dl);
1038 return CallInfo.first;
1041 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean
1042 /// of the given type. A target boolean is an integer value, not necessarily of
1043 /// type i1, the bits of which conform to getBooleanContents.
1044 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT VT) {
1045 DebugLoc dl = Bool.getDebugLoc();
1046 ISD::NodeType ExtendCode;
1047 switch (TLI.getBooleanContents()) {
1049 assert(false && "Unknown BooleanContent!");
1050 case TargetLowering::UndefinedBooleanContent:
1051 // Extend to VT by adding rubbish bits.
1052 ExtendCode = ISD::ANY_EXTEND;
1054 case TargetLowering::ZeroOrOneBooleanContent:
1055 // Extend to VT by adding zero bits.
1056 ExtendCode = ISD::ZERO_EXTEND;
1058 case TargetLowering::ZeroOrNegativeOneBooleanContent: {
1059 // Extend to VT by copying the sign bit.
1060 ExtendCode = ISD::SIGN_EXTEND;
1064 return DAG.getNode(ExtendCode, dl, VT, Bool);
1067 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT
1069 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1071 SDValue &Lo, SDValue &Hi) {
1072 DebugLoc dl = Op.getDebugLoc();
1073 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() ==
1074 Op.getValueType().getSizeInBits() && "Invalid integer splitting!");
1075 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op);
1076 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op,
1077 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy()));
1078 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi);
1081 /// SplitInteger - Return the lower and upper halves of Op's bits in a value
1082 /// type half the size of Op's.
1083 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1084 SDValue &Lo, SDValue &Hi) {
1085 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), Op.getValueType().getSizeInBits()/2);
1086 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi);
1090 //===----------------------------------------------------------------------===//
1092 //===----------------------------------------------------------------------===//
1094 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
1095 /// only uses types natively supported by the target. Returns "true" if it made
1098 /// Note that this is an involved process that may invalidate pointers into
1100 bool SelectionDAG::LegalizeTypes() {
1101 return DAGTypeLegalizer(*this).run();