//===-- LegalizeTypes.cpp - Common code for DAG type legalizer ------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the SelectionDAG::LegalizeTypes method. It transforms // an arbitrary well-formed SelectionDAG to only consist of legal types. This // is common code shared among the LegalizeTypes*.cpp files. // //===----------------------------------------------------------------------===// #include "LegalizeTypes.h" #include "llvm/ADT/SetVector.h" #include "llvm/IR/CallingConv.h" #include "llvm/IR/DataLayout.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; static cl::opt EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden); /// PerformExpensiveChecks - Do extensive, expensive, sanity checking. void DAGTypeLegalizer::PerformExpensiveChecks() { // If a node is not processed, then none of its values should be mapped by any // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. // If a node is processed, then each value with an illegal type must be mapped // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. // Values with a legal type may be mapped by ReplacedValues, but not by any of // the other maps. // Note that these invariants may not hold momentarily when processing a node: // the node being processed may be put in a map before being marked Processed. // Note that it is possible to have nodes marked NewNode in the DAG. This can // occur in two ways. Firstly, a node may be created during legalization but // never passed to the legalization core. This is usually due to the implicit // folding that occurs when using the DAG.getNode operators. Secondly, a new // node may be passed to the legalization core, but when analyzed may morph // into a different node, leaving the original node as a NewNode in the DAG. // A node may morph if one of its operands changes during analysis. Whether // it actually morphs or not depends on whether, after updating its operands, // it is equivalent to an existing node: if so, it morphs into that existing // node (CSE). An operand can change during analysis if the operand is a new // node that morphs, or it is a processed value that was mapped to some other // value (as recorded in ReplacedValues) in which case the operand is turned // into that other value. If a node morphs then the node it morphed into will // be used instead of it for legalization, however the original node continues // to live on in the DAG. // The conclusion is that though there may be nodes marked NewNode in the DAG, // all uses of such nodes are also marked NewNode: the result is a fungus of // NewNodes growing on top of the useful nodes, and perhaps using them, but // not used by them. // If a value is mapped by ReplacedValues, then it must have no uses, except // by nodes marked NewNode (see above). // The final node obtained by mapping by ReplacedValues is not marked NewNode. // Note that ReplacedValues should be applied iteratively. // Note that the ReplacedValues map may also map deleted nodes (by iterating // over the DAG we never dereference deleted nodes). This means that it may // also map nodes marked NewNode if the deallocated memory was reallocated as // another node, and that new node was not seen by the LegalizeTypes machinery // (for example because it was created but not used). In general, we cannot // distinguish between new nodes and deleted nodes. SmallVector NewNodes; for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), E = DAG.allnodes_end(); I != E; ++I) { // Remember nodes marked NewNode - they are subject to extra checking below. if (I->getNodeId() == NewNode) NewNodes.push_back(I); for (unsigned i = 0, e = I->getNumValues(); i != e; ++i) { SDValue Res(I, i); bool Failed = false; unsigned Mapped = 0; if (ReplacedValues.find(Res) != ReplacedValues.end()) { Mapped |= 1; // Check that remapped values are only used by nodes marked NewNode. for (SDNode::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE; ++UI) if (UI.getUse().getResNo() == i) assert(UI->getNodeId() == NewNode && "Remapped value has non-trivial use!"); // Check that the final result of applying ReplacedValues is not // marked NewNode. SDValue NewVal = ReplacedValues[Res]; DenseMap::iterator I = ReplacedValues.find(NewVal); while (I != ReplacedValues.end()) { NewVal = I->second; I = ReplacedValues.find(NewVal); } assert(NewVal.getNode()->getNodeId() != NewNode && "ReplacedValues maps to a new node!"); } if (PromotedIntegers.find(Res) != PromotedIntegers.end()) Mapped |= 2; if (SoftenedFloats.find(Res) != SoftenedFloats.end()) Mapped |= 4; if (ScalarizedVectors.find(Res) != ScalarizedVectors.end()) Mapped |= 8; if (ExpandedIntegers.find(Res) != ExpandedIntegers.end()) Mapped |= 16; if (ExpandedFloats.find(Res) != ExpandedFloats.end()) Mapped |= 32; if (SplitVectors.find(Res) != SplitVectors.end()) Mapped |= 64; if (WidenedVectors.find(Res) != WidenedVectors.end()) Mapped |= 128; if (I->getNodeId() != Processed) { // Since we allow ReplacedValues to map deleted nodes, it may map nodes // marked NewNode too, since a deleted node may have been reallocated as // another node that has not been seen by the LegalizeTypes machinery. if ((I->getNodeId() == NewNode && Mapped > 1) || (I->getNodeId() != NewNode && Mapped != 0)) { dbgs() << "Unprocessed value in a map!"; Failed = true; } } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(I)) { if (Mapped > 1) { dbgs() << "Value with legal type was transformed!"; Failed = true; } } else { if (Mapped == 0) { dbgs() << "Processed value not in any map!"; Failed = true; } else if (Mapped & (Mapped - 1)) { dbgs() << "Value in multiple maps!"; Failed = true; } } if (Failed) { if (Mapped & 1) dbgs() << " ReplacedValues"; if (Mapped & 2) dbgs() << " PromotedIntegers"; if (Mapped & 4) dbgs() << " SoftenedFloats"; if (Mapped & 8) dbgs() << " ScalarizedVectors"; if (Mapped & 16) dbgs() << " ExpandedIntegers"; if (Mapped & 32) dbgs() << " ExpandedFloats"; if (Mapped & 64) dbgs() << " SplitVectors"; if (Mapped & 128) dbgs() << " WidenedVectors"; dbgs() << "\n"; llvm_unreachable(0); } } } // Checked that NewNodes are only used by other NewNodes. for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) { SDNode *N = NewNodes[i]; for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end(); UI != UE; ++UI) assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!"); } } /// run - This is the main entry point for the type legalizer. This does a /// top-down traversal of the dag, legalizing types as it goes. Returns "true" /// if it made any changes. bool DAGTypeLegalizer::run() { bool Changed = false; // Create a dummy node (which is not added to allnodes), that adds a reference // to the root node, preventing it from being deleted, and tracking any // changes of the root. HandleSDNode Dummy(DAG.getRoot()); Dummy.setNodeId(Unanalyzed); // The root of the dag may dangle to deleted nodes until the type legalizer is // done. Set it to null to avoid confusion. DAG.setRoot(SDValue()); // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess' // (and remembering them) if they are leaves and assigning 'Unanalyzed' if // non-leaves. for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), E = DAG.allnodes_end(); I != E; ++I) { if (I->getNumOperands() == 0) { I->setNodeId(ReadyToProcess); Worklist.push_back(I); } else { I->setNodeId(Unanalyzed); } } // Now that we have a set of nodes to process, handle them all. while (!Worklist.empty()) { #ifndef XDEBUG if (EnableExpensiveChecks) #endif PerformExpensiveChecks(); SDNode *N = Worklist.back(); Worklist.pop_back(); assert(N->getNodeId() == ReadyToProcess && "Node should be ready if on worklist!"); if (IgnoreNodeResults(N)) goto ScanOperands; // Scan the values produced by the node, checking to see if any result // types are illegal. for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) { EVT ResultVT = N->getValueType(i); switch (getTypeAction(ResultVT)) { case TargetLowering::TypeLegal: break; // The following calls must take care of *all* of the node's results, // not just the illegal result they were passed (this includes results // with a legal type). Results can be remapped using ReplaceValueWith, // or their promoted/expanded/etc values registered in PromotedIntegers, // ExpandedIntegers etc. case TargetLowering::TypePromoteInteger: PromoteIntegerResult(N, i); Changed = true; goto NodeDone; case TargetLowering::TypeExpandInteger: ExpandIntegerResult(N, i); Changed = true; goto NodeDone; case TargetLowering::TypeSoftenFloat: SoftenFloatResult(N, i); Changed = true; goto NodeDone; case TargetLowering::TypeExpandFloat: ExpandFloatResult(N, i); Changed = true; goto NodeDone; case TargetLowering::TypeScalarizeVector: ScalarizeVectorResult(N, i); Changed = true; goto NodeDone; case TargetLowering::TypeSplitVector: SplitVectorResult(N, i); Changed = true; goto NodeDone; case TargetLowering::TypeWidenVector: WidenVectorResult(N, i); Changed = true; goto NodeDone; } } ScanOperands: // Scan the operand list for the node, handling any nodes with operands that // are illegal. { unsigned NumOperands = N->getNumOperands(); bool NeedsReanalyzing = false; unsigned i; for (i = 0; i != NumOperands; ++i) { if (IgnoreNodeResults(N->getOperand(i).getNode())) continue; EVT OpVT = N->getOperand(i).getValueType(); switch (getTypeAction(OpVT)) { case TargetLowering::TypeLegal: continue; // The following calls must either replace all of the node's results // using