Cute Chess  0.1
tbprobe.h
1 /*
2  * tbprobe.h
3  * (C) 2015 basil, all rights reserved,
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21  * DEALINGS IN THE SOFTWARE.
22  */
23 
24 #ifndef TBPROBE_H
25 #define TBPROBE_H
26 
27 #include "tbconfig.h"
28 
29 #ifdef __cplusplus
30 extern "C"
31 {
32 #endif
33 
34 #ifndef TB_NO_STDINT
35 #include <stdint.h>
36 #else
37 typedef unsigned char uint8_t;
38 typedef unsigned short uint16_t;
39 typedef unsigned uint32_t;
40 typedef long long unsigned uint64_t;
41 typedef char int8_t;
42 typedef short int16_t;
43 typedef int int32_t;
44 typedef long long int64_t;
45 #endif
46 
47 #ifndef TB_NO_STDBOOL
48 #include <stdbool.h>
49 #else
50 #ifndef __cplusplus
51 typedef uint8_t bool;
52 #define true 1
53 #define false 0
54 #endif
55 #endif
56 
57 /*
58  * Internal definitions. Do not call these functions directly.
59  */
60 extern bool tb_init_impl(const char *_path);
61 extern unsigned tb_probe_wdl_impl(
62  uint64_t _white,
63  uint64_t _black,
64  uint64_t _kings,
65  uint64_t _queens,
66  uint64_t _rooks,
67  uint64_t _bishops,
68  uint64_t _knights,
69  uint64_t _pawns,
70  unsigned _ep,
71  bool _turn);
72 extern unsigned tb_probe_root_impl(
73  uint64_t _white,
74  uint64_t _black,
75  uint64_t _kings,
76  uint64_t _queens,
77  uint64_t _rooks,
78  uint64_t _bishops,
79  uint64_t _knights,
80  uint64_t _pawns,
81  unsigned _rule50,
82  unsigned _ep,
83  bool _turn,
84  unsigned *_results);
85 
86 /****************************************************************************/
87 /* MAIN API */
88 /****************************************************************************/
89 
90 #define TB_MAX_MOVES (192+1)
91 
92 #define TB_CASTLING_K 0x1 /* White king-side. */
93 #define TB_CASTLING_Q 0x2 /* White queen-side. */
94 #define TB_CASTLING_k 0x4 /* Black king-side. */
95 #define TB_CASTLING_q 0x8 /* Black queen-side. */
96 
97 #define TB_LOSS 0 /* LOSS */
98 #define TB_BLESSED_LOSS 1 /* LOSS but 50-move draw */
99 #define TB_DRAW 2 /* DRAW */
100 #define TB_CURSED_WIN 3 /* WIN but 50-move draw */
101 #define TB_WIN 4 /* WIN */
102 
103 #define TB_PROMOTES_NONE 0
104 #define TB_PROMOTES_QUEEN 1
105 #define TB_PROMOTES_ROOK 2
106 #define TB_PROMOTES_BISHOP 3
107 #define TB_PROMOTES_KNIGHT 4
108 
109 #define TB_RESULT_WDL_MASK 0x0000000F
110 #define TB_RESULT_TO_MASK 0x000003F0
111 #define TB_RESULT_FROM_MASK 0x0000FC00
112 #define TB_RESULT_PROMOTES_MASK 0x00070000
113 #define TB_RESULT_EP_MASK 0x00080000
114 #define TB_RESULT_DTZ_MASK 0xFFF00000
115 #define TB_RESULT_WDL_SHIFT 0
116 #define TB_RESULT_TO_SHIFT 4
117 #define TB_RESULT_FROM_SHIFT 10
118 #define TB_RESULT_PROMOTES_SHIFT 16
119 #define TB_RESULT_EP_SHIFT 19
120 #define TB_RESULT_DTZ_SHIFT 20
121 
122 #define TB_GET_WDL(_res) \
123  (((_res) & TB_RESULT_WDL_MASK) >> TB_RESULT_WDL_SHIFT)
