stockfish-3.0.0+git20130508/ 0000755 0001750 0001750 00000000000 12142540127 014471 5 ustar oliver oliver stockfish-3.0.0+git20130508/Readme.md 0000644 0001750 0001750 00000006010 12142540127 016205 0 ustar oliver oliver ### Overview
Stockfish is a free UCI chess engine derived from Glaurung 2.1. It is
not a complete chess program and requires some UCI-compatible GUI
(e.g. XBoard with PolyGlot, eboard, Arena, Sigma Chess, Shredder, Chess
Partner or Fritz) in order to be used comfortably. Read the
documentation for your GUI of choice for information about how to use
Stockfish with it.
This version of Stockfish supports up to 64 CPUs, but has not been
tested thoroughly with more than 4. The program tries to detect the
number of CPUs on your computer and sets the number of search threads
accordingly, but please be aware that the detection is not always
correct. It is therefore recommended to inspect the value of the
*Threads* UCI parameter, and to make sure it equals the number of CPU
cores on your computer. If you are using more than eight threads, it is
recommended to raise the value of the *Min Split Depth* UCI parameter to 7.
### Files
This distribution of Stockfish consists of the following files:
* Readme.md, the file you are currently reading.
* Copying.txt, a text file containing the GNU General Public License.
* src/, a subdirectory containing the full source code, including a Makefile
that can be used to compile Stockfish on Unix-like systems. For further
information about how to compile Stockfish yourself read section below.
* polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot
adapter.
### Opening books
This version of Stockfish has support for PolyGlot opening books. For
information about how to create such books, consult the PolyGlot
documentation. The book file can be selected by setting the *Book File*
UCI parameter.
### Compiling it yourself
On Unix-like systems, it should be possible to compile Stockfish
directly from the source code with the included Makefile.
Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT
instruction, big-endian machines such as Power PC, and other platforms.
In general it is recommended to run `make help` to see a list of make
targets with corresponding descriptions. When not using Makefile to
compile (for instance with Microsoft MSVC) you need to manually
set/unset some switches in the compiler command line; see file *types.h*
for a quick reference.
### Terms of use
Stockfish is free, and distributed under the **GNU General Public License**
(GPL). Essentially, this means that you are free to do almost exactly
what you want with the program, including distributing it among your
friends, making it available for download from your web site, selling
it (either by itself or as part of some bigger software package), or
using it as the starting point for a software project of your own.
The only real limitation is that whenever you distribute Stockfish in
some way, you must always include the full source code, or a pointer
to where the source code can be found. If you make any changes to the
source code, these changes must also be made available under the GPL.
For full details, read the copy of the GPL found in the file named
*Copying.txt*
stockfish-3.0.0+git20130508/polyglot.ini 0000644 0001750 0001750 00000001402 12142540127 017040 0 ustar oliver oliver [PolyGlot]
EngineDir = .
EngineCommand = ./stockfish
Book = false
BookFile = book.bin
Log = false
LogFile = stockfish.log
Resign = true
ResignScore = 600
[Engine]
Use Search Log = false
Search Log Filename = SearchLog.txt
Book File = book.bin
Best Book Move = false
Contempt Factor = 0
Mobility (Middle Game) = 100
Mobility (Endgame) = 100
Passed Pawns (Middle Game) = 100
Passed Pawns (Endgame) = 100
Space = 100
Aggressiveness = 100
Cowardice = 100
Min Split Depth = 4
Max Threads per Split Point = 5
Threads = 1
Use Sleeping Threads = true
Hash = 128
Ponder = true
OwnBook = false
MultiPV = 1
Skill Level = 20
Emergency Move Horizon = 40
Emergency Base Time = 200
Emergency Move Time = 70
Minimum Thinking Time = 20
UCI_Chess960 = false
UCI_AnalyseMode = false
stockfish-3.0.0+git20130508/src/ 0000755 0001750 0001750 00000000000 12142540127 015260 5 ustar oliver oliver stockfish-3.0.0+git20130508/src/movepick.h 0000644 0001750 0001750 00000006377 12142540127 017263 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined MOVEPICK_H_INCLUDED
#define MOVEPICK_H_INCLUDED
#include // For std::max
#include // For memset
#include "movegen.h"
#include "position.h"
#include "search.h"
#include "types.h"
/// The Stats struct stores moves statistics. According to the template parameter
/// the class can store both History and Gains type statistics. History records
/// how often different moves have been successful or unsuccessful during the
/// current search and is used for reduction and move ordering decisions. Gains
/// records the move's best evaluation gain from one ply to the next and is used
/// for pruning decisions. Entries are stored according only to moving piece and
/// destination square, in particular two moves with different origin but same
/// destination and same piece will be considered identical.
template
struct Stats {
static const Value Max = Value(2000);
const Value* operator[](Piece p) const { return &table[p][0]; }
void clear() { memset(table, 0, sizeof(table)); }
void update(Piece p, Square to, Value v) {
if (Gain)
table[p][to] = std::max(v, table[p][to] - 1);
else if (abs(table[p][to] + v) < Max)
table[p][to] += v;
}
private:
Value table[PIECE_NB][SQUARE_NB];
};
typedef Stats History;
typedef Stats Gains;
/// MovePicker class is used to pick one pseudo legal move at a time from the
/// current position. The most important method is next_move(), which returns a
/// new pseudo legal move each time it is called, until there are no moves left,
/// when MOVE_NONE is returned. In order to improve the efficiency of the alpha
/// beta algorithm, MovePicker attempts to return the moves which are most likely
/// to get a cut-off first.
class MovePicker {
MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
public:
MovePicker(const Position&, Move, Depth, const History&, Search::Stack*, Value);
MovePicker(const Position&, Move, Depth, const History&, Square);
MovePicker(const Position&, Move, const History&, PieceType);
template Move next_move();
private:
template void score();
void generate_next();
const Position& pos;
const History& Hist;
Search::Stack* ss;
Depth depth;
Move ttMove;
MoveStack killers[2];
Square recaptureSquare;
int captureThreshold, phase;
MoveStack *cur, *end, *endQuiets, *endBadCaptures;
MoveStack moves[MAX_MOVES];
};
#endif // !defined(MOVEPICK_H_INCLUDED)
stockfish-3.0.0+git20130508/src/notation.h 0000644 0001750 0001750 00000002470 12142540127 017267 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(NOTATION_H_INCLUDED)
#define NOTATION_H_INCLUDED
#include
#include "types.h"
class Position;
std::string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
Move move_from_uci(const Position& pos, std::string& str);
const std::string move_to_uci(Move m, bool chess960);
const std::string move_to_san(Position& pos, Move m);
std::string pretty_pv(Position& pos, int depth, Value score, int64_t msecs, Move pv[]);
#endif // !defined(NOTATION_H_INCLUDED)
stockfish-3.0.0+git20130508/src/timeman.cpp 0000644 0001750 0001750 00000017324 12142540127 017425 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include "search.h"
#include "timeman.h"
#include "ucioption.h"
namespace {
/// Constants
const int MoveHorizon = 50; // Plan time management at most this many moves ahead
const float MaxRatio = 7.0f; // When in trouble, we can step over reserved time with this ratio
const float StealRatio = 0.33f; // However we must not steal time from remaining moves over this ratio
// MoveImportance[] is based on naive statistical analysis of "how many games are still undecided
// after n half-moves". Game is considered "undecided" as long as neither side has >275cp advantage.
// Data was extracted from CCRL game database with some simple filtering criteria.
const int MoveImportance[512] = {
7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780,
7780, 7780, 7780, 7780, 7778, 7778, 7776, 7776, 7776, 7773, 7770, 7768, 7766, 7763, 7757, 7751,
7743, 7735, 7724, 7713, 7696, 7689, 7670, 7656, 7627, 7605, 7571, 7549, 7522, 7493, 7462, 7425,
7385, 7350, 7308, 7272, 7230, 7180, 7139, 7094, 7055, 7010, 6959, 6902, 6841, 6778, 6705, 6651,
6569, 6508, 6435, 6378, 6323, 6253, 6152, 6085, 5995, 5931, 5859, 5794, 5717, 5646, 5544, 5462,
5364, 5282, 5172, 5078, 4988, 4901, 4831, 4764, 4688, 4609, 4536, 4443, 4365, 4293, 4225, 4155,
4085, 4005, 3927, 3844, 3765, 3693, 3634, 3560, 3479, 3404, 3331, 3268, 3207, 3146, 3077, 3011,
2947, 2894, 2828, 2776, 2727, 2676, 2626, 2589, 2538, 2490, 2442, 2394, 2345, 2302, 2243, 2192,
2156, 2115, 2078, 2043, 2004, 1967, 1922, 1893, 1845, 1809, 1772, 1736, 1702, 1674, 1640, 1605,
1566, 1536, 1509, 1479, 1452, 1423, 1388, 1362, 1332, 1304, 1289, 1266, 1250, 1228, 1206, 1180,
1160, 1134, 1118, 1100, 1080, 1068, 1051, 1034, 1012, 1001, 980, 960, 945, 934, 916, 900, 888,
878, 865, 852, 828, 807, 787, 770, 753, 744, 731, 722, 706, 700, 683, 676, 671, 664, 652, 641,
634, 627, 613, 604, 591, 582, 568, 560, 552, 540, 534, 529, 519, 509, 495, 484, 474, 467, 460,
450, 438, 427, 419, 410, 406, 399, 394, 387, 382, 377, 372, 366, 359, 353, 348, 343, 337, 333,
328, 321, 315, 309, 303, 298, 293, 287, 284, 281, 277, 273, 265, 261, 255, 251, 247, 241, 240,
235, 229, 218, 217, 213, 212, 208, 206, 197, 193, 191, 189, 185, 184, 180, 177, 172, 170, 170,
170, 166, 163, 159, 158, 156, 155, 151, 146, 141, 138, 136, 132, 130, 128, 125, 123, 122, 118,
118, 118, 117, 115, 114, 108, 107, 105, 105, 105, 102, 97, 97, 95, 94, 93, 91, 88, 86, 83, 80,
80, 79, 79, 79, 78, 76, 75, 72, 72, 71, 70, 68, 65, 63, 61, 61, 59, 59, 59, 58, 56, 55, 54, 54,
52, 49, 48, 48, 48, 48, 45, 45, 45, 44, 43, 41, 41, 41, 41, 40, 40, 38, 37, 36, 34, 34, 34, 33,
31, 29, 29, 29, 28, 28, 28, 28, 28, 28, 28, 27, 27, 27, 27, 27, 24, 24, 23, 23, 22, 21, 20, 20,
19, 19, 19, 19, 19, 18, 18, 18, 18, 17, 17, 17, 17, 17, 16, 16, 15, 15, 14, 14, 14, 12, 12, 11,
9, 9, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2,
2, 1, 1, 1, 1, 1, 1, 1 };
int move_importance(int ply) { return MoveImportance[std::min(ply, 511)]; }
/// Function Prototypes
enum TimeType { OptimumTime, MaxTime };
template
int remaining(int myTime, int movesToGo, int fullMoveNumber, int slowMover);
}
void TimeManager::pv_instability(int curChanges, int prevChanges) {
unstablePVExtraTime = curChanges * (optimumSearchTime / 2)
+ prevChanges * (optimumSearchTime / 3);
}
void TimeManager::init(const Search::LimitsType& limits, int currentPly, Color us)
{
/* We support four different kind of time controls:
increment == 0 && movesToGo == 0 means: x basetime [sudden death!]
increment == 0 && movesToGo != 0 means: x moves in y minutes
increment > 0 && movesToGo == 0 means: x basetime + z increment
increment > 0 && movesToGo != 0 means: x moves in y minutes + z increment
Time management is adjusted by following UCI parameters:
emergencyMoveHorizon: Be prepared to always play at least this many moves
emergencyBaseTime : Always attempt to keep at least this much time (in ms) at clock
emergencyMoveTime : Plus attempt to keep at least this much time for each remaining emergency move
minThinkingTime : No matter what, use at least this much thinking before doing the move
*/
int hypMTG, hypMyTime, t1, t2;
// Read uci parameters
int emergencyMoveHorizon = Options["Emergency Move Horizon"];
int emergencyBaseTime = Options["Emergency Base Time"];
int emergencyMoveTime = Options["Emergency Move Time"];
int minThinkingTime = Options["Minimum Thinking Time"];
int slowMover = Options["Slow Mover"];
// Initialize to maximum values but unstablePVExtraTime that is reset
unstablePVExtraTime = 0;
optimumSearchTime = maximumSearchTime = limits.time[us];
// We calculate optimum time usage for different hypothetic "moves to go"-values and choose the
// minimum of calculated search time values. Usually the greatest hypMTG gives the minimum values.
for (hypMTG = 1; hypMTG <= (limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon); hypMTG++)
{
// Calculate thinking time for hypothetic "moves to go"-value
hypMyTime = limits.time[us]
+ limits.inc[us] * (hypMTG - 1)
- emergencyBaseTime
- emergencyMoveTime * std::min(hypMTG, emergencyMoveHorizon);
hypMyTime = std::max(hypMyTime, 0);
t1 = minThinkingTime + remaining(hypMyTime, hypMTG, currentPly, slowMover);
t2 = minThinkingTime + remaining(hypMyTime, hypMTG, currentPly, slowMover);
optimumSearchTime = std::min(optimumSearchTime, t1);
maximumSearchTime = std::min(maximumSearchTime, t2);
}
if (Options["Ponder"])
optimumSearchTime += optimumSearchTime / 4;
// Make sure that maxSearchTime is not over absoluteMaxSearchTime
optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime);
}
namespace {
template
int remaining(int myTime, int movesToGo, int currentPly, int slowMover)
{
const float TMaxRatio = (T == OptimumTime ? 1 : MaxRatio);
const float TStealRatio = (T == OptimumTime ? 0 : StealRatio);
int thisMoveImportance = move_importance(currentPly) * slowMover / 100;
int otherMovesImportance = 0;
for (int i = 1; i < movesToGo; i++)
otherMovesImportance += move_importance(currentPly + 2 * i);
float ratio1 = (TMaxRatio * thisMoveImportance) / float(TMaxRatio * thisMoveImportance + otherMovesImportance);
float ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / float(thisMoveImportance + otherMovesImportance);
return int(floor(myTime * std::min(ratio1, ratio2)));
}
}
stockfish-3.0.0+git20130508/src/bitboard.cpp 0000644 0001750 0001750 00000025355 12142540127 017564 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include
#include "bitboard.h"
#include "bitcount.h"
#include "misc.h"
#include "rkiss.h"
CACHE_LINE_ALIGNMENT
Bitboard RMasks[SQUARE_NB];
Bitboard RMagics[SQUARE_NB];
Bitboard* RAttacks[SQUARE_NB];
unsigned RShifts[SQUARE_NB];
Bitboard BMasks[SQUARE_NB];
Bitboard BMagics[SQUARE_NB];
Bitboard* BAttacks[SQUARE_NB];
unsigned BShifts[SQUARE_NB];
Bitboard SquareBB[SQUARE_NB];
Bitboard FileBB[FILE_NB];
Bitboard RankBB[RANK_NB];
Bitboard AdjacentFilesBB[FILE_NB];
Bitboard ThisAndAdjacentFilesBB[FILE_NB];
Bitboard InFrontBB[COLOR_NB][RANK_NB];
Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
Bitboard DistanceRingsBB[SQUARE_NB][8];
Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
Bitboard AttackSpanMask[COLOR_NB][SQUARE_NB];
Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
int SquareDistance[SQUARE_NB][SQUARE_NB];
namespace {
// De Bruijn sequences. See chessprogramming.wikispaces.com/BitScan
const uint64_t DeBruijn_64 = 0x3F79D71B4CB0A89ULL;
const uint32_t DeBruijn_32 = 0x783A9B23;
CACHE_LINE_ALIGNMENT
int MS1BTable[256];
Square BSFTable[SQUARE_NB];
Bitboard RTable[0x19000]; // Storage space for rook attacks
Bitboard BTable[0x1480]; // Storage space for bishop attacks
typedef unsigned (Fn)(Square, Bitboard);
void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
Bitboard masks[], unsigned shifts[], Square deltas[], Fn index);
FORCE_INLINE unsigned bsf_index(Bitboard b) {
// Matt Taylor's folding for 32 bit systems, extended to 64 bits by Kim Walisch
b ^= (b - 1);
return Is64Bit ? (b * DeBruijn_64) >> 58
: ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26;
}
}
/// lsb()/msb() finds the least/most significant bit in a nonzero bitboard.