ReplaceValueWith, and return "false"; or update the node's // operands in place, and return "true". case TargetLowering::TypePromoteInteger: NeedsReanalyzing = PromoteIntegerOperand(N, i); Changed = true; break; case TargetLowering::TypeExpandInteger: NeedsReanalyzing = ExpandIntegerOperand(N, i); Changed = true; break; case TargetLowering::TypeSoftenFloat: NeedsReanalyzing = SoftenFloatOperand(N, i); Changed = true; break; case TargetLowering::TypeExpandFloat: NeedsReanalyzing = ExpandFloatOperand(N, i); Changed = true; break; case TargetLowering::TypeScalarizeVector: NeedsReanalyzing = ScalarizeVectorOperand(N, i); Changed = true; break; case TargetLowering::TypeSplitVector: NeedsReanalyzing = SplitVectorOperand(N, i); Changed = true; break; case TargetLowering::TypeWidenVector: NeedsReanalyzing = WidenVectorOperand(N, i); Changed = true; break; } break; } // The sub-method updated N in place. Check to see if any operands are new, // and if so, mark them. If the node needs revisiting, don't add all users // to the worklist etc. if (NeedsReanalyzing) { assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); N->setNodeId(NewNode); // Recompute the NodeId and correct processed operands, adding the node to // the worklist if ready. SDNode *M = AnalyzeNewNode(N); if (M == N) // The node didn't morph - nothing special to do, it will be revisited. continue; // The node morphed - this is equivalent to legalizing by replacing every // value of N with the corresponding value of M. So do that now. assert(N->getNumValues() == M->getNumValues() && "Node morphing changed the number of results!"); for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) // Replacing the value takes care of remapping the new value. ReplaceValueWith(SDValue(N, i), SDValue(M, i)); assert(N->getNodeId() == NewNode && "Unexpected node state!"); // The node continues to live on as part of the NewNode fungus that // grows on top of the useful nodes. Nothing more needs to be done // with it - move on to the next node. continue; } if (i == NumOperands) { DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n"); } } NodeDone: // If we reach here, the node was processed, potentially creating new nodes. // Mark it as processed and add its users to the worklist as appropriate. assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); N->setNodeId(Processed); for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); UI != E; ++UI) { SDNode *User = *UI; int NodeId = User->getNodeId(); // This node has two options: it can either be a new node or its Node ID // may be a count of the number of operands it has that are not ready. if (NodeId > 0) { User->setNodeId(NodeId-1); // If this was the last use it was waiting on, add it to the ready list. if (NodeId-1 == ReadyToProcess) Worklist.push_back(User); continue; } // If this is an unreachable new node, then ignore it. If it ever becomes // reachable by being used by a newly created node then it will be handled // by AnalyzeNewNode. if (NodeId == NewNode) continue; // Otherwise, this node is new: this is the first operand of it that // became ready. Its new NodeId is the number of operands it has minus 1 // (as this node is now processed). assert(NodeId == Unanalyzed && "Unknown node ID!"); User->setNodeId(User->getNumOperands() - 1); // If the node only has a single operand, it is now ready. if (User->getNumOperands() == 1) Worklist.push_back(User); } } #ifndef XDEBUG if (EnableExpensiveChecks) #endif PerformExpensiveChecks(); // If the root changed (e.g. it was a dead load) update the root. DAG.setRoot(Dummy.getValue()); // Remove dead nodes. This is important to do for cleanliness but also before // the checking loop below. Implicit folding by the DAG.getNode operators and // node morphing can cause unreachable nodes to be around with their flags set // to new. DAG.RemoveDeadNodes(); // In a debug build, scan all the nodes to make sure we found them all. This // ensures that there are no cycles and that everything got processed. #ifndef NDEBUG for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), E = DAG.allnodes_end(); I != E; ++I) { bool Failed = false; // Check that all result types are legal. if (!IgnoreNodeResults(I)) for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i) if (!isTypeLegal(I->getValueType(i))) { dbgs() << "Result type " << i << " illegal!\n"; Failed = true; } // Check that all operand types are legal. for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i) if (!IgnoreNodeResults(I->getOperand(i).getNode()) && !isTypeLegal(I->getOperand(i).getValueType())) { dbgs() << "Operand type " << i << " illegal!\n"; Failed = true; } if (I->getNodeId() != Processed) { if (I->getNodeId() == NewNode) dbgs() << "New node not analyzed?