/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 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
#include <algorithm>
#include <cassert>
-#include <cstring>
+#include <cstring> // For std::memset
#include <iomanip>
#include <sstream>
#include "bitcount.h"
+#include "misc.h"
#include "movegen.h"
-#include "notation.h"
#include "position.h"
#include "psqtab.h"
-#include "rkiss.h"
#include "thread.h"
#include "tt.h"
+#include "uci.h"
using std::string;
-static const string PieceToChar(" PNBRQK pnbrqk");
-
-CACHE_LINE_ALIGNMENT
-
Value PieceValue[PHASE_NB][PIECE_NB] = {
{ VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg },
{ VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } };
-static Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
-
namespace Zobrist {
Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
namespace {
+const string PieceToChar(" PNBRQK pnbrqk");
+Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+
// min_attacker() is a helper function used by see() to locate the least
// valuable attacker for the side to move, remove the attacker we just found
// from the bitboards and scan for new X-ray attacks behind it.
}
+/// operator<<(Position) returns an ASCII representation of the position
+
+std::ostream& operator<<(std::ostream& os, const Position& pos) {
+
+ os << "\n +---+---+---+---+---+---+---+---+\n";
+
+ for (Rank r = RANK_8; r >= RANK_1; --r)
+ {
+ for (File f = FILE_A; f <= FILE_H; ++f)
+ os << " | " << PieceToChar[pos.piece_on(make_square(f, r))];
+
+ os << " |\n +---+---+---+---+---+---+---+---+\n";
+ }
+
+ os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
+ << std::setfill('0') << std::setw(16) << pos.st->key << std::dec << "\nCheckers: ";
+
+ for (Bitboard b = pos.checkers(); b; )
+ os << UCI::square(pop_lsb(&b)) << " ";
+
+ return os;
+}
+
+
/// Position::init() initializes at startup the various arrays used to compute
/// hash keys and the piece square tables. The latter is a two-step operation:
/// Firstly, the white halves of the tables are copied from PSQT[] tables.
void Position::init() {
- RKISS rk;
+ PRNG rng(1070372);
for (Color c = WHITE; c <= BLACK; ++c)
for (PieceType pt = PAWN; pt <= KING; ++pt)
for (Square s = SQ_A1; s <= SQ_H8; ++s)
- Zobrist::psq[c][pt][s] = rk.rand<Key>();
+ Zobrist::psq[c][pt][s] = rng.rand<Key>();
for (File f = FILE_A; f <= FILE_H; ++f)
- Zobrist::enpassant[f] = rk.rand<Key>();
+ Zobrist::enpassant[f] = rng.rand<Key>();
- for (int cf = NO_CASTLING; cf <= ANY_CASTLING; ++cf)
+ for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr)
{
- Bitboard b = cf;
+ Bitboard b = cr;
while (b)
{
Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
- Zobrist::castling[cf] ^= k ? k : rk.rand<Key>();
+ Zobrist::castling[cr] ^= k ? k : rng.rand<Key>();
}
}
- Zobrist::side = rk.rand<Key>();
- Zobrist::exclusion = rk.rand<Key>();
+ Zobrist::side = rng.rand<Key>();
+ Zobrist::exclusion = rng.rand<Key>();
for (PieceType pt = PAWN; pt <= KING; ++pt)
{
}
-/// Position::operator=() creates a copy of 'pos'. We want the new born Position
-/// object to not depend on any external data so we detach state pointer from
-/// the source one.
+/// Position::operator=() creates a copy of 'pos' but detaching the state pointer
+/// from the source to be self-consistent and not depending on any external data.
Position& Position::operator=(const Position& pos) {
incremented after Black's move.
*/
- char col, row, token;
+ unsigned char col, row, token;
size_t idx;
Square sq = SQ_A8;
std::istringstream ss(fenStr);
for (rsq = relative_square(c, SQ_A1); type_of(piece_on(rsq)) != ROOK; ++rsq) {}
else if (token >= 'A' && token <= 'H')
- rsq = File(token - 'A') | relative_rank(c, RANK_1);
+ rsq = make_square(File(token - 'A'), relative_rank(c, RANK_1));
else
continue;
if ( ((ss >> col) && (col >= 'a' && col <= 'h'))
&& ((ss >> row) && (row == '3' || row == '6')))
{
- st->epSquare = File(col - 'a') | Rank(row - '1');
+ st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
if (!(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)))
st->epSquare = SQ_NONE;
// Convert from fullmove starting from 1 to ply starting from 0,
// handle also common incorrect FEN with fullmove = 0.
