2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
29 #include "direction.h"
34 const uint64_t BMult[64] = {
35 0x440049104032280ULL, 0x1021023c82008040ULL, 0x404040082000048ULL,
36 0x48c4440084048090ULL, 0x2801104026490000ULL, 0x4100880442040800ULL,
37 0x181011002e06040ULL, 0x9101004104200e00ULL, 0x1240848848310401ULL,
38 0x2000142828050024ULL, 0x1004024d5000ULL, 0x102044400800200ULL,
39 0x8108108820112000ULL, 0xa880818210c00046ULL, 0x4008008801082000ULL,
40 0x60882404049400ULL, 0x104402004240810ULL, 0xa002084250200ULL,
41 0x100b0880801100ULL, 0x4080201220101ULL, 0x44008080a00000ULL,
42 0x202200842000ULL, 0x5006004882d00808ULL, 0x200045080802ULL,
43 0x86100020200601ULL, 0xa802080a20112c02ULL, 0x80411218080900ULL,
44 0x200a0880080a0ULL, 0x9a01010000104000ULL, 0x28008003100080ULL,
45 0x211021004480417ULL, 0x401004188220806ULL, 0x825051400c2006ULL,
46 0x140c0210943000ULL, 0x242800300080ULL, 0xc2208120080200ULL,
47 0x2430008200002200ULL, 0x1010100112008040ULL, 0x8141050100020842ULL,
48 0x822081014405ULL, 0x800c049e40400804ULL, 0x4a0404028a000820ULL,
49 0x22060201041200ULL, 0x360904200840801ULL, 0x881a08208800400ULL,
50 0x60202c00400420ULL, 0x1204440086061400ULL, 0x8184042804040ULL,
51 0x64040315300400ULL, 0xc01008801090a00ULL, 0x808010401140c00ULL,
52 0x4004830c2020040ULL, 0x80005002020054ULL, 0x40000c14481a0490ULL,
53 0x10500101042048ULL, 0x1010100200424000ULL, 0x640901901040ULL,
54 0xa0201014840ULL, 0x840082aa011002ULL, 0x10010840084240aULL,
55 0x420400810420608ULL, 0x8d40230408102100ULL, 0x4a00200612222409ULL,
59 const uint64_t RMult[64] = {
60 0xa8002c000108020ULL, 0x4440200140003000ULL, 0x8080200010011880ULL,
61 0x380180080141000ULL, 0x1a00060008211044ULL, 0x410001000a0c0008ULL,
62 0x9500060004008100ULL, 0x100024284a20700ULL, 0x802140008000ULL,
63 0x80c01002a00840ULL, 0x402004282011020ULL, 0x9862000820420050ULL,
64 0x1001448011100ULL, 0x6432800200800400ULL, 0x40100010002000cULL,
65 0x2800d0010c080ULL, 0x90c0008000803042ULL, 0x4010004000200041ULL,
66 0x3010010200040ULL, 0xa40828028001000ULL, 0x123010008000430ULL,
67 0x24008004020080ULL, 0x60040001104802ULL, 0x582200028400d1ULL,
68 0x4000802080044000ULL, 0x408208200420308ULL, 0x610038080102000ULL,
69 0x3601000900100020ULL, 0x80080040180ULL, 0xc2020080040080ULL,
70 0x80084400100102ULL, 0x4022408200014401ULL, 0x40052040800082ULL,
71 0xb08200280804000ULL, 0x8a80a008801000ULL, 0x4000480080801000ULL,
72 0x911808800801401ULL, 0x822a003002001894ULL, 0x401068091400108aULL,
73 0x4a10a00004cULL, 0x2000800640008024ULL, 0x1486408102020020ULL,
74 0x100a000d50041ULL, 0x810050020b0020ULL, 0x204000800808004ULL,
