/*
 * 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_BUILDER_H_
#define ART_COMPILER_OPTIMIZING_BUILDER_H_

#include "dex_file.h"
#include "dex_file-inl.h"
#include "driver/compiler_driver.h"
#include "driver/dex_compilation_unit.h"
#include "primitive.h"
#include "utils/arena_object.h"
#include "utils/growable_array.h"
#include "nodes.h"

namespace art {

class Instruction;

class HGraphBuilder : public ValueObject {
 public:
  HGraphBuilder(ArenaAllocator* arena,
                DexCompilationUnit* dex_compilation_unit,
                const DexFile* dex_file,
                CompilerDriver* driver)
      : arena_(arena),
        branch_targets_(arena, 0),
        locals_(arena, 0),
        entry_block_(nullptr),
        exit_block_(nullptr),
        current_block_(nullptr),
        graph_(nullptr),
        constant0_(nullptr),
        constant1_(nullptr),
        dex_file_(dex_file),
        dex_compilation_unit_(dex_compilation_unit),
        compiler_driver_(driver),
        return_type_(Primitive::GetType(dex_compilation_unit_->GetShorty()[0])),
        code_start_(nullptr),
        latest_result_(nullptr) {}

  // Only for unit testing.
  HGraphBuilder(ArenaAllocator* arena, Primitive::Type return_type = Primitive::kPrimInt)
      : arena_(arena),
        branch_targets_(arena, 0),
        locals_(arena, 0),
        entry_block_(nullptr),
        exit_block_(nullptr),
        current_block_(nullptr),
        graph_(nullptr),
        constant0_(nullptr),
        constant1_(nullptr),
        dex_file_(nullptr),
        dex_compilation_unit_(nullptr),
        compiler_driver_(nullptr),
        return_type_(return_type),
        code_start_(nullptr),
        latest_result_(nullptr) {}

  HGraph* BuildGraph(const DexFile::CodeItem& code);

 private:
  // Analyzes the dex instruction and adds HInstruction to the graph
  // to execute that instruction. Returns whether the instruction can
  // be handled.
  bool AnalyzeDexInstruction(const Instruction& instruction, uint32_t dex_offset);

  // Finds all instructions that start a new block, and populates branch_targets_ with
  // the newly created blocks.
  void ComputeBranchTargets(const uint16_t* start, const uint16_t* end);
  void MaybeUpdateCurrentBlock(size_t index);
  HBasicBlock* FindBlockStartingAt(int32_t index) const;

  HIntConstant* GetIntConstant0();
  HIntConstant* GetIntConstant1();
  HIntConstant* GetIntConstant(int32_t constant);
  HLongConstant* GetLongConstant(int64_t constant);
  void InitializeLocals(uint16_t count);
  HLocal* GetLocalAt(int register_index) const;
  void UpdateLocal(int register_index, HInstruction* instruction) const;
  HInstruction* LoadLocal(int register_index, Primitive::Type type) const;
  void PotentiallyAddSuspendCheck(int32_t target_offset, uint32_t dex_offset);

  // Temporarily returns whether the compiler supports the parameters
  // of the method.
  bool InitializeParameters(uint16_t number_of_parameters);

  template<typename T>
  void Unop_12x(const Instruction& instruction, Primitive::Type type);

  template<typename T>
  void Binop_23x(const Instruction& instruction, Primitive::Type type);

  template<typename T>
  void Binop_12x(const Instruction& instruction, Primitive::Type type);

  template<typename T>
  void Binop_22b(const Instruction& instruction, bool reverse);

  template<typename T>
  void Binop_22s(const Instruction& instruction, bool reverse);

  template<typename T> void If_21t(const Instruction& instruction, uint32_t dex_offset);
  template<typename T> void If_22t(const Instruction& instruction, uint32_t dex_offset);

  void BuildReturn(const Instruction& instruction, Primitive::Type type);

  bool BuildFieldAccess(const Instruction& instruction, uint32_t dex_offset, bool is_get);
  void BuildArrayAccess(const Instruction& instruction,
                        uint32_t dex_offset,
                        bool is_get,
                        Primitive::Type anticipated_type);

  // Builds an invocation node and returns whether the instruction is supported.
  bool BuildInvoke(const Instruction& instruction,
                   uint32_t dex_offset,
                   uint32_t method_idx,
                   uint32_t number_of_vreg_arguments,
                   bool is_range,
                   uint32_t* args,
                   uint32_t register_index);

  // Builds a new array node and the instructions that fill it.
  void BuildFilledNewArray(uint32_t dex_offset,
                           uint32_t type_index,
                           uint32_t number_of_vreg_arguments,
                           bool is_range,
                           uint32_t* args,
                           uint32_t register_index);

  // Fills the given object with data as specified in the fill-array-data
  // instruction. Currently only used for non-reference and non-floating point
  // arrays.
  template <typename T>
  void BuildFillArrayData(HInstruction* object,
                          const T* data,
                          uint32_t element_count,
                          Primitive::Type anticipated_type,
                          uint32_t dex_offset);

  // Fills the given object with data as specified in the fill-array-data
  // instruction. The data must be for long and double arrays.
  void BuildFillWideArrayData(HInstruction* object,
                              const int64_t* data,
                              uint32_t element_count,
                              uint32_t dex_offset);

  ArenaAllocator* const arena_;

  // A list of the size of the dex code holding block information for
  // the method. If an entry contains a block, then the dex instruction
  // starting at that entry is the first instruction of a new block.
  GrowableArray<HBasicBlock*> branch_targets_;

  GrowableArray<HLocal*> locals_;

  HBasicBlock* entry_block_;
  HBasicBlock* exit_block_;
  HBasicBlock* current_block_;
  HGraph* graph_;

  HIntConstant* constant0_;
  HIntConstant* constant1_;

  const DexFile* const dex_file_;
  DexCompilationUnit* const dex_compilation_unit_;
  CompilerDriver* const compiler_driver_;
  const Primitive::Type return_type_;

  // The pointer in the dex file where the instructions of the code item
  // being currently compiled start.
  const uint16_t* code_start_;

  // The last invoke or fill-new-array being built. Only to be
  // used by move-result instructions.
  HInstruction* latest_result_;

  DISALLOW_COPY_AND_ASSIGN(HGraphBuilder);
};

}  // namespace art

#endif  // ART_COMPILER_OPTIMIZING_BUILDER_H_