2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #if !defined(VALUE_H_INCLUDED)
22 #define VALUE_H_INCLUDED
37 VALUE_TYPE_UPPER = 1, // Upper bound
38 VALUE_TYPE_LOWER = 2, // Lower bound
39 VALUE_TYPE_EXACT = VALUE_TYPE_UPPER | VALUE_TYPE_LOWER
45 VALUE_KNOWN_WIN = 15000,
47 VALUE_INFINITE = 30001,
49 VALUE_ENSURE_SIGNED = -1
54 SCALE_FACTOR_ZERO = 0,
55 SCALE_FACTOR_NORMAL = 64,
56 SCALE_FACTOR_MAX = 128,
57 SCALE_FACTOR_NONE = 255
61 /// Score enum keeps a midgame and an endgame value in a single
62 /// integer (enum), first LSB 16 bits are used to store endgame
63 /// value, while upper bits are used for midgame value.
65 // Compiler is free to choose the enum type as long as can keep
66 // its data, so ensure Score to be an integer type.
67 enum Score { ENSURE_32_BITS_SIZE_P = (1 << 16), ENSURE_32_BITS_SIZE_N = -(1 << 16)};
69 // Extracting the _signed_ lower and upper 16 bits it not so trivial
70 // because according to the standard a simple cast to short is
71 // implementation defined and so is a right shift of a signed integer.
72 inline Value mg_value(Score s) { return Value(((int(s) + 32768) & ~0xffff) / 0x10000); }
74 // Unfortunatly on Intel 64 bit we have a small speed regression, so use a faster code in
75 // this case, although not 100% standard compliant it seems to work for Intel and MSVC.
76 #if defined(IS_64BIT) && (!defined(__GNUC__) || defined(__INTEL_COMPILER))
77 inline Value eg_value(Score s) { return Value(int16_t(s & 0xffff)); }
79 inline Value eg_value(Score s) { return Value((int)(unsigned(s) & 0x7fffu) - (int)(unsigned(s) & 0x8000u)); }
82 inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }
84 // Division must be handled separately for each term
85 inline Score operator/(Score s, int i) { return make_score(mg_value(s) / i, eg_value(s) / i); }
87 // Only declared but not defined. We don't want to multiply two scores due to
88 // a very high risk of overflow. So user should explicitly convert to integer.
89 inline Score operator*(Score s1, Score s2);
93 //// Constants and variables
96 /// Piece values, middle game and endgame
98 /// Important: If the material values are changed, one must also
99 /// adjust the piece square tables, and the method game_phase() in the
102 /// Values modified by Joona Kiiski
104 const Value PawnValueMidgame = Value(0x0C6);
105 const Value PawnValueEndgame = Value(0x102);
106 const Value KnightValueMidgame = Value(0x331);
107 const Value KnightValueEndgame = Value(0x34E);
108 const Value BishopValueMidgame = Value(0x344);
109 const Value BishopValueEndgame = Value(0x359);
110 const Value RookValueMidgame = Value(0x4F6);
111 const Value RookValueEndgame = Value(0x4FE);
112 const Value QueenValueMidgame = Value(0x9D9);
113 const Value QueenValueEndgame = Value(0x9FE);
115 const Value PieceValueMidgame[17] = {
117 PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
118 RookValueMidgame, QueenValueMidgame,
119 Value(0), Value(0), Value(0),
120 PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
121 RookValueMidgame, QueenValueMidgame,
122 Value(0), Value(0), Value(0)
125 const Value PieceValueEndgame[17] = {
127 PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
128 RookValueEndgame, QueenValueEndgame,
129 Value(0), Value(0), Value(0),
130 PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
131 RookValueEndgame, QueenValueEndgame,
132 Value(0), Value(0), Value(0)
135 /// Bonus for having the side to move (modified by Joona Kiiski)
137 const Score TempoValue = make_score(48, 22);
141 //// Inline functions
144 inline Value operator+ (Value v, int i) { return Value(int(v) + i); }
145 inline Value operator- (Value v, int i) { return Value(int(v) - i); }
148 inline Value value_mate_in(int ply) {
149 return VALUE_MATE - ply;
152 inline Value value_mated_in(int ply) {
153 return -VALUE_MATE + ply;
156 inline bool is_upper_bound(ValueType vt) {
157 return (int(vt) & int(VALUE_TYPE_UPPER)) != 0;
160 inline bool is_lower_bound(ValueType vt) {
161 return (int(vt) & int(VALUE_TYPE_LOWER)) != 0;
164 inline Value piece_value_midgame(PieceType pt) {
165 return PieceValueMidgame[pt];
168 inline Value piece_value_endgame(PieceType pt) {
169 return PieceValueEndgame[pt];
172 inline Value piece_value_midgame(Piece p) {
173 return PieceValueMidgame[p];
176 inline Value piece_value_endgame(Piece p) {
177 return PieceValueEndgame[p];
180 #endif // !defined(VALUE_H_INCLUDED)