Subversion Repositories Games.Chess Giants

/*

 * tbprobe.h

 * (C) 2015 basil, all rights reserved,

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the "Software"),

 * to deal in the Software without restriction, including without limitation

 * the rights to use, copy, modify, merge, publish, distribute, sublicense,

 * and/or sell copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

 */

#ifndef TBPROBE_H

#  define TBPROBE_H

#  include "tbconfig.h"

#  ifdef __cplusplus

extern "C" {

#  endif

#  ifndef TB_NO_STDINT

#    include <stdint.h>

#  else

  typedef unsigned char uint8_t;

  typedef unsigned short uint16_t;

  typedef unsigned uint32_t;

  typedef long long unsigned uint64_t;

  typedef char int8_t;

  typedef short int16_t;

  typedef int int32_t;

  typedef long long int64_t;

#  endif

#  ifndef TB_NO_STDBOOL

#    include <stdbool.h>

#  else

#    ifndef __cplusplus

  typedef uint8_t bool;

#      define true    1

#      define false   0

#    endif

#  endif

/*

 * Internal definitions.  Do not call these functions directly.

 */

  extern bool tb_init_impl(const char *_path);

  extern unsigned tb_probe_wdl_impl(uint64_t _white, uint64_t _black,

      uint64_t _kings, uint64_t _queens, uint64_t _rooks, uint64_t _bishops,

      uint64_t _knights, uint64_t _pawns, unsigned _ep, bool _turn,

      uint64_t _hash);

  extern unsigned tb_probe_root_impl(uint64_t _white, uint64_t _black,

      uint64_t _kings, uint64_t _queens, uint64_t _rooks, uint64_t _bishops,

      uint64_t _knights, uint64_t _pawns, unsigned _rule50, unsigned _ep,

      bool _turn, unsigned *_results);

/****************************************************************************/

/* MAIN API                                                                 */

/****************************************************************************/

#  define TB_MAX_MOVES                (192+1)

#  define TB_CASTLING_K               0x1

 /* White king-side. */

#  define TB_CASTLING_Q               0x2

 /* White queen-side. */

#  define TB_CASTLING_k               0x4

 /* Black king-side. */

#  define TB_CASTLING_q               0x8

 /* Black queen-side. */

#  define TB_LOSS                     0

 /* LOSS */

#  define TB_BLESSED_LOSS             1

 /* LOSS but 50-move draw */

#  define TB_DRAW                     2

 /* DRAW */

#  define TB_CURSED_WIN               3

 /* WIN but 50-move draw  */

#  define TB_WIN                      4

 /* WIN  */

#  define TB_PROMOTES_NONE            0

#  define TB_PROMOTES_QUEEN           1

#  define TB_PROMOTES_ROOK            2

#  define TB_PROMOTES_BISHOP          3

#  define TB_PROMOTES_KNIGHT          4

#  define TB_RESULT_WDL_MASK          0x0000000F

#  define TB_RESULT_TO_MASK           0x000003F0

#  define TB_RESULT_FROM_MASK         0x0000FC00

#  define TB_RESULT_PROMOTES_MASK     0x00070000

#  define TB_RESULT_EP_MASK           0x00080000

#  define TB_RESULT_DTZ_MASK          0xFFF00000

#  define TB_RESULT_WDL_SHIFT         0

#  define TB_RESULT_TO_SHIFT          4

#  define TB_RESULT_FROM_SHIFT        10

#  define TB_RESULT_PROMOTES_SHIFT    16

#  define TB_RESULT_EP_SHIFT          19

#  define TB_RESULT_DTZ_SHIFT         20

#  define TB_GET_WDL(_res)                        \

    (((_res) & TB_RESULT_WDL_MASK) >> TB_RESULT_WDL_SHIFT)

#  define TB_GET_TO(_res)                         \

    (((_res) & TB_RESULT_TO_MASK) >> TB_RESULT_TO_SHIFT)

#  define TB_GET_FROM(_res)                       \

    (((_res) & TB_RESULT_FROM_MASK) >> TB_RESULT_FROM_SHIFT)

