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"
25 #define DEBUG_TYPE "legalize-types"
28 EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden);
30 /// PerformExpensiveChecks - Do extensive, expensive, sanity checking.
31 void DAGTypeLegalizer::PerformExpensiveChecks() {
32 // If a node is not processed, then none of its values should be mapped by any
33 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
35 // If a node is processed, then each value with an illegal type must be mapped
36 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
37 // Values with a legal type may be mapped by ReplacedValues, but not by any of
40 // Note that these invariants may not hold momentarily when processing a node:
41 // the node being processed may be put in a map before being marked Processed.
43 // Note that it is possible to have nodes marked NewNode in the DAG. This can
44 // occur in two ways. Firstly, a node may be created during legalization but
45 // never passed to the legalization core. This is usually due to the implicit
46 // folding that occurs when using the DAG.getNode operators. Secondly, a new
47 // node may be passed to the legalization core, but when analyzed may morph
48 // into a different node, leaving the original node as a NewNode in the DAG.
49 // A node may morph if one of its operands changes during analysis. Whether
50 // it actually morphs or not depends on whether, after updating its operands,
51 // it is equivalent to an existing node: if so, it morphs into that existing
52 // node (CSE). An operand can change during analysis if the operand is a new
53 // node that morphs, or it is a processed value that was mapped to some other
54 // value (as recorded in ReplacedValues) in which case the operand is turned
55 // into that other value. If a node morphs then the node it morphed into will
56 // be used instead of it for legalization, however the original node continues
57 // to live on in the DAG.
58 // The conclusion is that though there may be nodes marked NewNode in the DAG,
59 // all uses of such nodes are also marked NewNode: the result is a fungus of
60 // NewNodes growing on top of the useful nodes, and perhaps using them, but
63 // If a value is mapped by ReplacedValues, then it must have no uses, except
64 // by nodes marked NewNode (see above).
66 // The final node obtained by mapping by ReplacedValues is not marked NewNode.
67 // Note that ReplacedValues should be applied iteratively.
69 // Note that the ReplacedValues map may also map deleted nodes (by iterating
70 // over the DAG we never dereference deleted nodes). This means that it may
71 // also map nodes marked NewNode if the deallocated memory was reallocated as
72 // another node, and that new node was not seen by the LegalizeTypes machinery
73 // (for example because it was created but not used). In general, we cannot
74 // distinguish between new nodes and deleted nodes.
75 SmallVector<SDNode*, 16> NewNodes;
76 for (SDNode &Node : DAG.allnodes()) {
77 // Remember nodes marked NewNode - they are subject to extra checking below.
78 if (Node.getNodeId() == NewNode)
79 NewNodes.push_back(&Node);
81 for (unsigned i = 0, e = Node.getNumValues(); i != e; ++i) {
82 SDValue Res(&Node, i);
86 if (ReplacedValues.find(Res) != ReplacedValues.end()) {
88 // Check that remapped values are only used by nodes marked NewNode.
89 for (SDNode::use_iterator UI = Node.use_begin(), UE = Node.use_end();
91 if (UI.getUse().getResNo() == i)
92 assert(UI->getNodeId() == NewNode &&
93 "Remapped value has non-trivial use!");
95 // Check that the final result of applying ReplacedValues is not
97 SDValue NewVal = ReplacedValues[Res];
98 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(NewVal);
99 while (I != ReplacedValues.end()) {
101 I = ReplacedValues.find(NewVal);
103 assert(NewVal.getNode()->getNodeId() != NewNode &&
104 "ReplacedValues maps to a new node!");
106 if (PromotedIntegers.find(Res) != PromotedIntegers.end())
108 if (SoftenedFloats.find(Res) != SoftenedFloats.end())
110 if (ScalarizedVectors.find(Res) != ScalarizedVectors.end())
112 if (ExpandedIntegers.find(Res) != ExpandedIntegers.end())
114 if (ExpandedFloats.find(Res) != ExpandedFloats.end())
116 if (SplitVectors.find(Res) != SplitVectors.end())
118 if (WidenedVectors.find(Res) != WidenedVectors.end())
121 if (Node.getNodeId() != Processed) {
122 // Since we allow ReplacedValues to map deleted nodes, it may map nodes
123 // marked NewNode too, since a deleted node may have been reallocated as
124 // another node that has not been seen by the LegalizeTypes machinery.