\n"; else if (I->getNodeId() == Unanalyzed) dbgs() << "Unanalyzed node not noticed?\n"; else if (I->getNodeId() > 0) dbgs() << "Operand not processed?\n"; else if (I->getNodeId() == ReadyToProcess) dbgs() << "Not added to worklist?\n"; Failed = true; } if (Failed) { I->dump(&DAG); dbgs() << "\n"; llvm_unreachable(0); } } #endif return Changed; } /// AnalyzeNewNode - The specified node is the root of a subtree of potentially /// new nodes. Correct any processed operands (this may change the node) and /// calculate the NodeId. If the node itself changes to a processed node, it /// is not remapped - the caller needs to take care of this. /// Returns the potentially changed node. SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) { // If this was an existing node that is already done, we're done. if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed) return N; // Remove any stale map entries. ExpungeNode(N); // Okay, we know that this node is new. Recursively walk all of its operands // to see if they are new also. The depth of this walk is bounded by the size // of the new tree that was constructed (usually 2-3 nodes), so we don't worry // about revisiting of nodes. // // As we walk the operands, keep track of the number of nodes that are // processed. If non-zero, this will become the new nodeid of this node. // Operands may morph when they are analyzed. If so, the node will be // updated after all operands have been analyzed. Since this is rare, // the code tries to minimize overhead in the non-morphing case. SmallVector NewOps; unsigned NumProcessed = 0; for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { SDValue OrigOp = N->getOperand(i); SDValue Op = OrigOp; AnalyzeNewValue(Op); // Op may morph. if (Op.getNode()->getNodeId() == Processed) ++NumProcessed; if (!NewOps.empty()) { // Some previous operand changed. Add this one to the list. NewOps.push_back(Op); } else if (Op != OrigOp) { // This is the first operand to change - add all operands so far. NewOps.append(N->op_begin(), N->op_begin() + i); NewOps.push_back(Op); } } // Some operands changed - update the node. if (!NewOps.empty()) { SDNode *M = DAG.UpdateNodeOperands(N, &NewOps[0], NewOps.size()); if (M != N) { // The node morphed into a different node. Normally for this to happen // the original node would have to be marked NewNode. However this can // in theory momentarily not be the case while ReplaceValueWith is doing // its stuff. Mark the original node NewNode to help sanity checking. N->setNodeId(NewNode); if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed) // It morphed into a previously analyzed node - nothing more to do. return M; // It morphed into a different new node. Do the equivalent of passing // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need // to remap the operands, since they are the same as the operands we // remapped above. N = M; ExpungeNode(N); } } // Calculate the NodeId. N->setNodeId(N->getNumOperands() - NumProcessed); if (N->getNodeId() == ReadyToProcess) Worklist.push_back(N); return N; } /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed. /// If the node changes to a processed node, then remap it. void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) { Val.setNode(AnalyzeNewNode(Val.getNode())); if (Val.getNode()->getNodeId() == Processed) // We were passed a processed node, or it morphed into one - remap it. RemapValue(Val); } /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it. /// This can occur when a node is deleted then reallocated as a new node - /// the mapping in ReplacedValues applies to the deleted node, not the new /// one. /// The only map that can have a deleted node as a source is ReplacedValues. /// Other maps can have deleted nodes as targets, but since their looked-up /// values are always immediately remapped using RemapValue, resulting in a /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue /// always performs correct mappings. In order to keep the mapping correct, /// ExpungeNode should be called on any new nodes *before* adding them as /// either source or target to ReplacedValues (which typically means calling /// Expunge when a new node is first seen, since it may no longer be marked /// NewNode by the time it is added to ReplacedValues). void DAGTypeLegalizer::ExpungeNode(SDNode *N) { if (N->getNodeId() != NewNode) return; // If N is not remapped by ReplacedValues then there is nothing to do. unsigned i, e; for (i = 0, e = N->getNumValues(); i != e; ++i) if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end()) break; if (i == e) return; // Remove N from all maps - this is expensive but rare. for (DenseMap::iterator