/// pop_lsb() finds and clears the least significant bit in a nonzero bitboard.
#if !defined(USE_BSFQ)
Square lsb(Bitboard b) { return BSFTable[bsf_index(b)]; }
Square pop_lsb(Bitboard* b) {
Bitboard bb = *b;
*b = bb & (bb - 1);
return BSFTable[bsf_index(bb)];
}
Square msb(Bitboard b) {
unsigned b32;
int result = 0;
if (b > 0xFFFFFFFF)
{
b >>= 32;
result = 32;
}
b32 = unsigned(b);
if (b32 > 0xFFFF)
{
b32 >>= 16;
result += 16;
}
if (b32 > 0xFF)
{
b32 >>= 8;
result += 8;
}
return (Square)(result + MS1BTable[b32]);
}
#endif // !defined(USE_BSFQ)
/// Bitboards::print() prints a bitboard in an easily readable format to the
/// standard output. This is sometimes useful for debugging.
void Bitboards::print(Bitboard b) {
sync_cout;
for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
std::cout << "+---+---+---+---+---+---+---+---+" << '\n';
for (File file = FILE_A; file <= FILE_H; file++)
std::cout << "| " << (b & (file | rank) ? "X " : " ");
std::cout << "|\n";
}
std::cout << "+---+---+---+---+---+---+---+---+" << sync_endl;
}
/// Bitboards::init() initializes various bitboard arrays. It is called during
/// program initialization.
void Bitboards::init() {
for (int k = 0, i = 0; i < 8; i++)
while (k < (2 << i))
MS1BTable[k++] = i;
for (int i = 0; i < 64; i++)
BSFTable[bsf_index(1ULL << i)] = Square(i);
for (Square s = SQ_A1; s <= SQ_H8; s++)
SquareBB[s] = 1ULL << s;
FileBB[FILE_A] = FileABB;
RankBB[RANK_1] = Rank1BB;
for (int i = 1; i < 8; i++)
{
FileBB[i] = FileBB[i - 1] << 1;
RankBB[i] = RankBB[i - 1] << 8;
}
for (File f = FILE_A; f <= FILE_H; f++)
{
AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
ThisAndAdjacentFilesBB[f] = FileBB[f] | AdjacentFilesBB[f];
}
for (Rank r = RANK_1; r < RANK_8; r++)
InFrontBB[WHITE][r] = ~(InFrontBB[BLACK][r + 1] = InFrontBB[BLACK][r] | RankBB[r]);
for (Color c = WHITE; c <= BLACK; c++)
for (Square s = SQ_A1; s <= SQ_H8; s++)
{
ForwardBB[c][s] = InFrontBB[c][rank_of(s)] & FileBB[file_of(s)];
PassedPawnMask[c][s] = InFrontBB[c][rank_of(s)] & ThisAndAdjacentFilesBB[file_of(s)];
AttackSpanMask[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
}
for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
for (int d = 1; d < 8; d++)
for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
if (SquareDistance[s1][s2] == d)
DistanceRingsBB[s1][d - 1] |= s2;
int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 },
{}, {}, {}, { 9, 7, -7, -9, 8, 1, -1, -8 } };
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
for (Square s = SQ_A1; s <= SQ_H8; s++)
for (int k = 0; steps[pt][k]; k++)
{
Square to = s + Square(c == WHITE ? steps[pt][k] : -steps[pt][k]);
if (is_ok(to) && square_distance(s, to) < 3)
StepAttacksBB[make_piece(c, pt)][s] |= to;
}
Square RDeltas[] = { DELTA_N, DELTA_E, DELTA_S, DELTA_W };
Square BDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, magic_index);
init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, magic_index);
for (Square s = SQ_A1; s <= SQ_H8; s++)
{
PseudoAttacks[QUEEN][s] = PseudoAttacks[BISHOP][s] = attacks_bb(s, 0);
PseudoAttacks[QUEEN][s] |= PseudoAttacks[ ROOK][s] = attacks_bb< ROOK>(s, 0);
}
for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
if (PseudoAttacks[QUEEN][s1] & s2)
{
Square delta = (s2 - s1) / square_distance(s1, s2);
for (Square s = s1 + delta; s != s2; s += delta)
BetweenBB[s1][s2] |= s;
}
}
namespace {
Bitboard sliding_attack(Square deltas[], Square sq, Bitboard occupied) {
Bitboard attack = 0;
for (int i = 0; i < 4; i++)
for (Square s = sq + deltas[i];
is_ok(s) && square_distance(s, s - deltas[i]) == 1;
s += deltas[i])
{
attack |= s;
if (occupied & s)
break;
}
return attack;
}
Bitboard pick_random(RKISS& rk, int booster) {
// Values s1 and s2 are used to rotate the candidate magic of a
// quantity known to be the optimal to quickly find the magics.
int s1 = booster & 63, s2 = (booster >> 6) & 63;
Bitboard m = rk.rand();
m = (m >> s1) | (m << (64 - s1));
m &= rk.rand();
m = (m >> s2) | (m << (64 - s2));
return m & rk.rand();
}
// init_magics() computes all rook and bishop attacks at startup. Magic
// bitboards are used to look up attacks of sliding pieces. As a reference see
// chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we
// use the so called "fancy" approach.
void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
int MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 },
{ 1059, 3608, 605, 3234, 3326, 38, 2029, 3043 } };
RKISS rk;
Bitboard occupancy[4096], reference[4096], edges, b;
int i, size, booster;
// attacks[s] is a pointer to the beginning of the attacks table for square 's'
attacks[SQ_A1] = table;
for (Square s = SQ_A1; s <= SQ_H8; s++)
{
// Board edges are not considered in the relevant occupancies
edges = ((Rank1BB | Rank8BB) & ~rank_bb(s)) | ((FileABB | FileHBB) & ~file_bb(s));
// Given a square 's', the mask is the bitboard of sliding attacks from
// 's' computed on an empty board. The index must be big enough to contain
// all the attacks for each possible subset of the mask and so is 2 power
// the number of 1s of the mask. Hence we deduce the size of the shift to
// apply to the 64 or 32 bits word to get the index.
masks[s] = sliding_attack(deltas, s, 0) & ~edges;
shifts[s] = (Is64Bit ? 64 : 32) - popcount(masks[s]);
// Use Carry-Rippler trick to enumerate all subsets of masks[s] and
// store the corresponding sliding attack bitboard in reference[].
b = size = 0;
do {
occupancy[size] = b;
reference[size++] = sliding_attack(deltas, s, b);
b = (b - masks[s]) & masks[s];
} while (b);
// Set the offset for the table of the next square. We have individual
// table sizes for each square with "Fancy Magic Bitboards".
if (s < SQ_H8)
attacks[s + 1] = attacks[s] + size;
booster = MagicBoosters[Is64Bit][rank_of(s)];
// Find a magic for square 's' picking up an (almost) random number
// until we find the one that passes the verification test.
do {
do magics[s] = pick_random(rk, booster);
while (popcount((magics[s] * masks[s]) >> 56) < 6);
memset(attacks[s], 0, size * sizeof(Bitboard));
// A good magic must map every possible occupancy to an index that
// looks up the correct sliding attack in the attacks[s] database.
// Note that we build up the database for square 's' as a side
// effect of verifying the magic.
for (i = 0; i < size; i++)
{
Bitboard& attack = attacks[s][index(s, occupancy[i])];
if (attack && attack != reference[i])
break;
assert(reference[i] != 0);
attack = reference[i];
}
} while (i != size);
}
}
}
stockfish-3.0.0+git20130508/src/platform.h 0000644 0001750 0001750 00000010376 12142540127 017264 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(PLATFORM_H_INCLUDED)
#define PLATFORM_H_INCLUDED
#if defined(_MSC_VER)
// Disable some silly and noisy warning from MSVC compiler
#pragma warning(disable: 4127) // Conditional expression is constant
#pragma warning(disable: 4146) // Unary minus operator applied to unsigned type
#pragma warning(disable: 4800) // Forcing value to bool 'true' or 'false'
#pragma warning(disable: 4996) // Function _ftime() may be unsafe
// MSVC does not support
typedef signed __int8 int8_t;
typedef unsigned __int8 uint8_t;
typedef signed __int16 int16_t;
typedef unsigned __int16 uint16_t;
typedef signed __int32 int32_t;
typedef unsigned __int32 uint32_t;
typedef signed __int64 int64_t;
typedef unsigned __int64 uint64_t;
#else
# include
# include // Used by sysconf(_SC_NPROCESSORS_ONLN)
#endif
#if !defined(_WIN32) // Linux - Unix
# include
typedef timeval sys_time_t;
inline void system_time(sys_time_t* t) { gettimeofday(t, NULL); }
inline int64_t time_to_msec(const sys_time_t& t) { return t.tv_sec * 1000LL + t.tv_usec / 1000; }
# include
typedef pthread_mutex_t Lock;
typedef pthread_cond_t WaitCondition;
typedef pthread_t NativeHandle;
typedef void*(*pt_start_fn)(void*);
# define lock_init(x) pthread_mutex_init(&(x), NULL)
# define lock_grab(x) pthread_mutex_lock(&(x))
# define lock_release(x) pthread_mutex_unlock(&(x))
# define lock_destroy(x) pthread_mutex_destroy(&(x))
# define cond_destroy(x) pthread_cond_destroy(&(x))
# define cond_init(x) pthread_cond_init(&(x), NULL)
# define cond_signal(x) pthread_cond_signal(&(x))
# define cond_wait(x,y) pthread_cond_wait(&(x),&(y))
# define cond_timedwait(x,y,z) pthread_cond_timedwait(&(x),&(y),z)
# define thread_create(x,f,t) !pthread_create(&(x),NULL,(pt_start_fn)f,t)
# define thread_join(x) pthread_join(x, NULL)
#else // Windows and MinGW
# include
typedef _timeb sys_time_t;
inline void system_time(sys_time_t* t) { _ftime(t); }
inline int64_t time_to_msec(const sys_time_t& t) { return t.time * 1000LL + t.millitm; }
#if !defined(NOMINMAX)
# define NOMINMAX // disable macros min() and max()
#endif
#define WIN32_LEAN_AND_MEAN
#include
#undef WIN32_LEAN_AND_MEAN
#undef NOMINMAX
// We use critical sections on Windows to support Windows XP and older versions,
// unfortunatly cond_wait() is racy between lock_release() and WaitForSingleObject()
// but apart from this they have the same speed performance of SRW locks.
typedef CRITICAL_SECTION Lock;
typedef HANDLE WaitCondition;
typedef HANDLE NativeHandle;
// On Windows 95 and 98 parameter lpThreadId my not be null
inline DWORD* dwWin9xKludge() { static DWORD dw; return &dw; }
# define lock_init(x) InitializeCriticalSection(&(x))
# define lock_grab(x) EnterCriticalSection(&(x))
# define lock_release(x) LeaveCriticalSection(&(x))
# define lock_destroy(x) DeleteCriticalSection(&(x))
# define cond_init(x) { x = CreateEvent(0, FALSE, FALSE, 0); }
# define cond_destroy(x) CloseHandle(x)
# define cond_signal(x) SetEvent(x)
# define cond_wait(x,y) { lock_release(y); WaitForSingleObject(x, INFINITE); lock_grab(y); }
# define cond_timedwait(x,y,z) { lock_release(y); WaitForSingleObject(x,z); lock_grab(y); }
# define thread_create(x,f,t) (x = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)f,t,0,dwWin9xKludge()), x != NULL)
# define thread_join(x) { WaitForSingleObject(x, INFINITE); CloseHandle(x); }
#endif
#endif // !defined(PLATFORM_H_INCLUDED)
stockfish-3.0.0+git20130508/src/uci.cpp 0000644 0001750 0001750 00000016464 12142540127 016557 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include
#include
#include "evaluate.h"
#include "notation.h"
#include "position.h"
#include "search.h"
#include "thread.h"
#include "tt.h"
#include "ucioption.h"
using namespace std;
extern void benchmark(const Position& pos, istream& is);
namespace {
// FEN string of the initial position, normal chess
const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
// Keep track of position keys along the setup moves (from start position to the
// position just before to start searching). Needed by repetition draw detection.
Search::StateStackPtr SetupStates;
void set_option(istringstream& up);
void set_position(Position& pos, istringstream& up);
void go(const Position& pos, istringstream& up);
}
/// Wait for a command from the user, parse this text string as an UCI command,
/// and call the appropriate functions. Also intercepts EOF from stdin to ensure
/// that we exit gracefully if the GUI dies unexpectedly. In addition to the UCI
/// commands, the function also supports a few debug commands.
void UCI::loop(const string& args) {
Position pos(StartFEN, false, Threads.main_thread()); // The root position
string token, cmd = args;
do {
if (args.empty() && !getline(cin, cmd)) // Block here waiting for input
cmd = "quit";
istringstream is(cmd);
is >> skipws >> token;
if (token == "quit" || token == "stop" || token == "ponderhit")
{
// GUI sends 'ponderhit' to tell us to ponder on the same move the
// opponent has played. In case Signals.stopOnPonderhit is set we are
// waiting for 'ponderhit' to stop the search (for instance because we
// already ran out of time), otherwise we should continue searching but
// switching from pondering to normal search.
if (token != "ponderhit" || Search::Signals.stopOnPonderhit)
{
Search::Signals.stop = true;
Threads.main_thread()->notify_one(); // Could be sleeping
}
else
Search::Limits.ponder = false;
}
else if (token == "perft" && (is >> token)) // Read perft depth
{
stringstream ss;
ss << Options["Hash"] << " "
<< Options["Threads"] << " " << token << " current perft";
benchmark(pos, ss);
}
else if (token == "key")
sync_cout << hex << uppercase << setfill('0')
<< "position key: " << setw(16) << pos.key()
<< "\nmaterial key: " << setw(16) << pos.material_key()
<< "\npawn key: " << setw(16) << pos.pawn_key()
<< dec << sync_endl;
else if (token == "uci")
sync_cout << "id name " << engine_info(true)
<< "\n" << Options
<< "\nuciok" << sync_endl;
else if (token == "ucinewgame") TT.clear();
else if (token == "go") go(pos, is);
else if (token == "position") set_position(pos, is);
else if (token == "setoption") set_option(is);
else if (token == "flip") pos.flip();
else if (token == "bench") benchmark(pos, is);
else if (token == "d") sync_cout << pos.pretty() << sync_endl;
else if (token == "isready") sync_cout << "readyok" << sync_endl;
else if (token == "eval") sync_cout << Eval::trace(pos) << sync_endl;
else
sync_cout << "Unknown command: " << cmd << sync_endl;
} while (token != "quit" && args.empty()); // Args have one-shot behaviour
Threads.wait_for_think_finished(); // Cannot quit while search is running
}
namespace {
// set_position() is called when engine receives the "position" UCI command.