125 if ((Node.getNodeId() == NewNode && Mapped > 1) ||
126 (Node.getNodeId() != NewNode && Mapped != 0)) {
127 dbgs() << "Unprocessed value in a map!";
130 } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(&Node)) {
132 dbgs() << "Value with legal type was transformed!";
137 dbgs() << "Processed value not in any map!";
139 } else if (Mapped & (Mapped - 1)) {
140 dbgs() << "Value in multiple maps!";
147 dbgs() << " ReplacedValues";
149 dbgs() << " PromotedIntegers";
151 dbgs() << " SoftenedFloats";
153 dbgs() << " ScalarizedVectors";
155 dbgs() << " ExpandedIntegers";
157 dbgs() << " ExpandedFloats";
159 dbgs() << " SplitVectors";
161 dbgs() << " WidenedVectors";
163 llvm_unreachable(nullptr);
168 // Checked that NewNodes are only used by other NewNodes.
169 for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) {
170 SDNode *N = NewNodes[i];
171 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
173 assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!");
177 /// run - This is the main entry point for the type legalizer. This does a
178 /// top-down traversal of the dag, legalizing types as it goes. Returns "true"
179 /// if it made any changes.
180 bool DAGTypeLegalizer::run() {
181 bool Changed = false;
183 // Create a dummy node (which is not added to allnodes), that adds a reference
184 // to the root node, preventing it from being deleted, and tracking any
185 // changes of the root.
186 HandleSDNode Dummy(DAG.getRoot());
187 Dummy.setNodeId(Unanalyzed);
189 // The root of the dag may dangle to deleted nodes until the type legalizer is
190 // done. Set it to null to avoid confusion.
191 DAG.setRoot(SDValue());
193 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess'
194 // (and remembering them) if they are leaves and assigning 'Unanalyzed' if
196 for (SDNode &Node : DAG.allnodes()) {
197 if (Node.getNumOperands() == 0) {
198 Node.setNodeId(ReadyToProcess);
199 Worklist.push_back(&Node);
201 Node.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);
260 case TargetLowering::TypePromoteFloat:
261 PromoteFloatResult(N, i);
268 // Scan the operand list for the node, handling any nodes with operands that
271 unsigned NumOperands = N->getNumOperands();
272 bool NeedsReanalyzing = false;
274 for (i = 0; i != NumOperands; ++i) {
275 if (IgnoreNodeResults(N->getOperand(i).getNode()))
278 EVT OpVT = N->getOperand(i).getValueType();
279 switch (getTypeAction(OpVT)) {
280 case TargetLowering::TypeLegal:
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".
285 case TargetLowering::TypePromoteInteger:
286 NeedsReanalyzing = PromoteIntegerOperand(N, i);
289 case TargetLowering::TypeExpandInteger:
290 NeedsReanalyzing = ExpandIntegerOperand(N, i);
293 case TargetLowering::TypeSoftenFloat:
294 NeedsReanalyzing = SoftenFloatOperand(N, i);
297 case TargetLowering::TypeExpandFloat:
298 NeedsReanalyzing = ExpandFloatOperand(N, i);
301 case TargetLowering::TypeScalarizeVector:
302 NeedsReanalyzing = ScalarizeVectorOperand(N, i);
305 case TargetLowering::TypeSplitVector:
306 NeedsReanalyzing = SplitVectorOperand(N, i);
309 case TargetLowering::TypeWidenVector:
310 NeedsReanalyzing = WidenVectorOperand(N, i);
313 case TargetLowering::TypePromoteFloat:
314 NeedsReanalyzing = PromoteFloatOperand(N, i);
321 // The sub-method updated N in place. Check to see if any operands are new,
322 // and if so, mark them. If the node needs revisiting, don't add all users
323 // to the worklist etc.
324 if (NeedsReanalyzing) {
325 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
326 N->setNodeId(NewNode);
327 // Recompute the NodeId and correct processed operands, adding the node to
328 // the worklist if ready.