#  define TB_GET_PROMOTES(_res)                   \

    (((_res) & TB_RESULT_PROMOTES_MASK) >> TB_RESULT_PROMOTES_SHIFT)

#  define TB_GET_EP(_res)                         \

    (((_res) & TB_RESULT_EP_MASK) >> TB_RESULT_EP_SHIFT)

#  define TB_GET_DTZ(_res)                        \

    (((_res) & TB_RESULT_DTZ_MASK) >> TB_RESULT_DTZ_SHIFT)

#  define TB_SET_WDL(_res, _wdl)                  \

    (((_res) & ~TB_RESULT_WDL_MASK) |           \

     (((_wdl) << TB_RESULT_WDL_SHIFT) & TB_RESULT_WDL_MASK))

#  define TB_SET_TO(_res, _to)                    \

    (((_res) & ~TB_RESULT_TO_MASK) |            \

     (((_to) << TB_RESULT_TO_SHIFT) & TB_RESULT_TO_MASK))

#  define TB_SET_FROM(_res, _from)                \

    (((_res) & ~TB_RESULT_FROM_MASK) |          \

     (((_from) << TB_RESULT_FROM_SHIFT) & TB_RESULT_FROM_MASK))

#  define TB_SET_PROMOTES(_res, _promotes)        \

    (((_res) & ~TB_RESULT_PROMOTES_MASK) |      \

     (((_promotes) << TB_RESULT_PROMOTES_SHIFT) & TB_RESULT_PROMOTES_MASK))

#  define TB_SET_EP(_res, _ep)                    \

    (((_res) & ~TB_RESULT_EP_MASK) |            \

     (((_ep) << TB_RESULT_EP_SHIFT) & TB_RESULT_EP_MASK))

#  define TB_SET_DTZ(_res, _dtz)                  \

    (((_res) & ~TB_RESULT_DTZ_MASK) |           \

     (((_dtz) << TB_RESULT_DTZ_SHIFT) & TB_RESULT_DTZ_MASK))

#  define TB_RESULT_CHECKMATE         TB_SET_WDL(0, TB_WIN)

#  define TB_RESULT_STALEMATE         TB_SET_WDL(0, TB_DRAW)

#  define TB_RESULT_FAILED            0xFFFFFFFF

/*

 * The tablebase can be probed for any position where #pieces <= TB_LARGEST.

 */

  extern unsigned TB_LARGEST;

/*

 * Initialize the tablebase.

 *

 * PARAMETERS:

 * - path:

 *   The tablebase PATH string.

 *

 * RETURN:

 * - true=succes, false=failed.  The TB_LARGEST global will also be

 *   initialized.  If no tablebase files are found, then `true' is returned

 *   and TB_LARGEST is set to zero.

 */

  static inline bool tb_init(const char *_path) {

    return tb_init_impl(_path);

  }

/*

 * Probe the Win-Draw-Loss (WDL) table.

 *

 * PARAMETERS:

 * - white, black, kings, queens, rooks, bishops, knights, pawns:

 *   The current position (bitboards).

 * - rule50:

 *   The 50-move half-move clock.

 * - castling:

 *   Castling rights.  Set to zero if no castling is possible.

 * - ep:

 *   The en passant square (if exists).  Set to zero if there is no en passant

 *   square.

 * - turn:

 *   true=white, false=black

 *

 * RETURN:

 * - One of {TB_LOSS, TB_BLESSED_LOSS, TB_DRAW, TB_CURSED_WIN, TB_WIN}.

 *   Otherwise returns TB_RESULT_FAILED if the probe failed.

 *

 * NOTES:

 * - Engines should use this function during search.

 * - This function is thread safe assuming TB_NO_THREADS is disabled.