// The function sets up the position described in the given fen string ("fen")
// or the starting position ("startpos") and then makes the moves given in the
// following move list ("moves").
void set_position(Position& pos, istringstream& is) {
Move m;
string token, fen;
is >> token;
if (token == "startpos")
{
fen = StartFEN;
is >> token; // Consume "moves" token if any
}
else if (token == "fen")
while (is >> token && token != "moves")
fen += token + " ";
else
return;
pos.set(fen, Options["UCI_Chess960"], Threads.main_thread());
SetupStates = Search::StateStackPtr(new std::stack());
// Parse move list (if any)
while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
{
SetupStates->push(StateInfo());
pos.do_move(m, SetupStates->top());
}
}
// set_option() is called when engine receives the "setoption" UCI command. The
// function updates the UCI option ("name") to the given value ("value").
void set_option(istringstream& is) {
string token, name, value;
is >> token; // Consume "name" token
// Read option name (can contain spaces)
while (is >> token && token != "value")
name += string(" ", !name.empty()) + token;
// Read option value (can contain spaces)
while (is >> token)
value += string(" ", !value.empty()) + token;
if (Options.count(name))
Options[name] = value;
else
sync_cout << "No such option: " << name << sync_endl;
}
// go() is called when engine receives the "go" UCI command. The function sets
// the thinking time and other parameters from the input string, and starts
// the search.
void go(const Position& pos, istringstream& is) {
Search::LimitsType limits;
vector searchMoves;
string token;
while (is >> token)
{
if (token == "searchmoves")
while (is >> token)
searchMoves.push_back(move_from_uci(pos, token));
else if (token == "wtime") is >> limits.time[WHITE];
else if (token == "btime") is >> limits.time[BLACK];
else if (token == "winc") is >> limits.inc[WHITE];
else if (token == "binc") is >> limits.inc[BLACK];
else if (token == "movestogo") is >> limits.movestogo;
else if (token == "depth") is >> limits.depth;
else if (token == "nodes") is >> limits.nodes;
else if (token == "movetime") is >> limits.movetime;
else if (token == "mate") is >> limits.mate;
else if (token == "infinite") limits.infinite = true;
else if (token == "ponder") limits.ponder = true;
}
Threads.start_thinking(pos, limits, searchMoves, SetupStates);
}
}
stockfish-3.0.0+git20130508/src/movegen.h 0000644 0001750 0001750 00000003374 12142540127 017100 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(MOVEGEN_H_INCLUDED)
#define MOVEGEN_H_INCLUDED
#include "types.h"
enum GenType {
CAPTURES,
QUIETS,
QUIET_CHECKS,
EVASIONS,
NON_EVASIONS,
LEGAL
};
class Position;
template
MoveStack* generate(const Position& pos, MoveStack* mlist);
/// The MoveList struct is a simple wrapper around generate(), sometimes comes
/// handy to use this class instead of the low level generate() function.
template
struct MoveList {
explicit MoveList(const Position& pos) : cur(mlist), last(generate(pos, mlist)) {}
void operator++() { cur++; }
bool end() const { return cur == last; }
Move move() const { return cur->move; }
size_t size() const { return last - mlist; }
bool contains(Move m) const {
for (const MoveStack* it(mlist); it != last; ++it) if (it->move == m) return true;
return false;
}
private:
MoveStack mlist[MAX_MOVES];
MoveStack *cur, *last;
};
#endif // !defined(MOVEGEN_H_INCLUDED)
stockfish-3.0.0+git20130508/src/search.h 0000644 0001750 0001750 00000006455 12142540127 016710 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(SEARCH_H_INCLUDED)
#define SEARCH_H_INCLUDED
#include
#include
#include
#include
#include "misc.h"
#include "position.h"
#include "types.h"
struct SplitPoint;
namespace Search {
/// The Stack struct keeps track of the information we need to remember from
/// nodes shallower and deeper in the tree during the search. Each search thread
/// has its own array of Stack objects, indexed by the current ply.
struct Stack {
SplitPoint* splitPoint;
int ply;
Move currentMove;
Move excludedMove;
Move killers[2];
Depth reduction;
Value staticEval;
Value evalMargin;
int skipNullMove;
int futilityMoveCount;
};
/// RootMove struct is used for moves at the root of the tree. For each root
/// move we store a score, a node count, and a PV (really a refutation in the
/// case of moves which fail low). Score is normally set at -VALUE_INFINITE for
/// all non-pv moves.
struct RootMove {
RootMove(Move m) : score(-VALUE_INFINITE), prevScore(-VALUE_INFINITE) {
pv.push_back(m); pv.push_back(MOVE_NONE);
}
bool operator<(const RootMove& m) const { return score > m.score; } // Ascending sort
bool operator==(const Move& m) const { return pv[0] == m; }
void extract_pv_from_tt(Position& pos);
void insert_pv_in_tt(Position& pos);
Value score;
Value prevScore;
std::vector pv;
};
/// The LimitsType struct stores information sent by GUI about available time
/// to search the current move, maximum depth/time, if we are in analysis mode
/// or if we have to ponder while is our opponent's side to move.
struct LimitsType {
LimitsType() { memset(this, 0, sizeof(LimitsType)); }
bool use_time_management() const { return !(mate | movetime | depth | nodes | infinite); }
int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, nodes, movetime, mate, infinite, ponder;
};
/// The SignalsType struct stores volatile flags updated during the search
/// typically in an async fashion, for instance to stop the search by the GUI.
struct SignalsType {
bool stopOnPonderhit, firstRootMove, stop, failedLowAtRoot;
};
typedef std::auto_ptr > StateStackPtr;
extern volatile SignalsType Signals;
extern LimitsType Limits;
extern std::vector RootMoves;
extern Position RootPos;
extern Color RootColor;
extern Time::point SearchTime;
extern StateStackPtr SetupStates;
extern void init();
extern size_t perft(Position& pos, Depth depth);
extern void think();
} // namespace Search
#endif // !defined(SEARCH_H_INCLUDED)
stockfish-3.0.0+git20130508/src/misc.h 0000644 0001750 0001750 00000003616 12142540127 016372 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(MISC_H_INCLUDED)
#define MISC_H_INCLUDED
#include
#include
#include
#include "types.h"
extern const std::string engine_info(bool to_uci = false);
extern int cpu_count();
extern void timed_wait(WaitCondition&, Lock&, int);
extern void prefetch(char* addr);
extern void start_logger(bool b);
extern void dbg_hit_on(bool b);
extern void dbg_hit_on_c(bool c, bool b);
extern void dbg_mean_of(int v);
extern void dbg_print();
struct Log : public std::ofstream {
Log(const std::string& f = "log.txt") : std::ofstream(f.c_str(), std::ios::out | std::ios::app) {}
~Log() { if (is_open()) close(); }
};
namespace Time {
typedef int64_t point;
point now();
}
template
struct HashTable {
HashTable() : e(Size, Entry()) {}
Entry* operator[](Key k) { return &e[(uint32_t)k & (Size - 1)]; }
private:
std::vector e;
};
enum SyncCout { io_lock, io_unlock };
std::ostream& operator<<(std::ostream&, SyncCout);
#define sync_cout std::cout << io_lock
#define sync_endl std::endl << io_unlock
#endif // !defined(MISC_H_INCLUDED)
stockfish-3.0.0+git20130508/src/movepick.cpp 0000644 0001750 0001750 00000025742 12142540127 017613 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include "movepick.h"
#include "thread.h"
namespace {
enum Sequencer {
MAIN_SEARCH, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1, QUIETS_2_S1, BAD_CAPTURES_S1,
EVASION, EVASIONS_S2,
QSEARCH_0, CAPTURES_S3, QUIET_CHECKS_S3,
QSEARCH_1, CAPTURES_S4,
PROBCUT, CAPTURES_S5,
RECAPTURE, CAPTURES_S6,
STOP
};
// Our insertion sort, guaranteed to be stable, as is needed
void insertion_sort(MoveStack* begin, MoveStack* end)
{
MoveStack tmp, *p, *q;
for (p = begin + 1; p < end; ++p)
{
tmp = *p;
for (q = p; q != begin && *(q-1) < tmp; --q)
*q = *(q-1);
*q = tmp;
}
}
// Unary predicate used by std::partition to split positive scores from remaining
// ones so to sort separately the two sets, and with the second sort delayed.
inline bool has_positive_score(const MoveStack& ms) { return ms.score > 0; }
// Picks and moves to the front the best move in the range [begin, end),
// it is faster than sorting all the moves in advance when moves are few, as
// normally are the possible captures.
inline MoveStack* pick_best(MoveStack* begin, MoveStack* end)
{
std::swap(*begin, *std::max_element(begin, end));
return begin;
}
}
/// Constructors of the MovePicker class. As arguments we pass information
/// to help it to return the presumably good moves first, to decide which
/// moves to return (in the quiescence search, for instance, we only want to
/// search captures, promotions and some checks) and about how important good
/// move ordering is at the current node.
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
Search::Stack* s, Value beta) : pos(p), Hist(h), depth(d) {
assert(d > DEPTH_ZERO);
captureThreshold = 0;
cur = end = moves;
endBadCaptures = moves + MAX_MOVES - 1;
ss = s;
if (p.checkers())
phase = EVASION;
else
{
phase = MAIN_SEARCH;
killers[0].move = ss->killers[0];
killers[1].move = ss->killers[1];
// Consider sligtly negative captures as good if at low depth and far from beta
if (ss && ss->staticEval < beta - PawnValueMg && d < 3 * ONE_PLY)
captureThreshold = -PawnValueMg;
// Consider negative captures as good if still enough to reach beta
else if (ss && ss->staticEval > beta)
captureThreshold = beta - ss->staticEval;
}
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
end += (ttMove != MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
Square sq) : pos(p), Hist(h), cur(moves), end(moves) {
assert(d <= DEPTH_ZERO);
if (p.checkers())
phase = EVASION;
else if (d > DEPTH_QS_NO_CHECKS)
phase = QSEARCH_0;
else if (d > DEPTH_QS_RECAPTURES)
{
phase = QSEARCH_1;
// Skip TT move if is not a capture or a promotion, this avoids qsearch
// tree explosion due to a possible perpetual check or similar rare cases
// when TT table is full.
if (ttm && !pos.is_capture_or_promotion(ttm))
ttm = MOVE_NONE;
}
else
{
phase = RECAPTURE;
recaptureSquare = sq;
ttm = MOVE_NONE;
}
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
end += (ttMove != MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt)
: pos(p), Hist(h), cur(moves), end(moves) {
assert(!pos.checkers());
phase = PROBCUT;
// In ProbCut we generate only captures better than parent's captured piece
captureThreshold = PieceValue[MG][pt];
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
if (ttMove && (!pos.is_capture(ttMove) || pos.see(ttMove) <= captureThreshold))
ttMove = MOVE_NONE;
end += (ttMove != MOVE_NONE);
}
/// score() assign a numerical move ordering score to each move in a move list.
/// The moves with highest scores will be picked first.
template<>
void MovePicker::score() {
// Winning and equal captures in the main search are ordered by MVV/LVA.
// Suprisingly, this appears to perform slightly better than SEE based
// move ordering. The reason is probably that in a position with a winning
// capture, capturing a more valuable (but sufficiently defended) piece
// first usually doesn't hurt. The opponent will have to recapture, and
// the hanging piece will still be hanging (except in the unusual cases
// where it is possible to recapture with the hanging piece). Exchanging
// big pieces before capturing a hanging piece probably helps to reduce
// the subtree size.
// In main search we want to push captures with negative SEE values to
// badCaptures[] array, but instead of doing it now we delay till when
// the move has been picked up in pick_move_from_list(), this way we save
// some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
Move m;
for (MoveStack* it = moves; it != end; ++it)
{
m = it->move;
it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- type_of(pos.piece_moved(m));
if (type_of(m) == PROMOTION)
it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
else if (type_of(m) == ENPASSANT)
it->score += PieceValue[MG][PAWN];
}
}
template<>
void MovePicker::score() {
Move m;
for (MoveStack* it = moves; it != end; ++it)
{
m = it->move;
it->score = Hist[pos.piece_moved(m)][to_sq(m)];
}
}
template<>
void MovePicker::score() {
// Try good captures ordered by MVV/LVA, then non-captures if destination square
// is not under attack, ordered by history value, then bad-captures and quiet
// moves with a negative SEE. This last group is ordered by the SEE score.
Move m;
int seeScore;
for (MoveStack* it = moves; it != end; ++it)
{
m = it->move;
if ((seeScore = pos.see_sign(m)) < 0)
it->score = seeScore - History::Max; // At the bottom
else if (pos.is_capture(m))
it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- type_of(pos.piece_moved(m)) + History::Max;
else
it->score = Hist[pos.piece_moved(m)][to_sq(m)];
}
}
/// generate_next() generates, scores and sorts the next bunch of moves, when
/// there are no more moves to try for the current phase.
void MovePicker::generate_next() {
cur = moves;
switch (++phase) {
case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
end = generate(pos, moves);
score();
return;
case KILLERS_S1:
cur = killers;
end = cur + 2;
return;
case QUIETS_1_S1:
endQuiets = end = generate(pos, moves);
score();
end = std::partition(cur, end, has_positive_score);
insertion_sort(cur, end);
return;
case QUIETS_2_S1:
cur = end;
end = endQuiets;
if (depth >= 3 * ONE_PLY)
insertion_sort(cur, end);
return;
case BAD_CAPTURES_S1:
// Just pick them in reverse order to get MVV/LVA ordering
cur = moves + MAX_MOVES - 1;
end = endBadCaptures;
return;
case EVASIONS_S2:
end = generate(pos, moves);
if (end > moves + 1)
score();
return;
case QUIET_CHECKS_S3:
end = generate(pos, moves);
return;
case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
phase = STOP;
case STOP:
end = cur + 1; // Avoid another next_phase() call
return;
default:
assert(false);
}
}
/// next_move() is the most important method of the MovePicker class. It returns
/// a new pseudo legal move every time is called, until there are no more moves
/// left. It picks the move with the biggest score from a list of generated moves
/// taking care not returning the ttMove if has already been searched previously.
template<>
Move MovePicker::next_move() {
Move move;
while (true)
{
while (cur == end)
generate_next();
switch (phase) {
case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
cur++;
return ttMove;
case CAPTURES_S1:
move = pick_best(cur++, end)->move;
if (move != ttMove)
{
assert(captureThreshold <= 0); // Otherwise we cannot use see_sign()
if (pos.see_sign(move) >= captureThreshold)
return move;
// Losing capture, move it to the tail of the array
(endBadCaptures--)->move = move;
}
break;
case KILLERS_S1:
move = (cur++)->move;
if ( move != MOVE_NONE
&& pos.is_pseudo_legal(move)
&& move != ttMove
&& !pos.is_capture(move))
return move;
break;
case QUIETS_1_S1: case QUIETS_2_S1:
move = (cur++)->move;
if ( move != ttMove
&& move != killers[0].move
&& move != killers[1].move)
return move;
break;
case BAD_CAPTURES_S1:
return (cur--)->move;
case EVASIONS_S2: case CAPTURES_S3: case CAPTURES_S4:
move = pick_best(cur++, end)->move;
if (move != ttMove)
return move;
break;
case CAPTURES_S5:
move = pick_best(cur++, end)->move;
if (move != ttMove && pos.see(move) > captureThreshold)
return move;
break;
case CAPTURES_S6:
move = pick_best(cur++, end)->move;
if (to_sq(move) == recaptureSquare)
return move;
break;
case QUIET_CHECKS_S3:
move = (cur++)->move;
if (move != ttMove)
return move;
break;
case STOP:
return MOVE_NONE;
default:
assert(false);
}
}
}
/// Version of next_move() to use at split point nodes where the move is grabbed
/// from the split point's shared MovePicker object. This function is not thread
/// safe so must be lock protected by the caller.
template<>
Move MovePicker::next_move() { return ss->splitPoint->movePicker->next_move(); }
stockfish-3.0.0+git20130508/src/movegen.cpp 0000644 0001750 0001750 00000035160 12142540127 017431 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include "movegen.h"
#include "position.h"
/// Simple macro to wrap a very common while loop, no facny, no flexibility,
/// hardcoded names 'mlist' and 'from'.
