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 #define DEBUG_TYPE "legalize-types"
17 #include "LegalizeTypes.h"
18 #include "llvm/ADT/SetVector.h"
19 #include "llvm/IR/CallingConv.h"
20 #include "llvm/IR/DataLayout.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/raw_ostream.h"
27 EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden);
29 /// PerformExpensiveChecks - Do extensive, expensive, sanity checking.
30 void DAGTypeLegalizer::PerformExpensiveChecks() {
31 // If a node is not processed, then none of its values should be mapped by any
32 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
34 // If a node is processed, then each value with an illegal type must be mapped
35 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues.
36 // Values with a legal type may be mapped by ReplacedValues, but not by any of
39 // Note that these invariants may not hold momentarily when processing a node:
40 // the node being processed may be put in a map before being marked Processed.
42 // Note that it is possible to have nodes marked NewNode in the DAG. This can
43 // occur in two ways. Firstly, a node may be created during legalization but
44 // never passed to the legalization core. This is usually due to the implicit
45 // folding that occurs when using the DAG.getNode operators. Secondly, a new
46 // node may be passed to the legalization core, but when analyzed may morph
47 // into a different node, leaving the original node as a NewNode in the DAG.
48 // A node may morph if one of its operands changes during analysis. Whether
49 // it actually morphs or not depends on whether, after updating its operands,
50 // it is equivalent to an existing node: if so, it morphs into that existing
51 // node (CSE). An operand can change during analysis if the operand is a new
52 // node that morphs, or it is a processed value that was mapped to some other
53 // value (as recorded in ReplacedValues) in which case the operand is turned
54 // into that other value. If a node morphs then the node it morphed into will
55 // be used instead of it for legalization, however the original node continues
56 // to live on in the DAG.
57 // The conclusion is that though there may be nodes marked NewNode in the DAG,
58 // all uses of such nodes are also marked NewNode: the result is a fungus of
59 // NewNodes growing on top of the useful nodes, and perhaps using them, but
62 // If a value is mapped by ReplacedValues, then it must have no uses, except
63 // by nodes marked NewNode (see above).
65 // The final node obtained by mapping by ReplacedValues is not marked NewNode.
66 // Note that ReplacedValues should be applied iteratively.
68 // Note that the ReplacedValues map may also map deleted nodes (by iterating
69 // over the DAG we never dereference deleted nodes). This means that it may
70 // also map nodes marked NewNode if the deallocated memory was reallocated as
71 // another node, and that new node was not seen by the LegalizeTypes machinery
72 // (for example because it was created but not used). In general, we cannot
73 // distinguish between new nodes and deleted nodes.
74 SmallVector<SDNode*, 16> NewNodes;
75 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
76 E = DAG.allnodes_end(); I != E; ++I) {
77 // Remember nodes marked NewNode - they are subject to extra checking below.
78 if (I->getNodeId() == NewNode)
79 NewNodes.push_back(I);
81 for (unsigned i = 0, e = I->getNumValues(); i != e; ++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 = I->use_begin(), UE = I->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 (I->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 ((I->getNodeId() == NewNode && Mapped > 1) ||
126 (I->getNodeId() != NewNode && Mapped != 0)) {
127 dbgs() << "Unprocessed value in a map!";
130 } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(I)) {
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 (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
197 E = DAG.allnodes_end(); I != E; ++I) {
198 if (I->getNumOperands() == 0) {
199 I->setNodeId(ReadyToProcess);
200 Worklist.push_back(I);
202 I->setNodeId(Unanalyzed);
206 // Now that we have a set of nodes to process, handle them all.
207 while (!Worklist.empty()) {
209 if (EnableExpensiveChecks)
211 PerformExpensiveChecks();
213 SDNode *N = Worklist.back();
215 assert(N->getNodeId() == ReadyToProcess &&
216 "Node should be ready if on worklist!");
218 if (IgnoreNodeResults(N))
221 // Scan the values produced by the node, checking to see if any result
222 // types are illegal.
