| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| #pragma once |
| |
| #if ENABLE(DFG_JIT) |
| |
| #include "DFGAbstractValue.h" |
| #include "DFGBranchDirection.h" |
| #include "DFGFlowMap.h" |
| #include "DFGGraph.h" |
| #include "DFGNode.h" |
| |
| namespace JSC { namespace DFG { |
| |
| class InPlaceAbstractState { |
| WTF_MAKE_FAST_ALLOCATED; |
| public: |
| InPlaceAbstractState(Graph&); |
| |
| ~InPlaceAbstractState(); |
| |
| explicit operator bool() const { return true; } |
| |
| void createValueForNode(NodeFlowProjection) { } |
| |
| AbstractValue& forNode(NodeFlowProjection node) |
| { |
| return m_abstractValues.at(node); |
| } |
| |
| AbstractValue& forNode(Edge edge) |
| { |
| return forNode(edge.node()); |
| } |
| |
| Operands<AbstractValue>& variables() |
| { |
| return m_variables; |
| } |
| |
| // Call this before beginning CFA to initialize the abstract values of |
| // arguments, and to indicate which blocks should be listed for CFA |
| // execution. |
| void initialize(); |
| |
| // Start abstractly executing the given basic block. Initializes the |
| // notion of abstract state to what we believe it to be at the head |
| // of the basic block, according to the basic block's data structures. |
| // This method also sets cfaShouldRevisit to false. |
| void beginBasicBlock(BasicBlock*); |
| |
| BasicBlock* block() const { return m_block; } |
| |
| // Finish abstractly executing a basic block. If MergeToTail or |
| // MergeToSuccessors is passed, then this merges everything we have |
| // learned about how the state changes during this block's execution into |
| // the block's data structures. |
| // |
| // Returns true if the state of the block at the tail was changed, |
| // and, if the state at the heads of successors was changed. |
| // A true return means that you must revisit (at least) the successor |
| // blocks. This also sets cfaShouldRevisit to true for basic blocks |
| // that must be visited next. |
| bool endBasicBlock(); |
| |
| // Reset the AbstractState. This throws away any results, and at this point |
| // you can safely call beginBasicBlock() on any basic block. |
| void reset(); |
| |
| // Did the last executed node clobber the world? |
| bool didClobber() const { return m_didClobber; } |
| |
| // Are structures currently clobbered? |
| StructureClobberState structureClobberState() const { return m_structureClobberState; } |
| |
| // Is the execution state still valid? This will be false if execute() has |
| // returned false previously. |
| bool isValid() const { return m_isValid; } |
| |
| // Merge the abstract state stored at the first block's tail into the second |
| // block's head. Returns true if the second block's state changed. If so, |
| // that block must be abstractly interpreted again. This also sets |
| // to->cfaShouldRevisit to true, if it returns true, or if to has not been |
| // visited yet. |
| bool merge(BasicBlock* from, BasicBlock* to); |
| |
| // Merge the abstract state stored at the block's tail into all of its |
| // successors. Returns true if any of the successors' states changed. Note |
| // that this is automatically called in endBasicBlock() if MergeMode is |
| // MergeToSuccessors. |
| bool mergeToSuccessors(BasicBlock*); |
| |
| // Methods intended to be called from AbstractInterpreter. |
| void setDidClobber(bool didClobber) { m_didClobber = didClobber; } |
| void setStructureClobberState(StructureClobberState value) { m_structureClobberState = value; } |
| void setIsValid(bool isValid) { m_isValid = isValid; } |
| void setBranchDirection(BranchDirection branchDirection) { m_branchDirection = branchDirection; } |
| |
| // This method is evil - it causes a huge maintenance headache and there is a gross amount of |
| // code devoted to it. It would be much nicer to just always run the constant folder on each |
| // block. But, the last time we did it, it was a 1% SunSpider regression: |
| // https://bugs.webkit.org/show_bug.cgi?id=133947 |
| // So, we should probably keep this method. |
| void setFoundConstants(bool foundConstants) { m_foundConstants = foundConstants; } |
| |
| private: |
| void mergeStateAtTail(AbstractValue& destination, AbstractValue& inVariable, Node*); |
| |
| static bool mergeVariableBetweenBlocks(AbstractValue& destination, AbstractValue& source, Node* destinationNode, Node* sourceNode); |
| |
| Graph& m_graph; |
| |
| FlowMap<AbstractValue>& m_abstractValues; |
| Operands<AbstractValue> m_variables; |
| BasicBlock* m_block; |
| |
| bool m_foundConstants; |
| |
| bool m_isValid; |
| bool m_didClobber; |
| StructureClobberState m_structureClobberState; |
| |
| BranchDirection m_branchDirection; // This is only set for blocks that end in Branch and that execute to completion (i.e. m_isValid == true). |
| }; |
| |
| } } // namespace JSC::DFG |
| |
| #endif // ENABLE(DFG_JIT) |