75 0x20048100a000cULL, 0x112000831020004ULL, 0x9000040810002ULL,
76 0x440490200208200ULL, 0x8910401000200040ULL, 0x6404200050008480ULL,
77 0x4b824a2010010100ULL, 0x4080801810c0080ULL, 0x400802a0080ULL,
78 0x8224080110026400ULL, 0x40002c4104088200ULL, 0x1002100104a0282ULL,
79 0x1208400811048021ULL, 0x3201014a40d02001ULL, 0x5100019200501ULL,
80 0x101000208001005ULL, 0x2008450080702ULL, 0x1002080301d00cULL,
84 const int BShift[64] = {
85 58, 59, 59, 59, 59, 59, 59, 58, 59, 59, 59, 59, 59, 59, 59, 59,
86 59, 59, 57, 57, 57, 57, 59, 59, 59, 59, 57, 55, 55, 57, 59, 59,
87 59, 59, 57, 55, 55, 57, 59, 59, 59, 59, 57, 57, 57, 57, 59, 59,
88 59, 59, 59, 59, 59, 59, 59, 59, 58, 59, 59, 59, 59, 59, 59, 58
91 const int RShift[64] = {
92 52, 53, 53, 53, 53, 53, 53, 52, 53, 54, 54, 54, 54, 54, 54, 53,
93 53, 54, 54, 54, 54, 54, 54, 53, 53, 54, 54, 54, 54, 54, 54, 53,
94 53, 54, 54, 54, 54, 54, 54, 53, 53, 54, 54, 54, 54, 54, 54, 53,
95 53, 54, 54, 54, 54, 54, 54, 53, 52, 53, 53, 53, 53, 53, 53, 52
98 #else // if !defined(IS_64BIT)
100 const uint64_t BMult[64] = {
101 0x54142844c6a22981ULL, 0x710358a6ea25c19eULL, 0x704f746d63a4a8dcULL,
102 0xbfed1a0b80f838c5ULL, 0x90561d5631e62110ULL, 0x2804260376e60944ULL,
103 0x84a656409aa76871ULL, 0xf0267f64c28b6197ULL, 0x70764ebb762f0585ULL,
104 0x92aa09e0cfe161deULL, 0x41ee1f6bb266f60eULL, 0xddcbf04f6039c444ULL,
105 0x5a3fab7bac0d988aULL, 0xd3727877fa4eaa03ULL, 0xd988402d868ddaaeULL,
106 0x812b291afa075c7cULL, 0x94faf987b685a932ULL, 0x3ed867d8470d08dbULL,
107 0x92517660b8901de8ULL, 0x2d97e43e058814b4ULL, 0x880a10c220b25582ULL,
108 0xc7c6520d1f1a0477ULL, 0xdbfc7fbcd7656aa6ULL, 0x78b1b9bfb1a2b84fULL,
109 0x2f20037f112a0bc1ULL, 0x657171ea2269a916ULL, 0xc08302b07142210eULL,
110 0x880a4403064080bULL, 0x3602420842208c00ULL, 0x852800dc7e0b6602ULL,
111 0x595a3fbbaa0f03b2ULL, 0x9f01411558159d5eULL, 0x2b4a4a5f88b394f2ULL,
112 0x4afcbffc292dd03aULL, 0x4a4094a3b3f10522ULL, 0xb06f00b491f30048ULL,
113 0xd5b3820280d77004ULL, 0x8b2e01e7c8e57a75ULL, 0x2d342794e886c2e6ULL,
114 0xc302c410cde21461ULL, 0x111f426f1379c274ULL, 0xe0569220abb31588ULL,
115 0x5026d3064d453324ULL, 0xe2076040c343cd8aULL, 0x93efd1e1738021eeULL,
116 0xb680804bed143132ULL, 0x44e361b21986944cULL, 0x44c60170ef5c598cULL,
117 0xf4da475c195c9c94ULL, 0xa3afbb5f72060b1dULL, 0xbc75f410e41c4ffcULL,
118 0xb51c099390520922ULL, 0x902c011f8f8ec368ULL, 0x950b56b3d6f5490aULL,
119 0x3909e0635bf202d0ULL, 0x5744f90206ec10ccULL, 0xdc59fd76317abbc1ULL,
120 0x881c7c67fcbfc4f6ULL, 0x47ca41e7e440d423ULL, 0xeb0c88112048d004ULL,
121 0x51c60e04359aef1aULL, 0x1aa1fe0e957a5554ULL, 0xdd9448db4f5e3104ULL,
122 0xdc01f6dca4bebbdcULL,