329 SDNode *M = AnalyzeNewNode(N);
331 // The node didn't morph - nothing special to do, it will be revisited.
334 // The node morphed - this is equivalent to legalizing by replacing every
335 // value of N with the corresponding value of M. So do that now.
336 assert(N->getNumValues() == M->getNumValues() &&
337 "Node morphing changed the number of results!");
338 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
339 // Replacing the value takes care of remapping the new value.
340 ReplaceValueWith(SDValue(N, i), SDValue(M, i));
341 assert(N->getNodeId() == NewNode && "Unexpected node state!");
342 // The node continues to live on as part of the NewNode fungus that
343 // grows on top of the useful nodes. Nothing more needs to be done
344 // with it - move on to the next node.
348 if (i == NumOperands) {
349 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n");
354 // If we reach here, the node was processed, potentially creating new nodes.
355 // Mark it as processed and add its users to the worklist as appropriate.
356 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
357 N->setNodeId(Processed);
359 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
362 int NodeId = User->getNodeId();
364 // This node has two options: it can either be a new node or its Node ID
365 // may be a count of the number of operands it has that are not ready.
367 User->setNodeId(NodeId-1);
369 // If this was the last use it was waiting on, add it to the ready list.
370 if (NodeId-1 == ReadyToProcess)
371 Worklist.push_back(User);
375 // If this is an unreachable new node, then ignore it. If it ever becomes
376 // reachable by being used by a newly created node then it will be handled
377 // by AnalyzeNewNode.
378 if (NodeId == NewNode)
381 // Otherwise, this node is new: this is the first operand of it that
382 // became ready. Its new NodeId is the number of operands it has minus 1
383 // (as this node is now processed).
384 assert(NodeId == Unanalyzed && "Unknown node ID!");
385 User->setNodeId(User->getNumOperands() - 1);
387 // If the node only has a single operand, it is now ready.
388 if (User->getNumOperands() == 1)
389 Worklist.push_back(User);
394 if (EnableExpensiveChecks)
396 PerformExpensiveChecks();
398 // If the root changed (e.g. it was a dead load) update the root.
399 DAG.setRoot(Dummy.getValue());
401 // Remove dead nodes. This is important to do for cleanliness but also before
402 // the checking loop below. Implicit folding by the DAG.getNode operators and
403 // node morphing can cause unreachable nodes to be around with their flags set
405 DAG.RemoveDeadNodes();
407 // In a debug build, scan all the nodes to make sure we found them all. This
408 // ensures that there are no cycles and that everything got processed.
410 for (SDNode &Node : DAG.allnodes()) {
413 // Check that all result types are legal.
414 if (!IgnoreNodeResults(&Node))
415 for (unsigned i = 0, NumVals = Node.getNumValues(); i < NumVals; ++i)
416 if (!isTypeLegal(Node.getValueType(i))) {
417 dbgs() << "Result type " << i << " illegal!\n";
421 // Check that all operand types are legal.
422 for (unsigned i = 0, NumOps = Node.getNumOperands(); i < NumOps; ++i)
423 if (!IgnoreNodeResults(Node.getOperand(i).getNode()) &&
424 !isTypeLegal(Node.getOperand(i).getValueType())) {
425 dbgs() << "Operand type " << i << " illegal!\n";
429 if (Node.getNodeId() != Processed) {
430 if (Node.getNodeId() == NewNode)
431 dbgs() << "New node not analyzed?\n";
432 else if (Node.getNodeId() == Unanalyzed)
433 dbgs() << "Unanalyzed node not noticed?\n";
434 else if (Node.getNodeId() > 0)
435 dbgs() << "Operand not processed?\n";
436 else if (Node.getNodeId() == ReadyToProcess)
437 dbgs() << "Not added to worklist?\n";
442 Node.dump(&DAG); dbgs() << "\n";
443 llvm_unreachable(nullptr);
451 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially
452 /// new nodes. Correct any processed operands (this may change the node) and
453 /// calculate the NodeId. If the node itself changes to a processed node, it
454 /// is not remapped - the caller needs to take care of this.
