/*
 * Copyright (C) 2025 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_INSTRUCTION_LIST_H_
#define ART_COMPILER_OPTIMIZING_INSTRUCTION_LIST_H_

#include "base/value_object.h"
#include "base/macros.h"

namespace art HIDDEN {

class HBasicBlock;
class HInstruction;

class HInstructionList final : public ValueObject {
 public:
  HInstructionList() : first_instruction_(nullptr), last_instruction_(nullptr) {}

  void AddInstruction(HInstruction* instruction);
  void RemoveInstruction(HInstruction* instruction);

  // Insert `instruction` before/after an existing instruction `cursor`.
  void InsertInstructionBefore(HInstruction* instruction, HInstruction* cursor);
  void InsertInstructionAfter(HInstruction* instruction, HInstruction* cursor);

  // Return true if this list contains `instruction`.
  bool Contains(HInstruction* instruction) const;

  // Return true if `instruction1` is found before `instruction2` in this instruction
  // list and false otherwise.  Abort if none of these instructions is found.
  bool FoundBefore(const HInstruction* instruction1,
                   const HInstruction* instruction2) const;

  bool IsEmpty() const { return first_instruction_ == nullptr; }
  void Clear() { first_instruction_ = last_instruction_ = nullptr; }

  // Update the block of all instructions to be `block`.
  void SetBlockOfInstructions(HBasicBlock* block) const;

  void AddAfter(HInstruction* cursor, const HInstructionList& instruction_list);
  void AddBefore(HInstruction* cursor, const HInstructionList& instruction_list);
  void Add(const HInstructionList& instruction_list);

  // Return the number of instructions in the list. This is an expensive operation.
  size_t CountSize() const;

 private:
  HInstruction* first_instruction_;
  HInstruction* last_instruction_;

  friend class HBasicBlock;
  friend class HGraph;
  friend class HInstruction;
  friend class HInstructionIteratorPrefetchNext;
  friend class HInstructionIterator;
  friend class HBackwardInstructionIteratorPrefetchNext;

  DISALLOW_COPY_AND_ASSIGN(HInstructionList);
};

}  // namespace art

#endif  // ART_COMPILER_OPTIMIZING_INSTRUCTION_LIST_H_