125 const uint64_t RMult[64] = {
126 0xd7445cdec88002c0ULL, 0xd0a505c1f2001722ULL, 0xe065d1c896002182ULL,
127 0x9a8c41e75a000892ULL, 0x8900b10c89002aa8ULL, 0x9b28d1c1d60005a2ULL,
128 0x15d6c88de002d9aULL, 0xb1dbfc802e8016a9ULL, 0x149a1042d9d60029ULL,
129 0xb9c08050599e002fULL, 0x132208c3af300403ULL, 0xc1000ce2e9c50070ULL,
130 0x9d9aa13c99020012ULL, 0xb6b078daf71e0046ULL, 0x9d880182fb6e002eULL,
131 0x52889f467e850037ULL, 0xda6dc008d19a8480ULL, 0x468286034f902420ULL,
132 0x7140ac09dc54c020ULL, 0xd76ffffa39548808ULL, 0xea901c4141500808ULL,
133 0xc91004093f953a02ULL, 0x2882afa8f6bb402ULL, 0xaebe335692442c01ULL,
134 0xe904a22079fb91eULL, 0x13a514851055f606ULL, 0x76c782018c8fe632ULL,
135 0x1dc012a9d116da06ULL, 0x3c9e0037264fffa6ULL, 0x2036002853c6e4a2ULL,
136 0xe3fe08500afb47d4ULL, 0xf38af25c86b025c2ULL, 0xc0800e2182cf9a40ULL,
137 0x72002480d1f60673ULL, 0x2500200bae6e9b53ULL, 0xc60018c1eefca252ULL,
138 0x600590473e3608aULL, 0x46002c4ab3fe51b2ULL, 0xa200011486bcc8d2ULL,
139 0xb680078095784c63ULL, 0x2742002639bf11aeULL, 0xc7d60021a5bdb142ULL,
140 0xc8c04016bb83d820ULL, 0xbd520028123b4842ULL, 0x9d1600344ac2a832ULL,
141 0x6a808005631c8a05ULL, 0x604600a148d5389aULL, 0xe2e40103d40dea65ULL,
142 0x945b5a0087c62a81ULL, 0x12dc200cd82d28eULL, 0x2431c600b5f9ef76ULL,
143 0xfb142a006a9b314aULL, 0x6870e00a1c97d62ULL, 0x2a9db2004a2689a2ULL,
144 0xd3594600caf5d1a2ULL, 0xee0e4900439344a7ULL, 0x89c4d266ca25007aULL,
145 0x3e0013a2743f97e3ULL, 0x180e31a0431378aULL, 0x3a9e465a4d42a512ULL,
146 0x98d0a11a0c0d9cc2ULL, 0x8e711c1aba19b01eULL, 0x8dcdc836dd201142ULL,
147 0x5ac08a4735370479ULL,
150 const int BShift[64] = {
151 26, 27, 27, 27, 27, 27, 27, 26, 27, 27, 27, 27, 27, 27, 27, 27,
152 27, 27, 25, 25, 25, 25, 27, 27, 27, 27, 25, 23, 23, 25, 27, 27,
153 27, 27, 25, 23, 23, 25, 27, 27, 27, 27, 25, 25, 25, 25, 27, 27,
154 27, 27, 27, 27, 27, 27, 27, 27, 26, 27, 27, 27, 27, 27, 27, 26
157 const int RShift[64] = {
158 20, 21, 21, 21, 21, 21, 21, 20, 21, 22, 22, 22, 22, 22, 22, 21,
159 21, 22, 22, 22, 22, 22, 22, 21, 21, 22, 22, 22, 22, 22, 22, 21,
160 21, 22, 22, 22, 22, 22, 22, 21, 21, 22, 22, 22, 22, 22, 22, 21,
161 21, 22, 22, 22, 22, 22, 22, 21, 20, 21, 21, 21, 21, 21, 21, 20
164 #endif // defined(IS_64BIT)
166 const Bitboard SquaresByColorBB[2] = { BlackSquaresBB, WhiteSquaresBB };
168 const Bitboard FileBB[8] = {
169 FileABB, FileBBB, FileCBB, FileDBB, FileEBB, FileFBB, FileGBB, FileHBB
172 const Bitboard NeighboringFilesBB[8] = {
173 FileBBB, FileABB|FileCBB, FileBBB|FileDBB, FileCBB|FileEBB,
174 FileDBB|FileFBB, FileEBB|FileGBB, FileFBB|FileHBB, FileGBB
177 const Bitboard ThisAndNeighboringFilesBB[8] = {