455 /// Returns the potentially changed node.
456 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) {
457 // If this was an existing node that is already done, we're done.
458 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed)
461 // Remove any stale map entries.
464 // Okay, we know that this node is new. Recursively walk all of its operands
465 // to see if they are new also. The depth of this walk is bounded by the size
466 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry
467 // about revisiting of nodes.
469 // As we walk the operands, keep track of the number of nodes that are
470 // processed. If non-zero, this will become the new nodeid of this node.
471 // Operands may morph when they are analyzed. If so, the node will be
472 // updated after all operands have been analyzed. Since this is rare,
473 // the code tries to minimize overhead in the non-morphing case.
475 SmallVector<SDValue, 8> NewOps;
476 unsigned NumProcessed = 0;
477 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
478 SDValue OrigOp = N->getOperand(i);
481 AnalyzeNewValue(Op); // Op may morph.
483 if (Op.getNode()->getNodeId() == Processed)
486 if (!NewOps.empty()) {
487 // Some previous operand changed. Add this one to the list.
488 NewOps.push_back(Op);
489 } else if (Op != OrigOp) {
490 // This is the first operand to change - add all operands so far.
491 NewOps.append(N->op_begin(), N->op_begin() + i);
492 NewOps.push_back(Op);
496 // Some operands changed - update the node.
497 if (!NewOps.empty()) {
498 SDNode *M = DAG.UpdateNodeOperands(N, NewOps);
500 // The node morphed into a different node. Normally for this to happen
501 // the original node would have to be marked NewNode. However this can
502 // in theory momentarily not be the case while ReplaceValueWith is doing
503 // its stuff. Mark the original node NewNode to help sanity checking.
504 N->setNodeId(NewNode);
505 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed)
506 // It morphed into a previously analyzed node - nothing more to do.
509 // It morphed into a different new node. Do the equivalent of passing
510 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need
511 // to remap the operands, since they are the same as the operands we
518 // Calculate the NodeId.
519 N->setNodeId(N->getNumOperands() - NumProcessed);
520 if (N->getNodeId() == ReadyToProcess)
521 Worklist.push_back(N);
526 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed.
527 /// If the node changes to a processed node, then remap it.
528 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) {
529 Val.setNode(AnalyzeNewNode(Val.getNode()));
530 if (Val.getNode()->getNodeId() == Processed)
531 // We were passed a processed node, or it morphed into one - remap it.
535 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it.
536 /// This can occur when a node is deleted then reallocated as a new node -
537 /// the mapping in ReplacedValues applies to the deleted node, not the new
539 /// The only map that can have a deleted node as a source is ReplacedValues.
540 /// Other maps can have deleted nodes as targets, but since their looked-up
541 /// values are always immediately remapped using RemapValue, resulting in a
542 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue
543 /// always performs correct mappings. In order to keep the mapping correct,
544 /// ExpungeNode should be called on any new nodes *before* adding them as
545 /// either source or target to ReplacedValues (which typically means calling
546 /// Expunge when a new node is first seen, since it may no longer be marked
547 /// NewNode by the time it is added to ReplacedValues).
548 void DAGTypeLegalizer::ExpungeNode(SDNode *N) {
549 if (N->getNodeId() != NewNode)
552 // If N is not remapped by ReplacedValues then there is nothing to do.
554 for (i = 0, e = N->getNumValues(); i != e; ++i)
555 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end())
561 // Remove N from all maps - this is expensive but rare.
563 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(),
564 E = PromotedIntegers.end(); I != E; ++I) {
565 assert(I->first.getNode() != N);
566 RemapValue(I->second);
569 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(),
570 E = SoftenedFloats.end(); I != E; ++I) {
571 assert(I->first.getNode() != N);
572 RemapValue(I->second);
575 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(),
576 E = ScalarizedVectors.end(); I != E; ++I) {
577 assert(I->first.getNode() != N);
578 RemapValue(I->second);
581 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(),
582 E = WidenedVectors.end(); I != E; ++I) {
583 assert(I->first.getNode() != N);
584 RemapValue(I->second);
587 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
588 I = ExpandedIntegers.begin(), E = ExpandedIntegers.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 = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) {
596 assert(I->first.getNode() != N);
597 RemapValue(I->second.first);
598 RemapValue(I->second.second);
601 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
602 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) {
603 assert(I->first.getNode() != N);
604 RemapValue(I->second.first);
605 RemapValue(I->second.second);
608 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(),
609 E = ReplacedValues.end(); I != E; ++I)
610 RemapValue(I->second);
612 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
613 ReplacedValues.erase(SDValue(N, i));
616 /// RemapValue - If the specified value was already legalized to another value,
617 /// replace it by that value.