124 #define TB_GET_TO(_res) \
125  (((_res) & TB_RESULT_TO_MASK) >> TB_RESULT_TO_SHIFT)
126 #define TB_GET_FROM(_res) \
127  (((_res) & TB_RESULT_FROM_MASK) >> TB_RESULT_FROM_SHIFT)
128 #define TB_GET_PROMOTES(_res) \
129  (((_res) & TB_RESULT_PROMOTES_MASK) >> TB_RESULT_PROMOTES_SHIFT)
130 #define TB_GET_EP(_res) \
131  (((_res) & TB_RESULT_EP_MASK) >> TB_RESULT_EP_SHIFT)
132 #define TB_GET_DTZ(_res) \
133  (((_res) & TB_RESULT_DTZ_MASK) >> TB_RESULT_DTZ_SHIFT)
134 
135 #define TB_SET_WDL(_res, _wdl) \
136  (((_res) & ~TB_RESULT_WDL_MASK) | \
137  (((_wdl) << TB_RESULT_WDL_SHIFT) & TB_RESULT_WDL_MASK))
138 #define TB_SET_TO(_res, _to) \
139  (((_res) & ~TB_RESULT_TO_MASK) | \
140  (((_to) << TB_RESULT_TO_SHIFT) & TB_RESULT_TO_MASK))
141 #define TB_SET_FROM(_res, _from) \
142  (((_res) & ~TB_RESULT_FROM_MASK) | \
143  (((_from) << TB_RESULT_FROM_SHIFT) & TB_RESULT_FROM_MASK))
144 #define TB_SET_PROMOTES(_res, _promotes) \
145  (((_res) & ~TB_RESULT_PROMOTES_MASK) | \
146  (((_promotes) << TB_RESULT_PROMOTES_SHIFT) & TB_RESULT_PROMOTES_MASK))
147 #define TB_SET_EP(_res, _ep) \
148  (((_res) & ~TB_RESULT_EP_MASK) | \
149  (((_ep) << TB_RESULT_EP_SHIFT) & TB_RESULT_EP_MASK))
150 #define TB_SET_DTZ(_res, _dtz) \
151  (((_res) & ~TB_RESULT_DTZ_MASK) | \
152  (((_dtz) << TB_RESULT_DTZ_SHIFT) & TB_RESULT_DTZ_MASK))
153 
154 #define TB_RESULT_CHECKMATE TB_SET_WDL(0, TB_WIN)
155 #define TB_RESULT_STALEMATE TB_SET_WDL(0, TB_DRAW)
156 #define TB_RESULT_FAILED 0xFFFFFFFF
157 
158 /*
159  * The tablebase can be probed for any position where #pieces <= TB_LARGEST.
160  */
161 extern unsigned TB_LARGEST;
162 
163 /*
164  * Initialize the tablebase.
165  *
166  * PARAMETERS:
167  * - path:
168  * The tablebase PATH string.
169  *
170  * RETURN:
171  * - true=succes, false=failed. The TB_LARGEST global will also be
172  * initialized. If no tablebase files are found, then `true' is returned
173  * and TB_LARGEST is set to zero.
174  */
175 static inline bool tb_init(const char *_path)
176 {
177  return tb_init_impl(_path);
178 }
179 
180 /*
181  * Probe the Win-Draw-Loss (WDL) table.
182  *
183  * PARAMETERS:
184  * - white, black, kings, queens, rooks, bishops, knights, pawns:
185  * The current position (bitboards).
186  * - rule50:
187  * The 50-move half-move clock.
188  * - castling:
189  * Castling rights. Set to zero if no castling is possible.
190  * - ep:
191  * The en passant square (if exists). Set to zero if there is no en passant
192  * square.
193  * - turn:
194  * true=white, false=black
195  *
196  * RETURN:
197  * - One of {TB_LOSS, TB_BLESSED_LOSS, TB_DRAW, TB_CURSED_WIN, TB_WIN}.
198  * Otherwise returns TB_RESULT_FAILED if the probe failed.
199  *
200  * NOTES:
201  * - Engines should use this function during search.
202  * - This function is thread safe assuming TB_NO_THREADS is disabled.
