2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2009 Marco Costalba
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 = 3, // Exact score
40 VALUE_TYPE_EVAL = 4, // Evaluation cache
41 VALUE_TYPE_EV_UP = 5, // Evaluation cache for upper bound
42 VALUE_TYPE_EV_LO = 6 // Evaluation cache for lower bound
48 VALUE_KNOWN_WIN = 15000,
50 VALUE_INFINITE = 30001,
52 VALUE_ENSURE_SIGNED = -1
56 /// Score enum keeps a midgame and an endgame value in a single
57 /// integer (enum), first LSB 16 bits are used to store endgame
58 /// value, while upper bits are used for midgame value.
60 // Compiler is free to choose the enum type as long as can keep
61 // its data, so ensure Score to be an integer type.
62 enum Score { ENSURE_32_BITS_SIZE_P = (1 << 16), ENSURE_32_BITS_SIZE_N = -(1 << 16)};
64 // Extracting the _signed_ lower and upper 16 bits it not so trivial
65 // because according to the standard a simple cast to short is
66 // implementation defined and so is a right shift of a signed integer.
67 inline Value mg_value(Score s) { return Value(((int(s) + 32768) & ~0xffff) / 0x10000); }
69 // Unfortunatly on Intel 64 bit we have a small speed regression, so use a faster code in
70 // this case, although not 100% standard compliant it seems to work for Intel and MSVC.
71 #if defined(IS_64BIT) && (!defined(__GNUC__) || defined(__INTEL_COMPILER))
72 inline Value eg_value(Score s) { return Value(int16_t(s & 0xffff)); }
74 inline Value eg_value(Score s) { return Value((int)(unsigned(s) & 0x7fffu) - (int)(unsigned(s) & 0x8000u)); }
77 inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }
79 inline Score operator-(Score s) { return Score(-int(s)); }
80 inline Score operator+(Score s1, Score s2) { return Score(int(s1) + int(s2)); }
81 inline Score operator-(Score s1, Score s2) { return Score(int(s1) - int(s2)); }
82 inline void operator+=(Score& s1, Score s2) { s1 = Score(int(s1) + int(s2)); }
83 inline void operator-=(Score& s1, Score s2) { s1 = Score(int(s1) - int(s2)); }
84 inline Score operator*(int i, Score s) { return Score(i * int(s)); }
86 // Division must be handled separately for each term
87 inline Score operator/(Score s, int i) { return make_score(mg_value(s) / i, eg_value(s) / i); }
89 // Only declared but not defined. We don't want to multiply two scores due to
90 // a very high risk of overflow. So user should explicitly convert to integer.
91 inline Score operator*(Score s1, Score s2);
95 //// Constants and variables
98 /// Piece values, middle game and endgame
100 /// Important: If the material values are changed, one must also
101 /// adjust the piece square tables, and the method game_phase() in the
104 /// Values modified by Joona Kiiski
106 const Value PawnValueMidgame = Value(0x0C6);
107 const Value PawnValueEndgame = Value(0x102);
108 const Value KnightValueMidgame = Value(0x331);
109 const Value KnightValueEndgame = Value(0x34E);
110 const Value BishopValueMidgame = Value(0x344);
111 const Value BishopValueEndgame = Value(0x359);
112 const Value RookValueMidgame = Value(0x4F6);
113 const Value RookValueEndgame = Value(0x4FE);
114 const Value QueenValueMidgame = Value(0x9D9);
115 const Value QueenValueEndgame = Value(0x9FE);
117 const Value PieceValueMidgame[17] = {
119 PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
120 RookValueMidgame, QueenValueMidgame,
121 Value(0), Value(0), Value(0),
122 PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
123 RookValueMidgame, QueenValueMidgame,
124 Value(0), Value(0), Value(0)
127 const Value PieceValueEndgame[17] = {
129 PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
130 RookValueEndgame, QueenValueEndgame,
131 Value(0), Value(0), Value(0),
132 PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
133 RookValueEndgame, QueenValueEndgame,
134 Value(0), Value(0), Value(0)
137 /// Bonus for having the side to move (modified by Joona Kiiski)
139 const Score TempoValue = make_score(48, 22);
143 //// Inline functions
146 inline Value operator+ (Value v, int i) { return Value(int(v) + i); }
147 inline Value operator+ (Value v1, Value v2) { return Value(int(v1) + int(v2)); }
148 inline void operator+= (Value &v1, Value v2) {
149 v1 = Value(int(v1) + int(v2));
151 inline Value operator- (Value v, int i) { return Value(int(v) - i); }
152 inline Value operator- (Value v) { return Value(-int(v)); }
153 inline Value operator- (Value v1, Value v2) { return Value(int(v1) - int(v2)); }
154 inline void operator-= (Value &v1, Value v2) {
155 v1 = Value(int(v1) - int(v2));
157 inline Value operator* (Value v, int i) { return Value(int(v) * i); }
158 inline void operator*= (Value &v, int i) { v = Value(int(v) * i); }
159 inline Value operator* (int i, Value v) { return Value(int(v) * i); }
160 inline Value operator/ (Value v, int i) { return Value(int(v) / i); }
161 inline void operator/= (Value &v, int i) { v = Value(int(v) / i); }
164 inline Value value_mate_in(int ply) {
165 return Value(VALUE_MATE - Value(ply));
168 inline Value value_mated_in(int ply) {
169 return Value(-VALUE_MATE + Value(ply));
172 inline bool is_upper_bound(ValueType vt) {
173 return (int(vt) & int(VALUE_TYPE_UPPER)) != 0;
176 inline bool is_lower_bound(ValueType vt) {
177 return (int(vt) & int(VALUE_TYPE_LOWER)) != 0;
180 inline Value piece_value_midgame(PieceType pt) {
181 return PieceValueMidgame[pt];
184 inline Value piece_value_endgame(PieceType pt) {
185 return PieceValueEndgame[pt];
188 inline Value piece_value_midgame(Piece p) {
189 return PieceValueMidgame[p];
192 inline Value piece_value_endgame(Piece p) {
193 return PieceValueEndgame[p];
201 extern Value value_to_tt(Value v, int ply);
202 extern Value value_from_tt(Value v, int ply);
203 extern int value_to_centipawns(Value v);
204 extern Value value_from_centipawns(int cp);
205 extern const std::string value_to_string(Value v);
208 #endif // !defined(VALUE_H_INCLUDED)