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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, 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
///
/// -DUSE_POPCNT | Add runtime support for use of popcnt asm-instruction. Works
/// | only in 64-bit mode and requires hardware with popcnt support.
+///
+/// -DUSE_PEXT | Add runtime support for use of pext asm-instruction. Works
+/// | only in 64-bit mode and requires hardware with pext support.
#include <cassert>
#include <cctype>
#include <climits>
+#include <cstdint>
#include <cstdlib>
+#include <algorithm>
-#include "platform.h"
+#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'
+#endif
/// Predefined macros hell:
///
/// _WIN32 Building on Windows (any)
/// _WIN64 Building on Windows 64 bit
-#if defined(_WIN64) && !defined(IS_64BIT) // Last condition means Makefile is not used
-# include <intrin.h> // MSVC popcnt and bsfq instrinsics
+#if defined(_WIN64) && defined(_MSC_VER) // No Makefile used
+# include <intrin.h> // Microsoft header for _BitScanForward64()
# define IS_64BIT
-# define USE_BSFQ
#endif
-#if defined(USE_POPCNT) && defined(__INTEL_COMPILER) && defined(_MSC_VER)
-# include <nmmintrin.h> // Intel header for _mm_popcnt_u64() intrinsic
+#if defined(USE_POPCNT) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
+# include <nmmintrin.h> // Intel and Microsoft header for _mm_popcnt_u64()
#endif
#if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
#if defined(USE_PEXT)
# include <immintrin.h> // Header for _pext_u64() intrinsic
+# define pext(b, m) _pext_u64(b, m)
#else
-# define _pext_u64(b, m) (0)
-#endif
-
-#ifdef _MSC_VER
-# define FORCE_INLINE __forceinline
-#elif defined(__GNUC__)
-# define FORCE_INLINE inline __attribute__((always_inline))
-#else
-# define FORCE_INLINE inline
+# define pext(b, m) 0
#endif
#ifdef USE_POPCNT
-const bool HasPopCnt = true;
+constexpr bool HasPopCnt = true;
#else
-const bool HasPopCnt = false;
+constexpr bool HasPopCnt = false;
#endif
#ifdef USE_PEXT
-const bool HasPext = true;
+constexpr bool HasPext = true;
#else
-const bool HasPext = false;
+constexpr bool HasPext = false;
#endif
#ifdef IS_64BIT
-const bool Is64Bit = true;
+constexpr bool Is64Bit = true;
#else
-const bool Is64Bit = false;
+constexpr bool Is64Bit = false;
#endif
typedef uint64_t Key;
typedef uint64_t Bitboard;
-const int MAX_MOVES = 256;
-const int MAX_PLY = 128;
+constexpr int MAX_MOVES = 256;
+constexpr int MAX_PLY = 246;
/// A move needs 16 bits to be stored
///
/// any normal move destination square is always different from origin square
/// while MOVE_NONE and MOVE_NULL have the same origin and destination square.
-enum Move {
+enum Move : int {
MOVE_NONE,
MOVE_NULL = 65
};
};
enum Color {
- WHITE, BLACK, NO_COLOR, COLOR_NB = 2
+ WHITE, BLACK, COLOR_NB = 2
};
-enum CastlingSide {
- KING_SIDE, QUEEN_SIDE, CASTLING_SIDE_NB = 2
-};
-
-enum CastlingRight {
+enum CastlingRights {
NO_CASTLING,
WHITE_OO,
WHITE_OOO = WHITE_OO << 1,
BLACK_OO = WHITE_OO << 2,
BLACK_OOO = WHITE_OO << 3,
- ANY_CASTLING = WHITE_OO | WHITE_OOO | BLACK_OO | BLACK_OOO,
- CASTLING_RIGHT_NB = 16
-};
-template<Color C, CastlingSide S> struct MakeCastling {
- static const CastlingRight
- right = C == WHITE ? S == QUEEN_SIDE ? WHITE_OOO : WHITE_OO
- : S == QUEEN_SIDE ? BLACK_OOO : BLACK_OO;