#define SERIALIZE(b) while (b) (*mlist++).move = make_move(from, pop_lsb(&b))
/// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
#define SERIALIZE_PAWNS(b, d) while (b) { Square to = pop_lsb(&b); \
(*mlist++).move = make_move(to - (d), to); }
namespace {
template
MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
if (pos.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side)))
return mlist;
// After castling, the rook and king final positions are the same in Chess960
// as they would be in standard chess.
Square kfrom = pos.king_square(us);
Square rfrom = pos.castle_rook_square(us, Side);
Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
Bitboard enemies = pos.pieces(~us);
assert(!pos.checkers());
const int K = Chess960 ? kto > kfrom ? -1 : 1
: Side == KING_SIDE ? -1 : 1;
for (Square s = kto; s != kfrom; s += (Square)K)
if (pos.attackers_to(s) & enemies)
return mlist;
// Because we generate only legal castling moves we need to verify that
// when moving the castling rook we do not discover some hidden checker.
// For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
if (Chess960 && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
return mlist;
(*mlist++).move = make(kfrom, rfrom);
if (Checks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
mlist--;
return mlist;
}
template
inline Bitboard move_pawns(Bitboard p) {
return Delta == DELTA_N ? p << 8
: Delta == DELTA_S ? p >> 8
: Delta == DELTA_NE ? (p & ~FileHBB) << 9
: Delta == DELTA_SE ? (p & ~FileHBB) >> 7
: Delta == DELTA_NW ? (p & ~FileABB) << 7
: Delta == DELTA_SW ? (p & ~FileABB) >> 9 : 0;
}
template
inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7,
Bitboard target, const CheckInfo* ci) {
Bitboard b = move_pawns(pawnsOn7) & target;
while (b)
{
Square to = pop_lsb(&b);
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
(*mlist++).move = make(to - Delta, to, QUEEN);
if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
(*mlist++).move = make(to - Delta, to, ROOK);
(*mlist++).move = make(to - Delta, to, BISHOP);
(*mlist++).move = make(to - Delta, to, KNIGHT);
}
// Knight-promotion is the only one that can give a direct check not
// already included in the queen-promotion.
if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
(*mlist++).move = make(to - Delta, to, KNIGHT);
else
(void)ci; // Silence a warning under MSVC
}
return mlist;
}
template
MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist,
Bitboard target, const CheckInfo* ci) {
// Compute our parametrized parameters at compile time, named according to
// the point of view of white side.
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
const Square RIGHT = (Us == WHITE ? DELTA_NE : DELTA_SW);
const Square LEFT = (Us == WHITE ? DELTA_NW : DELTA_SE);
Bitboard b1, b2, dc1, dc2, emptySquares;
Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB;
Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
Bitboard enemies = (Type == EVASIONS ? pos.pieces(Them) & target:
Type == CAPTURES ? target : pos.pieces(Them));
// Single and double pawn pushes, no promotions
if (Type != CAPTURES)
{
emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
b1 = move_pawns(pawnsNotOn7) & emptySquares;
b2 = move_pawns(b1 & TRank3BB) & emptySquares;
if (Type == EVASIONS) // Consider only blocking squares
{
b1 &= target;
b2 &= target;
}
if (Type == QUIET_CHECKS)
{
b1 &= pos.attacks_from(ci->ksq, Them);
b2 &= pos.attacks_from(ci->ksq, Them);
// Add pawn pushes which give discovered check. This is possible only
// if the pawn is not on the same file as the enemy king, because we
// don't generate captures. Note that a possible discovery check
// promotion has been already generated among captures.
if (pawnsNotOn7 & ci->dcCandidates)
{
dc1 = move_pawns(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
dc2 = move_pawns(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
}
}
SERIALIZE_PAWNS(b1, UP);
SERIALIZE_PAWNS(b2, UP + UP);
}
// Promotions and underpromotions
if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB)))
{
if (Type == CAPTURES)
emptySquares = ~pos.pieces();
if (Type == EVASIONS)
emptySquares &= target;
mlist = generate_promotions(mlist, pawnsOn7, enemies, ci);
mlist = generate_promotions(mlist, pawnsOn7, enemies, ci);
mlist = generate_promotions(mlist, pawnsOn7, emptySquares, ci);
}
// Standard and en-passant captures
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
{
b1 = move_pawns(pawnsNotOn7) & enemies;
b2 = move_pawns(pawnsNotOn7) & enemies;
SERIALIZE_PAWNS(b1, RIGHT);
SERIALIZE_PAWNS(b2, LEFT);
if (pos.ep_square() != SQ_NONE)
{
assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
// An en passant capture can be an evasion only if the checking piece
// is the double pushed pawn and so is in the target. Otherwise this
// is a discovery check and we are forced to do otherwise.
if (Type == EVASIONS && !(target & (pos.ep_square() - UP)))
return mlist;
b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them);
assert(b1);
while (b1)
(*mlist++).move = make(pop_lsb(&b1), pos.ep_square());
}
}
return mlist;
}
template FORCE_INLINE
MoveStack* generate_moves(const Position& pos, MoveStack* mlist, Color us,
Bitboard target, const CheckInfo* ci) {
assert(Pt != KING && Pt != PAWN);
const Square* pl = pos.piece_list(us, Pt);
for (Square from = *pl; from != SQ_NONE; from = *++pl)
{
if (Checks)
{
if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
&& !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
continue;
if (ci->dcCandidates && (ci->dcCandidates & from))
continue;
}
Bitboard b = pos.attacks_from(from) & target;
if (Checks)
b &= ci->checkSq[Pt];
SERIALIZE(b);
}
return mlist;
}
template FORCE_INLINE
MoveStack* generate_all(const Position& pos, MoveStack* mlist, Color us,
Bitboard target, const CheckInfo* ci = NULL) {
const bool Checks = Type == QUIET_CHECKS;
mlist = (us == WHITE ? generate_pawn_moves(pos, mlist, target, ci)
: generate_pawn_moves(pos, mlist, target, ci));
mlist = generate_moves(pos, mlist, us, target, ci);
mlist = generate_moves(pos, mlist, us, target, ci);
mlist = generate_moves(pos, mlist, us, target, ci);
mlist = generate_moves(pos, mlist, us, target, ci);
if (Type != QUIET_CHECKS && Type != EVASIONS)
{
Square from = pos.king_square(us);
Bitboard b = pos.attacks_from(from) & target;
SERIALIZE(b);
}
if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
{
if (pos.is_chess960())
{
mlist = generate_castle(pos, mlist, us);
mlist = generate_castle(pos, mlist, us);
}
else
{
mlist = generate_castle(pos, mlist, us);
mlist = generate_castle(pos, mlist, us);
}
}
return mlist;
}
} // namespace
/// generate generates all pseudo-legal captures and queen
/// promotions. Returns a pointer to the end of the move list.
///
/// generate generates all pseudo-legal non-captures and
/// underpromotions. Returns a pointer to the end of the move list.
///
/// generate generates all pseudo-legal captures and
/// non-captures. Returns a pointer to the end of the move list.
template
MoveStack* generate(const Position& pos, MoveStack* mlist) {
assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
assert(!pos.checkers());
Color us = pos.side_to_move();
Bitboard target = Type == CAPTURES ? pos.pieces(~us)
: Type == QUIETS ? ~pos.pieces()
: Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
return generate_all(pos, mlist, us, target);
}
// Explicit template instantiations
template MoveStack* generate(const Position&, MoveStack*);
template MoveStack* generate(const Position&, MoveStack*);
template MoveStack* generate(const Position&, MoveStack*);
/// generate generates all pseudo-legal non-captures and knight
/// underpromotions that give check. Returns a pointer to the end of the move list.
template<>
MoveStack* generate(const Position& pos, MoveStack* mlist) {
assert(!pos.checkers());
CheckInfo ci(pos);
Bitboard dc = ci.dcCandidates;
while (dc)
{
Square from = pop_lsb(&dc);
PieceType pt = type_of(pos.piece_on(from));
if (pt == PAWN)
continue; // Will be generated togheter with direct checks
Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
if (pt == KING)
b &= ~PseudoAttacks[QUEEN][ci.ksq];
SERIALIZE(b);
}
return generate_all(pos, mlist, pos.side_to_move(), ~pos.pieces(), &ci);
}
/// generate generates all pseudo-legal check evasions when the side
/// to move is in check. Returns a pointer to the end of the move list.
template<>
MoveStack* generate(const Position& pos, MoveStack* mlist) {
assert(pos.checkers());
Square from, checksq;
int checkersCnt = 0;
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
Bitboard sliderAttacks = 0;
Bitboard b = pos.checkers();
assert(pos.checkers());
// Find squares attacked by slider checkers, we will remove them from the king
// evasions so to skip known illegal moves avoiding useless legality check later.
do
{
checkersCnt++;
checksq = pop_lsb(&b);
assert(color_of(pos.piece_on(checksq)) == ~us);
switch (type_of(pos.piece_on(checksq)))
{
case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break;
case QUEEN:
// If queen and king are far or not on a diagonal line we can safely
// remove all the squares attacked in the other direction becuase are
// not reachable by the king anyway.
if (between_bb(ksq, checksq) || !(PseudoAttacks[BISHOP][checksq] & ksq))
sliderAttacks |= PseudoAttacks[QUEEN][checksq];
// Otherwise we need to use real rook attacks to check if king is safe
// to move in the other direction. For example: king in B2, queen in A1
// a knight in B1, and we can safely move to C1.
else
sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from(checksq);
default:
break;
}
} while (b);
// Generate evasions for king, capture and non capture moves
b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks;
from = ksq;
SERIALIZE(b);
if (checkersCnt > 1)
return mlist; // Double check, only a king move can save the day
// Generate blocking evasions or captures of the checking piece
Bitboard target = between_bb(checksq, ksq) | pos.checkers();
return generate_all(pos, mlist, us, target);
}
/// generate generates all the legal moves in the given position
template<>
MoveStack* generate(const Position& pos, MoveStack* mlist) {
MoveStack *end, *cur = mlist;
Bitboard pinned = pos.pinned_pieces();
Square ksq = pos.king_square(pos.side_to_move());
end = pos.checkers() ? generate(pos, mlist)
: generate(pos, mlist);
while (cur != end)
if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
&& !pos.pl_move_is_legal(cur->move, pinned))
cur->move = (--end)->move;
else
cur++;
return end;
}
stockfish-3.0.0+git20130508/src/timeman.h 0000644 0001750 0001750 00000002666 12142540127 017075 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(TIMEMAN_H_INCLUDED)
#define TIMEMAN_H_INCLUDED
/// The TimeManager class computes the optimal time to think depending on the
/// maximum available time, the move game number and other parameters.
class TimeManager {
public:
void init(const Search::LimitsType& limits, int currentPly, Color us);
void pv_instability(int curChanges, int prevChanges);
int available_time() const { return optimumSearchTime + unstablePVExtraTime; }
int maximum_time() const { return maximumSearchTime; }
private:
int optimumSearchTime;
int maximumSearchTime;
int unstablePVExtraTime;
};
#endif // !defined(TIMEMAN_H_INCLUDED)
stockfish-3.0.0+git20130508/src/endgame.cpp 0000644 0001750 0001750 00000105156 12142540127 017374 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include "bitboard.h"
#include "bitcount.h"
#include "endgame.h"
#include "movegen.h"
using std::string;
namespace {
// Table used to drive the defending king towards the edge of the board
// in KX vs K and KQ vs KR endgames.
const int MateTable[SQUARE_NB] = {
100, 90, 80, 70, 70, 80, 90, 100,
90, 70, 60, 50, 50, 60, 70, 90,
80, 60, 40, 30, 30, 40, 60, 80,
70, 50, 30, 20, 20, 30, 50, 70,
70, 50, 30, 20, 20, 30, 50, 70,
80, 60, 40, 30, 30, 40, 60, 80,
90, 70, 60, 50, 50, 60, 70, 90,
100, 90, 80, 70, 70, 80, 90, 100,
};
// Table used to drive the defending king towards a corner square of the
// right color in KBN vs K endgames.
const int KBNKMateTable[SQUARE_NB] = {
200, 190, 180, 170, 160, 150, 140, 130,
190, 180, 170, 160, 150, 140, 130, 140,
180, 170, 155, 140, 140, 125, 140, 150,
170, 160, 140, 120, 110, 140, 150, 160,
160, 150, 140, 110, 120, 140, 160, 170,
150, 140, 125, 140, 140, 155, 170, 180,
140, 130, 140, 150, 160, 170, 180, 190,
130, 140, 150, 160, 170, 180, 190, 200
};
// The attacking side is given a descending bonus based on distance between
// the two kings in basic endgames.
const int DistanceBonus[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
// Get the material key of a Position out of the given endgame key code
// like "KBPKN". The trick here is to first forge an ad-hoc fen string
// and then let a Position object to do the work for us. Note that the
// fen string could correspond to an illegal position.