223 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) {
224 EVT ResultVT = N->getValueType(i);
225 switch (getTypeAction(ResultVT)) {
226 case TargetLowering::TypeLegal:
228 // The following calls must take care of *all* of the node's results,
229 // not just the illegal result they were passed (this includes results
230 // with a legal type). Results can be remapped using ReplaceValueWith,
231 // or their promoted/expanded/etc values registered in PromotedIntegers,
232 // ExpandedIntegers etc.
233 case TargetLowering::TypePromoteInteger:
234 PromoteIntegerResult(N, i);
237 case TargetLowering::TypeExpandInteger:
238 ExpandIntegerResult(N, i);
241 case TargetLowering::TypeSoftenFloat:
242 SoftenFloatResult(N, i);
245 case TargetLowering::TypeExpandFloat:
246 ExpandFloatResult(N, i);
249 case TargetLowering::TypeScalarizeVector:
250 ScalarizeVectorResult(N, i);
253 case TargetLowering::TypeSplitVector:
254 SplitVectorResult(N, i);
257 case TargetLowering::TypeWidenVector:
258 WidenVectorResult(N, i);
265 // Scan the operand list for the node, handling any nodes with operands that
268 unsigned NumOperands = N->getNumOperands();
269 bool NeedsReanalyzing = false;
271 for (i = 0; i != NumOperands; ++i) {
272 if (IgnoreNodeResults(N->getOperand(i).getNode()))
275 EVT OpVT = N->getOperand(i).getValueType();
276 switch (getTypeAction(OpVT)) {
277 case TargetLowering::TypeLegal:
279 // The following calls must either replace all of the node's results
280 // using ReplaceValueWith, and return "false"; or update the node's
281 // operands in place, and return "true".
282 case TargetLowering::TypePromoteInteger:
283 NeedsReanalyzing = PromoteIntegerOperand(N, i);
286 case TargetLowering::TypeExpandInteger:
287 NeedsReanalyzing = ExpandIntegerOperand(N, i);
290 case TargetLowering::TypeSoftenFloat:
291 NeedsReanalyzing = SoftenFloatOperand(N, i);
294 case TargetLowering::TypeExpandFloat:
295 NeedsReanalyzing = ExpandFloatOperand(N, i);
298 case TargetLowering::TypeScalarizeVector:
299 NeedsReanalyzing = ScalarizeVectorOperand(N, i);
302 case TargetLowering::TypeSplitVector:
303 NeedsReanalyzing = SplitVectorOperand(N, i);
306 case TargetLowering::TypeWidenVector:
307 NeedsReanalyzing = WidenVectorOperand(N, i);
314 // The sub-method updated N in place. Check to see if any operands are new,
315 // and if so, mark them. If the node needs revisiting, don't add all users
316 // to the worklist etc.
317 if (NeedsReanalyzing) {
318 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
319 N->setNodeId(NewNode);
320 // Recompute the NodeId and correct processed operands, adding the node to
321 // the worklist if ready.
322 SDNode *M = AnalyzeNewNode(N);
324 // The node didn't morph - nothing special to do, it will be revisited.
327 // The node morphed - this is equivalent to legalizing by replacing every
328 // value of N with the corresponding value of M. So do that now.
329 assert(N->getNumValues() == M->getNumValues() &&
330 "Node morphing changed the number of results!");
331 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
332 // Replacing the value takes care of remapping the new value.
333 ReplaceValueWith(SDValue(N, i), SDValue(M, i));
334 assert(N->getNodeId() == NewNode && "Unexpected node state!");
335 // The node continues to live on as part of the NewNode fungus that
336 // grows on top of the useful nodes. Nothing more needs to be done
337 // with it - move on to the next node.
341 if (i == NumOperands) {
342 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n");
347 // If we reach here, the node was processed, potentially creating new nodes.
348 // Mark it as processed and add its users to the worklist as appropriate.
349 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?");
350 N->setNodeId(Processed);
352 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
355 int NodeId = User->getNodeId();
357 // This node has two options: it can either be a new node or its Node ID
358 // may be a count of the number of operands it has that are not ready.