178 FileABB|FileBBB, FileABB|FileBBB|FileCBB,
179 FileBBB|FileCBB|FileDBB, FileCBB|FileDBB|FileEBB,
180 FileDBB|FileEBB|FileFBB, FileEBB|FileFBB|FileGBB,
181 FileFBB|FileGBB|FileHBB, FileGBB|FileHBB
184 const Bitboard RankBB[8] = {
185 Rank1BB, Rank2BB, Rank3BB, Rank4BB, Rank5BB, Rank6BB, Rank7BB, Rank8BB
188 const Bitboard RelativeRankBB[2][8] = {
189 { Rank1BB, Rank2BB, Rank3BB, Rank4BB, Rank5BB, Rank6BB, Rank7BB, Rank8BB },
190 { Rank8BB, Rank7BB, Rank6BB, Rank5BB, Rank4BB, Rank3BB, Rank2BB, Rank1BB }
193 const Bitboard InFrontBB[2][8] = {
194 { Rank2BB | Rank3BB | Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
195 Rank3BB | Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
196 Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
197 Rank5BB | Rank6BB | Rank7BB | Rank8BB,
198 Rank6BB | Rank7BB | Rank8BB,
206 Rank3BB | Rank2BB | Rank1BB,
207 Rank4BB | Rank3BB | Rank2BB | Rank1BB,
208 Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB,
209 Rank6BB | Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB,
210 Rank7BB | Rank6BB | Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB
215 int RAttackIndex[64];
216 Bitboard RAttacks[0x19000];
219 int BAttackIndex[64];
220 Bitboard BAttacks[0x1480];
222 Bitboard SetMaskBB[65];
223 Bitboard ClearMaskBB[65];
225 Bitboard StepAttackBB[16][64];
226 Bitboard RayBB[64][8];
227 Bitboard BetweenBB[64][64];
229 Bitboard PassedPawnMask[2][64];
230 Bitboard OutpostMask[2][64];
232 Bitboard BishopPseudoAttacks[64];
233 Bitboard RookPseudoAttacks[64];
234 Bitboard QueenPseudoAttacks[64];
236 uint8_t BitCount8Bit[256];
240 //// Local definitions
246 void init_ray_bitboards();
248 void init_between_bitboards();
249 void init_pseudo_attacks();
250 Bitboard index_to_bitboard(int index, Bitboard mask);
251 Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
252 int fmin, int fmax, int rmin, int rmax);
253 void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
254 const int shift[], const Bitboard mult[], int deltas[][2]);
262 /// print_bitboard() prints a bitboard in an easily readable format to the
263 /// standard output. This is sometimes useful for debugging.
265 void print_bitboard(Bitboard b) {
267 for (Rank r = RANK_8; r >= RANK_1; r--)
269 std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
270 for (File f = FILE_A; f <= FILE_H; f++)
271 std::cout << "| " << (bit_is_set(b, make_square(f, r))? 'X' : ' ') << ' ';
273 std::cout << "|" << std::endl;
275 std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
279 /// init_bitboards() initializes various bitboard arrays. It is called during
280 /// program initialization.