Key key(const string& code, Color c) {
assert(code.length() > 0 && code.length() < 8);
assert(code[0] == 'K');
string sides[] = { code.substr(code.find('K', 1)), // Weaker
code.substr(0, code.find('K', 1)) }; // Stronger
std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
string fen = sides[0] + char('0' + int(8 - code.length()))
+ sides[1] + "/8/8/8/8/8/8/8 w - - 0 10";
return Position(fen, false, NULL).material_key();
}
template
void delete_endgame(const typename M::value_type& p) { delete p.second; }
} // namespace
/// Endgames members definitions
Endgames::Endgames() {
add("KPK");
add("KNNK");
add("KBNK");
add("KRKP");
add("KRKB");
add("KRKN");
add("KQKP");
add("KQKR");
add("KBBKN");
add("KNPK");
add("KNPKB");
add("KRPKR");
add("KBPKB");
add("KBPKN");
add("KBPPKB");
add("KRPPKRP");
}
Endgames::~Endgames() {
for_each(m1.begin(), m1.end(), delete_endgame);
for_each(m2.begin(), m2.end(), delete_endgame);
}
template
void Endgames::add(const string& code) {
map((Endgame*)0)[key(code, WHITE)] = new Endgame(WHITE);
map((Endgame*)0)[key(code, BLACK)] = new Endgame(BLACK);
}
/// Mate with KX vs K. This function is used to evaluate positions with
/// King and plenty of material vs a lone king. It simply gives the
/// attacking side a bonus for driving the defending king towards the edge
/// of the board, and for keeping the distance between the two kings small.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
// Stalemate detection with lone king
if ( pos.side_to_move() == weakerSide
&& !pos.checkers()
&& !MoveList(pos).size()) {
return VALUE_DRAW;
}
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Value result = pos.non_pawn_material(strongerSide)
+ pos.piece_count(strongerSide, PAWN) * PawnValueEg
+ MateTable[loserKSq]
+ DistanceBonus[square_distance(winnerKSq, loserKSq)];
if ( pos.piece_count(strongerSide, QUEEN)
|| pos.piece_count(strongerSide, ROOK)
|| pos.bishop_pair(strongerSide)) {
result += VALUE_KNOWN_WIN;
}
return strongerSide == pos.side_to_move() ? result : -result;
}
/// Mate with KBN vs K. This is similar to KX vs K, but we have to drive the
/// defending king towards a corner square of the right color.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
assert(pos.non_pawn_material(strongerSide) == KnightValueMg + BishopValueMg);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(strongerSide, KNIGHT) == 1);
assert(pos.piece_count(strongerSide, PAWN) == 0);
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square bishopSq = pos.piece_list(strongerSide, BISHOP)[0];
// kbnk_mate_table() tries to drive toward corners A1 or H8,
// if we have a bishop that cannot reach the above squares we
// mirror the kings so to drive enemy toward corners A8 or H1.
if (opposite_colors(bishopSq, SQ_A1))
{
winnerKSq = mirror(winnerKSq);
loserKSq = mirror(loserKSq);
}
Value result = VALUE_KNOWN_WIN
+ DistanceBonus[square_distance(winnerKSq, loserKSq)]
+ KBNKMateTable[loserKSq];
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KP vs K. This endgame is evaluated with the help of a bitbase.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(strongerSide, PAWN) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square wksq, bksq, wpsq;
Color us;
if (strongerSide == WHITE)
{
wksq = pos.king_square(WHITE);
bksq = pos.king_square(BLACK);
wpsq = pos.piece_list(WHITE, PAWN)[0];
us = pos.side_to_move();
}
else
{
wksq = ~pos.king_square(BLACK);
bksq = ~pos.king_square(WHITE);
wpsq = ~pos.piece_list(BLACK, PAWN)[0];
us = ~pos.side_to_move();
}
if (file_of(wpsq) >= FILE_E)
{
wksq = mirror(wksq);
bksq = mirror(bksq);
wpsq = mirror(wpsq);
}
if (!Bitbases::probe_kpk(wksq, wpsq, bksq, us))
return VALUE_DRAW;
Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(wpsq));
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KR vs KP. This is a somewhat tricky endgame to evaluate precisely without
/// a bitbase. The function below returns drawish scores when the pawn is
/// far advanced with support of the king, while the attacking king is far
/// away.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.non_pawn_material(weakerSide) == 0);
assert(pos.piece_count(weakerSide, PAWN) == 1);
Square wksq, wrsq, bksq, bpsq;
int tempo = (pos.side_to_move() == strongerSide);
wksq = pos.king_square(strongerSide);
wrsq = pos.piece_list(strongerSide, ROOK)[0];
bksq = pos.king_square(weakerSide);
bpsq = pos.piece_list(weakerSide, PAWN)[0];
if (strongerSide == BLACK)
{
wksq = ~wksq;
wrsq = ~wrsq;
bksq = ~bksq;
bpsq = ~bpsq;
}
Square queeningSq = file_of(bpsq) | RANK_1;
Value result;
// If the stronger side's king is in front of the pawn, it's a win
if (wksq < bpsq && file_of(wksq) == file_of(bpsq))
result = RookValueEg - Value(square_distance(wksq, bpsq));
// If the weaker side's king is too far from the pawn and the rook,
// it's a win
else if ( square_distance(bksq, bpsq) - (tempo ^ 1) >= 3
&& square_distance(bksq, wrsq) >= 3)
result = RookValueEg - Value(square_distance(wksq, bpsq));
// If the pawn is far advanced and supported by the defending king,
// the position is drawish
else if ( rank_of(bksq) <= RANK_3
&& square_distance(bksq, bpsq) == 1
&& rank_of(wksq) >= RANK_4
&& square_distance(wksq, bpsq) - tempo > 2)
result = Value(80 - square_distance(wksq, bpsq) * 8);
else
result = Value(200)
- Value(square_distance(wksq, bpsq + DELTA_S) * 8)
+ Value(square_distance(bksq, bpsq + DELTA_S) * 8)
+ Value(square_distance(bpsq, queeningSq) * 8);
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KR vs KB. This is very simple, and always returns drawish scores. The
/// score is slightly bigger when the defending king is close to the edge.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.non_pawn_material(weakerSide) == BishopValueMg);
assert(pos.piece_count(weakerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
Value result = Value(MateTable[pos.king_square(weakerSide)]);
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KR vs KN. The attacking side has slightly better winning chances than
/// in KR vs KB, particularly if the king and the knight are far apart.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.non_pawn_material(weakerSide) == KnightValueMg);
assert(pos.piece_count(weakerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, KNIGHT) == 1);
const int penalty[8] = { 0, 10, 14, 20, 30, 42, 58, 80 };
Square bksq = pos.king_square(weakerSide);
Square bnsq = pos.piece_list(weakerSide, KNIGHT)[0];
Value result = Value(MateTable[bksq] + penalty[square_distance(bksq, bnsq)]);
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KQ vs KP. In general, a win for the stronger side, however, there are a few
/// important exceptions. Pawn on 7th rank, A,C,F or H file, with king next can
/// be a draw, so we scale down to distance between kings only.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.non_pawn_material(weakerSide) == 0);
assert(pos.piece_count(weakerSide, PAWN) == 1);
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square pawnSq = pos.piece_list(weakerSide, PAWN)[0];
Value result = QueenValueEg
- PawnValueEg
+ DistanceBonus[square_distance(winnerKSq, loserKSq)];
if ( square_distance(loserKSq, pawnSq) == 1
&& relative_rank(weakerSide, pawnSq) == RANK_7)
{
File f = file_of(pawnSq);
if (f == FILE_A || f == FILE_C || f == FILE_F || f == FILE_H)
result = Value(DistanceBonus[square_distance(winnerKSq, loserKSq)]);
}
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KQ vs KR. This is almost identical to KX vs K: We give the attacking
/// king a bonus for having the kings close together, and for forcing the
/// defending king towards the edge. If we also take care to avoid null move
/// for the defending side in the search, this is usually sufficient to be
/// able to win KQ vs KR.
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.non_pawn_material(weakerSide) == RookValueMg);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Value result = QueenValueEg
- RookValueEg
+ MateTable[loserKSq]
+ DistanceBonus[square_distance(winnerKSq, loserKSq)];
return strongerSide == pos.side_to_move() ? result : -result;
}
template<>
Value Endgame::operator()(const Position& pos) const {
assert(pos.piece_count(strongerSide, BISHOP) == 2);
assert(pos.non_pawn_material(strongerSide) == 2*BishopValueMg);
assert(pos.piece_count(weakerSide, KNIGHT) == 1);
assert(pos.non_pawn_material(weakerSide) == KnightValueMg);
assert(!pos.pieces(PAWN));
Value result = BishopValueEg;
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
Square nsq = pos.piece_list(weakerSide, KNIGHT)[0];
// Bonus for attacking king close to defending king
result += Value(DistanceBonus[square_distance(wksq, bksq)]);
// Bonus for driving the defending king and knight apart
result += Value(square_distance(bksq, nsq) * 32);
// Bonus for restricting the knight's mobility
result += Value((8 - popcount(pos.attacks_from(nsq))) * 8);
return strongerSide == pos.side_to_move() ? result : -result;
}
/// K and two minors vs K and one or two minors or K and two knights against
/// king alone are always draw.
template<>
Value Endgame::operator()(const Position&) const {
return VALUE_DRAW;
}
template<>
Value Endgame::operator()(const Position&) const {
return VALUE_DRAW;
}
/// K, bishop and one or more pawns vs K. It checks for draws with rook pawns and
/// a bishop of the wrong color. If such a draw is detected, SCALE_FACTOR_DRAW
/// is returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling
/// will be used.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMg);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(strongerSide, PAWN) >= 1);
// No assertions about the material of weakerSide, because we want draws to
// be detected even when the weaker side has some pawns.
Bitboard pawns = pos.pieces(strongerSide, PAWN);
File pawnFile = file_of(pos.piece_list(strongerSide, PAWN)[0]);
// All pawns are on a single rook file ?
if ( (pawnFile == FILE_A || pawnFile == FILE_H)
&& !(pawns & ~file_bb(pawnFile)))
{
Square bishopSq = pos.piece_list(strongerSide, BISHOP)[0];
Square queeningSq = relative_square(strongerSide, pawnFile | RANK_8);
Square kingSq = pos.king_square(weakerSide);
if ( opposite_colors(queeningSq, bishopSq)
&& abs(file_of(kingSq) - pawnFile) <= 1)
{
// The bishop has the wrong color, and the defending king is on the
// file of the pawn(s) or the adjacent file. Find the rank of the
// frontmost pawn.
Rank rank;
if (strongerSide == WHITE)
{
for (rank = RANK_7; !(rank_bb(rank) & pawns); rank--) {}
assert(rank >= RANK_2 && rank <= RANK_7);
}
else
{
for (rank = RANK_2; !(rank_bb(rank) & pawns); rank++) {}
rank = Rank(rank ^ 7); // HACK to get the relative rank
assert(rank >= RANK_2 && rank <= RANK_7);
}
// If the defending king has distance 1 to the promotion square or
// is placed somewhere in front of the pawn, it's a draw.
if ( square_distance(kingSq, queeningSq) <= 1
|| relative_rank(strongerSide, kingSq) >= rank)
return SCALE_FACTOR_DRAW;
}
}
// All pawns on same B or G file? Then potential draw
if ( (pawnFile == FILE_B || pawnFile == FILE_G)
&& !(pos.pieces(PAWN) & ~file_bb(pawnFile))
&& pos.non_pawn_material(weakerSide) == 0
&& pos.piece_count(weakerSide, PAWN) >= 1)
{
// Get weaker pawn closest to opponent's queening square
Bitboard wkPawns = pos.pieces(weakerSide, PAWN);
Square weakerPawnSq = strongerSide == WHITE ? msb(wkPawns) : lsb(wkPawns);
Square strongerKingSq = pos.king_square(strongerSide);
Square weakerKingSq = pos.king_square(weakerSide);
Square bishopSq = pos.piece_list(strongerSide, BISHOP)[0];
// Draw if weaker pawn is on rank 7, bishop can't attack the pawn, and
// weaker king can stop opposing opponent's king from penetrating.
if ( relative_rank(strongerSide, weakerPawnSq) == RANK_7
&& opposite_colors(bishopSq, weakerPawnSq)
&& square_distance(weakerPawnSq, weakerKingSq) <= square_distance(weakerPawnSq, strongerKingSq))
return SCALE_FACTOR_DRAW;
}
return SCALE_FACTOR_NONE;
}
/// K and queen vs K, rook and one or more pawns. It tests for fortress draws with
/// a rook on the third rank defended by a pawn.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMg);
assert(pos.piece_count(strongerSide, QUEEN) == 1);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, ROOK) == 1);
assert(pos.piece_count(weakerSide, PAWN) >= 1);
Square kingSq = pos.king_square(weakerSide);
if ( relative_rank(weakerSide, kingSq) <= RANK_2
&& relative_rank(weakerSide, pos.king_square(strongerSide)) >= RANK_4
&& (pos.pieces(weakerSide, ROOK) & rank_bb(relative_rank(weakerSide, RANK_3)))
&& (pos.pieces(weakerSide, PAWN) & rank_bb(relative_rank(weakerSide, RANK_2)))
&& (pos.attacks_from(kingSq) & pos.pieces(weakerSide, PAWN)))
{
Square rsq = pos.piece_list(weakerSide, ROOK)[0];
if (pos.attacks_from(rsq, strongerSide) & pos.pieces(weakerSide, PAWN))
return SCALE_FACTOR_DRAW;
}
return SCALE_FACTOR_NONE;
}
/// K, rook and one pawn vs K and a rook. This function knows a handful of the
/// most important classes of drawn positions, but is far from perfect. It would
/// probably be a good idea to add more knowledge in the future.
///
/// It would also be nice to rewrite the actual code for this function,
/// which is mostly copied from Glaurung 1.x, and not very pretty.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 1);
assert(pos.non_pawn_material(weakerSide) == RookValueMg);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square wksq = pos.king_square(strongerSide);
Square wrsq = pos.piece_list(strongerSide, ROOK)[0];
Square wpsq = pos.piece_list(strongerSide, PAWN)[0];
Square bksq = pos.king_square(weakerSide);
Square brsq = pos.piece_list(weakerSide, ROOK)[0];
// Orient the board in such a way that the stronger side is white, and the
// pawn is on the left half of the board.
if (strongerSide == BLACK)
{
wksq = ~wksq;
wrsq = ~wrsq;
wpsq = ~wpsq;
bksq = ~bksq;
brsq = ~brsq;
}
if (file_of(wpsq) > FILE_D)
{
wksq = mirror(wksq);
wrsq = mirror(wrsq);
wpsq = mirror(wpsq);
bksq = mirror(bksq);
brsq = mirror(brsq);
}
File f = file_of(wpsq);
Rank r = rank_of(wpsq);
Square queeningSq = f | RANK_8;
int tempo = (pos.side_to_move() == strongerSide);
// If the pawn is not too far advanced and the defending king defends the
// queening square, use the third-rank defence.
if ( r <= RANK_5
&& square_distance(bksq, queeningSq) <= 1
&& wksq <= SQ_H5
&& (rank_of(brsq) == RANK_6 || (r <= RANK_3 && rank_of(wrsq) != RANK_6)))
return SCALE_FACTOR_DRAW;
// The defending side saves a draw by checking from behind in case the pawn
// has advanced to the 6th rank with the king behind.
if ( r == RANK_6
&& square_distance(bksq, queeningSq) <= 1
&& rank_of(wksq) + tempo <= RANK_6
&& (rank_of(brsq) == RANK_1 || (!tempo && abs(file_of(brsq) - f) >= 3)))
return SCALE_FACTOR_DRAW;
if ( r >= RANK_6
&& bksq == queeningSq
&& rank_of(brsq) == RANK_1
&& (!tempo || square_distance(wksq, wpsq) >= 2))
return SCALE_FACTOR_DRAW;
// White pawn on a7 and rook on a8 is a draw if black's king is on g7 or h7
// and the black rook is behind the pawn.
if ( wpsq == SQ_A7
&& wrsq == SQ_A8
&& (bksq == SQ_H7 || bksq == SQ_G7)
&& file_of(brsq) == FILE_A
&& (rank_of(brsq) <= RANK_3 || file_of(wksq) >= FILE_D || rank_of(wksq) <= RANK_5))
return SCALE_FACTOR_DRAW;
// If the defending king blocks the pawn and the attacking king is too far
// away, it's a draw.
if ( r <= RANK_5
&& bksq == wpsq + DELTA_N
&& square_distance(wksq, wpsq) - tempo >= 2
&& square_distance(wksq, brsq) - tempo >= 2)
return SCALE_FACTOR_DRAW;
// Pawn on the 7th rank supported by the rook from behind usually wins if the
// attacking king is closer to the queening square than the defending king,
// and the defending king cannot gain tempi by threatening the attacking rook.
