/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+
+#include "psqt.h"
+
+#include <algorithm>
+
+#include "bitboard.h"
#include "types.h"
-namespace PSQT {
+namespace Stockfish {
-#define S(mg, eg) make_score(mg, eg)
+namespace
+{
-// Bonus[PieceType][Square / 2] contains Piece-Square scores. For each piece
-// type on a given square a (middlegame, endgame) score pair is assigned. Table
-// is defined for files A..D and white side: it is symmetric for black side and
-// second half of the files.
-const Score Bonus[][int(SQUARE_NB) / 2] = {
+auto constexpr S = make_score;
+
+// 'Bonus' contains Piece-Square parameters.
+// Scores are explicit for files A to D, implicitly mirrored for E to H.
+constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
+ { },
{ },
- { // Pawn
- S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0),
- S(-22, 4), S( 3,-6), S( 7, 8), S( 3,-1),
- S(-25,-3), S( -7,-4), S(18, 4), S(24, 5),
- S(-27, 1), S(-15, 2), S(15,-8), S(30,-2),
- S(-14, 7), S( 0,12), S(-2, 4), S(18,-3),
- S(-12, 8), S(-13,-5), S(-6, 1), S(-4, 7),
- S(-17, 1), S( 10,-9), S(-4, 1), S(-6,16),
- S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0)
- },
{ // Knight
- S(-144,-98), S(-109,-83), S(-85,-51), S(-73,-16),
- S( -88,-68), S( -43,-53), S(-19,-21), S( -7, 14),
- S( -69,-53), S( -24,-38), S( 0, -6), S( 12, 29),
- S( -28,-42), S( 17,-27), S( 41, 5), S( 53, 40),
- S( -30,-42), S( 15,-27), S( 39, 5), S( 51, 40),
- S( -10,-53), S( 35,-38), S( 59, -6), S( 71, 29),
- S( -64,-68), S( -19,-53), S( 5,-21), S( 17, 14),
- S(-200,-98), S( -65,-83), S(-41,-51), S(-29,-16)
+ { S(-175, -96), S(-92,-65), S(-74,-49), S(-73,-21) },
+ { S( -77, -67), S(-41,-54), S(-27,-18), S(-15, 8) },
+ { S( -61, -40), S(-17,-27), S( 6, -8), S( 12, 29) },
+ { S( -35, -35), S( 8, -2), S( 40, 13), S( 49, 28) },
+ { S( -34, -45), S( 13,-16), S( 44, 9), S( 51, 39) },
+ { S( -9, -51), S( 22,-44), S( 58,-16), S( 53, 17) },
+ { S( -67, -69), S(-27,-50), S( 4,-51), S( 37, 12) },
+ { S(-201,-100), S(-83,-88), S(-56,-56), S(-26,-17) }
},
{ // Bishop
- S(-54,-65), S(-27,-42), S(-34,-44), S(-43,-26),
- S(-29,-43), S( 8,-20), S( 1,-22), S( -8, -4),
- S(-20,-33), S( 17,-10), S( 10,-12), S( 1, 6),
- S(-19,-35), S( 18,-12), S( 11,-14), S( 2, 4),
- S(-22,-35), S( 15,-12), S( 8,-14), S( -1, 4),
- S(-28,-33), S( 9,-10), S( 2,-12), S( -7, 6),
- S(-32,-43), S( 5,-20), S( -2,-22), S(-11, -4),
- S(-49,-65), S(-22,-42), S(-29,-44), S(-38,-26)
+ { S(-37,-40), S(-4 ,-21), S( -6,-26), S(-16, -8) },
+ { S(-11,-26), S( 6, -9), S( 13,-12), S( 3, 1) },
+ { S(-5 ,-11), S( 15, -1), S( -4, -1), S( 12, 7) },
+ { S(-4 ,-14), S( 8, -4), S( 18, 0), S( 27, 12) },
+ { S(-8 ,-12), S( 20, -1), S( 15,-10), S( 22, 11) },
+ { S(-11,-21), S( 4, 4), S( 1, 3), S( 8, 4) },
+ { S(-12,-22), S(-10,-14), S( 4, -1), S( 0, 1) },
+ { S(-34,-32), S( 1,-29), S(-10,-26), S(-16,-17) }
},
{ // Rook
- S(-22, 3), S(-17, 3), S(-12, 3), S(-8, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3),
- S(-22, 3), S( -7, 3), S( -2, 3), S( 2, 3),
- S(-11, 3), S( 4, 3), S( 9, 3), S(13, 3),
- S(-22, 3), S(-17, 3), S(-12, 3), S(-8, 3)
+ { S(-31, -9), S(-20,-13), S(-14,-10), S(-5, -9) },
+ { S(-21,-12), S(-13, -9), S( -8, -1), S( 6, -2) },
+ { S(-25, 6), S(-11, -8), S( -1, -2), S( 3, -6) },
+ { S(-13, -6), S( -5, 1), S( -4, -9), S(-6, 7) },
+ { S(-27, -5), S(-15, 8), S( -4, 7), S( 3, -6) },
+ { S(-22, 6), S( -2, 1), S( 6, -7), S(12, 10) },
+ { S( -2, 4), S( 12, 5), S( 16, 20), S(18, -5) },
+ { S(-17, 18), S(-19, 0), S( -1, 19), S( 9, 13) }
},
{ // Queen
- S(-2,-80), S(-2,-54), S(-2,-42), S(-2,-30),
- S(-2,-54), S( 8,-30), S( 8,-18), S( 8, -6),
- S(-2,-42), S( 8,-18), S( 8, -6), S( 8, 6),
- S(-2,-30), S( 8, -6), S( 8, 6), S( 8, 18),