360 User->setNodeId(NodeId-1);
362 // If this was the last use it was waiting on, add it to the ready list.
363 if (NodeId-1 == ReadyToProcess)
364 Worklist.push_back(User);
368 // If this is an unreachable new node, then ignore it. If it ever becomes
369 // reachable by being used by a newly created node then it will be handled
370 // by AnalyzeNewNode.
371 if (NodeId == NewNode)
374 // Otherwise, this node is new: this is the first operand of it that
375 // became ready. Its new NodeId is the number of operands it has minus 1
376 // (as this node is now processed).
377 assert(NodeId == Unanalyzed && "Unknown node ID!");
378 User->setNodeId(User->getNumOperands() - 1);
380 // If the node only has a single operand, it is now ready.
381 if (User->getNumOperands() == 1)
382 Worklist.push_back(User);
387 if (EnableExpensiveChecks)
389 PerformExpensiveChecks();
391 // If the root changed (e.g. it was a dead load) update the root.
392 DAG.setRoot(Dummy.getValue());
394 // Remove dead nodes. This is important to do for cleanliness but also before
395 // the checking loop below. Implicit folding by the DAG.getNode operators and
396 // node morphing can cause unreachable nodes to be around with their flags set
398 DAG.RemoveDeadNodes();
400 // In a debug build, scan all the nodes to make sure we found them all. This
401 // ensures that there are no cycles and that everything got processed.
403 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
404 E = DAG.allnodes_end(); I != E; ++I) {
407 // Check that all result types are legal.
408 if (!IgnoreNodeResults(I))
409 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i)
410 if (!isTypeLegal(I->getValueType(i))) {
411 dbgs() << "Result type " << i << " illegal!\n";
415 // Check that all operand types are legal.
416 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i)
417 if (!IgnoreNodeResults(I->getOperand(i).getNode()) &&
418 !isTypeLegal(I->getOperand(i).getValueType())) {
419 dbgs() << "Operand type " << i << " illegal!\n";
423 if (I->getNodeId() != Processed) {
424 if (I->getNodeId() == NewNode)
425 dbgs() << "New node not analyzed?\n";
426 else if (I->getNodeId() == Unanalyzed)
427 dbgs() << "Unanalyzed node not noticed?\n";
428 else if (I->getNodeId() > 0)
429 dbgs() << "Operand not processed?\n";
430 else if (I->getNodeId() == ReadyToProcess)
431 dbgs() << "Not added to worklist?\n";
436 I->dump(&DAG); dbgs() << "\n";
437 llvm_unreachable(nullptr);
445 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially
446 /// new nodes. Correct any processed operands (this may change the node) and
447 /// calculate the NodeId. If the node itself changes to a processed node, it
448 /// is not remapped - the caller needs to take care of this.
449 /// Returns the potentially changed node.
450 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) {
451 // If this was an existing node that is already done, we're done.
452 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed)
455 // Remove any stale map entries.
458 // Okay, we know that this node is new. Recursively walk all of its operands
459 // to see if they are new also. The depth of this walk is bounded by the size
460 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry
461 // about revisiting of nodes.
463 // As we walk the operands, keep track of the number of nodes that are
464 // processed. If non-zero, this will become the new nodeid of this node.
465 // Operands may morph when they are analyzed. If so, the node will be
466 // updated after all operands have been analyzed. Since this is rare,
467 // the code tries to minimize overhead in the non-morphing case.
469 SmallVector<SDValue, 8> NewOps;
470 unsigned NumProcessed = 0;
471 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
472 SDValue OrigOp = N->getOperand(i);
475 AnalyzeNewValue(Op); // Op may morph.
477 if (Op.getNode()->getNodeId() == Processed)
480 if (!NewOps.empty()) {
481 // Some previous operand changed. Add this one to the list.
482 NewOps.push_back(Op);
483 } else if (Op != OrigOp) {
484 // This is the first operand to change - add all operands so far.
485 NewOps.append(N->op_begin(), N->op_begin() + i);
486 NewOps.push_back(Op);
490 // Some operands changed - update the node.