+ KING_SIDE = WHITE_OO | BLACK_OO,
+ QUEEN_SIDE = WHITE_OOO | BLACK_OOO,
+ WHITE_CASTLING = WHITE_OO | WHITE_OOO,
+ BLACK_CASTLING = BLACK_OO | BLACK_OOO,
+ ANY_CASTLING = WHITE_CASTLING | BLACK_CASTLING,
+
+ CASTLING_RIGHT_NB = 16
};
enum Phase {
enum ScaleFactor {
SCALE_FACTOR_DRAW = 0,
- SCALE_FACTOR_ONEPAWN = 48,
SCALE_FACTOR_NORMAL = 64,
SCALE_FACTOR_MAX = 128,
SCALE_FACTOR_NONE = 255
BOUND_EXACT = BOUND_UPPER | BOUND_LOWER
};
-enum Value {
+enum Value : int {
VALUE_ZERO = 0,
VALUE_DRAW = 0,
VALUE_KNOWN_WIN = 10000,
VALUE_MATE_IN_MAX_PLY = VALUE_MATE - 2 * MAX_PLY,
VALUE_MATED_IN_MAX_PLY = -VALUE_MATE + 2 * MAX_PLY,
- VALUE_ENSURE_INTEGER_SIZE_P = INT_MAX,
- VALUE_ENSURE_INTEGER_SIZE_N = INT_MIN,
-
- PawnValueMg = 198, PawnValueEg = 258,
- KnightValueMg = 817, KnightValueEg = 846,
- BishopValueMg = 836, BishopValueEg = 857,
- RookValueMg = 1270, RookValueEg = 1278,
- QueenValueMg = 2521, QueenValueEg = 2558,
+ PawnValueMg = 128, PawnValueEg = 213,
+ KnightValueMg = 782, KnightValueEg = 865,
+ BishopValueMg = 830, BishopValueEg = 918,
+ RookValueMg = 1289, RookValueEg = 1378,
+ QueenValueMg = 2529, QueenValueEg = 2687,
- MidgameLimit = 15581, EndgameLimit = 3998
+ MidgameLimit = 15258, EndgameLimit = 3915
};
enum PieceType {
PIECE_NB = 16
};
-enum Depth {
+extern Value PieceValue[PHASE_NB][PIECE_NB];
- ONE_PLY = 1,
+typedef int Depth;
+
+enum : int {
- DEPTH_ZERO = 0,
DEPTH_QS_CHECKS = 0,
DEPTH_QS_NO_CHECKS = -1,
DEPTH_QS_RECAPTURES = -5,
- DEPTH_NONE = -6,
- DEPTH_MAX = MAX_PLY
+ DEPTH_NONE = -6,
+ DEPTH_OFFSET = DEPTH_NONE,
};
-enum Square {
+enum Square : int {
SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1,
SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2,
SQ_A3, SQ_B3, SQ_C3, SQ_D3, SQ_E3, SQ_F3, SQ_G3, SQ_H3,
SQ_A8, SQ_B8, SQ_C8, SQ_D8, SQ_E8, SQ_F8, SQ_G8, SQ_H8,
SQ_NONE,
- SQUARE_NB = 64,
+ SQUARE_NB = 64
+};
- DELTA_N = 8,
- DELTA_E = 1,
- DELTA_S = -8,
- DELTA_W = -1,
+enum Direction : int {
+ NORTH = 8,
+ EAST = 1,
+ SOUTH = -NORTH,
+ WEST = -EAST,
- DELTA_NN = DELTA_N + DELTA_N,
- DELTA_NE = DELTA_N + DELTA_E,
- DELTA_SE = DELTA_S + DELTA_E,
- DELTA_SS = DELTA_S + DELTA_S,
- DELTA_SW = DELTA_S + DELTA_W,
- DELTA_NW = DELTA_N + DELTA_W
+ NORTH_EAST = NORTH + EAST,
+ SOUTH_EAST = SOUTH + EAST,
+ SOUTH_WEST = SOUTH + WEST,
+ NORTH_WEST = NORTH + WEST
};
-enum File {
+enum File : int {
FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NB
};
-enum Rank {
+enum Rank : int {
RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB
};
-/// Score enum stores a middlegame and an endgame value in a single integer.
-/// The least significant 16 bits are used to store the endgame value and
-/// the upper 16 bits are used to store the middlegame value. The compiler
-/// is free to choose the enum type as long as it can store the data, so we
-/// ensure that Score is an integer type by assigning some big int values.
-enum Score {
- SCORE_ZERO,
- SCORE_ENSURE_INTEGER_SIZE_P = INT_MAX,
- SCORE_ENSURE_INTEGER_SIZE_N = INT_MIN
-};
+/// Score enum stores a middlegame and an endgame value in a single integer (enum).
+/// The least significant 16 bits are used to store the middlegame value and the
+/// upper 16 bits are used to store the endgame value. We have to take care to
+/// avoid left-shifting a signed int to avoid undefined behavior.