if ( r == RANK_7
&& f != FILE_A
&& file_of(wrsq) == f
&& wrsq != queeningSq
&& (square_distance(wksq, queeningSq) < square_distance(bksq, queeningSq) - 2 + tempo)
&& (square_distance(wksq, queeningSq) < square_distance(bksq, wrsq) + tempo))
return ScaleFactor(SCALE_FACTOR_MAX - 2 * square_distance(wksq, queeningSq));
// Similar to the above, but with the pawn further back
if ( f != FILE_A
&& file_of(wrsq) == f
&& wrsq < wpsq
&& (square_distance(wksq, queeningSq) < square_distance(bksq, queeningSq) - 2 + tempo)
&& (square_distance(wksq, wpsq + DELTA_N) < square_distance(bksq, wpsq + DELTA_N) - 2 + tempo)
&& ( square_distance(bksq, wrsq) + tempo >= 3
|| ( square_distance(wksq, queeningSq) < square_distance(bksq, wrsq) + tempo
&& (square_distance(wksq, wpsq + DELTA_N) < square_distance(bksq, wrsq) + tempo))))
return ScaleFactor( SCALE_FACTOR_MAX
- 8 * square_distance(wpsq, queeningSq)
- 2 * square_distance(wksq, queeningSq));
// If the pawn is not far advanced, and the defending king is somewhere in
// the pawn's path, it's probably a draw.
if (r <= RANK_4 && bksq > wpsq)
{
if (file_of(bksq) == file_of(wpsq))
return ScaleFactor(10);
if ( abs(file_of(bksq) - file_of(wpsq)) == 1
&& square_distance(wksq, bksq) > 2)
return ScaleFactor(24 - 2 * square_distance(wksq, bksq));
}
return SCALE_FACTOR_NONE;
}
/// K, rook and two pawns vs K, rook and one pawn. There is only a single
/// pattern: If the stronger side has no passed pawns and the defending king
/// is actively placed, the position is drawish.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMg);
assert(pos.piece_count(strongerSide, PAWN) == 2);
assert(pos.non_pawn_material(weakerSide) == RookValueMg);
assert(pos.piece_count(weakerSide, PAWN) == 1);
Square wpsq1 = pos.piece_list(strongerSide, PAWN)[0];
Square wpsq2 = pos.piece_list(strongerSide, PAWN)[1];
Square bksq = pos.king_square(weakerSide);
// Does the stronger side have a passed pawn?
if ( pos.pawn_is_passed(strongerSide, wpsq1)
|| pos.pawn_is_passed(strongerSide, wpsq2))
return SCALE_FACTOR_NONE;
Rank r = std::max(relative_rank(strongerSide, wpsq1), relative_rank(strongerSide, wpsq2));
if ( file_distance(bksq, wpsq1) <= 1
&& file_distance(bksq, wpsq2) <= 1
&& relative_rank(strongerSide, bksq) > r)
{
switch (r) {
case RANK_2: return ScaleFactor(10);
case RANK_3: return ScaleFactor(10);
case RANK_4: return ScaleFactor(15);
case RANK_5: return ScaleFactor(20);
case RANK_6: return ScaleFactor(40);
default: assert(false);
}
}
return SCALE_FACTOR_NONE;
}
/// K and two or more pawns vs K. There is just a single rule here: If all pawns
/// are on the same rook file and are blocked by the defending king, it's a draw.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.piece_count(strongerSide, PAWN) >= 2);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square ksq = pos.king_square(weakerSide);
Bitboard pawns = pos.pieces(strongerSide, PAWN);
// Are all pawns on the 'a' file?
if (!(pawns & ~FileABB))
{
// Does the defending king block the pawns?
if ( square_distance(ksq, relative_square(strongerSide, SQ_A8)) <= 1
|| ( file_of(ksq) == FILE_A
&& !(in_front_bb(strongerSide, ksq) & pawns)))
return SCALE_FACTOR_DRAW;
}
// Are all pawns on the 'h' file?
else if (!(pawns & ~FileHBB))
{
// Does the defending king block the pawns?
if ( square_distance(ksq, relative_square(strongerSide, SQ_H8)) <= 1
|| ( file_of(ksq) == FILE_H
&& !(in_front_bb(strongerSide, ksq) & pawns)))
return SCALE_FACTOR_DRAW;
}
return SCALE_FACTOR_NONE;
}
/// K, bishop and a pawn vs K and a bishop. There are two rules: If the defending
/// king is somewhere along the path of the pawn, and the square of the king is
/// not of the same color as the stronger side's bishop, it's a draw. If the two
/// bishops have opposite color, it's almost always a draw.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMg);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(strongerSide, PAWN) == 1);
assert(pos.non_pawn_material(weakerSide) == BishopValueMg);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP)[0];
Square weakerBishopSq = pos.piece_list(weakerSide, BISHOP)[0];
Square weakerKingSq = pos.king_square(weakerSide);
// Case 1: Defending king blocks the pawn, and cannot be driven away
if ( file_of(weakerKingSq) == file_of(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
&& ( opposite_colors(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
return SCALE_FACTOR_DRAW;
// Case 2: Opposite colored bishops
if (opposite_colors(strongerBishopSq, weakerBishopSq))
{
// We assume that the position is drawn in the following three situations:
//
// a. The pawn is on rank 5 or further back.
// b. The defending king is somewhere in the pawn's path.
// c. The defending bishop attacks some square along the pawn's path,
// and is at least three squares away from the pawn.
//
// These rules are probably not perfect, but in practice they work
// reasonably well.
if (relative_rank(strongerSide, pawnSq) <= RANK_5)
return SCALE_FACTOR_DRAW;
else
{
Bitboard path = forward_bb(strongerSide, pawnSq);
if (path & pos.pieces(weakerSide, KING))
return SCALE_FACTOR_DRAW;
if ( (pos.attacks_from(weakerBishopSq) & path)
&& square_distance(weakerBishopSq, pawnSq) >= 3)
return SCALE_FACTOR_DRAW;
}
}
return SCALE_FACTOR_NONE;
}
/// K, bishop and two pawns vs K and bishop. It detects a few basic draws with
/// opposite-colored bishops.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMg);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(strongerSide, PAWN) == 2);
assert(pos.non_pawn_material(weakerSide) == BishopValueMg);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square wbsq = pos.piece_list(strongerSide, BISHOP)[0];
Square bbsq = pos.piece_list(weakerSide, BISHOP)[0];
if (!opposite_colors(wbsq, bbsq))
return SCALE_FACTOR_NONE;
Square ksq = pos.king_square(weakerSide);
Square psq1 = pos.piece_list(strongerSide, PAWN)[0];
Square psq2 = pos.piece_list(strongerSide, PAWN)[1];
Rank r1 = rank_of(psq1);
Rank r2 = rank_of(psq2);
Square blockSq1, blockSq2;
if (relative_rank(strongerSide, psq1) > relative_rank(strongerSide, psq2))
{
blockSq1 = psq1 + pawn_push(strongerSide);
blockSq2 = file_of(psq2) | rank_of(psq1);
}
else
{
blockSq1 = psq2 + pawn_push(strongerSide);
blockSq2 = file_of(psq1) | rank_of(psq2);
}
switch (file_distance(psq1, psq2))
{
case 0:
// Both pawns are on the same file. Easy draw if defender firmly controls
// some square in the frontmost pawn's path.
if ( file_of(ksq) == file_of(blockSq1)
&& relative_rank(strongerSide, ksq) >= relative_rank(strongerSide, blockSq1)
&& opposite_colors(ksq, wbsq))
return SCALE_FACTOR_DRAW;
else
return SCALE_FACTOR_NONE;
case 1:
// Pawns on adjacent files. Draw if defender firmly controls the square
// in front of the frontmost pawn's path, and the square diagonally behind
// this square on the file of the other pawn.
if ( ksq == blockSq1
&& opposite_colors(ksq, wbsq)
&& ( bbsq == blockSq2
|| (pos.attacks_from(blockSq2) & pos.pieces(weakerSide, BISHOP))
|| abs(r1 - r2) >= 2))
return SCALE_FACTOR_DRAW;
else if ( ksq == blockSq2
&& opposite_colors(ksq, wbsq)
&& ( bbsq == blockSq1
|| (pos.attacks_from(blockSq1) & pos.pieces(weakerSide, BISHOP))))
return SCALE_FACTOR_DRAW;
else
return SCALE_FACTOR_NONE;
default:
// The pawns are not on the same file or adjacent files. No scaling.
return SCALE_FACTOR_NONE;
}
}
/// K, bisop and a pawn vs K and knight. There is a single rule: If the defending
/// king is somewhere along the path of the pawn, and the square of the king is
/// not of the same color as the stronger side's bishop, it's a draw.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMg);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(strongerSide, PAWN) == 1);
assert(pos.non_pawn_material(weakerSide) == KnightValueMg);
assert(pos.piece_count(weakerSide, KNIGHT) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP)[0];
Square weakerKingSq = pos.king_square(weakerSide);
if ( file_of(weakerKingSq) == file_of(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
&& ( opposite_colors(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
}
/// K, knight and a pawn vs K. There is a single rule: If the pawn is a rook pawn
/// on the 7th rank and the defending king prevents the pawn from advancing, the
/// position is drawn.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == KnightValueMg);
assert(pos.piece_count(strongerSide, KNIGHT) == 1);
assert(pos.piece_count(strongerSide, PAWN) == 1);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
Square weakerKingSq = pos.king_square(weakerSide);
if ( pawnSq == relative_square(strongerSide, SQ_A7)
&& square_distance(weakerKingSq, relative_square(strongerSide, SQ_A8)) <= 1)
return SCALE_FACTOR_DRAW;
if ( pawnSq == relative_square(strongerSide, SQ_H7)
&& square_distance(weakerKingSq, relative_square(strongerSide, SQ_H8)) <= 1)
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
}
/// K, knight and a pawn vs K and bishop. If knight can block bishop from taking
/// pawn, it's a win. Otherwise, drawn.
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
Square bishopSq = pos.piece_list(weakerSide, BISHOP)[0];
Square weakerKingSq = pos.king_square(weakerSide);
// King needs to get close to promoting pawn to prevent knight from blocking.
// Rules for this are very tricky, so just approximate.
if (forward_bb(strongerSide, pawnSq) & pos.attacks_from(bishopSq))
return ScaleFactor(square_distance(weakerKingSq, pawnSq));
return SCALE_FACTOR_NONE;
}
/// K and a pawn vs K and a pawn. This is done by removing the weakest side's
/// pawn and probing the KP vs K bitbase: If the weakest side has a draw without
/// the pawn, she probably has at least a draw with the pawn as well. The exception
/// is when the stronger side's pawn is far advanced and not on a rook file; in
/// this case it is often possible to win (e.g. 8/4k3/3p4/3P4/6K1/8/8/8 w - - 0 1).
template<>
ScaleFactor Endgame::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(WHITE, PAWN) == 1);
assert(pos.piece_count(BLACK, PAWN) == 1);
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
Square wpsq = pos.piece_list(strongerSide, PAWN)[0];
Color us = pos.side_to_move();
if (strongerSide == BLACK)
{
wksq = ~wksq;
bksq = ~bksq;
wpsq = ~wpsq;
us = ~us;
}
if (file_of(wpsq) >= FILE_E)
{
wksq = mirror(wksq);
bksq = mirror(bksq);
wpsq = mirror(wpsq);
}
// If the pawn has advanced to the fifth rank or further, and is not a
// rook pawn, it's too dangerous to assume that it's at least a draw.
if ( rank_of(wpsq) >= RANK_5
&& file_of(wpsq) != FILE_A)
return SCALE_FACTOR_NONE;
// Probe the KPK bitbase with the weakest side's pawn removed. If it's a draw,
// it's probably at least a draw even with the pawn.
return Bitbases::probe_kpk(wksq, wpsq, bksq, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
}
stockfish-3.0.0+git20130508/src/position.h 0000644 0001750 0001750 00000027750 12142540127 017310 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#if !defined(POSITION_H_INCLUDED)
#define POSITION_H_INCLUDED
#include
#include
#include "bitboard.h"
#include "types.h"
/// The checkInfo struct is initialized at c'tor time and keeps info used
/// to detect if a move gives check.
class Position;
struct Thread;
struct CheckInfo {
explicit CheckInfo(const Position&);
Bitboard dcCandidates;
Bitboard pinned;
Bitboard checkSq[PIECE_TYPE_NB];
Square ksq;
};
/// The StateInfo struct stores information we need to restore a Position
/// object to its previous state when we retract a move. Whenever a move
/// is made on the board (by calling Position::do_move), a StateInfo object
/// must be passed as a parameter.
struct StateInfo {
Key pawnKey, materialKey;
Value npMaterial[COLOR_NB];
int castleRights, rule50, pliesFromNull;
Score psqScore;
Square epSquare;
Key key;
Bitboard checkersBB;
PieceType capturedType;
StateInfo* previous;
};
/// When making a move the current StateInfo up to 'key' excluded is copied to
/// the new one. Here we calculate the quad words (64bits) needed to be copied.
const size_t StateCopySize64 = offsetof(StateInfo, key) / sizeof(uint64_t) + 1;
/// The position data structure. A position consists of the following data:
///
/// * For each piece type, a bitboard representing the squares occupied
/// by pieces of that type.
/// * For each color, a bitboard representing the squares occupied by
/// pieces of that color.
/// * A bitboard of all occupied squares.
/// * A bitboard of all checking pieces.
/// * A 64-entry array of pieces, indexed by the squares of the board.
/// * The current side to move.
/// * Information about the castling rights for both sides.
/// * The initial files of the kings and both pairs of rooks. This is
/// used to implement the Chess960 castling rules.
/// * The en passant square (which is SQ_NONE if no en passant capture is
/// possible).
/// * The squares of the kings for both sides.
/// * Hash keys for the position itself, the current pawn structure, and
/// the current material situation.
/// * Hash keys for all previous positions in the game for detecting
/// repetition draws.