618 void DAGTypeLegalizer::RemapValue(SDValue &N) {
619 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N);
620 if (I != ReplacedValues.end()) {
621 // Use path compression to speed up future lookups if values get multiply
622 // replaced with other values.
623 RemapValue(I->second);
626 // Note that it is possible to have N.getNode()->getNodeId() == NewNode at
627 // this point because it is possible for a node to be put in the map before
633 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for
634 /// updates to nodes and recomputes their ready state.
635 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener {
636 DAGTypeLegalizer &DTL;
637 SmallSetVector<SDNode*, 16> &NodesToAnalyze;
639 explicit NodeUpdateListener(DAGTypeLegalizer &dtl,
640 SmallSetVector<SDNode*, 16> &nta)
641 : SelectionDAG::DAGUpdateListener(dtl.getDAG()),
642 DTL(dtl), NodesToAnalyze(nta) {}
644 void NodeDeleted(SDNode *N, SDNode *E) override {
645 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
646 N->getNodeId() != DAGTypeLegalizer::Processed &&
647 "Invalid node ID for RAUW deletion!");
648 // It is possible, though rare, for the deleted node N to occur as a
649 // target in a map, so note the replacement N -> E in ReplacedValues.
650 assert(E && "Node not replaced?");
651 DTL.NoteDeletion(N, E);
653 // In theory the deleted node could also have been scheduled for analysis.
654 // So remove it from the set of nodes which will be analyzed.
655 NodesToAnalyze.remove(N);
657 // In general nothing needs to be done for E, since it didn't change but
658 // only gained new uses. However N -> E was just added to ReplacedValues,
659 // and the result of a ReplacedValues mapping is not allowed to be marked
660 // NewNode. So if E is marked NewNode, then it needs to be analyzed.
661 if (E->getNodeId() == DAGTypeLegalizer::NewNode)
662 NodesToAnalyze.insert(E);
665 void NodeUpdated(SDNode *N) override {
666 // Node updates can mean pretty much anything. It is possible that an
667 // operand was set to something already processed (f.e.) in which case
668 // this node could become ready. Recompute its flags.
669 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess &&
670 N->getNodeId() != DAGTypeLegalizer::Processed &&
671 "Invalid node ID for RAUW deletion!");
672 N->setNodeId(DAGTypeLegalizer::NewNode);
673 NodesToAnalyze.insert(N);
679 /// ReplaceValueWith - The specified value was legalized to the specified other
680 /// value. Update the DAG and NodeIds replacing any uses of From to use To
682 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) {
683 assert(From.getNode() != To.getNode() && "Potential legalization loop!");
685 // If expansion produced new nodes, make sure they are properly marked.
686 ExpungeNode(From.getNode());
687 AnalyzeNewValue(To); // Expunges To.
689 // Anything that used the old node should now use the new one. Note that this
690 // can potentially cause recursive merging.
691 SmallSetVector<SDNode*, 16> NodesToAnalyze;
692 NodeUpdateListener NUL(*this, NodesToAnalyze);
694 DAG.ReplaceAllUsesOfValueWith(From, To);
696 // The old node may still be present in a map like ExpandedIntegers or
697 // PromotedIntegers. Inform maps about the replacement.
698 ReplacedValues[From] = To;
700 // Process the list of nodes that need to be reanalyzed.