491 if (!NewOps.empty()) {
492 SDNode *M = DAG.UpdateNodeOperands(N, &NewOps[0], NewOps.size());
494 // The node morphed into a different node. Normally for this to happen
495 // the original node would have to be marked NewNode. However this can
496 // in theory momentarily not be the case while ReplaceValueWith is doing
497 // its stuff. Mark the original node NewNode to help sanity checking.
498 N->setNodeId(NewNode);
499 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed)
500 // It morphed into a previously analyzed node - nothing more to do.
503 // It morphed into a different new node. Do the equivalent of passing
504 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need
505 // to remap the operands, since they are the same as the operands we
512 // Calculate the NodeId.
513 N->setNodeId(N->getNumOperands() - NumProcessed);
514 if (N->getNodeId() == ReadyToProcess)
515 Worklist.push_back(N);
520 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed.
521 /// If the node changes to a processed node, then remap it.
522 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) {
523 Val.setNode(AnalyzeNewNode(Val.getNode()));
524 if (Val.getNode()->getNodeId() == Processed)
525 // We were passed a processed node, or it morphed into one - remap it.
529 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it.
530 /// This can occur when a node is deleted then reallocated as a new node -
531 /// the mapping in ReplacedValues applies to the deleted node, not the new
533 /// The only map that can have a deleted node as a source is ReplacedValues.
534 /// Other maps can have deleted nodes as targets, but since their looked-up
535 /// values are always immediately remapped using RemapValue, resulting in a
536 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue
537 /// always performs correct mappings. In order to keep the mapping correct,
538 /// ExpungeNode should be called on any new nodes *before* adding them as
539 /// either source or target to ReplacedValues (which typically means calling
540 /// Expunge when a new node is first seen, since it may no longer be marked
541 /// NewNode by the time it is added to ReplacedValues).
542 void DAGTypeLegalizer::ExpungeNode(SDNode *N) {
543 if (N->getNodeId() != NewNode)
546 // If N is not remapped by ReplacedValues then there is nothing to do.
548 for (i = 0, e = N->getNumValues(); i != e; ++i)
549 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end())
555 // Remove N from all maps - this is expensive but rare.
557 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(),
558 E = PromotedIntegers.end(); I != E; ++I) {
559 assert(I->first.getNode() != N);
560 RemapValue(I->second);
563 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(),
564 E = SoftenedFloats.end(); I != E; ++I) {
565 assert(I->first.getNode() != N);
566 RemapValue(I->second);
569 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(),
570 E = ScalarizedVectors.end(); I != E; ++I) {
571 assert(I->first.getNode() != N);
572 RemapValue(I->second);
575 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(),
576 E = WidenedVectors.end(); I != E; ++I) {
577 assert(I->first.getNode() != N);
578 RemapValue(I->second);
581 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
582 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){
583 assert(I->first.getNode() != N);
584 RemapValue(I->second.first);
585 RemapValue(I->second.second);
588 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
589 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) {
590 assert(I->first.getNode() != N);
591 RemapValue(I->second.first);
592 RemapValue(I->second.second);
595 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator
596 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) {
597 assert(I->first.getNode() != N);
598 RemapValue(I->second.first);
599 RemapValue(I->second.second);
602 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(),
603 E = ReplacedValues.end(); I != E; ++I)
604 RemapValue(I->second);
606 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
607 ReplacedValues.erase(SDValue(N, i));
610 /// RemapValue - If the specified value was already legalized to another value,
611 /// replace it by that value.
612 void DAGTypeLegalizer::RemapValue(SDValue &N) {
613 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N);
614 if (I != ReplacedValues.end()) {
615 // Use path compression to speed up future lookups if values get multiply
616 // replaced with other values.
617 RemapValue(I->second);
620 // Note that it is possible to have N.getNode()->getNodeId() == NewNode at
621 // this point because it is possible for a node to be put in the map before
627 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for
628 /// updates to nodes and recomputes their ready state.