/// * A counter for detecting 50 move rule draws.
class Position {
public:
Position() {}
Position(const Position& p, Thread* t) { *this = p; thisThread = t; }
Position(const std::string& f, bool c960, Thread* t) { set(f, c960, t); }
Position& operator=(const Position&);
// Text input/output
void set(const std::string& fen, bool isChess960, Thread* th);
const std::string fen() const;
const std::string pretty(Move m = MOVE_NONE) const;
// Position representation
Bitboard pieces() const;
Bitboard pieces(PieceType pt) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
Bitboard pieces(Color c) const;
Bitboard pieces(Color c, PieceType pt) const;
Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
Piece piece_on(Square s) const;
Square king_square(Color c) const;
Square ep_square() const;
bool is_empty(Square s) const;
const Square* piece_list(Color c, PieceType pt) const;
int piece_count(Color c, PieceType pt) const;
// Castling
int can_castle(CastleRight f) const;
int can_castle(Color c) const;
bool castle_impeded(Color c, CastlingSide s) const;
Square castle_rook_square(Color c, CastlingSide s) const;
// Checking
Bitboard checkers() const;
Bitboard discovered_check_candidates() const;
Bitboard pinned_pieces() const;
// Attacks to/from a given square
Bitboard attackers_to(Square s) const;
Bitboard attackers_to(Square s, Bitboard occ) const;
Bitboard attacks_from(Piece p, Square s) const;
static Bitboard attacks_from(Piece p, Square s, Bitboard occ);
template Bitboard attacks_from(Square s) const;
template Bitboard attacks_from(Square s, Color c) const;
// Properties of moves
bool move_gives_check(Move m, const CheckInfo& ci) const;
bool pl_move_is_legal(Move m, Bitboard pinned) const;
bool is_pseudo_legal(const Move m) const;
bool is_capture(Move m) const;
bool is_capture_or_promotion(Move m) const;
bool is_passed_pawn_push(Move m) const;
Piece piece_moved(Move m) const;
PieceType captured_piece_type() const;
// Piece specific
bool pawn_is_passed(Color c, Square s) const;
bool pawn_on_7th(Color c) const;
bool opposite_bishops() const;
bool bishop_pair(Color c) const;
// Doing and undoing moves
void do_move(Move m, StateInfo& st);
void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
void undo_move(Move m);
void do_null_move(StateInfo& st);
void undo_null_move();
// Static exchange evaluation
int see(Move m, int asymmThreshold = 0) const;
int see_sign(Move m) const;
// Accessing hash keys
Key key() const;
Key exclusion_key() const;
Key pawn_key() const;
Key material_key() const;
// Incremental piece-square evaluation
Score psq_score() const;
Score psq_delta(Piece p, Square from, Square to) const;
Value non_pawn_material(Color c) const;
// Other properties of the position
Color side_to_move() const;
int game_ply() const;
bool is_chess960() const;
Thread* this_thread() const;
int64_t nodes_searched() const;
void set_nodes_searched(int64_t n);
bool is_draw() const;
// Position consistency check, for debugging
bool pos_is_ok(int* failedStep = NULL) const;
void flip();
private:
// Initialization helpers (used while setting up a position)
void clear();
void put_piece(Piece p, Square s);
void set_castle_right(Color c, Square rfrom);
// Helper functions
void do_castle(Square kfrom, Square kto, Square rfrom, Square rto);
template Bitboard hidden_checkers() const;
// Computing hash keys from scratch (for initialization and debugging)
Key compute_key() const;
Key compute_pawn_key() const;
Key compute_material_key() const;
// Computing incremental evaluation scores and material counts
Score compute_psq_score() const;
Value compute_non_pawn_material(Color c) const;
// Board and pieces
Piece board[SQUARE_NB];
Bitboard byTypeBB[PIECE_TYPE_NB];
Bitboard byColorBB[COLOR_NB];
int pieceCount[COLOR_NB][PIECE_TYPE_NB];
Square pieceList[COLOR_NB][PIECE_TYPE_NB][16];
int index[SQUARE_NB];
// Other info
int castleRightsMask[SQUARE_NB];
Square castleRookSquare[COLOR_NB][CASTLING_SIDE_NB];
Bitboard castlePath[COLOR_NB][CASTLING_SIDE_NB];
StateInfo startState;
int64_t nodes;
int gamePly;
Color sideToMove;
Thread* thisThread;
StateInfo* st;
int chess960;
};
inline int64_t Position::nodes_searched() const {
return nodes;
}
inline void Position::set_nodes_searched(int64_t n) {
nodes = n;
}
inline Piece Position::piece_on(Square s) const {
return board[s];
}
inline Piece Position::piece_moved(Move m) const {
return board[from_sq(m)];
}
inline bool Position::is_empty(Square s) const {
return board[s] == NO_PIECE;
}
inline Color Position::side_to_move() const {
return sideToMove;
}
inline Bitboard Position::pieces() const {
return byTypeBB[ALL_PIECES];
}
inline Bitboard Position::pieces(PieceType pt) const {
return byTypeBB[pt];
}
inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
return byTypeBB[pt1] | byTypeBB[pt2];
}
inline Bitboard Position::pieces(Color c) const {
return byColorBB[c];
}
inline Bitboard Position::pieces(Color c, PieceType pt) const {
return byColorBB[c] & byTypeBB[pt];
}
inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
return byColorBB[c] & (byTypeBB[pt1] | byTypeBB[pt2]);
}
inline int Position::piece_count(Color c, PieceType pt) const {
return pieceCount[c][pt];
}
inline const Square* Position::piece_list(Color c, PieceType pt) const {
return pieceList[c][pt];
}
inline Square Position::ep_square() const {
return st->epSquare;
}
inline Square Position::king_square(Color c) const {
return pieceList[c][KING][0];
}
inline int Position::can_castle(CastleRight f) const {
return st->castleRights & f;
}
inline int Position::can_castle(Color c) const {
return st->castleRights & ((WHITE_OO | WHITE_OOO) << (2 * c));
}
inline bool Position::castle_impeded(Color c, CastlingSide s) const {
return byTypeBB[ALL_PIECES] & castlePath[c][s];
}
inline Square Position::castle_rook_square(Color c, CastlingSide s) const {
return castleRookSquare[c][s];
}
template
inline Bitboard Position::attacks_from(Square s) const {
return Pt == BISHOP || Pt == ROOK ? attacks_bb(s, pieces())
: Pt == QUEEN ? attacks_from(s) | attacks_from(s)
: StepAttacksBB[Pt][s];
}
template<>
inline Bitboard Position::attacks_from(Square s, Color c) const {
return StepAttacksBB[make_piece(c, PAWN)][s];
}
inline Bitboard Position::attacks_from(Piece p, Square s) const {
return attacks_from(p, s, byTypeBB[ALL_PIECES]);
}
inline Bitboard Position::attackers_to(Square s) const {
return attackers_to(s, byTypeBB[ALL_PIECES]);
}
inline Bitboard Position::checkers() const {
return st->checkersBB;
}
inline Bitboard Position::discovered_check_candidates() const {
return hidden_checkers();
}
inline Bitboard Position::pinned_pieces() const {
return hidden_checkers();
}
inline bool Position::pawn_is_passed(Color c, Square s) const {
return !(pieces(~c, PAWN) & passed_pawn_mask(c, s));
}
inline Key Position::key() const {
return st->key;
}
inline Key Position::exclusion_key() const {
return st->key ^ Zobrist::exclusion;
}
inline Key Position::pawn_key() const {
return st->pawnKey;
}
inline Key Position::material_key() const {
return st->materialKey;
}
inline Score Position::psq_delta(Piece p, Square from, Square to) const {
return pieceSquareTable[p][to] - pieceSquareTable[p][from];
}
inline Score Position::psq_score() const {
return st->psqScore;
}
inline Value Position::non_pawn_material(Color c) const {
return st->npMaterial[c];
}
inline bool Position::is_passed_pawn_push(Move m) const {
return type_of(piece_moved(m)) == PAWN
&& pawn_is_passed(sideToMove, to_sq(m));
}
inline int Position::game_ply() const {
return gamePly;
}
inline bool Position::opposite_bishops() const {
return pieceCount[WHITE][BISHOP] == 1
&& pieceCount[BLACK][BISHOP] == 1
&& opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
}
inline bool Position::bishop_pair(Color c) const {
return pieceCount[c][BISHOP] >= 2
&& opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]);
}
inline bool Position::pawn_on_7th(Color c) const {
return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
}
inline bool Position::is_chess960() const {
return chess960;
}
inline bool Position::is_capture_or_promotion(Move m) const {
assert(is_ok(m));
return type_of(m) ? type_of(m) != CASTLE : !is_empty(to_sq(m));
}
inline bool Position::is_capture(Move m) const {
// Note that castle is coded as "king captures the rook"
assert(is_ok(m));
return (!is_empty(to_sq(m)) && type_of(m) != CASTLE) || type_of(m) == ENPASSANT;
}
inline PieceType Position::captured_piece_type() const {
return st->capturedType;
}
inline Thread* Position::this_thread() const {
return thisThread;
}
#endif // !defined(POSITION_H_INCLUDED)
stockfish-3.0.0+git20130508/src/bitbase.cpp 0000644 0001750 0001750 00000013244 12142540127 017401 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include "bitboard.h"
#include "types.h"
namespace {
// The possible pawns squares are 24, the first 4 files and ranks from 2 to 7
const unsigned IndexMax = 2*24*64*64; // stm * psq * wksq * bksq = 196608
// Each uint32_t stores results of 32 positions, one per bit
uint32_t KPKBitbase[IndexMax / 32];
// A KPK bitbase index is an integer in [0, IndexMax] range
//
// Information is mapped in a way that minimizes number of iterations:
//
// bit 0- 5: white king square (from SQ_A1 to SQ_H8)
// bit 6-11: black king square (from SQ_A1 to SQ_H8)
// bit 12: side to move (WHITE or BLACK)
// bit 13-14: white pawn file (from FILE_A to FILE_D)
// bit 15-17: white pawn 6 - rank (from 6 - RANK_7 to 6 - RANK_2)
unsigned index(Color us, Square bksq, Square wksq, Square psq) {
return wksq + (bksq << 6) + (us << 12) + (file_of(psq) << 13) + ((6 - rank_of(psq)) << 15);
}
enum Result {
INVALID = 0,
UNKNOWN = 1,
DRAW = 2,
WIN = 4
};
inline Result& operator|=(Result& r, Result v) { return r = Result(r | v); }
struct KPKPosition {
operator Result() const { return res; }
Result classify_leaf(unsigned idx);
Result classify(const std::vector& db)
{ return us == WHITE ? classify(db) : classify(db); }
private:
template Result classify(const std::vector& db);
Color us;
Square bksq, wksq, psq;
Result res;
};
} // namespace
bool Bitbases::probe_kpk(Square wksq, Square wpsq, Square bksq, Color us) {
assert(file_of(wpsq) <= FILE_D);
unsigned idx = index(us, bksq, wksq, wpsq);
return KPKBitbase[idx / 32] & (1 << (idx & 0x1F));
}
void Bitbases::init_kpk() {
unsigned idx, repeat = 1;
std::vector db(IndexMax);
// Initialize db with known win / draw positions
for (idx = 0; idx < IndexMax; idx++)
db[idx].classify_leaf(idx);
// Iterate through the positions until no more of the unknown positions can be
// changed to either wins or draws (15 cycles needed).
while (repeat)
for (repeat = idx = 0; idx < IndexMax; idx++)
if (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN)
repeat = 1;
// Map 32 results into one KPKBitbase[] entry
for (idx = 0; idx < IndexMax; idx++)
if (db[idx] == WIN)
KPKBitbase[idx / 32] |= 1 << (idx & 0x1F);
}
namespace {
Result KPKPosition::classify_leaf(unsigned idx) {
wksq = Square((idx >> 0) & 0x3F);
bksq = Square((idx >> 6) & 0x3F);
us = Color((idx >> 12) & 0x01);
psq = File((idx >> 13) & 3) | Rank(6 - (idx >> 15));
// Check if two pieces are on the same square or if a king can be captured
if ( wksq == psq || wksq == bksq || bksq == psq
|| (StepAttacksBB[KING][wksq] & bksq)
|| (us == WHITE && (StepAttacksBB[PAWN][psq] & bksq)))
return res = INVALID;
if (us == WHITE)
{
// Immediate win if pawn can be promoted without getting captured
if ( rank_of(psq) == RANK_7
&& wksq != psq + DELTA_N
&& ( square_distance(bksq, psq + DELTA_N) > 1
||(StepAttacksBB[KING][wksq] & (psq + DELTA_N))))
return res = WIN;
}
// Immediate draw if is stalemate or king captures undefended pawn
else if ( !(StepAttacksBB[KING][bksq] & ~(StepAttacksBB[KING][wksq] | StepAttacksBB[PAWN][psq]))
|| (StepAttacksBB[KING][bksq] & psq & ~StepAttacksBB[KING][wksq]))
return res = DRAW;
return res = UNKNOWN;
}
template
Result KPKPosition::classify(const std::vector& db) {
// White to Move: If one move leads to a position classified as WIN, the result
// of the current position is WIN. If all moves lead to positions classified
// as DRAW, the current position is classified DRAW otherwise the current
// position is classified as UNKNOWN.
//
// Black to Move: If one move leads to a position classified as DRAW, the result
// of the current position is DRAW. If all moves lead to positions classified
// as WIN, the position is classified WIN otherwise the current position is
// classified UNKNOWN.
Result r = INVALID;
Bitboard b = StepAttacksBB[KING][Us == WHITE ? wksq : bksq];
while (b)
r |= Us == WHITE ? db[index(~Us, bksq, pop_lsb(&b), psq)]
: db[index(~Us, pop_lsb(&b), wksq, psq)];
if (Us == WHITE && rank_of(psq) < RANK_7)
{
Square s = psq + DELTA_N;
r |= db[index(BLACK, bksq, wksq, s)]; // Single push
if (rank_of(s) == RANK_3 && s != wksq && s != bksq)
r |= db[index(BLACK, bksq, wksq, s + DELTA_N)]; // Double push
}
if (Us == WHITE)
return res = r & WIN ? WIN : r & UNKNOWN ? UNKNOWN : DRAW;
else
return res = r & DRAW ? DRAW : r & UNKNOWN ? UNKNOWN : WIN;
}
} // namespace
stockfish-3.0.0+git20130508/src/main.cpp 0000644 0001750 0001750 00000002567 12142540127 016722 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include "bitboard.h"
#include "evaluate.h"
#include "position.h"
#include "search.h"
#include "thread.h"
#include "tt.h"
#include "ucioption.h"
int main(int argc, char* argv[]) {
std::cout << engine_info() << std::endl;
UCI::init(Options);
Bitboards::init();
Zobrist::init();
Bitbases::init_kpk();
Search::init();
Eval::init();
Threads.init();
TT.set_size(Options["Hash"]);
std::string args;
for (int i = 1; i < argc; i++)
args += std::string(argv[i]) + " ";
UCI::loop(args);
Threads.exit();
}
stockfish-3.0.0+git20130508/src/evaluate.cpp 0000644 0001750 0001750 00000140025 12142540127 017574 0 ustar oliver oliver /*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish 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.
Stockfish 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 .
*/
#include
#include
#include
#include
#include "bitcount.h"
#include "evaluate.h"
#include "material.h"
#include "pawns.h"
#include "thread.h"
#include "ucioption.h"
namespace {
// Struct EvalInfo contains various information computed and collected
// by the evaluation functions.
struct EvalInfo {
// Pointers to material and pawn hash table entries
Material::Entry* mi;
Pawns::Entry* pi;
// attackedBy[color][piece type] is a bitboard representing all squares
// attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
// contains all squares attacked by the given color.
Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
// kingRing[color] is the zone around the king which is considered
// by the king safety evaluation. This consists of the squares directly
// adjacent to the king, and the three (or two, for a king on an edge file)
// squares two ranks in front of the king. For instance, if black's king
// is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
// f7, g7, h7, f6, g6 and h6.
Bitboard kingRing[COLOR_NB];
// kingAttackersCount[color] is the number of pieces of the given color
// which attack a square in the kingRing of the enemy king.
int kingAttackersCount[COLOR_NB];
// kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
// given color which attack a square in the kingRing of the enemy king. The
// weights of the individual piece types are given by the variables
// QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
// KnightAttackWeight in evaluate.cpp
int kingAttackersWeight[COLOR_NB];
// kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
// directly adjacent to the king of the given color. Pieces which attack
// more than one square are counted multiple times. For instance, if black's
// king is on g8 and there's a white knight on g5, this knight adds
// 2 to kingAdjacentZoneAttacksCount[BLACK].
int kingAdjacentZoneAttacksCount[COLOR_NB];
};
// Evaluation grain size, must be a power of 2
const int GrainSize = 8;
// Evaluation weights, initialized from UCI options
enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem };
Score Weights[6];
typedef Value V;
#define S(mg, eg) make_score(mg, eg)
// Internal evaluation weights. These are applied on top of the evaluation
// weights read from UCI parameters. The purpose is to be able to change
// the evaluation weights while keeping the default values of the UCI
// parameters at 100, which looks prettier.