701 while (!NodesToAnalyze.empty()) {
702 SDNode *N = NodesToAnalyze.back();
703 NodesToAnalyze.pop_back();
704 if (N->getNodeId() != DAGTypeLegalizer::NewNode)
705 // The node was analyzed while reanalyzing an earlier node - it is safe
706 // to skip. Note that this is not a morphing node - otherwise it would
707 // still be marked NewNode.
710 // Analyze the node's operands and recalculate the node ID.
711 SDNode *M = AnalyzeNewNode(N);
713 // The node morphed into a different node. Make everyone use the new
715 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!");
716 assert(N->getNumValues() == M->getNumValues() &&
717 "Node morphing changed the number of results!");
718 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
719 SDValue OldVal(N, i);
720 SDValue NewVal(M, i);
721 if (M->getNodeId() == Processed)
723 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal);
724 // OldVal may be a target of the ReplacedValues map which was marked
725 // NewNode to force reanalysis because it was updated. Ensure that
726 // anything that ReplacedValues mapped to OldVal will now be mapped
727 // all the way to NewVal.
728 ReplacedValues[OldVal] = NewVal;
730 // The original node continues to exist in the DAG, marked NewNode.
733 // When recursively update nodes with new nodes, it is possible to have
734 // new uses of From due to CSE. If this happens, replace the new uses of
736 } while (!From.use_empty());
739 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
740 assert(Result.getValueType() ==
741 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
742 "Invalid type for promoted integer");
743 AnalyzeNewValue(Result);
745 SDValue &OpEntry = PromotedIntegers[Op];
746 assert(!OpEntry.getNode() && "Node is already promoted!");
750 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
751 assert(Result.getValueType() ==
752 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
753 "Invalid type for softened float");
754 AnalyzeNewValue(Result);
756 SDValue &OpEntry = SoftenedFloats[Op];
757 assert(!OpEntry.getNode() && "Node is already converted to integer!");
761 void DAGTypeLegalizer::SetPromotedFloat(SDValue Op, SDValue Result) {
762 assert(Result.getValueType() ==
763 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
764 "Invalid type for promoted float");
765 AnalyzeNewValue(Result);
767 SDValue &OpEntry = PromotedFloats[Op];
768 assert(!OpEntry.getNode() && "Node is already promoted!");
772 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
773 // Note that in some cases vector operation operands may be greater than
774 // the vector element type. For example BUILD_VECTOR of type <1 x i1> with
775 // a constant i8 operand.
776 assert(Result.getValueType().getSizeInBits() >=
777 Op.getValueType().getVectorElementType().getSizeInBits() &&
778 "Invalid type for scalarized vector");
779 AnalyzeNewValue(Result);
781 SDValue &OpEntry = ScalarizedVectors[Op];
782 assert(!OpEntry.getNode() && "Node is already scalarized!");
786 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
788 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
789 RemapValue(Entry.first);
790 RemapValue(Entry.second);
791 assert(Entry.first.getNode() && "Operand isn't expanded");
796 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
798 assert(Lo.getValueType() ==
799 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
800 Hi.getValueType() == Lo.getValueType() &&
801 "Invalid type for expanded integer");
802 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
806 // Remember that this is the result of the node.
807 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
808 assert(!Entry.first.getNode() && "Node already expanded");
813 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
815 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
816 RemapValue(Entry.first);
817 RemapValue(Entry.second);
818 assert(Entry.first.getNode() && "Operand isn't expanded");
823 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
825 assert(Lo.getValueType() ==
826 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
827 Hi.getValueType() == Lo.getValueType() &&
828 "Invalid type for expanded float");
829 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
833 // Remember that this is the result of the node.
834 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
835 assert(!Entry.first.getNode() && "Node already expanded");
840 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
842 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
843 RemapValue(Entry.first);
844 RemapValue(Entry.second);
845 assert(Entry.first.getNode() && "Operand isn't split");
850 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
852 assert(Lo.getValueType().getVectorElementType() ==
853 Op.getValueType().getVectorElementType() &&
854 2*Lo.getValueType().getVectorNumElements() ==
855 Op.getValueType().getVectorNumElements() &&
856 Hi.getValueType() == Lo.getValueType() &&
857 "Invalid type for split vector");
858 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
862 // Remember that this is the result of the node.