629 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener {
630 DAGTypeLegalizer &DTL;
631 SmallSetVector<SDNode*, 16> &NodesToAnalyze;
633 explicit NodeUpdateListener(DAGTypeLegalizer &dtl,
634 SmallSetVector<SDNode*, 16> &nta)
635 : SelectionDAG::DAGUpdateListener(dtl.getDAG()),
636 DTL(dtl), NodesToAnalyze(nta) {}
638 void NodeDeleted(SDNode *N, SDNode *E) override {
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 void NodeUpdated(SDNode *N) override {
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);
688 DAG.ReplaceAllUsesOfValueWith(From, To);
690 // The old node may still be present in a map like ExpandedIntegers or
691 // PromotedIntegers. Inform maps about the replacement.
692 ReplacedValues[From] = To;
694 // Process the list of nodes that need to be reanalyzed.
695 while (!NodesToAnalyze.empty()) {
696 SDNode *N = NodesToAnalyze.back();
697 NodesToAnalyze.pop_back();
698 if (N->getNodeId() != DAGTypeLegalizer::NewNode)
699 // The node was analyzed while reanalyzing an earlier node - it is safe
700 // to skip. Note that this is not a morphing node - otherwise it would
701 // still be marked NewNode.
704 // Analyze the node's operands and recalculate the node ID.
705 SDNode *M = AnalyzeNewNode(N);
707 // The node morphed into a different node. Make everyone use the new
709 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!");
710 assert(N->getNumValues() == M->getNumValues() &&
711 "Node morphing changed the number of results!");
712 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
713 SDValue OldVal(N, i);
714 SDValue NewVal(M, i);
715 if (M->getNodeId() == Processed)
717 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal);
718 // OldVal may be a target of the ReplacedValues map which was marked
719 // NewNode to force reanalysis because it was updated. Ensure that
720 // anything that ReplacedValues mapped to OldVal will now be mapped
721 // all the way to NewVal.
722 ReplacedValues[OldVal] = NewVal;
724 // The original node continues to exist in the DAG, marked NewNode.
727 // When recursively update nodes with new nodes, it is possible to have
728 // new uses of From due to CSE. If this happens, replace the new uses of
730 } while (!From.use_empty());
733 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
734 assert(Result.getValueType() ==
735 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
736 "Invalid type for promoted integer");
737 AnalyzeNewValue(Result);
739 SDValue &OpEntry = PromotedIntegers[Op];
740 assert(!OpEntry.getNode() && "Node is already promoted!");
744 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
745 assert(Result.getValueType() ==
746 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
747 "Invalid type for softened float");
748 AnalyzeNewValue(Result);
750 SDValue &OpEntry = SoftenedFloats[Op];
751 assert(!OpEntry.getNode() && "Node is already converted to integer!");
755 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
756 // Note that in some cases vector operation operands may be greater than
757 // the vector element type. For example BUILD_VECTOR of type <1 x i1> with
758 // a constant i8 operand.
759 assert(Result.getValueType().getSizeInBits() >=
760 Op.getValueType().getVectorElementType().getSizeInBits() &&
761 "Invalid type for scalarized vector");
762 AnalyzeNewValue(Result);
764 SDValue &OpEntry = ScalarizedVectors[Op];
765 assert(!OpEntry.getNode() && "Node is already scalarized!");
769 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
771 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
772 RemapValue(Entry.first);
773 RemapValue(Entry.second);
774 assert(Entry.first.getNode() && "Operand isn't expanded");
779 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
781 assert(Lo.getValueType() ==
782 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
783 Hi.getValueType() == Lo.getValueType() &&
784 "Invalid type for expanded integer");
785 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
789 // Remember that this is the result of the node.
790 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op];
791 assert(!Entry.first.getNode() && "Node already expanded");
796 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
798 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
799 RemapValue(Entry.first);
800 RemapValue(Entry.second);
801 assert(Entry.first.getNode() && "Operand isn't expanded");
806 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
808 assert(Lo.getValueType() ==
809 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
810 Hi.getValueType() == Lo.getValueType() &&
811 "Invalid type for expanded float");
812 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
816 // Remember that this is the result of the node.