//
// Values modified by Joona Kiiski
const Score WeightsInternal[] = {
S(289, 344), S(221, 273), S(46, 0), S(271, 0), S(307, 0)
};
// MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
// end game, indexed by piece type and number of attacked squares not occupied
// by friendly pieces.
const Score MobilityBonus[][32] = {
{}, {},
{ S(-38,-33), S(-25,-23), S(-12,-13), S( 0, -3), S(12, 7), S(25, 17), // Knights
S( 31, 22), S( 38, 27), S( 38, 27) },
{ S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12), S(31, 26), S(45, 40), // Bishops
S( 57, 52), S( 65, 60), S( 71, 65), S(74, 69), S(76, 71), S(78, 73),
S( 79, 74), S( 80, 75), S( 81, 76), S(81, 76) },
{ S(-20,-36), S(-14,-19), S( -8, -3), S(-2, 13), S( 4, 29), S(10, 46), // Rooks
S( 14, 62), S( 19, 79), S( 23, 95), S(26,106), S(27,111), S(28,114),
S( 29,116), S( 30,117), S( 31,118), S(32,118) },
{ S(-10,-18), S( -8,-13), S( -6, -7), S(-3, -2), S(-1, 3), S( 1, 8), // Queens
S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34),
S( 16, 35), S( 17, 35), S( 18, 35), S(20, 35), S(20, 35), S(20, 35),
S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
S( 20, 35), S( 20, 35) }
};
// OutpostBonus[PieceType][Square] contains outpost bonuses of knights and
// bishops, indexed by piece type and square (from white's point of view).
const Value OutpostBonus[][SQUARE_NB] = {
{
// A B C D E F G H
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },
{
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
};
// ThreatBonus[attacking][attacked] contains threat bonuses according to
// which piece type attacks which one.
const Score ThreatBonus[][PIECE_TYPE_NB] = {
{}, {},
{ S(0, 0), S( 7, 39), S( 0, 0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
{ S(0, 0), S( 7, 39), S(24, 49), S( 0, 0), S(41,100), S(41,100) }, // BISHOP
{ S(0, 0), S( 0, 22), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK
{ S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
};
// ThreatenedByPawnPenalty[PieceType] contains a penalty according to which
// piece type is attacked by an enemy pawn.
const Score ThreatenedByPawnPenalty[] = {
S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
};
#undef S
const Score BishopPinBonus = make_score(66, 11);
// Bonus for having the side to move (modified by Joona Kiiski)
const Score Tempo = make_score(24, 11);
// Rooks and queens on the 7th rank
const Score RookOn7thBonus = make_score(11, 20);
const Score QueenOn7thBonus = make_score( 3, 8);
// Rooks and queens attacking pawns on the same rank
const Score RookOnPawnBonus = make_score(10, 28);
const Score QueenOnPawnBonus = make_score( 4, 20);
// Rooks on open files (modified by Joona Kiiski)
const Score RookOpenFileBonus = make_score(43, 21);
const Score RookHalfOpenFileBonus = make_score(19, 10);
// Penalty for rooks trapped inside a friendly king which has lost the
// right to castle.
const Value TrappedRookPenalty = Value(180);
// Penalty for bishop with pawns on the same coloured squares
const Score BishopPawnsPenalty = make_score(8, 12);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
// happen in Chess960 games.
const Score TrappedBishopA1H1Penalty = make_score(100, 100);
// Penalty for an undefended bishop or knight
const Score UndefendedMinorPenalty = make_score(25, 10);
// The SpaceMask[Color] contains the area of the board which is considered
// by the space evaluation. In the middle game, each side is given a bonus
// based on how many squares inside this area are safe and available for
// friendly minor pieces.
const Bitboard SpaceMask[] = {
(1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
(1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
(1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
(1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
(1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
(1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
};
// King danger constants and variables. The king danger scores are taken
// from the KingDangerTable[]. Various little "meta-bonuses" measuring
// the strength of the enemy attack are added up into an integer, which
// is used as an index to KingDangerTable[].
//
// KingAttackWeights[PieceType] contains king attack weights by piece type
const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
// Bonuses for enemy's safe checks
const int QueenContactCheckBonus = 6;
const int RookContactCheckBonus = 4;
const int QueenCheckBonus = 3;
const int RookCheckBonus = 2;
const int BishopCheckBonus = 1;
const int KnightCheckBonus = 1;
// InitKingDanger[Square] contains penalties based on the position of the
// defending king, indexed by king's square (from white's point of view).
const int InitKingDanger[] = {
2, 0, 2, 5, 5, 2, 0, 2,
2, 2, 4, 8, 8, 4, 2, 2,
7, 10, 12, 12, 12, 12, 10, 7,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15
};
// KingDangerTable[Color][attackUnits] contains the actual king danger
// weighted scores, indexed by color and by a calculated integer number.
Score KingDangerTable[COLOR_NB][128];
// TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
// evaluation terms, used when tracing.
Score TracedScores[COLOR_NB][16];
std::stringstream TraceStream;
enum TracedType {
PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
};
// Function prototypes
template
Value do_evaluate(const Position& pos, Value& margin);
template
void init_eval_info(const Position& pos, EvalInfo& ei);
template
Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
template
Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
template
Score evaluate_threats(const Position& pos, EvalInfo& ei);
template
int evaluate_space(const Position& pos, EvalInfo& ei);
template
Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
double to_cp(Value v);
void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
void trace_row(const char* name, int idx);
}
namespace Eval {
/// evaluate() is the main evaluation function. It always computes two
/// values, an endgame score and a middle game score, and interpolates
/// between them based on the remaining material.
Value evaluate(const Position& pos, Value& margin) {
return do_evaluate(pos, margin);
}
/// init() computes evaluation weights from the corresponding UCI parameters
/// and setup king tables.
void init() {
Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
const int MaxSlope = 30;
const int Peak = 1280;
for (int t = 0, i = 1; i < 100; i++)
{
t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
}
}
/// trace() is like evaluate() but instead of a value returns a string suitable
/// to be print on stdout with the detailed descriptions and values of each
/// evaluation term. Used mainly for debugging.
std::string trace(const Position& pos) {
Value margin;
std::string totals;
Search::RootColor = pos.side_to_move();
TraceStream.str("");
TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
memset(TracedScores, 0, 2 * 16 * sizeof(Score));
do_evaluate(pos, margin);
totals = TraceStream.str();
TraceStream.str("");
TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
<< " | MG EG | MG EG | MG EG \n"
<< "---------------------+-------------+-------------+---------------\n";
trace_row("Material, PST, Tempo", PST);
trace_row("Material imbalance", IMBALANCE);
trace_row("Pawns", PAWN);
trace_row("Knights", KNIGHT);
trace_row("Bishops", BISHOP);
trace_row("Rooks", ROOK);
trace_row("Queens", QUEEN);
trace_row("Mobility", MOBILITY);
trace_row("King safety", KING);
trace_row("Threats", THREAT);
trace_row("Passed pawns", PASSED);
trace_row("Unstoppable pawns", UNSTOPPABLE);
trace_row("Space", SPACE);
TraceStream << "---------------------+-------------+-------------+---------------\n";
trace_row("Total", TOTAL);
TraceStream << totals;
return TraceStream.str();
}
} // namespace Eval
namespace {
template
Value do_evaluate(const Position& pos, Value& margin) {
assert(!pos.checkers());
EvalInfo ei;
Value margins[COLOR_NB];
Score score, mobilityWhite, mobilityBlack;
Thread* th = pos.this_thread();
// margins[] store the uncertainty estimation of position's evaluation
// that typically is used by the search for pruning decisions.
margins[WHITE] = margins[BLACK] = VALUE_ZERO;
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables) and adding
// Tempo bonus. Score is computed from the point of view of white.
score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
// Probe the material hash table
ei.mi = Material::probe(pos, th->materialTable, th->endgames);
score += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (ei.mi->specialized_eval_exists())
{
margin = VALUE_ZERO;
return ei.mi->evaluate(pos);
}
// Probe the pawn hash table
ei.pi = Pawns::probe(pos, th->pawnsTable);
score += ei.pi->pawns_value();
// Initialize attack and king safety bitboards
init_eval_info(pos, ei);
init_eval_info(pos, ei);
// Evaluate pieces and mobility
score += evaluate_pieces_of_color(pos, ei, mobilityWhite)
- evaluate_pieces_of_color(pos, ei, mobilityBlack);
score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
score += evaluate_king(pos, ei, margins)
- evaluate_king(pos, ei, margins);
// Evaluate tactical threats, we need full attack information including king
score += evaluate_threats(pos, ei)
- evaluate_threats(pos, ei);
// Evaluate passed pawns, we need full attack information including king
score += evaluate_passed_pawns(pos, ei)
- evaluate_passed_pawns(pos, ei);
// If one side has only a king, check whether exists any unstoppable passed pawn
if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
score += evaluate_unstoppable_pawns(pos, ei);
// Evaluate space for both sides, only in middle-game.
if (ei.mi->space_weight())
{
int s = evaluate_space(pos, ei) - evaluate_space(pos, ei);
score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
}
// Scale winning side if position is more drawish that what it appears
ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
: ei.mi->scale_factor(pos, BLACK);
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
if ( ei.mi->game_phase() < PHASE_MIDGAME
&& pos.opposite_bishops()
&& sf == SCALE_FACTOR_NORMAL)
{
// Only the two bishops ?
if ( pos.non_pawn_material(WHITE) == BishopValueMg
&& pos.non_pawn_material(BLACK) == BishopValueMg)
{
// Check for KBP vs KB with only a single pawn that is almost
// certainly a draw or at least two pawns.
bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
}
else
// Endgame with opposite-colored bishops, but also other pieces. Still
// a bit drawish, but not as drawish as with only the two bishops.
sf = ScaleFactor(50);
}
margin = margins[pos.side_to_move()];
Value v = interpolate(score, ei.mi->game_phase(), sf);
// In case of tracing add all single evaluation contributions for both white and black
if (Trace)
{
trace_add(PST, pos.psq_score());
trace_add(IMBALANCE, ei.mi->material_value());
trace_add(PAWN, ei.pi->pawns_value());
trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
trace_add(THREAT, evaluate_threats(pos, ei), evaluate_threats(pos, ei));
trace_add(PASSED, evaluate_passed_pawns(pos, ei), evaluate_passed_pawns(pos, ei));
trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
Score w = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0);
Score b = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0);
trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
trace_add(TOTAL, score);
TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
<< ", Black: " << to_cp(margins[BLACK])
<< "\nScaling: " << std::noshowpos
<< std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
<< std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
<< std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
<< "Total evaluation: " << to_cp(v);
}
return pos.side_to_move() == WHITE ? v : -v;
}
// init_eval_info() initializes king bitboards for given color adding
// pawn attacks. To be done at the beginning of the evaluation.
template
void init_eval_info(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them));
ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
// Init king safety tables only if we are going to use them
if ( pos.piece_count(Us, QUEEN)
&& pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
{
ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
b &= ei.attackedBy[Us][PAWN];
ei.kingAttackersCount[Us] = b ? popcount(b) / 2 : 0;
ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
} else
ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
}
// evaluate_outposts() evaluates bishop and knight outposts squares
template
Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
assert (Piece == BISHOP || Piece == KNIGHT);
// Initial bonus based on square
Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
// Increase bonus if supported by pawn, especially if the opponent has
// no minor piece which can exchange the outpost piece.
if (bonus && (ei.attackedBy[Us][PAWN] & s))
{
if ( !pos.pieces(Them, KNIGHT)
&& !(same_color_squares(s) & pos.pieces(Them, BISHOP)))
bonus += bonus + bonus / 2;
else
bonus += bonus / 2;
}
return make_score(bonus, bonus);
}
// evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
template
Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
Bitboard b;
Square s, ksq;
int mob;
File f;
Score score = SCORE_ZERO;
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square* pl = pos.piece_list(Us, Piece);
ei.attackedBy[Us][Piece] = 0;
while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
if (Piece == KNIGHT || Piece == QUEEN)
b = pos.attacks_from(s);
else if (Piece == BISHOP)
b = attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
else if (Piece == ROOK)
b = attacks_bb(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
else
assert(false);
ei.attackedBy[Us][Piece] |= b;
if (b & ei.kingRing[Them])
{
ei.kingAttackersCount[Us]++;
ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
Bitboard bb = (b & ei.attackedBy[Them][KING]);
if (bb)
ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb);
}
mob = (Piece != QUEEN ? popcount(b & mobilityArea)
: popcount(b & mobilityArea));
mobility += MobilityBonus[Piece][mob];
// Decrease score if we are attacked by an enemy pawn. Remaining part
// of threat evaluation must be done later when we have full attack info.
if (ei.attackedBy[Them][PAWN] & s)
score -= ThreatenedByPawnPenalty[Piece];
// Otherwise give a bonus if we are a bishop and can pin a piece or
// can give a discovered check through an x-ray attack.
else if ( Piece == BISHOP
&& (PseudoAttacks[Piece][pos.king_square(Them)] & s)
&& !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
score += BishopPinBonus;
// Penalty for bishop with same coloured pawns
if (Piece == BISHOP)
score -= BishopPawnsPenalty * ei.pi->pawns_on_same_color_squares(Us, s);
// Bishop and knight outposts squares
if ( (Piece == BISHOP || Piece == KNIGHT)
&& !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
score += evaluate_outposts(pos, ei, s);
if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5)
{
// Major piece on 7th rank
if ( relative_rank(Us, s) == RANK_7
&& relative_rank(Us, pos.king_square(Them)) == RANK_8)
score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
// Major piece attacking pawns on the same rank
Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s);
if (pawns)
score += (Piece == ROOK ? RookOnPawnBonus
: QueenOnPawnBonus) * popcount(pawns);
}
// Special extra evaluation for bishops
if (Piece == BISHOP && pos.is_chess960())
{
// An important Chess960 pattern: A cornered bishop blocked by
// a friendly pawn diagonally in front of it is a very serious
// problem, especially when that pawn is also blocked.
if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
{
Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
if (pos.piece_on(s + d) == make_piece(Us, PAWN))
{
if (!pos.is_empty(s + d + pawn_push(Us)))
score -= 2*TrappedBishopA1H1Penalty;
else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
score -= TrappedBishopA1H1Penalty;
else
score -= TrappedBishopA1H1Penalty / 2;
}
}
}
// Special extra evaluation for rooks
if (Piece == ROOK)
{
// Open and half-open files
f = file_of(s);
if (ei.pi->file_is_half_open(Us, f))
{
if (ei.pi->file_is_half_open(Them, f))
score += RookOpenFileBonus;
else
score += RookHalfOpenFileBonus;
}
if (mob > 6 || ei.pi->file_is_half_open(Us, f))
continue;
ksq = pos.king_square(Us);
// Penalize rooks which are trapped inside a king. Penalize more if
// king has lost right to castle.
if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
&& rank_of(ksq) == rank_of(s)
&& relative_rank(Us, ksq) == RANK_1
&& !ei.pi->has_open_file_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E))
score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
: (TrappedRookPenalty - mob * 16), 0);
}
}
if (Trace)
TracedScores[Us][Piece] = score;
return score;
}
// evaluate_threats<>() assigns bonuses according to the type of attacking piece
// and the type of attacked one.
template
Score evaluate_threats(const Position& pos, EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b, undefendedMinors, weakEnemies;
Score score = SCORE_ZERO;
// Undefended minors get penalized even if not under attack
undefendedMinors = pos.pieces(Them, BISHOP, KNIGHT)
& ~ei.attackedBy[Them][ALL_PIECES];
if (undefendedMinors)
score += UndefendedMinorPenalty;
// Enemy pieces not defended by a pawn and under our attack
weakEnemies = pos.pieces(Them)
& ~ei.attackedBy[Them][PAWN]
& ei.attackedBy[Us][ALL_PIECES];
if (!weakEnemies)
return score;
// Add bonus according to type of attacked enemy piece and to the
// type of attacking piece, from knights to queens. Kings are not
// considered because are already handled in king evaluation.
for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
{
b = ei.attackedBy[Us][pt1] & weakEnemies;
if (b)
for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
if (b & pos.pieces(pt2))
score += ThreatBonus[pt1][pt2];
}
return score;
}
// evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
// pieces of a given color.
template