| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * Licensed 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. |
| */ |
| |
| #ifndef ART_COMPILER_OPTIMIZING_NODES_H_ |
| #define ART_COMPILER_OPTIMIZING_NODES_H_ |
| |
| #include "utils/allocation.h" |
| #include "utils/growable_array.h" |
| #include "dex/arena_bit_vector.h" |
| |
| namespace art { |
| |
| class HBasicBlock; |
| class HInstruction; |
| class HGraphVisitor; |
| |
| static const int kDefaultNumberOfBlocks = 8; |
| static const int kDefaultNumberOfSuccessors = 2; |
| static const int kDefaultNumberOfPredecessors = 2; |
| static const int kDefaultNumberOfBackEdges = 1; |
| |
| // Control-flow graph of a method. Contains a list of basic blocks. |
| class HGraph : public ArenaObject { |
| public: |
| explicit HGraph(ArenaAllocator* arena) |
| : arena_(arena), |
| blocks_(arena, kDefaultNumberOfBlocks), |
| dominator_order_(arena, kDefaultNumberOfBlocks) { } |
| |
| ArenaAllocator* arena() const { return arena_; } |
| const GrowableArray<HBasicBlock*>* blocks() const { return &blocks_; } |
| |
| void AddBlock(HBasicBlock* block); |
| void BuildDominatorTree(); |
| |
| private: |
| HBasicBlock* FindCommonDominator(HBasicBlock* first, HBasicBlock* second) const; |
| void VisitBlockForDominatorTree(HBasicBlock* block, |
| HBasicBlock* predecessor, |
| GrowableArray<size_t>* visits); |
| void FindBackEdges(ArenaBitVector* visited) const; |
| void VisitBlockForBackEdges(HBasicBlock* block, |
| ArenaBitVector* visited, |
| ArenaBitVector* visiting) const; |
| void RemoveDeadBlocks(const ArenaBitVector& visited) const; |
| |
| HBasicBlock* GetEntryBlock() const { return blocks_.Get(0); } |
| |
| ArenaAllocator* const arena_; |
| |
| // List of blocks in insertion order. |
| GrowableArray<HBasicBlock*> blocks_; |
| |
| // List of blocks to perform a pre-order dominator tree traversal. |
| GrowableArray<HBasicBlock*> dominator_order_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HGraph); |
| }; |
| |
| class HLoopInformation : public ArenaObject { |
| public: |
| HLoopInformation(HBasicBlock* header, HGraph* graph) |
| : header_(header), |
| back_edges_(graph->arena(), kDefaultNumberOfBackEdges) { } |
| |
| void AddBackEdge(HBasicBlock* back_edge) { |
| back_edges_.Add(back_edge); |
| } |
| |
| int NumberOfBackEdges() const { |
| return back_edges_.Size(); |
| } |
| |
| private: |
| HBasicBlock* header_; |
| GrowableArray<HBasicBlock*> back_edges_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HLoopInformation); |
| }; |
| |
| // A block in a method. Contains the list of instructions represented |
| // as a double linked list. Each block knows its predecessors and |
| // successors. |
| class HBasicBlock : public ArenaObject { |
| public: |
| explicit HBasicBlock(HGraph* graph) |
| : graph_(graph), |
| predecessors_(graph->arena(), kDefaultNumberOfPredecessors), |
| successors_(graph->arena(), kDefaultNumberOfSuccessors), |
| first_instruction_(nullptr), |
| last_instruction_(nullptr), |
| loop_information_(nullptr), |
| dominator_(nullptr), |
| block_id_(-1) { } |
| |
| const GrowableArray<HBasicBlock*>* predecessors() const { |
| return &predecessors_; |
| } |
| |
| const GrowableArray<HBasicBlock*>* successors() const { |
| return &successors_; |
| } |
| |
| void AddBackEdge(HBasicBlock* back_edge) { |
| if (loop_information_ == nullptr) { |
| loop_information_ = new (graph_->arena()) HLoopInformation(this, graph_); |
| } |
| loop_information_->AddBackEdge(back_edge); |
| } |
| |
| HGraph* graph() const { return graph_; } |
| |
| int block_id() const { return block_id_; } |
| void set_block_id(int id) { block_id_ = id; } |
| |
| HBasicBlock* dominator() const { return dominator_; } |
| void set_dominator(HBasicBlock* dominator) { dominator_ = dominator; } |
| |
| int NumberOfBackEdges() const { |
| return loop_information_ == nullptr |
| ? 0 |
| : loop_information_->NumberOfBackEdges(); |
| } |
| |
| HInstruction* first_instruction() const { return first_instruction_; } |
| HInstruction* last_instruction() const { return last_instruction_; } |
| |
| void AddSuccessor(HBasicBlock* block) { |
| successors_.Add(block); |
| block->predecessors_.Add(this); |
| } |
| |
| void RemovePredecessor(HBasicBlock* block) { |
| predecessors_.Delete(block); |
| } |
| |
| void AddInstruction(HInstruction* instruction); |
| |
| private: |
| HGraph* const graph_; |
| GrowableArray<HBasicBlock*> predecessors_; |
| GrowableArray<HBasicBlock*> successors_; |
| HInstruction* first_instruction_; |
| HInstruction* last_instruction_; |
| HLoopInformation* loop_information_; |
| HBasicBlock* dominator_; |
| int block_id_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HBasicBlock); |
| }; |
| |
| #define FOR_EACH_INSTRUCTION(M) \ |
| M(Exit) \ |
| M(Goto) \ |
| M(If) \ |