282 void init_bitboards() {
284 int rookDeltas[4][2] = {{0,1},{0,-1},{1,0},{-1,0}};
285 int bishopDeltas[4][2] = {{1,1},{-1,1},{1,-1},{-1,-1}};
288 init_ray_bitboards();
290 init_between_bitboards();
291 init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
292 init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas);
293 init_pseudo_attacks();
297 /// first_1() finds the least significant nonzero bit in a nonzero bitboard.
298 /// pop_1st_bit() finds and clears the least significant nonzero bit in a
299 /// nonzero bitboard.
301 #if defined(IS_64BIT) && !defined(USE_BSFQ)
303 static CACHE_LINE_ALIGNMENT
304 const int BitTable[64] = {
305 0, 1, 2, 7, 3, 13, 8, 19, 4, 25, 14, 28, 9, 34, 20, 40, 5, 17, 26, 38, 15,
306 46, 29, 48, 10, 31, 35, 54, 21, 50, 41, 57, 63, 6, 12, 18, 24, 27, 33, 39,
307 16, 37, 45, 47, 30, 53, 49, 56, 62, 11, 23, 32, 36, 44, 52, 55, 61, 22, 43,
311 Square first_1(Bitboard b) {
312 return Square(BitTable[((b & -b) * 0x218a392cd3d5dbfULL) >> 58]);
315 Square pop_1st_bit(Bitboard* b) {
318 return Square(BitTable[((bb & -bb) * 0x218a392cd3d5dbfULL) >> 58]);
321 #elif !defined(USE_BSFQ)
323 static CACHE_LINE_ALIGNMENT
324 const int BitTable[64] = {
325 63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
326 51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
327 26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
328 58, 20, 37, 17, 36, 8
331 Square first_1(Bitboard b) {
334 uint32_t fold = int(b) ^ int(b >> 32);
335 return Square(BitTable[(fold * 0x783a9b23) >> 26]);
343 #if defined (BIGENDIAN)
353 Square pop_1st_bit(Bitboard* bb) {
362 ret = Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
363 u.dw.l &= (u.dw.l - 1);
367 ret = Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
368 u.dw.h &= (u.dw.h - 1);
375 // Optimized bitScanReverse32() implementation by Pascal Georges. Note
376 // that first bit is 1, this allow to differentiate between 0 and 1.
377 static CACHE_LINE_ALIGNMENT
378 const char MsbTable[256] = {
379 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
380 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
381 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7,
382 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
383 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
384 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
385 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
386 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
387 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
388 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
389 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
392 int bitScanReverse32(uint32_t b)
406 return result + MsbTable[b];
411 // All functions below are used to precompute various bitboards during
412 // program initialization. Some of the functions may be difficult to
413 // understand, but they all seem to work correctly, and it should never
414 // be necessary to touch any of them.