863 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
864 assert(!Entry.first.getNode() && "Node already split");
869 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
870 assert(Result.getValueType() ==
871 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
872 "Invalid type for widened vector");
873 AnalyzeNewValue(Result);
875 SDValue &OpEntry = WidenedVectors[Op];
876 assert(!OpEntry.getNode() && "Node already widened!");
881 //===----------------------------------------------------------------------===//
883 //===----------------------------------------------------------------------===//
885 /// BitConvertToInteger - Convert to an integer of the same size.
886 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) {
887 unsigned BitWidth = Op.getValueType().getSizeInBits();
888 return DAG.getNode(ISD::BITCAST, SDLoc(Op),
889 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op);
892 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the
894 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) {
895 assert(Op.getValueType().isVector() && "Only applies to vectors!");
896 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits();
897 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth);
898 unsigned NumElts = Op.getValueType().getVectorNumElements();
899 return DAG.getNode(ISD::BITCAST, SDLoc(Op),
900 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op);
903 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op,
906 // Create the stack frame object. Make sure it is aligned for both
907 // the source and destination types.
908 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT);
909 // Emit a store to the stack slot.
910 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr,
911 MachinePointerInfo(), false, false, 0);
912 // Result is a load from the stack slot.
913 return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(),
914 false, false, false, 0);
917 /// CustomLowerNode - Replace the node's results with custom code provided
918 /// by the target and return "true", or do nothing and return "false".
919 /// The last parameter is FALSE if we are dealing with a node with legal
920 /// result types and illegal operand. The second parameter denotes the type of
921 /// illegal OperandNo in that case.
922 /// The last parameter being TRUE means we are dealing with a
923 /// node with illegal result types. The second parameter denotes the type of
924 /// illegal ResNo in that case.
925 bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) {
926 // See if the target wants to custom lower this node.
927 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
930 SmallVector<SDValue, 8> Results;
932 TLI.ReplaceNodeResults(N, Results, DAG);
934 TLI.LowerOperationWrapper(N, Results, DAG);
937 // The target didn't want to custom lower it after all.
940 // When called from DAGTypeLegalizer::ExpandIntegerResult, we might need to
941 // provide the same kind of custom splitting behavior.
942 if (Results.size() == N->getNumValues() + 1 && LegalizeResult) {
943 // We've legalized a return type by splitting it. If there is a chain,
945 SetExpandedInteger(SDValue(N, 0), Results[0], Results[1]);
946 if (N->getNumValues() > 1)
947 ReplaceValueWith(SDValue(N, 1), Results[2]);
951 // Make everything that once used N's values now use those in Results instead.
952 assert(Results.size() == N->getNumValues() &&
953 "Custom lowering returned the wrong number of results!");
954 for (unsigned i = 0, e = Results.size(); i != e; ++i) {
955 ReplaceValueWith(SDValue(N, i), Results[i]);
961 /// CustomWidenLowerNode - Widen the node's results with custom code provided
962 /// by the target and return "true", or do nothing and return "false".
963 bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) {
964 // See if the target wants to custom lower this node.
965 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
968 SmallVector<SDValue, 8> Results;
969 TLI.ReplaceNodeResults(N, Results, DAG);
972 // The target didn't want to custom widen lower its result after all.
975 // Update the widening map.
976 assert(Results.size() == N->getNumValues() &&
977 "Custom lowering returned the wrong number of results!");
978 for (unsigned i = 0, e = Results.size(); i != e; ++i)
979 SetWidenedVector(SDValue(N, i), Results[i]);
983 SDValue DAGTypeLegalizer::DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo) {
984 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
986 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
987 return SDValue(N->getOperand(ResNo));
990 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and
991 /// high parts of the given value.
992 void DAGTypeLegalizer::GetPairElements(SDValue Pair,
993 SDValue &Lo, SDValue &Hi) {
995 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType());
996 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
997 DAG.getIntPtrConstant(0, dl));
998 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
999 DAG.getIntPtrConstant(1, dl));
1002 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT,
1005 // Make sure the index type is big enough to compute in.
