/*

  This file is part of solidity.

  solidity is free software: you can redistribute it and/or modify

  it under the terms of the GNU General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  solidity is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License

  along with solidity.  If not, see <http://www.gnu.org/licenses/>.

*/

// SPDX-License-Identifier: GPL-3.0

#pragma once

#include <libyul/backends/evm/AbstractAssembly.h>

#include <libyul/backends/evm/ssa/SSACFGTypes.h>

#include <libyul/backends/evm/ssa/spill/MemoryAddressing.h>

#include <libevmasm/Instruction.h>

namespace solidity::yul::ssa::spill

{

/// Emits the two memory accesses that move a spilled variable between the stack and its reserved memory slot.

class Emitter

{

public:

  Emitter(

    MemoryAddressing const& _addressing,

    FunctionGraphID const _cfgIdx,

    AbstractAssembly& _assembly

  ):

    m_addressing(&_addressing),

    m_cfgIdx(_cfgIdx),

    m_assembly(&_assembly)

  {

  }

  [[nodiscard]] bool hasAddress(SpillKey const _key) const

  {

    return m_addressing->hasAddress(m_cfgIdx, _key);

  }

  /// Materializes the spilled variable `_key` on the stack top: `PUSH addr; MLOAD`. Dual of emitStore.

  void emitLoad(SpillKey const _key) const

  {

    m_assembly->appendConstant(m_addressing->addressOf(m_cfgIdx, _key));

    m_assembly->appendInstruction(evmasm::Instruction::MLOAD);

  }

  /// Writes the stack-top value into the spill slot of `_key`, consuming it: `PUSH addr; MSTORE`.

  /// Dual of emitLoad. The value must already be on the stack top.

  void emitStore(SpillKey const _key) const

  {

    m_assembly->appendConstant(m_addressing->addressOf(m_cfgIdx, _key));

    m_assembly->appendInstruction(evmasm::Instruction::MSTORE);

  }

private:

  MemoryAddressing const* m_addressing;

  FunctionGraphID m_cfgIdx;

  AbstractAssembly* m_assembly;

};

}