OpenSTA/include/sta/Wireload.hh

// OpenSTA, Static Timing Analyzer
// Copyright (c) 2026, Parallax Software, Inc.
// 
// This program 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.
// 
// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
// 
// The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software.
// 
// Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 
// This notice may not be removed or altered from any source distribution.

#pragma once

#include <string>
#include <string_view>
#include <utility>
#include <vector>

#include "LibertyClass.hh"

namespace sta {

class WireloadForArea;

using FanoutLength = std::pair<float,float>;
using FanoutLengthSeq = std::vector<FanoutLength*>;
using WireloadForAreaSeq = std::vector<WireloadForArea*>;

const char *
wireloadTreeString(WireloadTree tree);
WireloadTree
stringWireloadTree(std::string_view wire_load_type);

const char *
wireloadModeString(WireloadMode wire_load_mode);
WireloadMode
stringWireloadMode(std::string_view wire_load_mode);

class Wireload
{
public:
  Wireload(std::string name,
           LibertyLibrary *library);
  Wireload(std::string name,
           LibertyLibrary *library,
           float area,
           float resistance,
           float capacitance,
           float slope);
  virtual ~Wireload();
  const std::string &name() const { return name_; }
  void setArea(float area);
  void setResistance(float res);
  void setCapacitance(float cap);
  void setSlope(float slope);
  void addFanoutLength(float fanout,
                       float length);
  // Find wireload resistance/capacitance for fanout.
  virtual void findWireload(float fanout,
                            const OperatingConditions *op_cond,
                            float &cap,
                            float &res) const;

protected:
  std::string name_;
  LibertyLibrary *library_;
  float area_;
  float resistance_;
  float capacitance_;
  // Fanout length extrapolation slope.
  float slope_;
  FanoutLengthSeq fanout_lengths_;
};

class WireloadSelection
{
public:
  WireloadSelection(std::string name);
  ~WireloadSelection();
  const std::string &name() const { return name_; }
  void addWireloadFromArea(float min_area,
                           float max_area,
                           const Wireload *wireload);
  const Wireload *findWireload(float area) const;

private:
  const std::string name_;
  WireloadForAreaSeq wireloads_;
};

} // namespace sta