- S(-2,-30), S( 8, -6), S( 8, 6), S( 8, 18),
- S(-2,-42), S( 8,-18), S( 8, -6), S( 8, 6),
- S(-2,-54), S( 8,-30), S( 8,-18), S( 8, -6),
- S(-2,-80), S(-2,-54), S(-2,-42), S(-2,-30)
+ { S( 3,-69), S(-5,-57), S(-5,-47), S( 4,-26) },
+ { S(-3,-54), S( 5,-31), S( 8,-22), S(12, -4) },
+ { S(-3,-39), S( 6,-18), S(13, -9), S( 7, 3) },
+ { S( 4,-23), S( 5, -3), S( 9, 13), S( 8, 24) },
+ { S( 0,-29), S(14, -6), S(12, 9), S( 5, 21) },
+ { S(-4,-38), S(10,-18), S( 6,-11), S( 8, 1) },
+ { S(-5,-50), S( 6,-27), S(10,-24), S( 8, -8) },
+ { S(-2,-74), S(-2,-52), S( 1,-43), S(-2,-34) }
},
{ // King
- S(298, 27), S(332, 81), S(273,108), S(225,116),
- S(287, 74), S(321,128), S(262,155), S(214,163),
- S(224,111), S(258,165), S(199,192), S(151,200),
- S(196,135), S(230,189), S(171,216), S(123,224),
- S(173,135), S(207,189), S(148,216), S(100,224),
- S(146,111), S(180,165), S(121,192), S( 73,200),
- S(119, 74), S(153,128), S( 94,155), S( 46,163),
- S( 98, 27), S(132, 81), S( 73,108), S( 25,116)
+ { S(271, 1), S(327, 45), S(271, 85), S(198, 76) },
+ { S(278, 53), S(303,100), S(234,133), S(179,135) },
+ { S(195, 88), S(258,130), S(169,169), S(120,175) },
+ { S(164,103), S(190,156), S(138,172), S( 98,172) },
+ { S(154, 96), S(179,166), S(105,199), S( 70,199) },
+ { S(123, 92), S(145,172), S( 81,184), S( 31,191) },
+ { S( 88, 47), S(120,121), S( 65,116), S( 33,131) },
+ { S( 59, 11), S( 89, 59), S( 45, 73), S( -1, 78) }
}
};
-#undef S
+constexpr Score PBonus[RANK_NB][FILE_NB] =
+ { // Pawn (asymmetric distribution)
+ { },
+ { S( 2, -8), S( 4, -6), S( 11, 9), S( 18, 5), S( 16, 16), S( 21, 6), S( 9, -6), S( -3,-18) },
+ { S( -9, -9), S(-15, -7), S( 11,-10), S( 15, 5), S( 31, 2), S( 23, 3), S( 6, -8), S(-20, -5) },
+ { S( -3, 7), S(-20, 1), S( 8, -8), S( 19, -2), S( 39,-14), S( 17,-13), S( 2,-11), S( -5, -6) },
+ { S( 11, 12), S( -4, 6), S(-11, 2), S( 2, -6), S( 11, -5), S( 0, -4), S(-12, 14), S( 5, 9) },
+ { S( 3, 27), S(-11, 18), S( -6, 19), S( 22, 29), S( -8, 30), S( -5, 9), S(-14, 8), S(-11, 14) },
+ { S( -7, -1), S( 6,-14), S( -2, 13), S(-11, 22), S( 4, 24), S(-14, 17), S( 10, 7), S( -9, 7) }
+ };
-Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+} // namespace
-// init() initializes piece square tables: the white halves of the tables are
-// copied from Bonus[] adding the piece value, then the black halves of the
-// tables are initialized by flipping and changing the sign of the white scores.
+
+namespace PSQT
+{
+
+Score psq[PIECE_NB][SQUARE_NB];
+
+// PSQT::init() initializes piece-square tables: the white halves of the tables are
+// copied from Bonus[] and PBonus[], adding the piece value, then the black halves of
+// the tables are initialized by flipping and changing the sign of the white scores.
void init() {
- for (PieceType pt = PAWN; pt <= KING; ++pt)
+ for (Piece pc : {W_PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING})
{
- PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt];
- PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt];
+ Score score = make_score(PieceValue[MG][pc], PieceValue[EG][pc]);
- Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]);
-
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
- // Flip to the left half of the board and subtract 4 for each rank
- int ss = (file_of(s) < FILE_E ? s : s ^ 7) - 4 * rank_of(s);
- psq[BLACK][pt][~s] = -(psq[WHITE][pt][s] = v + Bonus[pt][ss]);
- }
+ for (Square s = SQ_A1; s <= SQ_H8; ++s)
+ {
+ File f = File(edge_distance(file_of(s)));
+ psq[ pc][s] = score + (type_of(pc) == PAWN ? PBonus[rank_of(s)][file_of(s)]
+ : Bonus[pc][rank_of(s)][f]);
+ psq[~pc][flip_rank(s)] = -psq[pc][s];
+ }
}
}
} // namespace PSQT
+
+} // namespace Stockfish