| //===-- LegalizeTypes.cpp - Common code for DAG type legalizer ------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // 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 "SDNodeDbgValue.h" |
| #include "llvm/ADT/SetVector.h" |
| #include "llvm/CodeGen/MachineFunction.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; |
| |
| #define DEBUG_TYPE "legalize-types" |
| |
| static cl::opt<bool> |
| EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden); |
| |
| /// 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<SDNode*, 16> NewNodes; |
| for (SDNode &Node : DAG.allnodes()) { |
| // Remember nodes marked NewNode - they are subject to extra checking below. |
| if (Node.getNodeId() == NewNode) |
| NewNodes.push_back(&Node); |
| |
| for (unsigned i = 0, e = Node.getNumValues(); i != e; ++i) { |
| SDValue Res(&Node, i); |
| bool Failed = false; |
| // Don't create a value in map. |
| auto ResId = (ValueToIdMap.count(Res)) ? ValueToIdMap[Res] : 0; |
| |
| unsigned Mapped = 0; |
| if (ResId && (ReplacedValues.find(ResId) != ReplacedValues.end())) { |
| Mapped |= 1; |
| // Check that remapped values are only used by nodes marked NewNode. |
| for (SDNode::use_iterator UI = Node.use_begin(), UE = Node.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. |
| auto NewValId = ReplacedValues[ResId]; |
| auto I = ReplacedValues.find(NewValId); |
| while (I != ReplacedValues.end()) { |
| NewValId = I->second; |
| I = ReplacedValues.find(NewValId); |
| } |
| SDValue NewVal = getSDValue(NewValId); |
| (void)NewVal; |
| assert(NewVal.getNode()->getNodeId() != NewNode && |
| "ReplacedValues maps to a new node!"); |
| } |
| if (ResId && PromotedIntegers.find(ResId) != PromotedIntegers.end()) |
| Mapped |= 2; |
| if (ResId && SoftenedFloats.find(ResId) != SoftenedFloats.end()) |
| Mapped |= 4; |
| if (ResId && ScalarizedVectors.find(ResId) != ScalarizedVectors.end()) |
| Mapped |= 8; |
| if (ResId && ExpandedIntegers.find(ResId) != ExpandedIntegers.end()) |
| Mapped |= 16; |
| if (ResId && ExpandedFloats.find(ResId) != ExpandedFloats.end()) |
| Mapped |= 32; |
| if (ResId && SplitVectors.find(ResId) != SplitVectors.end()) |
| Mapped |= 64; |
| if (ResId && WidenedVectors.find(ResId) != WidenedVectors.end()) |
| Mapped |= 128; |
| if (ResId && PromotedFloats.find(ResId) != PromotedFloats.end()) |
| Mapped |= 256; |
| |
| if (Node.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 ((Node.getNodeId() == NewNode && Mapped > 1) || |
| (Node.getNodeId() != NewNode && Mapped != 0)) { |
| dbgs() << "Unprocessed value in a map!"; |
| Failed = true; |
| } |
| } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(&Node)) { |
| 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"; |
| if (Mapped & 256) |
| dbgs() << " PromotedFloats"; |
| dbgs() << "\n"; |
| llvm_unreachable(nullptr); |
| } |
| } |
| } |
| |
| // 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!"); |
| } |
| } |
| |
| /// 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 (SDNode &Node : DAG.allnodes()) { |
| if (Node.getNumOperands() == 0) { |
| Node.setNodeId(ReadyToProcess); |
| Worklist.push_back(&Node); |
| } else { |
| Node.setNodeId(Unanalyzed); |
| } |
| } |
| |
| // Now that we have a set of nodes to process, handle them all. |
| while (!Worklist.empty()) { |
| #ifndef EXPENSIVE_CHECKS |
| if (EnableExpensiveChecks) |
| #endif |
| PerformExpensiveChecks(); |
| |
| SDNode *N = Worklist.back(); |
| Worklist.pop_back(); |
| assert(N->getNodeId() == ReadyToProcess && |
| "Node should be ready if on worklist!"); |
| |
| LLVM_DEBUG(dbgs() << "Legalizing node: "; N->dump(&DAG)); |
| if (IgnoreNodeResults(N)) { |
| LLVM_DEBUG(dbgs() << "Ignoring node results\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); |
| LLVM_DEBUG(dbgs() << "Analyzing result type: " << ResultVT.getEVTString() |
| << "\n"); |
| switch (getTypeAction(ResultVT)) { |
| case TargetLowering::TypeLegal: |
| LLVM_DEBUG(dbgs() << "Legal result type\n"); |
| 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; |
| case TargetLowering::TypePromoteFloat: |
| PromoteFloatResult(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; |
| |
| const auto Op = N->getOperand(i); |
| LLVM_DEBUG(dbgs() << "Analyzing operand: "; Op.dump(&DAG)); |