I = PromotedIntegers.begin(), E = PromotedIntegers.end(); I != E; ++I) { assert(I->first.getNode() != N); RemapValue(I->second); } for (DenseMap::iterator I = SoftenedFloats.begin(), E = SoftenedFloats.end(); I != E; ++I) { assert(I->first.getNode() != N); RemapValue(I->second); } for (DenseMap::iterator I = ScalarizedVectors.begin(), E = ScalarizedVectors.end(); I != E; ++I) { assert(I->first.getNode() != N); RemapValue(I->second); } for (DenseMap::iterator I = WidenedVectors.begin(), E = WidenedVectors.end(); I != E; ++I) { assert(I->first.getNode() != N); RemapValue(I->second); } for (DenseMap >::iterator I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){ assert(I->first.getNode() != N); RemapValue(I->second.first); RemapValue(I->second.second); } for (DenseMap >::iterator I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) { assert(I->first.getNode() != N); RemapValue(I->second.first); RemapValue(I->second.second); } for (DenseMap >::iterator I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) { assert(I->first.getNode() != N); RemapValue(I->second.first); RemapValue(I->second.second); } for (DenseMap::iterator I = ReplacedValues.begin(), E = ReplacedValues.end(); I != E; ++I) RemapValue(I->second); for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) ReplacedValues.erase(SDValue(N, i)); } /// RemapValue - If the specified value was already legalized to another value, /// replace it by that value. void DAGTypeLegalizer::RemapValue(SDValue &N) { DenseMap::iterator I = ReplacedValues.find(N); if (I != ReplacedValues.end()) { // Use path compression to speed up future lookups if values get multiply // replaced with other values. RemapValue(I->second); N = I->second; // Note that it is possible to have N.getNode()->getNodeId() == NewNode at // this point because it is possible for a node to be put in the map before // being processed. } } namespace { /// NodeUpdateListener - This class is a DAGUpdateListener that listens for /// updates to nodes and recomputes their ready state. class NodeUpdateListener : public SelectionDAG::DAGUpdateListener { DAGTypeLegalizer &DTL; SmallSetVector &NodesToAnalyze; public: explicit NodeUpdateListener(DAGTypeLegalizer &dtl, SmallSetVector &nta) : SelectionDAG::DAGUpdateListener(dtl.getDAG()), DTL(dtl), NodesToAnalyze(nta) {} virtual void NodeDeleted(SDNode *N, SDNode *E) { assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && N->getNodeId() != DAGTypeLegalizer::Processed && "Invalid node ID for RAUW deletion!"); // It is possible, though rare, for the deleted node N to occur as a // target in a map, so note the replacement N -> E in ReplacedValues. assert(E && "Node not replaced?"); DTL.NoteDeletion(N, E); // In theory the deleted node could also have been scheduled for analysis. // So remove it from the set of nodes which will be analyzed. NodesToAnalyze.remove(N); // In general nothing needs to be done for E, since it didn't change but // only gained new uses. However N -> E was just added to ReplacedValues, // and the result of a ReplacedValues mapping is not allowed to be marked // NewNode. So if E is marked NewNode, then it needs to be analyzed. if (E->getNodeId() == DAGTypeLegalizer::NewNode) NodesToAnalyze.insert(E); } virtual void NodeUpdated(SDNode *N) { // Node updates can mean pretty much anything. It is possible that an // operand was set to something already processed (f.e.) in which case // this node could become ready. Recompute its flags. assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && N->getNodeId() != DAGTypeLegalizer::Processed && "Invalid node ID for RAUW deletion!"); N->setNodeId(DAGTypeLegalizer::NewNode); NodesToAnalyze.insert(N); } }; } /// ReplaceValueWith - The specified value was legalized to the specified other /// value. Update the DAG and NodeIds replacing any uses of From to use To /// instead. void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { assert(From.getNode() != To.getNode() && "Potential legalization loop!"); // If expansion produced new nodes, make sure they are properly marked. ExpungeNode(From.getNode()); AnalyzeNewValue(To); // Expunges To. // Anything that used the old node should now use the new one. Note that this // can potentially cause recursive merging. SmallSetVector NodesToAnalyze; NodeUpdateListener NUL(*this, NodesToAnalyze); do { DAG.ReplaceAllUsesOfValueWith(From, To); // The old node may still be present in a map like ExpandedIntegers or // PromotedIntegers. Inform maps about the replacement. ReplacedValues[From] = To; // Process the list of nodes that need to be reanalyzed. while (!NodesToAnalyze.empty()) { SDNode *N = NodesToAnalyze.back(); NodesToAnalyze.pop_back(); if (N->getNodeId() != DAGTypeLegalizer::NewNode) // The node was analyzed while reanalyzing an earlier node - it is safe // to skip. Note that this is not a morphing node - otherwise it would // still be marked NewNode. continue; // Analyze the node's operands and recalculate the node ID. SDNode *M = AnalyzeNewNode(N); if (M != N) { // The node morphed into a different node. Make everyone use the new // node instead. assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!"); assert(N->getNumValues() == M->getNumValues() && "Node morphing changed the number of results!"); for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) { SDValue OldVal(N, i); SDValue NewVal(M, i); if (M->getNodeId() == Processed) RemapValue(NewVal); DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal); // OldVal may be a target of the ReplacedValues map which was marked // NewNode to force reanalysis because it was updated. Ensure that // anything that ReplacedValues mapped to OldVal will now be mapped // all the way to NewVal. ReplacedValues[OldVal] = NewVal; } // The original node continues to exist in the DAG, marked NewNode. } } // When recursively update nodes with new nodes, it is possible to have // new uses of From due to CSE. If this happens, replace the new uses of // From with To. } while (!From.use_empty()); } void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) { assert(Result.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && "Invalid type for promoted integer"); AnalyzeNewValue(Result); SDValue &OpEntry = PromotedIntegers[Op]; assert(OpEntry.getNode() == 0 && "Node is already promoted!"); OpEntry = Result; } void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { assert(Result.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && "Invalid type for softened float"); AnalyzeNewValue(Result); SDValue &OpEntry = SoftenedFloats[Op]; assert(OpEntry.getNode() == 0 && "Node is already converted to integer!"); OpEntry = Result; } void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) { // Note that in some cases vector operation operands may be greater than // the vector element type. For example BUILD_VECTOR of type <1 x i1> with // a constant i8 operand. assert(Result.getValueType().getSizeInBits() >= Op.getValueType().getVectorElementType().getSizeInBits() && "Invalid type for scalarized vector"); AnalyzeNewValue(Result); SDValue &OpEntry = ScalarizedVectors[Op]; assert(OpEntry.getNode() == 0 && "Node is already scalarized!"); OpEntry = Result; } void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, SDValue &Hi) { std::pair &Entry = ExpandedIntegers[Op]; RemapValue(Entry.first); RemapValue(Entry.second); assert(Entry.first.getNode() && "Operand isn't expanded"); Lo = Entry.first; Hi = Entry.second; } void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, SDValue Hi) { assert(Lo.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && Hi.getValueType() == Lo.getValueType() && "Invalid type for expanded integer"); // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. AnalyzeNewValue(Lo); AnalyzeNewValue(Hi); // Remember that this is the result of the node. std::pair &Entry = ExpandedIntegers[Op]; assert(Entry.first.getNode() == 0 && "Node already expanded"); Entry.first = Lo; Entry.second = Hi; } void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, SDValue &Hi) { std::pair &Entry = ExpandedFloats[Op]; RemapValue(Entry.first); RemapValue(Entry.second); assert(Entry.first.getNode() && "Operand isn't expanded"); Lo = Entry.first; Hi = Entry.second; } void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo, SDValue Hi) { assert(Lo.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && Hi.getValueType() == Lo.getValueType() && "Invalid type for expanded float"); // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. AnalyzeNewValue(Lo); AnalyzeNewValue(Hi); // Remember that this is the result of the node. std::pair &Entry = ExpandedFloats[Op]; assert(Entry.first.getNode() == 0 && "Node already expanded"); Entry.first = Lo; Entry.second = Hi; } void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, SDValue &Hi) { std::pair &Entry = SplitVectors[Op]; RemapValue(Entry.first); RemapValue(Entry.second); assert(Entry.first.getNode() && "Operand isn't split"); Lo = Entry.first; Hi = Entry.second; } void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo, SDValue Hi) { assert(Lo.getValueType().getVectorElementType() == Op.getValueType().getVectorElementType() && 2*Lo.getValueType().getVectorNumElements() == Op.getValueType().getVectorNumElements() && Hi.getValueType() == Lo.getValueType() && "Invalid type for split vector"); // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. AnalyzeNewValue(Lo); AnalyzeNewValue(Hi); // Remember