/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2008-2010 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 <http://www.gnu.org/licenses/>.
*/
////
enum ValueType {
- VALUE_TYPE_NONE = 0,
+ VALUE_TYPE_NONE = 0,
VALUE_TYPE_UPPER = 1, // Upper bound
VALUE_TYPE_LOWER = 2, // Lower bound
- VALUE_TYPE_EXACT = 3 // Exact score
+ VALUE_TYPE_EXACT = VALUE_TYPE_UPPER | VALUE_TYPE_LOWER
};
enum Value {
- VALUE_DRAW = 0,
+ VALUE_ZERO = 0,
+ VALUE_DRAW = 0,
VALUE_KNOWN_WIN = 15000,
- VALUE_MATE = 30000,
- VALUE_INFINITE = 30001,
- VALUE_NONE = 30002
+ VALUE_MATE = 30000,
+ VALUE_INFINITE = 30001,
+ VALUE_NONE = 30002,
+ VALUE_ENSURE_SIGNED = -1
};
+ENABLE_OPERATORS_ON(Value);
-////
-//// Constants and variables
-////
-/// Piece values, middle game and endgame
-
-/// Important: If the material values are changed, one must also
-/// adjust the piece square tables, and the method game_phase() in the
-/// Position class!
-
-const Value PawnValueMidgame = Value(0xCC);
-const Value PawnValueEndgame = Value(0x100);
-const Value KnightValueMidgame = Value(0x340);
-const Value KnightValueEndgame = Value(0x340);
-const Value BishopValueMidgame = Value(0x340);
-const Value BishopValueEndgame = Value(0x340);
-const Value RookValueMidgame = Value(0x505);
-const Value RookValueEndgame = Value(0x505);
-const Value QueenValueMidgame = Value(0xA00);
-const Value QueenValueEndgame = Value(0xA00);
-
-const Value PieceValueMidgame[17] = {
- Value(0),
- PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
- RookValueMidgame, QueenValueMidgame,
- Value(0), Value(0), Value(0),
- PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
- RookValueMidgame, QueenValueMidgame,
- Value(0), Value(0), Value(0)
+enum ScaleFactor {
+ SCALE_FACTOR_ZERO = 0,
+ SCALE_FACTOR_NORMAL = 64,
+ SCALE_FACTOR_MAX = 128,
+ SCALE_FACTOR_NONE = 255
};
-const Value PieceValueEndgame[17] = {
- Value(0),
- PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
- RookValueEndgame, QueenValueEndgame,
- Value(0), Value(0), Value(0),
- PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
- RookValueEndgame, QueenValueEndgame,
- Value(0), Value(0), Value(0)
+
+/// Score enum keeps a midgame and an endgame value in a single
+/// integer (enum), first LSB 16 bits are used to store endgame
+/// value, while upper bits are used for midgame value.
+
+// Compiler is free to choose the enum type as long as can keep
+// its data, so ensure Score to be an integer type.
+enum Score {
+ SCORE_ZERO = 0,
+ SCORE_ENSURE_32_BITS_SIZE_P = (1 << 16),
+ SCORE_ENSURE_32_BITS_SIZE_N = -(1 << 16)
};
-/// Bonus for having the side to move
+ENABLE_OPERATORS_ON(Score);
+
+
+// Extracting the _signed_ lower and upper 16 bits it not so trivial
+// because according to the standard a simple cast to short is
+// implementation defined and so is a right shift of a signed integer.
+inline Value mg_value(Score s) { return Value(((int(s) + 32768) & ~0xffff) / 0x10000); }
-const Value TempoValueMidgame = Value(50);
-const Value TempoValueEndgame = Value(20);
+// Unfortunatly on Intel 64 bit we have a small speed regression, so use a faster code in
+// this case, although not 100% standard compliant it seems to work for Intel and MSVC.
+#if defined(IS_64BIT) && (!defined(__GNUC__) || defined(__INTEL_COMPILER))
+inline Value eg_value(Score s) { return Value(int16_t(s & 0xffff)); }
+#else
+inline Value eg_value(Score s) { return Value((int)(unsigned(s) & 0x7fffu) - (int)(unsigned(s) & 0x8000u)); }
+#endif
+
+inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }
+
+// Division must be handled separately for each term
+inline Score operator/(Score s, int i) { return make_score(mg_value(s) / i, eg_value(s) / i); }
+
+// Only declared but not defined. We don't want to multiply two scores due to
+// a very high risk of overflow. So user should explicitly convert to integer.
+inline Score operator*(Score s1, Score s2);
////
////
inline Value operator+ (Value v, int i) { return Value(int(v) + i); }
-inline Value operator+ (Value v1, Value v2) { return Value(int(v1) + int(v2)); }
-inline void operator+= (Value &v1, Value v2) {
- v1 = Value(int(v1) + int(v2));
-}
inline Value operator- (Value v, int i) { return Value(int(v) - i); }
-inline Value operator- (Value v) { return Value(-int(v)); }
-inline Value operator- (Value v1, Value v2) { return Value(int(v1) - int(v2)); }
-inline void operator-= (Value &v1, Value v2) {
- v1 = Value(int(v1) - int(v2));
-}
-inline Value operator* (Value v, int i) { return Value(int(v) * i); }
-inline void operator*= (Value &v, int i) { v = Value(int(v) * i); }
-inline Value operator* (int i, Value v) { return Value(int(v) * i); }
-inline Value operator/ (Value v, int i) { return Value(int(v) / i); }
-inline void operator/= (Value &v, int i) { v = Value(int(v) / i); }
inline Value value_mate_in(int ply) {
- return Value(VALUE_MATE - Value(ply));
-}
-
-inline Value value_mated_in(int ply) {
- return Value(-VALUE_MATE + Value(ply));
-}
-
-inline bool is_upper_bound(ValueType vt) {
- return (int(vt) & int(VALUE_TYPE_UPPER)) != 0;
-}
-
-inline bool is_lower_bound(ValueType vt) {
- return (int(vt) & int(VALUE_TYPE_LOWER)) != 0;
-}
-
-inline Value piece_value_midgame(PieceType pt) {
- return PieceValueMidgame[pt];
-}
-
-inline Value piece_value_endgame(PieceType pt) {
- return PieceValueEndgame[pt];
-}
-
-inline Value piece_value_midgame(Piece p) {
- return PieceValueMidgame[p];
+ return VALUE_MATE - ply;
}
-inline Value piece_value_endgame(Piece p) {
- return PieceValueEndgame[p];
+inline Value value_mated_in(int ply) {
+ return -VALUE_MATE + ply;
}
-
-////
-//// Prototypes
-////
-
-extern Value value_to_tt(Value v, int ply);
-extern Value value_from_tt(Value v, int ply);
-extern int value_to_centipawns(Value v);
-extern Value value_from_centipawns(int cp);
-extern const std::string value_to_string(Value v);
-
-
#endif // !defined(VALUE_H_INCLUDED)