| M(ReturnVoid) \ |
| |
| #define DECLARE_INSTRUCTION(type) \ |
| virtual void Accept(HGraphVisitor* visitor); \ |
| virtual const char* DebugName() const { return #type; } \ |
| |
| class HInstruction : public ArenaObject { |
| public: |
| HInstruction() : previous_(nullptr), next_(nullptr) { } |
| virtual ~HInstruction() { } |
| |
| HInstruction* next() const { return next_; } |
| HInstruction* previous() const { return previous_; } |
| |
| virtual intptr_t InputCount() const = 0; |
| virtual HInstruction* InputAt(intptr_t i) const = 0; |
| |
| virtual void Accept(HGraphVisitor* visitor) = 0; |
| virtual const char* DebugName() const = 0; |
| |
| private: |
| HInstruction* previous_; |
| HInstruction* next_; |
| |
| friend class HBasicBlock; |
| |
| DISALLOW_COPY_AND_ASSIGN(HInstruction); |
| }; |
| |
| class HInstructionIterator : public ValueObject { |
| public: |
| explicit HInstructionIterator(HBasicBlock* block) |
| : instruction_(block->first_instruction()) { |
| next_ = Done() ? nullptr : instruction_->next(); |
| } |
| |
| inline bool Done() const { return instruction_ == nullptr; } |
| inline HInstruction* Current() { return instruction_; } |
| inline void Advance() { |
| instruction_ = next_; |
| next_ = Done() ? nullptr : instruction_->next(); |
| } |
| |
| private: |
| HInstruction* instruction_; |
| HInstruction* next_; |
| }; |
| |
| // An embedded container with N elements of type T. Used (with partial |
| // specialization for N=0) because embedded arrays cannot have size 0. |
| template<typename T, intptr_t N> |
| class EmbeddedArray { |
| public: |
| EmbeddedArray() : elements_() { } |
| |
| intptr_t length() const { return N; } |
| |
| const T& operator[](intptr_t i) const { |
| ASSERT(i < length()); |
| return elements_[i]; |
| } |
| |
| T& operator[](intptr_t i) { |
| ASSERT(i < length()); |
| return elements_[i]; |
| } |
| |
| const T& At(intptr_t i) const { |
| return (*this)[i]; |
| } |
| |
| void SetAt(intptr_t i, const T& val) { |
| (*this)[i] = val; |
| } |
| |
| private: |
| T elements_[N]; |
| }; |
| |
| template<typename T> |
| class EmbeddedArray<T, 0> { |
| public: |
| intptr_t length() const { return 0; } |
| const T& operator[](intptr_t i) const { |
| LOG(FATAL) << "Unreachable"; |
| static T sentinel = 0; |
| return sentinel; |
| } |
| T& operator[](intptr_t i) { |
| LOG(FATAL) << "Unreachable"; |
| static T sentinel = 0; |
| return sentinel; |
| } |
| }; |
| |
| template<intptr_t N> |
| class HTemplateInstruction: public HInstruction { |
| public: |
| HTemplateInstruction<N>() : inputs_() { } |
| virtual ~HTemplateInstruction() { } |
| |
| virtual intptr_t InputCount() const { return N; } |
| virtual HInstruction* InputAt(intptr_t i) const { return inputs_[i]; } |
| |
| private: |
| EmbeddedArray<HInstruction*, N> inputs_; |
| }; |
| |
| // Represents dex's RETURN_VOID opcode. A HReturnVoid is a control flow |
| // instruction that branches to the exit block. |
| class HReturnVoid : public HTemplateInstruction<0> { |
| public: |
| HReturnVoid() { } |
| |
| DECLARE_INSTRUCTION(ReturnVoid) |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(HReturnVoid); |
| }; |
| |
| // The exit instruction is the only instruction of the exit block. |
| // Instructions aborting the method (HTrow and HReturn) must branch to the |
| // exit block. |
| class HExit : public HTemplateInstruction<0> { |
| public: |
| HExit() { } |
| |
| DECLARE_INSTRUCTION(Exit) |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(HExit); |
| }; |
| |
| // Jumps from one block to another. |
| class HGoto : public HTemplateInstruction<0> { |
| public: |
| HGoto() { } |
| |
| DECLARE_INSTRUCTION(Goto) |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(HGoto); |
| }; |
| |
| // Conditional branch. A block ending with an HIf instruction must have |
| // two successors. |
| // TODO: Make it take an input. |
| class HIf : public HTemplateInstruction<0> { |
| public: |
| HIf() { } |
| |
| DECLARE_INSTRUCTION(If) |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(HIf); |
| }; |
| |
| class HGraphVisitor : public ValueObject { |
| public: |
| explicit HGraphVisitor(HGraph* graph) : graph_(graph) { } |
| virtual ~HGraphVisitor() { } |
| |
| virtual void VisitInstruction(HInstruction* instruction) { } |
| virtual void VisitBasicBlock(HBasicBlock* block); |
| |
| void VisitInsertionOrder(); |
| |
| // Visit functions for instruction classes. |
| #define DECLARE_VISIT_INSTRUCTION(name) \ |
| virtual void Visit##name(H##name* instr) { VisitInstruction(instr); } |
| |
| FOR_EACH_INSTRUCTION(DECLARE_VISIT_INSTRUCTION) |
| |
| #undef DECLARE_VISIT_INSTRUCTION |
| |
| private: |
| HGraph* graph_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HGraphVisitor); |
| }; |
| |
| } // namespace art |
| |
| #endif // ART_COMPILER_OPTIMIZING_NODES_H_ |