// 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 <cstdint>
#include <cstddef>

namespace sta {

const size_t hash_init_value = 5381;

// Dan Bernstein, comp.lang.c.
inline size_t
hashSum(size_t hash,
        size_t add)
{
  // hash * 31 ^ add.
  return ((hash << 5) + hash) ^ add;
}

inline void
hashIncr(size_t &hash,
         size_t add)
{
  // hash * 31 ^ add.
  hash = ((hash << 5) + hash) ^ add;
}

inline size_t
nextMersenne(size_t n)
{
  return (n + 1) * 2 - 1;
}

// Sadly necessary until c++ std::hash works for char *.
size_t
hashString(const char *str);

// Pointer hashing is strongly discouraged because it causes results to change
// from run to run. Use Network::id functions instead.
#if __WORDSIZE == 64
  #define hashPtr(ptr) (reinterpret_cast<intptr_t>(ptr) >> 3)
#else
  #define hashPtr(ptr) (reinterpret_cast<intptr_t>(ptr) >> 2)
#endif

} // namespace