| EVT OpVT = Op.getValueType(); |
| switch (getTypeAction(OpVT)) { |
| case TargetLowering::TypeLegal: |
| LLVM_DEBUG(dbgs() << "Legal operand\n"); |
| 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; |
| case TargetLowering::TypePromoteFloat: |
| NeedsReanalyzing = PromoteFloatOperand(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) { |
| LLVM_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 EXPENSIVE_CHECKS |
| 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 (SDNode &Node : DAG.allnodes()) { |
| bool Failed = false; |
| |
| // Check that all result types are legal. |
| if (!IgnoreNodeResults(&Node)) |
| for (unsigned i = 0, NumVals = Node.getNumValues(); i < NumVals; ++i) |
| if (!isTypeLegal(Node.getValueType(i))) { |
| dbgs() << "Result type " << i << " illegal: "; |
| Node.dump(&DAG); |
| Failed = true; |
| } |
| |
| // Check that all operand types are legal. |
| for (unsigned i = 0, NumOps = Node.getNumOperands(); i < NumOps; ++i) |
| if (!IgnoreNodeResults(Node.getOperand(i).getNode()) && |
| !isTypeLegal(Node.getOperand(i).getValueType())) { |
| dbgs() << "Operand type " << i << " illegal: "; |
| Node.getOperand(i).dump(&DAG); |
| Failed = true; |
| } |
| |
| if (Node.getNodeId() != Processed) { |
| if (Node.getNodeId() == NewNode) |
| dbgs() << "New node not analyzed?\n"; |
| else if (Node.getNodeId() == Unanalyzed) |
| dbgs() << "Unanalyzed node not noticed?\n"; |
| else if (Node.getNodeId() > 0) |
| dbgs() << "Operand not processed?\n"; |
| else if (Node.getNodeId() == ReadyToProcess) |
| dbgs() << "Not added to worklist?\n"; |
| Failed = true; |
| } |
| |
| if (Failed) { |
| Node.dump(&DAG); dbgs() << "\n"; |
| llvm_unreachable(nullptr); |
| } |
| } |
| #endif |
| |
| return Changed; |
| } |
| |
| /// 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; |
| |
| // 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. |
| |
| std::vector<SDValue> 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.insert(NewOps.end(), 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); |
| 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; |
| } |
| } |
| |
| // Calculate the NodeId. |
| N->setNodeId(N->getNumOperands() - NumProcessed); |
| if (N->getNodeId() == ReadyToProcess) |
| Worklist.push_back(N); |
| |
| return N; |
| } |
| |
| /// 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); |
| } |
| |
| /// If the specified value was already legalized to another value, |
| /// replace it by that value. |
| void DAGTypeLegalizer::RemapValue(SDValue &V) { |
| auto Id = getTableId(V); |
| V = getSDValue(Id); |
| } |
| |
| void DAGTypeLegalizer::RemapId(TableId &Id) { |
| auto I = ReplacedValues.find(Id); |
| if (I != ReplacedValues.end()) { |
| assert(Id != I->second && "Id is mapped to itself."); |
| // Use path compression to speed up future lookups if values get multiply |
| // replaced with other values. |
| RemapId(I->second); |
| Id = I->second; |
| |
| // Note that N = IdToValueMap[Id] 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 { |
| /// This class is a DAGUpdateListener that listens for updates to nodes and |
| /// recomputes their ready state. |
| class NodeUpdateListener : public SelectionDAG::DAGUpdateListener { |
| DAGTypeLegalizer &DTL; |
| SmallSetVector<SDNode*, 16> &NodesToAnalyze; |
| public: |
| explicit NodeUpdateListener(DAGTypeLegalizer &dtl, |
| SmallSetVector<SDNode*, 16> &nta) |
| : SelectionDAG::DAGUpdateListener(dtl.getDAG()), |
| DTL(dtl), NodesToAnalyze(nta) {} |
| |
| void NodeDeleted(SDNode *N, SDNode *E) override { |
| 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); |
| } |
| |
| void NodeUpdated(SDNode *N) override { |
| // 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); |
| } |
| }; |
| } |
| |
| |
| /// 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. |
| AnalyzeNewValue(To); |
| |
| // Anything that used the old node should now use the new one. Note that this |
| // can potentially cause recursive merging. |
| SmallSetVector<SDNode*, 16> NodesToAnalyze; |
| NodeUpdateListener NUL(*this, NodesToAnalyze); |
| do { |
| |
| // The old node may be present in a map like ExpandedIntegers or |
| // PromotedIntegers. Inform maps about the replacement. |
| auto FromId = getTableId(From); |
| auto ToId = getTableId(To); |