 */ static inline unsigned tb_probe_wdl(

      uint64_t _white, uint64_t _black, uint64_t _kings, uint64_t _queens,

      uint64_t _rooks, uint64_t _bishops, uint64_t _knights, uint64_t _pawns,

      unsigned _rule50, unsigned _castling, unsigned _ep, bool _turn,

      uint64_t _hash) {

    if (_castling != 0)

      return TB_RESULT_FAILED;

    if (_rule50 != 0)

      return TB_RESULT_FAILED;

    return tb_probe_wdl_impl(_white, _black, _kings, _queens, _rooks,

        _bishops, _knights, _pawns, _ep, _turn, _hash);

  }

/*

 * Probe the Distance-To-Zero (DTZ) table.

 *

 * PARAMETERS:

 * - white, black, kings, queens, rooks, bishops, knights, pawns:

 *   The current position (bitboards).

 * - rule50:

 *   The 50-move half-move clock.

 * - castling:

 *   Castling rights.  Set to zero if no castling is possible.

 * - ep:

 *   The en passant square (if exists).  Set to zero if there is no en passant

 *   square.

 * - turn:

 *   true=white, false=black

 * - results (OPTIONAL):

 *   Alternative results, one for each possible legal move.  The passed array

 *   must be TB_MAX_MOVES in size.

 *   If alternative results are not desired then set results=NULL.

 *

 * RETURN:

 * - A TB_RESULT value comprising:

 *   1) The WDL value (TB_GET_WDL)

 *   2) The suggested move (TB_GET_FROM, TB_GET_TO, TB_GET_PROMOTES, TB_GET_EP)

 *   3) The DTZ value (TB_GET_DTZ)

 *   The suggested move is guaranteed to preserved the WDL value.

 *

 *   Otherwise:

 *   1) TB_RESULT_STALEMATE is returned if the position is in stalemate.

 *   2) TB_RESULT_CHECKMATE is returned if the position is in checkmate.

 *   3) TB_RESULT_FAILED is returned if the probe failed.

 *

 *   If results!=NULL, then a TB_RESULT for each legal move will be generated

 *   and stored in the results array.  The results array will be terminated

 *   by TB_RESULT_FAILED.

 *

 * NOTES:

 * - Engines can use this function to probe at the root.  This function should

 *   not be used during search.

 * - DTZ tablebases can suggest unnatural moves, especially for losing

 *   positions.  Engines may prefer to traditional search combined with WDL

 *   move filtering using the alternative results array.

 * - This function is NOT thread safe.  For engines this function should only

 *   be called once at the root per search.

 */

  static inline unsigned tb_probe_root(uint64_t _white, uint64_t _black,

      uint64_t _kings, uint64_t _queens, uint64_t _rooks, uint64_t _bishops,

      uint64_t _knights, uint64_t _pawns, unsigned _rule50,

      unsigned _castling, unsigned _ep, bool _turn, unsigned *_results) {

    if (_castling != 0)

      return TB_RESULT_FAILED;

    return tb_probe_root_impl(_white, _black, _kings, _queens, _rooks,

        _bishops, _knights, _pawns, _rule50, _ep, _turn, _results);

  }

/****************************************************************************/

/* HELPER API                                                               */

/****************************************************************************/

/*

 * The HELPER API provides some useful additional functions.  It is optional

 * and can be disabled by defining TB_NO_HELPER_API.  Engines should disable

 * the HELPER API.

 */

#  ifndef TB_NO_HELPER_API

  extern unsigned tb_pop_count(uint64_t _bb);

  extern unsigned tb_lsb(uint64_t _bb);

  extern uint64_t tb_pop_lsb(uint64_t _bb);

  extern uint64_t tb_king_attacks(unsigned _square);

  extern uint64_t tb_queen_attacks(unsigned _square, uint64_t _occ);

  extern uint64_t tb_rook_attacks(unsigned _square, uint64_t _occ);

  extern uint64_t tb_bishop_attacks(unsigned _square, uint64_t _occ);

  extern uint64_t tb_knight_attacks(unsigned _square);

  extern uint64_t tb_pawn_attacks(unsigned _square, bool _color);

#  endif

#  ifdef __cplusplus

}

#  endif

#endif