that this is the result of the node. std::pair &Entry = SplitVectors[Op]; assert(Entry.first.getNode() == 0 && "Node already split"); Entry.first = Lo; Entry.second = Hi; } void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { assert(Result.getValueType() == TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && "Invalid type for widened vector"); AnalyzeNewValue(Result); SDValue &OpEntry = WidenedVectors[Op]; assert(OpEntry.getNode() == 0 && "Node already widened!"); OpEntry = Result; } //===----------------------------------------------------------------------===// // Utilities. //===----------------------------------------------------------------------===// /// BitConvertToInteger - Convert to an integer of the same size. SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { unsigned BitWidth = Op.getValueType().getSizeInBits(); return DAG.getNode(ISD::BITCAST, SDLoc(Op), EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op); } /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the /// same size. SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) { assert(Op.getValueType().isVector() && "Only applies to vectors!"); unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits(); EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth); unsigned NumElts = Op.getValueType().getVectorNumElements(); return DAG.getNode(ISD::BITCAST, SDLoc(Op), EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op); } SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op, EVT DestVT) { SDLoc dl(Op); // Create the stack frame object. Make sure it is aligned for both // the source and destination types. SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT); // Emit a store to the stack slot. SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr, MachinePointerInfo(), false, false, 0); // Result is a load from the stack slot. return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(), false, false, false, 0); } /// CustomLowerNode - Replace the node's results with custom code provided /// by the target and return "true", or do nothing and return "false". /// The last parameter is FALSE if we are dealing with a node with legal /// result types and illegal operand. The second parameter denotes the type of /// illegal OperandNo in that case. /// The last parameter being TRUE means we are dealing with a /// node with illegal result types. The second parameter denotes the type of /// illegal ResNo in that case. bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) { // See if the target wants to custom lower this node. if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) return false; SmallVector Results; if (LegalizeResult) TLI.ReplaceNodeResults(N, Results, DAG); else TLI.LowerOperationWrapper(N, Results, DAG); if (Results.empty()) // The target didn't want to custom lower it after all. return false; // Make everything that once used N's values now use those in Results instead. assert(Results.size() == N->getNumValues() && "Custom lowering returned the wrong number of results!"); for (unsigned i = 0, e = Results.size(); i != e; ++i) { ReplaceValueWith(SDValue(N, i), Results[i]); } return true; } /// CustomWidenLowerNode - Widen the node's results with custom code provided /// by the target and return "true", or do nothing and return "false". bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) { // See if the target wants to custom lower this node. if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) return false; SmallVector Results; TLI.ReplaceNodeResults(N, Results, DAG); if (Results.empty()) // The target didn't want to custom widen lower its result after all. return false; // Update the widening map. assert(Results.size() == N->getNumValues() && "Custom lowering returned the wrong number of results!"); for (unsigned i = 0, e = Results.size(); i != e; ++i) SetWidenedVector(SDValue(N, i), Results[i]); return true; } SDValue DAGTypeLegalizer::DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo) { for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) if (i != ResNo) ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); return SDValue(N->getOperand(ResNo)); } /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and /// high parts of the given value. void DAGTypeLegalizer::GetPairElements(SDValue Pair, SDValue &Lo, SDValue &Hi) { SDLoc dl(Pair); EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType()); Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, DAG.getIntPtrConstant(0)); Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, DAG.getIntPtrConstant(1)); } SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT, SDValue Index) { SDLoc dl(Index); // Make sure the index type is big enough to compute in. Index = DAG.getZExtOrTrunc(Index, dl, TLI.getPointerTy()); // Calculate the element offset and add it to the pointer. unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size. Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index, DAG.getConstant(EltSize, Index.getValueType())); return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr); } /// JoinIntegers - Build an integer with low bits Lo and high bits Hi. SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) { // Arbitrarily use dlHi for result SDLoc SDLoc dlHi(Hi); SDLoc dlLo(Lo); EVT LVT = Lo.getValueType(); EVT HVT = Hi.getValueType(); EVT NVT = EVT::getIntegerVT(*DAG.getContext(), LVT.getSizeInBits() + HVT.getSizeInBits()); Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo); Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi); Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi, DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy())); return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi); } /// LibCallify - Convert the node into a libcall with the same prototype. SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N, bool isSigned) { unsigned NumOps = N->getNumOperands(); SDLoc dl(N); if (NumOps == 0) { return TLI.makeLibCall(DAG, LC, N->getValueType(0), 0, 0, isSigned, dl).first; } else if (NumOps == 1) { SDValue Op = N->getOperand(0); return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Op, 1, isSigned, dl).first; } else if (NumOps == 2) { SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) }; return TLI.makeLibCall(DAG, LC, N->getValueType(0), Ops, 2, isSigned, dl).first; } SmallVector Ops(NumOps); for (unsigned i = 0; i < NumOps; ++i) Ops[i] = N->getOperand(i); return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Ops[0], NumOps, isSigned, dl).first; } // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to // ExpandLibCall except that the first operand is the in-chain. std::pair DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned) { SDValue InChain = Node->getOperand(0); TargetLowering::ArgListTy Args; TargetLowering::ArgListEntry Entry; for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) { EVT ArgVT = Node->getOperand(i).getValueType(); Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext()); Entry.Node = Node->getOperand(i); Entry.Ty = ArgTy; Entry.isSExt = isSigned; Entry.isZExt = !isSigned; Args.push_back(Entry); } SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), TLI.getPointerTy()); Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext()); TargetLowering:: CallLoweringInfo CLI(InChain, RetTy, isSigned, !isSigned, false, false, 0, TLI.getLibcallCallingConv(LC), /*isTailCall=*/false, /*doesNotReturn=*/false, /*isReturnValueUsed=*/true, Callee, Args, DAG, SDLoc(Node)); std::pair CallInfo = TLI.LowerCallTo(CLI); return CallInfo; } /// PromoteTargetBoolean - Promote the given target boolean to a target boolean /// of the given type. A target boolean is an integer value, not necessarily of /// type i1, the bits of which conform to getBooleanContents. SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT VT) { SDLoc dl(Bool); ISD::NodeType ExtendCode = TargetLowering::getExtendForContent(TLI.getBooleanContents(VT.isVector())); return DAG.getNode(ExtendCode, dl, VT, Bool); } /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT /// bits in Hi. void DAGTypeLegalizer::SplitInteger(SDValue Op, EVT LoVT, EVT HiVT, SDValue &Lo, SDValue &Hi) { SDLoc dl(Op); assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() == Op.getValueType().getSizeInBits() && "Invalid integer splitting!"); Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op); Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op, DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy())); Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi); } /// SplitInteger - Return the lower and upper halves of Op's bits in a value /// type half the size of Op's. void DAGTypeLegalizer::SplitInteger(SDValue Op, SDValue &Lo, SDValue &Hi) { EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), Op.getValueType().getSizeInBits()/2); SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); } //===----------------------------------------------------------------------===// // Entry Point //===----------------------------------------------------------------------===// /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that /// only uses types natively supported by the target. Returns "true" if it made /// any changes. /// /// Note that this is an involved process that may invalidate pointers into /// the graph. bool SelectionDAG::LegalizeTypes() { return DAGTypeLegalizer(*this).run(); }