| |
| if (FromId != ToId) |
| ReplacedValues[FromId] = ToId; |
| DAG.ReplaceAllUsesOfValueWith(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); |
| // 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. |
| auto OldValId = getTableId(OldVal); |
| auto NewValId = getTableId(NewVal); |
| DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal); |
| if (OldValId != NewValId) |
| ReplacedValues[OldValId] = NewValId; |
| } |
| // 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); |
| |
| auto &OpIdEntry = PromotedIntegers[getTableId(Op)]; |
| assert((OpIdEntry == 0) && "Node is already promoted!"); |
| OpIdEntry = getTableId(Result); |
| Result->setFlags(Op->getFlags()); |
| |
| DAG.transferDbgValues(Op, Result); |
| } |
| |
| void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { |
| assert(Result.getValueType() == |
| TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && |
| "Invalid type for softened float"); |
| AnalyzeNewValue(Result); |
| |
| auto &OpIdEntry = SoftenedFloats[getTableId(Op)]; |
| assert((OpIdEntry == 0) && "Node is already converted to integer!"); |
| OpIdEntry = getTableId(Result); |
| } |
| |
| void DAGTypeLegalizer::SetPromotedFloat(SDValue Op, SDValue Result) { |
| assert(Result.getValueType() == |
| TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && |
| "Invalid type for promoted float"); |
| AnalyzeNewValue(Result); |
| |
| auto &OpIdEntry = PromotedFloats[getTableId(Op)]; |
| assert((OpIdEntry == 0) && "Node is already promoted!"); |
| OpIdEntry = getTableId(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.getValueSizeInBits() >= Op.getScalarValueSizeInBits() && |
| "Invalid type for scalarized vector"); |
| AnalyzeNewValue(Result); |
| |
| auto &OpIdEntry = ScalarizedVectors[getTableId(Op)]; |
| assert((OpIdEntry == 0) && "Node is already scalarized!"); |
| OpIdEntry = getTableId(Result); |
| } |
| |
| void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, |
| SDValue &Hi) { |
| std::pair<TableId, TableId> &Entry = ExpandedIntegers[getTableId(Op)]; |
| assert((Entry.first != 0) && "Operand isn't expanded"); |
| Lo = getSDValue(Entry.first); |
| Hi = getSDValue(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); |
| |
| // Transfer debug values. Don't invalidate the source debug value until it's |
| // been transferred to the high and low bits. |
| if (DAG.getDataLayout().isBigEndian()) { |
| DAG.transferDbgValues(Op, Hi, 0, Hi.getValueSizeInBits(), false); |
| DAG.transferDbgValues(Op, Lo, Hi.getValueSizeInBits(), |
| Lo.getValueSizeInBits()); |
| } else { |
| DAG.transferDbgValues(Op, Lo, 0, Lo.getValueSizeInBits(), false); |
| DAG.transferDbgValues(Op, Hi, Lo.getValueSizeInBits(), |
| Hi.getValueSizeInBits()); |
| } |
| |
| // Remember that this is the result of the node. |
| std::pair<TableId, TableId> &Entry = ExpandedIntegers[getTableId(Op)]; |
| assert((Entry.first == 0) && "Node already expanded"); |
| Entry.first = getTableId(Lo); |
| Entry.second = getTableId(Hi); |
| } |
| |
| void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, |
| SDValue &Hi) { |
| std::pair<TableId, TableId> &Entry = ExpandedFloats[getTableId(Op)]; |
| assert((Entry.first != 0) && "Operand isn't expanded"); |
| Lo = getSDValue(Entry.first); |
| Hi = getSDValue(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); |
| |
| std::pair<TableId, TableId> &Entry = ExpandedFloats[getTableId(Op)]; |
| assert((Entry.first == 0) && "Node already expanded"); |
| Entry.first = getTableId(Lo); |
| Entry.second = getTableId(Hi); |
| } |
| |
| void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, |
| SDValue &Hi) { |
| std::pair<TableId, TableId> &Entry = SplitVectors[getTableId(Op)]; |
| Lo = getSDValue(Entry.first); |
| Hi = getSDValue(Entry.second); |
| assert(Lo.getNode() && "Operand isn't split"); |
| ; |
| } |
| |
| 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<TableId, TableId> &Entry = SplitVectors[getTableId(Op)]; |
| assert((Entry.first == 0) && "Node already split"); |
| Entry.first = getTableId(Lo); |
| Entry.second = getTableId(Hi); |
| } |
| |
| void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { |
| assert(Result.getValueType() == |
| TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && |
| "Invalid type for widened vector"); |
| AnalyzeNewValue(Result); |
| |
| auto &OpIdEntry = WidenedVectors[getTableId(Op)]; |
| assert((OpIdEntry == 0) && "Node already widened!"); |
| OpIdEntry = getTableId(Result); |
| } |
| |
| |
| //===----------------------------------------------------------------------===// |
| // Utilities. |
| //===----------------------------------------------------------------------===// |
| |
| /// Convert to an integer of the same size. |
| SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { |
| unsigned BitWidth = Op.getValueSizeInBits(); |
| return DAG.getNode(ISD::BITCAST, SDLoc(Op), |
| EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op); |
| } |
| |
| /// 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.getScalarValueSizeInBits(); |
| EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth); |
| auto EltCnt = Op.getValueType().getVectorElementCount(); |
| return DAG.getNode(ISD::BITCAST, SDLoc(Op), |
| EVT::getVectorVT(*DAG.getContext(), EltNVT, EltCnt), 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()); |
| // Result is a load from the stack slot. |
| return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo()); |
| } |
| |
| /// 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<SDValue, 8> 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; |
| |
| // When called from DAGTypeLegalizer::ExpandIntegerResult, we might need to |
| // provide the same kind of custom splitting behavior. |
| if (Results.size() == N->getNumValues() + 1 && LegalizeResult) { |
| // We've legalized a return type by splitting it. If there is a chain, |
| // replace that too. |
| SetExpandedInteger(SDValue(N, 0), Results[0], Results[1]); |
| if (N->getNumValues() > 1) |
| ReplaceValueWith(SDValue(N, 1), Results[2]); |
| return true; |
| } |
| |
| // 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; |
| } |
| |
| |
| /// 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<SDValue, 8> 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) { |
| // If this is a chain output just replace it. |
| if (Results[i].getValueType() == MVT::Other) |
| ReplaceValueWith(SDValue(N, i), Results[i]); |
| else |
| 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)); |
| } |
| |
| /// 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, dl)); |
| Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, |
| DAG.getIntPtrConstant(1, dl)); |
| } |
| |
| /// 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()); |
| |
| EVT ShiftAmtVT = TLI.getShiftAmountTy(NVT, DAG.getDataLayout(), false); |
| 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(), dlHi, ShiftAmtVT)); |
| return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi); |
| } |
| |
| /// 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. |
| /// |
| /// ValVT is the type of values that produced the boolean. |
| SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT ValVT) { |
| SDLoc dl(Bool); |
| EVT BoolVT = getSetCCResultType(ValVT); |
| ISD::NodeType ExtendCode = |
| TargetLowering::getExtendForContent(TLI.getBooleanContents(ValVT)); |
| return DAG.getNode(ExtendCode, dl, BoolVT, Bool); |
| } |
| |
| /// 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.getValueSizeInBits() && "Invalid integer splitting!"); |
| Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op); |
| unsigned ReqShiftAmountInBits = |
| Log2_32_Ceil(Op.getValueType().getSizeInBits()); |
| MVT ShiftAmountTy = |
| TLI.getScalarShiftAmountTy(DAG.getDataLayout(), Op.getValueType()); |
| if (ReqShiftAmountInBits > ShiftAmountTy.getSizeInBits()) |
| ShiftAmountTy = MVT::getIntegerVT(NextPowerOf2(ReqShiftAmountInBits)); |
| Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op, |
| DAG.getConstant(LoVT.getSizeInBits(), dl, ShiftAmountTy)); |
| Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi); |
| } |
| |
| /// 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.getValueSizeInBits() / 2); |
| SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); |
| } |
| |
| |
| //===----------------------------------------------------------------------===// |
| // Entry Point |
| //===----------------------------------------------------------------------===// |
| |
| /// 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(); |
| } |