418 SetMaskBB[SQ_NONE] = 0ULL;
419 ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
421 for (Square s = SQ_A1; s <= SQ_H8; s++)
423 SetMaskBB[s] = (1ULL << s);
424 ClearMaskBB[s] = ~SetMaskBB[s];
427 for (Color c = WHITE; c <= BLACK; c++)
428 for (Square s = SQ_A1; s <= SQ_H8; s++)
430 PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s);
431 OutpostMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
434 for (Bitboard b = 0ULL; b < 256ULL; b++)
435 BitCount8Bit[b] = (uint8_t)count_1s(b);
438 int remove_bit_8(int i) { return ((i & ~15) >> 1) | (i & 7); }
440 void init_ray_bitboards() {
442 int d[8] = {1, -1, 16, -16, 17, -17, 15, -15};
444 for (int i = 0; i < 128; i = (i + 9) & ~8)
445 for (int j = 0; j < 8; j++)
447 RayBB[remove_bit_8(i)][j] = EmptyBoardBB;
448 for (int k = i + d[j]; (k & 0x88) == 0; k += d[j])
449 set_bit(&(RayBB[remove_bit_8(i)][j]), Square(remove_bit_8(k)));
453 void init_attacks() {
455 const int step[16][8] = {
457 {7,9,0}, {17,15,10,6,-6,-10,-15,-17}, {9,7,-7,-9,0}, {8,1,-1,-8,0},
458 {9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}, {0}, {0},
459 {-7,-9,0}, {17,15,10,6,-6,-10,-15,-17}, {9,7,-7,-9,0}, {8,1,-1,-8,0},
460 {9,7,-7,-9,8,1,-1,-8}, {9,7,-7,-9,8,1,-1,-8}
463 for (int i = 0; i < 64; i++)
464 for (int j = 0; j <= int(BK); j++)
466 StepAttackBB[j][i] = EmptyBoardBB;
467 for (int k = 0; k < 8 && step[j][k] != 0; k++)
469 int l = i + step[j][k];
470 if (l >= 0 && l < 64 && abs((i & 7) - (l & 7)) < 3)
471 StepAttackBB[j][i] |= (1ULL << l);
476 Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
477 int fmin=0, int fmax=7, int rmin=0, int rmax=7) {
478 Bitboard result = 0ULL;
482 for (int i = 0; i < dirs; i++)
484 int dx = deltas[i][0];
485 int dy = deltas[i][1];
489 while ( (dx == 0 || (f >= fmin && f <= fmax))
490 && (dy == 0 || (r >= rmin && r <= rmax)))
492 result |= (1ULL << (f + r*8));
493 if (block & (1ULL << (f + r*8)))
503 void init_between_bitboards() {
505 const SquareDelta step[8] = { DELTA_E, DELTA_W, DELTA_N, DELTA_S,
506 DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE };
508 for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
509 for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
511 BetweenBB[s1][s2] = EmptyBoardBB;
512 SignedDirection d = signed_direction_between_squares(s1, s2);
514 if (d != SIGNED_DIR_NONE)
516 for (Square s3 = s1 + step[d]; s3 != s2; s3 += step[d])
517 set_bit(&(BetweenBB[s1][s2]), s3);
522 Bitboard index_to_bitboard(int index, Bitboard mask) {
524 Bitboard result = 0ULL;
525 int bits = count_1s(mask);
527 for (int i = 0; i < bits; i++)
529 int j = pop_1st_bit(&mask);
530 if (index & (1 << i))
531 result |= (1ULL << j);
536 void init_sliding_attacks(Bitboard attacks[], int attackIndex[], Bitboard mask[],
537 const int shift[], const Bitboard mult[], int deltas[][2]) {
539 for (int i = 0, index = 0; i < 64; i++)
541 attackIndex[i] = index;
542 mask[i] = sliding_attacks(i, 0ULL, 4, deltas, 1, 6, 1, 6);
544 #if defined(IS_64BIT)
545 int j = (1 << (64 - shift[i]));
547 int j = (1 << (32 - shift[i]));
550 for (int k = 0; k < j; k++)
552 #if defined(IS_64BIT)
553 Bitboard b = index_to_bitboard(k, mask[i]);
554 attacks[index + ((b * mult[i]) >> shift[i])] = sliding_attacks(i, b, 4, deltas);
556 Bitboard b = index_to_bitboard(k, mask[i]);
557 unsigned v = int(b) * int(mult[i]) ^ int(b >> 32) * int(mult[i] >> 32);
558 attacks[index + (v >> shift[i])] = sliding_attacks(i, b, 4, deltas);
565 void init_pseudo_attacks() {
567 for (Square s = SQ_A1; s <= SQ_H8; s++)
569 BishopPseudoAttacks[s] = bishop_attacks_bb(s, EmptyBoardBB);
570 RookPseudoAttacks[s] = rook_attacks_bb(s, EmptyBoardBB);
571 QueenPseudoAttacks[s] = queen_attacks_bb(s, EmptyBoardBB);