directStatementEvaluator.hpp

/*
 * CoDiPack, a Code Differentiation Package
 *
 * Copyright (C) 2015-2025 Chair for Scientific Computing (SciComp), University of Kaiserslautern-Landau
 * Homepage: http://scicomp.rptu.de
 * Contact:  Prof. Nicolas R. Gauger (codi@scicomp.uni-kl.de)
 *
 * Lead developers: Max Sagebaum, Johannes Blühdorn (SciComp, University of Kaiserslautern-Landau)
 *
 * This file is part of CoDiPack (http://scicomp.rptu.de/software/codi).
 *
 * CoDiPack 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.
 *
 * CoDiPack 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 CoDiPack.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 * For other licensing options please contact us.
 *
 * Authors:
 *  - SciComp, University of Kaiserslautern-Landau:
 *    - Max Sagebaum
 *    - Johannes Blühdorn
 *    - Former members:
 *      - Tim Albring
 */
#pragma once
 
#include <algorithm>
#include <functional>
#include <type_traits>
 
#include "../../expressions/activeType.hpp"
#include "../../misc/macros.hpp"
#include "../misc/assignStatement.hpp"
#include "statementEvaluatorInterface.hpp"

namespace codi {

  struct PrimalTapeStatementFunctions {
    public:
 
      using Handle = void*;  
 
      std::array<Handle, (size_t)StatementCall::N_Elements> funcs;  

      template<typename... Args>
      PrimalTapeStatementFunctions(Args... args) : funcs{args...} {}
  };

  template<typename Generator, typename Stmt>
  struct DirectStatementEvaluatorStaticStore {
    public:

      static PrimalTapeStatementFunctions const staticStore;

      template<StatementCall... types>
      static PrimalTapeStatementFunctions gen() {
        using Handle = typename PrimalTapeStatementFunctions::Handle;
 
        return PrimalTapeStatementFunctions(
            reinterpret_cast<Handle>(Generator::template StatementCallGenerator<types, Stmt>::evaluate)...);
      }
  };
 
  template<typename Generator, typename Stmt>
  PrimalTapeStatementFunctions const DirectStatementEvaluatorStaticStore<Generator, Stmt>::staticStore =
      DirectStatementEvaluatorStaticStore<Generator, Stmt>::gen<CODI_STMT_CALL_GEN_ARGS>();

  struct DirectStatementEvaluator : public StatementEvaluatorInterface {
    public:
 
      /*******************************************************************************/
 
      using Handle = PrimalTapeStatementFunctions const*;  

      template<StatementCall type, typename Tape, typename... Args>
      static void call(Handle const& h, Args&&... args) {
        using Stmt = AssignStatement<ActiveType<Tape>, ActiveType<Tape>>;
        using CallGen = typename Tape::template StatementCallGenerator<type, Stmt>;
 
        using Function = decltype(&CallGen::evaluate);
 
        ((Function)h->funcs[(size_t)type])(std::forward<Args>(args)...);
      }

      template<typename Tape, typename Generator, typename Stmt>
      static Handle createHandle() {
        return &DirectStatementEvaluatorStaticStore<Generator, Stmt>::staticStore;
      }

  };
}