1006 Index = DAG.getZExtOrTrunc(Index, dl, TLI.getPointerTy(DAG.getDataLayout()));
1008 // Calculate the element offset and add it to the pointer.
1009 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size.
1011 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
1012 DAG.getConstant(EltSize, dl, Index.getValueType()));
1013 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr);
1016 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
1017 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) {
1018 // Arbitrarily use dlHi for result SDLoc
1021 EVT LVT = Lo.getValueType();
1022 EVT HVT = Hi.getValueType();
1023 EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
1024 LVT.getSizeInBits() + HVT.getSizeInBits());
1026 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo);
1027 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi);
1028 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi,
1029 DAG.getConstant(LVT.getSizeInBits(), dlHi,
1030 TLI.getPointerTy(DAG.getDataLayout())));
1031 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi);
1034 /// LibCallify - Convert the node into a libcall with the same prototype.
1035 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N,
1037 unsigned NumOps = N->getNumOperands();
1040 return TLI.makeLibCall(DAG, LC, N->getValueType(0), nullptr, 0, isSigned,
1042 } else if (NumOps == 1) {
1043 SDValue Op = N->getOperand(0);
1044 return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Op, 1, isSigned,
1046 } else if (NumOps == 2) {
1047 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) };
1048 return TLI.makeLibCall(DAG, LC, N->getValueType(0), Ops, 2, isSigned,
1051 SmallVector<SDValue, 8> Ops(NumOps);
1052 for (unsigned i = 0; i < NumOps; ++i)
1053 Ops[i] = N->getOperand(i);
1055 return TLI.makeLibCall(DAG, LC, N->getValueType(0),
1056 &Ops[0], NumOps, isSigned, dl).first;
1059 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to
1060 // ExpandLibCall except that the first operand is the in-chain.
1061 std::pair<SDValue, SDValue>
1062 DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC,
1065 SDValue InChain = Node->getOperand(0);
1067 TargetLowering::ArgListTy Args;
1068 TargetLowering::ArgListEntry Entry;
1069 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
1070 EVT ArgVT = Node->getOperand(i).getValueType();
1071 Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1072 Entry.Node = Node->getOperand(i);
1074 Entry.isSExt = isSigned;
1075 Entry.isZExt = !isSigned;
1076 Args.push_back(Entry);
1078 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1079 TLI.getPointerTy(DAG.getDataLayout()));
1081 Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
1083 TargetLowering::CallLoweringInfo CLI(DAG);
1084 CLI.setDebugLoc(SDLoc(Node)).setChain(InChain)
1085 .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0)
1086 .setSExtResult(isSigned).setZExtResult(!isSigned);
1088 std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
1093 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean
1094 /// of the given type. A target boolean is an integer value, not necessarily of
1095 /// type i1, the bits of which conform to getBooleanContents.
1097 /// ValVT is the type of values that produced the boolean.
1098 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT ValVT) {
1100 EVT BoolVT = getSetCCResultType(ValVT);
1101 ISD::NodeType ExtendCode =
1102 TargetLowering::getExtendForContent(TLI.getBooleanContents(ValVT));
1103 return DAG.getNode(ExtendCode, dl, BoolVT, Bool);
1106 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT
1108 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1110 SDValue &Lo, SDValue &Hi) {
1112 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() ==
1113 Op.getValueType().getSizeInBits() && "Invalid integer splitting!");
1114 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op);
1115 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op,
1116 DAG.getConstant(LoVT.getSizeInBits(), dl,
1117 TLI.getPointerTy(DAG.getDataLayout())));
1118 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi);
1121 /// SplitInteger - Return the lower and upper halves of Op's bits in a value
1122 /// type half the size of Op's.
1123 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1124 SDValue &Lo, SDValue &Hi) {
1125 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(),
1126 Op.getValueType().getSizeInBits()/2);
1127 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi);
1131 //===----------------------------------------------------------------------===//
1133 //===----------------------------------------------------------------------===//
1135 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
1136 /// only uses types natively supported by the target. Returns "true" if it made
1139 /// Note that this is an involved process that may invalidate pointers into
1141 bool SelectionDAG::LegalizeTypes() {
1142 return DAGTypeLegalizer(*this).run();