817 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op];
818 assert(!Entry.first.getNode() && "Node already expanded");
823 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
825 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
826 RemapValue(Entry.first);
827 RemapValue(Entry.second);
828 assert(Entry.first.getNode() && "Operand isn't split");
833 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
835 assert(Lo.getValueType().getVectorElementType() ==
836 Op.getValueType().getVectorElementType() &&
837 2*Lo.getValueType().getVectorNumElements() ==
838 Op.getValueType().getVectorNumElements() &&
839 Hi.getValueType() == Lo.getValueType() &&
840 "Invalid type for split vector");
841 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant.
845 // Remember that this is the result of the node.
846 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op];
847 assert(!Entry.first.getNode() && "Node already split");
852 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
853 assert(Result.getValueType() ==
854 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) &&
855 "Invalid type for widened vector");
856 AnalyzeNewValue(Result);
858 SDValue &OpEntry = WidenedVectors[Op];
859 assert(!OpEntry.getNode() && "Node already widened!");
864 //===----------------------------------------------------------------------===//
866 //===----------------------------------------------------------------------===//
868 /// BitConvertToInteger - Convert to an integer of the same size.
869 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) {
870 unsigned BitWidth = Op.getValueType().getSizeInBits();
871 return DAG.getNode(ISD::BITCAST, SDLoc(Op),
872 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op);
875 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the
877 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) {
878 assert(Op.getValueType().isVector() && "Only applies to vectors!");
879 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits();
880 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth);
881 unsigned NumElts = Op.getValueType().getVectorNumElements();
882 return DAG.getNode(ISD::BITCAST, SDLoc(Op),
883 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op);
886 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op,
889 // Create the stack frame object. Make sure it is aligned for both
890 // the source and destination types.
891 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT);
892 // Emit a store to the stack slot.
893 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr,
894 MachinePointerInfo(), false, false, 0);
895 // Result is a load from the stack slot.
896 return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(),
897 false, false, false, 0);
900 /// CustomLowerNode - Replace the node's results with custom code provided
901 /// by the target and return "true", or do nothing and return "false".
902 /// The last parameter is FALSE if we are dealing with a node with legal
903 /// result types and illegal operand. The second parameter denotes the type of
904 /// illegal OperandNo in that case.
905 /// The last parameter being TRUE means we are dealing with a
906 /// node with illegal result types. The second parameter denotes the type of
907 /// illegal ResNo in that case.
908 bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) {
909 // See if the target wants to custom lower this node.
910 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
913 SmallVector<SDValue, 8> Results;
915 TLI.ReplaceNodeResults(N, Results, DAG);
917 TLI.LowerOperationWrapper(N, Results, DAG);
920 // The target didn't want to custom lower it after all.
923 // Make everything that once used N's values now use those in Results instead.
924 assert(Results.size() == N->getNumValues() &&
925 "Custom lowering returned the wrong number of results!");
926 for (unsigned i = 0, e = Results.size(); i != e; ++i) {
927 ReplaceValueWith(SDValue(N, i), Results[i]);
933 /// CustomWidenLowerNode - Widen the node's results with custom code provided
934 /// by the target and return "true", or do nothing and return "false".
935 bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) {
936 // See if the target wants to custom lower this node.
937 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom)
940 SmallVector<SDValue, 8> Results;
941 TLI.ReplaceNodeResults(N, Results, DAG);
944 // The target didn't want to custom widen lower its result after all.
947 // Update the widening map.
948 assert(Results.size() == N->getNumValues() &&
949 "Custom lowering returned the wrong number of results!");
950 for (unsigned i = 0, e = Results.size(); i != e; ++i)
951 SetWidenedVector(SDValue(N, i), Results[i]);
955 SDValue DAGTypeLegalizer::DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo) {
956 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i)
958 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i)));
959 return SDValue(N->getOperand(ResNo));
962 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and
963 /// high parts of the given value.
964 void DAGTypeLegalizer::GetPairElements(SDValue Pair,
965 SDValue &Lo, SDValue &Hi) {
967 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType());
968 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
969 DAG.getIntPtrConstant(0));
970 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair,
971 DAG.getIntPtrConstant(1));
974 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT,
977 // Make sure the index type is big enough to compute in.