+enum Score : int { SCORE_ZERO };
-inline Score make_score(int mg, int eg) {
- return Score((mg << 16) + eg);
+constexpr Score make_score(int mg, int eg) {
+ return Score((int)((unsigned int)eg << 16) + mg);
}
/// Extracting the signed lower and upper 16 bits is 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 eg_value(Score s) {
+ union { uint16_t u; int16_t s; } eg = { uint16_t(unsigned(s + 0x8000) >> 16) };
+ return Value(eg.s);
+}
+
inline Value mg_value(Score s) {
- return Value(((s + 0x8000) & ~0xFFFF) / 0x10000);
+ union { uint16_t u; int16_t s; } mg = { uint16_t(unsigned(s)) };
+ return Value(mg.s);
}
-inline Value eg_value(Score s) {
- return Value((int)(unsigned(s) & 0x7FFFU) - (int)(unsigned(s) & 0x8000U));
-}
-
-#define ENABLE_BASE_OPERATORS_ON(T) \
-inline T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
-inline T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
-inline T operator*(int i, T d) { return T(i * int(d)); } \
-inline T operator*(T d, int i) { return T(int(d) * i); } \
-inline T operator-(T d) { return T(-int(d)); } \
-inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; } \
-inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; } \
-inline T& operator*=(T& d, int i) { return d = T(int(d) * i); }
-
-#define ENABLE_FULL_OPERATORS_ON(T) \
-ENABLE_BASE_OPERATORS_ON(T) \
-inline T& operator++(T& d) { return d = T(int(d) + 1); } \
-inline T& operator--(T& d) { return d = T(int(d) - 1); } \
-inline T operator/(T d, int i) { return T(int(d) / i); } \
-inline int operator/(T d1, T d2) { return int(d1) / int(d2); } \
+#define ENABLE_BASE_OPERATORS_ON(T) \
+constexpr T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
+constexpr T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
+constexpr T operator-(T d) { return T(-int(d)); } \
+inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; } \
+inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; }
+
+#define ENABLE_INCR_OPERATORS_ON(T) \
+inline T& operator++(T& d) { return d = T(int(d) + 1); } \
+inline T& operator--(T& d) { return d = T(int(d) - 1); }
+
+#define ENABLE_FULL_OPERATORS_ON(T) \
+ENABLE_BASE_OPERATORS_ON(T) \
+constexpr T operator*(int i, T d) { return T(i * int(d)); } \
+constexpr T operator*(T d, int i) { return T(int(d) * i); } \
+constexpr T operator/(T d, int i) { return T(int(d) / i); } \
+constexpr int operator/(T d1, T d2) { return int(d1) / int(d2); } \
+inline T& operator*=(T& d, int i) { return d = T(int(d) * i); } \
inline T& operator/=(T& d, int i) { return d = T(int(d) / i); }
ENABLE_FULL_OPERATORS_ON(Value)
-ENABLE_FULL_OPERATORS_ON(PieceType)
-ENABLE_FULL_OPERATORS_ON(Piece)
-ENABLE_FULL_OPERATORS_ON(Color)
-ENABLE_FULL_OPERATORS_ON(Depth)
-ENABLE_FULL_OPERATORS_ON(Square)
-ENABLE_FULL_OPERATORS_ON(File)
-ENABLE_FULL_OPERATORS_ON(Rank)
+ENABLE_FULL_OPERATORS_ON(Direction)
+
+ENABLE_INCR_OPERATORS_ON(PieceType)
+ENABLE_INCR_OPERATORS_ON(Piece)
+ENABLE_INCR_OPERATORS_ON(Square)
+ENABLE_INCR_OPERATORS_ON(File)
+ENABLE_INCR_OPERATORS_ON(Rank)
ENABLE_BASE_OPERATORS_ON(Score)
#undef ENABLE_FULL_OPERATORS_ON
+#undef ENABLE_INCR_OPERATORS_ON
#undef ENABLE_BASE_OPERATORS_ON
/// Additional operators to add integers to a Value
-inline Value operator+(Value v, int i) { return Value(int(v) + i); }
-inline Value operator-(Value v, int i) { return Value(int(v) - i); }
+constexpr Value operator+(Value v, int i) { return Value(int(v) + i); }
+constexpr Value operator-(Value v, int i) { return Value(int(v) - i); }
inline Value& operator+=(Value& v, int i) { return v = v + i; }
inline Value& operator-=(Value& v, int i) { return v = v - i; }
+/// Additional operators to add a Direction to a Square
+constexpr Square operator+(Square s, Direction d) { return Square(int(s) + int(d)); }
+constexpr Square operator-(Square s, Direction d) { return Square(int(s) - int(d)); }
+inline Square& operator+=(Square& s, Direction d) { return s = s + d; }
+inline Square& operator-=(Square& s, Direction d) { return s = s - d; }
+
/// 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);
+Score operator*(Score, Score) = delete;
/// Division of a Score 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);
}
-extern Value PieceValue[PHASE_NB][PIECE_NB];
+/// Multiplication of a Score by an integer. We check for overflow in debug mode.