203  */
204 static inline unsigned tb_probe_wdl(
205  uint64_t _white,
206  uint64_t _black,
207  uint64_t _kings,
208  uint64_t _queens,
209  uint64_t _rooks,
210  uint64_t _bishops,
211  uint64_t _knights,
212  uint64_t _pawns,
213  unsigned _rule50,
214  unsigned _castling,
215  unsigned _ep,
216  bool _turn)
217 {
218  if (_castling != 0)
219  return TB_RESULT_FAILED;
220  if (_rule50 != 0)
221  return TB_RESULT_FAILED;
222  return tb_probe_wdl_impl(_white, _black, _kings, _queens, _rooks,
223  _bishops, _knights, _pawns, _ep, _turn);
224 }
225 
226 /*
227  * Probe the Distance-To-Zero (DTZ) table.
228  *
229  * PARAMETERS:
230  * - white, black, kings, queens, rooks, bishops, knights, pawns:
231  * The current position (bitboards).
232  * - rule50:
233  * The 50-move half-move clock.
234  * - castling:
235  * Castling rights. Set to zero if no castling is possible.
236  * - ep:
237  * The en passant square (if exists). Set to zero if there is no en passant
238  * square.
239  * - turn:
240  * true=white, false=black
241  * - results (OPTIONAL):
242  * Alternative results, one for each possible legal move. The passed array
243  * must be TB_MAX_MOVES in size.
244  * If alternative results are not desired then set results=NULL.
245  *
246  * RETURN:
247  * - A TB_RESULT value comprising:
248  * 1) The WDL value (TB_GET_WDL)
249  * 2) The suggested move (TB_GET_FROM, TB_GET_TO, TB_GET_PROMOTES, TB_GET_EP)
250  * 3) The DTZ value (TB_GET_DTZ)
251  * The suggested move is guaranteed to preserved the WDL value.
252  *
253  * Otherwise:
254  * 1) TB_RESULT_STALEMATE is returned if the position is in stalemate.
255  * 2) TB_RESULT_CHECKMATE is returned if the position is in checkmate.
256  * 3) TB_RESULT_FAILED is returned if the probe failed.
257  *
258  * If results!=NULL, then a TB_RESULT for each legal move will be generated
259  * and stored in the results array. The results array will be terminated
260  * by TB_RESULT_FAILED.
261  *
262  * NOTES:
263  * - Engines can use this function to probe at the root. This function should
264  * not be used during search.
265  * - DTZ tablebases can suggest unnatural moves, especially for losing
266  * positions. Engines may prefer to traditional search combined with WDL
267  * move filtering using the alternative results array.
268  * - This function is NOT thread safe. For engines this function should only
269  * be called once at the root per search.
270  */
271 static inline unsigned tb_probe_root(
272  uint64_t _white,
273  uint64_t _black,
274  uint64_t _kings,
275  uint64_t _queens,
276  uint64_t _rooks,
277  uint64_t _bishops,
278  uint64_t _knights,
279  uint64_t _pawns,
280  unsigned _rule50,
281  unsigned _castling,
282  unsigned _ep,
283  bool _turn,
284  unsigned *_results)
285 {
286  if (_castling != 0)
287  return TB_RESULT_FAILED;
288  return tb_probe_root_impl(_white, _black, _kings, _queens, _rooks,
289  _bishops, _knights, _pawns, _rule50, _ep, _turn, _results);
290 }
291 
292 /****************************************************************************/
293 /* HELPER API */
294 /****************************************************************************/
295 
296 /*
297  * The HELPER API provides some useful additional functions. It is optional
298  * and can be disabled by defining TB_NO_HELPER_API. Engines should disable
299  * the HELPER API.
300  */
301 
302 #ifndef TB_NO_HELPER_API
303 
304 extern unsigned tb_pop_count(uint64_t _bb);
305 extern unsigned tb_lsb(uint64_t _bb);
306 extern uint64_t tb_pop_lsb(uint64_t _bb);
307 extern uint64_t tb_king_attacks(unsigned _square);
308 extern uint64_t tb_queen_attacks(unsigned _square, uint64_t _occ);
309 extern uint64_t tb_rook_attacks(unsigned _square, uint64_t _occ);
310 extern uint64_t tb_bishop_attacks(unsigned _square, uint64_t _occ);
311 extern uint64_t tb_knight_attacks(unsigned _square);
312 extern uint64_t tb_pawn_attacks(unsigned _square, bool _color);
313 
314 #endif
315 
316 #ifdef __cplusplus
317 }
318 #endif
319 
320 #endif
Generated by   doxygen 1.8.11