978 Index = DAG.getZExtOrTrunc(Index, dl, TLI.getPointerTy());
980 // Calculate the element offset and add it to the pointer.
981 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size.
983 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
984 DAG.getConstant(EltSize, Index.getValueType()));
985 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr);
988 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi.
989 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) {
990 // Arbitrarily use dlHi for result SDLoc
993 EVT LVT = Lo.getValueType();
994 EVT HVT = Hi.getValueType();
995 EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
996 LVT.getSizeInBits() + HVT.getSizeInBits());
998 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo);
999 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi);
1000 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi,
1001 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy()));
1002 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi);
1005 /// LibCallify - Convert the node into a libcall with the same prototype.
1006 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N,
1008 unsigned NumOps = N->getNumOperands();
1011 return TLI.makeLibCall(DAG, LC, N->getValueType(0), nullptr, 0, isSigned,
1013 } else if (NumOps == 1) {
1014 SDValue Op = N->getOperand(0);
1015 return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Op, 1, isSigned,
1017 } else if (NumOps == 2) {
1018 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) };
1019 return TLI.makeLibCall(DAG, LC, N->getValueType(0), Ops, 2, isSigned,
1022 SmallVector<SDValue, 8> Ops(NumOps);
1023 for (unsigned i = 0; i < NumOps; ++i)
1024 Ops[i] = N->getOperand(i);
1026 return TLI.makeLibCall(DAG, LC, N->getValueType(0),
1027 &Ops[0], NumOps, isSigned, dl).first;
1030 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to
1031 // ExpandLibCall except that the first operand is the in-chain.
1032 std::pair<SDValue, SDValue>
1033 DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC,
1036 SDValue InChain = Node->getOperand(0);
1038 TargetLowering::ArgListTy Args;
1039 TargetLowering::ArgListEntry Entry;
1040 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) {
1041 EVT ArgVT = Node->getOperand(i).getValueType();
1042 Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1043 Entry.Node = Node->getOperand(i);
1045 Entry.isSExt = isSigned;
1046 Entry.isZExt = !isSigned;
1047 Args.push_back(Entry);
1049 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
1050 TLI.getPointerTy());
1052 Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext());
1054 CallLoweringInfo CLI(InChain, RetTy, isSigned, !isSigned, false, false,
1055 0, TLI.getLibcallCallingConv(LC), /*isTailCall=*/false,
1056 /*doesNotReturn=*/false, /*isReturnValueUsed=*/true,
1057 Callee, Args, DAG, SDLoc(Node));
1058 std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
1063 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean
1064 /// of the given type. A target boolean is an integer value, not necessarily of
1065 /// type i1, the bits of which conform to getBooleanContents.
1066 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT VT) {
1068 ISD::NodeType ExtendCode =
1069 TargetLowering::getExtendForContent(TLI.getBooleanContents(VT.isVector()));
1070 return DAG.getNode(ExtendCode, dl, VT, Bool);
1073 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT
1075 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1077 SDValue &Lo, SDValue &Hi) {
1079 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() ==
1080 Op.getValueType().getSizeInBits() && "Invalid integer splitting!");
1081 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op);
1082 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op,
1083 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy()));
1084 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi);
1087 /// SplitInteger - Return the lower and upper halves of Op's bits in a value
1088 /// type half the size of Op's.
1089 void DAGTypeLegalizer::SplitInteger(SDValue Op,
1090 SDValue &Lo, SDValue &Hi) {
1091 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(),
1092 Op.getValueType().getSizeInBits()/2);
1093 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi);
1097 //===----------------------------------------------------------------------===//
1099 //===----------------------------------------------------------------------===//
1101 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that
1102 /// only uses types natively supported by the target. Returns "true" if it made
1105 /// Note that this is an involved process that may invalidate pointers into
1107 bool SelectionDAG::LegalizeTypes() {
1108 return DAGTypeLegalizer(*this).run();