+inline Score operator*(Score s, int i) {
+
+ Score result = Score(int(s) * i);
+
+ assert(eg_value(result) == (i * eg_value(s)));
+ assert(mg_value(result) == (i * mg_value(s)));
+ assert((i == 0) || (result / i) == s);
-inline Color operator~(Color c) {
- return Color(c ^ BLACK);
+ return result;
}
-inline Square operator~(Square s) {
+/// Multiplication of a Score by a boolean
+inline Score operator*(Score s, bool b) {
+ return Score(int(s) * int(b));
+}
+
+constexpr Color operator~(Color c) {
+ return Color(c ^ BLACK); // Toggle color
+}
+
+constexpr Square operator~(Square s) {
return Square(s ^ SQ_A8); // Vertical flip SQ_A1 -> SQ_A8
}
-inline CastlingRight operator|(Color c, CastlingSide s) {
- return CastlingRight(WHITE_OO << ((s == QUEEN_SIDE) + 2 * c));
+constexpr Piece operator~(Piece pc) {
+ return Piece(pc ^ 8); // Swap color of piece B_KNIGHT -> W_KNIGHT
}
-inline Value mate_in(int ply) {
+inline File map_to_queenside(File f) {
+ return std::min(f, File(FILE_H - f)); // Map files ABCDEFGH to files ABCDDCBA
+}
+
+constexpr CastlingRights operator&(Color c, CastlingRights cr) {
+ return CastlingRights((c == WHITE ? WHITE_CASTLING : BLACK_CASTLING) & cr);
+}
+
+constexpr Value mate_in(int ply) {
return VALUE_MATE - ply;
}
-inline Value mated_in(int ply) {
+constexpr Value mated_in(int ply) {
return -VALUE_MATE + ply;
}
-inline Square make_square(File f, Rank r) {
- return Square((r << 3) | f);
+constexpr Square make_square(File f, Rank r) {
+ return Square((r << 3) + f);
}
-inline Piece make_piece(Color c, PieceType pt) {
- return Piece((c << 3) | pt);
+constexpr Piece make_piece(Color c, PieceType pt) {
+ return Piece((c << 3) + pt);
}
-inline PieceType type_of(Piece pc) {
+constexpr PieceType type_of(Piece pc) {
return PieceType(pc & 7);
}
return Color(pc >> 3);
}
-inline bool is_ok(Square s) {
+constexpr bool is_ok(Square s) {
return s >= SQ_A1 && s <= SQ_H8;
}
-inline File file_of(Square s) {
+constexpr File file_of(Square s) {
return File(s & 7);
}
-inline Rank rank_of(Square s) {
+constexpr Rank rank_of(Square s) {
return Rank(s >> 3);
}
-inline Square relative_square(Color c, Square s) {
+constexpr Square relative_square(Color c, Square s) {
return Square(s ^ (c * 56));
}
-inline Rank relative_rank(Color c, Rank r) {
+constexpr Rank relative_rank(Color c, Rank r) {
return Rank(r ^ (c * 7));
}
-inline Rank relative_rank(Color c, Square s) {
+constexpr Rank relative_rank(Color c, Square s) {
return relative_rank(c, rank_of(s));
}
-inline bool opposite_colors(Square s1, Square s2) {
- int s = int(s1) ^ int(s2);
- return ((s >> 3) ^ s) & 1;
-}
-
-inline Square pawn_push(Color c) {
- return c == WHITE ? DELTA_N : DELTA_S;
+constexpr Direction pawn_push(Color c) {
+ return c == WHITE ? NORTH : SOUTH;
}
-inline Square from_sq(Move m) {
+constexpr Square from_sq(Move m) {
return Square((m >> 6) & 0x3F);
}
-inline Square to_sq(Move m) {
+constexpr Square to_sq(Move m) {
return Square(m & 0x3F);
}
-inline MoveType type_of(Move m) {
+constexpr int from_to(Move m) {
+ return m & 0xFFF;
+}
+
+constexpr MoveType type_of(Move m) {
return MoveType(m & (3 << 14));
}
-inline PieceType promotion_type(Move m) {
- return PieceType(((m >> 12) & 3) + 2);
+constexpr PieceType promotion_type(Move m) {
+ return PieceType(((m >> 12) & 3) + KNIGHT);
+}
+
+constexpr Move make_move(Square from, Square to) {
+ return Move((from << 6) + to);
}
-inline Move make_move(Square from, Square to) {
- return Move(to | (from << 6));
+constexpr Move reverse_move(Move m) {
+ return make_move(to_sq(m), from_sq(m));
}
template<MoveType T>
-inline Move make(Square from, Square to, PieceType pt = KNIGHT) {
- return Move(to | (from << 6) | T | ((pt - KNIGHT) << 12));
+constexpr Move make(Square from, Square to, PieceType pt = KNIGHT) {
+ return Move(T + ((pt - KNIGHT) << 12) + (from << 6) + to);
}
-inline bool is_ok(Move m) {
+constexpr bool is_ok(Move m) {
return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
}
projects / stockfish / blobdiff