- gamePly = std::max(2 * (gamePly - 1), 0) + int(sideToMove == BLACK);
+ gamePly = std::max(2 * (gamePly - 1), 0) + (sideToMove == BLACK);
chess960 = isChess960;
thisThread = th;
void Position::set_state(StateInfo* si) const {
si->key = si->pawnKey = si->materialKey = 0;
- si->npMaterial[WHITE] = si->npMaterial[BLACK] = VALUE_ZERO;
+ si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
si->psq = SCORE_ZERO;
si->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
for (Color c = WHITE; c <= BLACK; ++c)
for (PieceType pt = KNIGHT; pt <= QUEEN; ++pt)
- si->npMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt];
+ si->nonPawnMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt];
}
int emptyCnt;
std::ostringstream ss;
- for (Rank rank = RANK_8; rank >= RANK_1; --rank)
+ for (Rank r = RANK_8; r >= RANK_1; --r)
{
- for (File file = FILE_A; file <= FILE_H; ++file)
+ for (File f = FILE_A; f <= FILE_H; ++f)
{
- for (emptyCnt = 0; file <= FILE_H && empty(file | rank); ++file)
+ for (emptyCnt = 0; f <= FILE_H && empty(make_square(f, r)); ++f)
++emptyCnt;
if (emptyCnt)
ss << emptyCnt;
- if (file <= FILE_H)
- ss << PieceToChar[piece_on(file | rank)];
+ if (f <= FILE_H)
+ ss << PieceToChar[piece_on(make_square(f, r))];
}
- if (rank > RANK_1)
+ if (r > RANK_1)
ss << '/';
}
ss << (sideToMove == WHITE ? " w " : " b ");
if (can_castle(WHITE_OO))
- ss << (chess960 ? to_char(file_of(castling_rook_square(WHITE | KING_SIDE)), false) : 'K');
+ ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE | KING_SIDE))) : 'K');
if (can_castle(WHITE_OOO))
- ss << (chess960 ? to_char(file_of(castling_rook_square(WHITE | QUEEN_SIDE)), false) : 'Q');
+ ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE | QUEEN_SIDE))) : 'Q');
if (can_castle(BLACK_OO))
- ss << (chess960 ? to_char(file_of(castling_rook_square(BLACK | KING_SIDE)), true) : 'k');
+ ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK | KING_SIDE))) : 'k');
if (can_castle(BLACK_OOO))
- ss << (chess960 ? to_char(file_of(castling_rook_square(BLACK | QUEEN_SIDE)), true) : 'q');
+ ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK | QUEEN_SIDE))) : 'q');
if (!can_castle(WHITE) && !can_castle(BLACK))
ss << '-';
- ss << (ep_square() == SQ_NONE ? " - " : " " + to_string(ep_square()) + " ")
- << st->rule50 << " " << 1 + (gamePly - int(sideToMove == BLACK)) / 2;
+ ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::square(ep_square()) + " ")
+ << st->rule50 << " " << 1 + (gamePly - (sideToMove == BLACK)) / 2;
return ss.str();
}
-/// Position::pretty() returns an ASCII representation of the position to be
-/// printed to the standard output together with the move's san notation.
-
-const string Position::pretty(Move move) const {
-
- const string dottedLine = "\n+---+---+---+---+---+---+---+---+";
- const string twoRows = dottedLine + "\n| | . | | . | | . | | . |"
- + dottedLine + "\n| . | | . | | . | | . | |";
-
- string brd = twoRows + twoRows + twoRows + twoRows + dottedLine;
+/// Position::game_phase() calculates the game phase interpolating total non-pawn
+/// material between endgame and midgame limits.
- for (Bitboard b = pieces(); b; )
- {
- Square s = pop_lsb(&b);
- brd[513 - 68 * rank_of(s) + 4 * file_of(s)] = PieceToChar[piece_on(s)];
- }
-
- std::ostringstream ss;
+Phase Position::game_phase() const {
- if (move)
- ss << "\nMove: " << (sideToMove == BLACK ? ".." : "")
- << move_to_san(*const_cast<Position*>(this), move);
+ Value npm = st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
- ss << brd << "\nFen: " << fen() << "\nKey: " << std::hex << std::uppercase
- << std::setfill('0') << std::setw(16) << st->key << "\nCheckers: ";
+ npm = std::max(EndgameLimit, std::min(npm, MidgameLimit));
- for (Bitboard b = checkers(); b; )
- ss << to_string(pop_lsb(&b)) << " ";
-
- ss << "\nLegal moves: ";
- for (MoveList<LEGAL> it(*this); *it; ++it)
- ss << move_to_san(*const_cast<Position*>(this), *it) << " ";
-
- return ss.str();
+ return Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
}
/// Position::attackers_to() computes a bitboard of all pieces which attack a
-/// given square. Slider attacks use the occ bitboard to indicate occupancy.
+/// given square. Slider attacks use the occupied bitboard to indicate occupancy.
-Bitboard Position::attackers_to(Square s, Bitboard occ) const {
+Bitboard Position::attackers_to(Square s, Bitboard occupied) const {
- return (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
- | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
- | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
- | (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN))
- | (attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN))
- | (attacks_from<KING>(s) & pieces(KING));
+ return (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
+ | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
+ | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
+ | (attacks_bb<ROOK>(s, occupied) & pieces(ROOK, QUEEN))
+ | (attacks_bb<BISHOP>(s, occupied) & pieces(BISHOP, QUEEN))
+ | (attacks_from<KING>(s) & pieces(KING));
}
Square ksq = king_square(us);
Square to = to_sq(m);
Square capsq = to - pawn_push(us);
- Bitboard occ = (pieces() ^ from ^ capsq) | to;
+ Bitboard occupied = (pieces() ^ from ^ capsq) | to;
assert(to == ep_square());
assert(moved_piece(m) == make_piece(us, PAWN));
assert(piece_on(capsq) == make_piece(~us, PAWN));
assert(piece_on(to) == NO_PIECE);
- return !(attacks_bb< ROOK>(ksq, occ) & pieces(~us, QUEEN, ROOK))
- && !(attacks_bb<BISHOP>(ksq, occ) & pieces(~us, QUEEN, BISHOP));
+ return !(attacks_bb< ROOK>(ksq, occupied) & pieces(~us, QUEEN, ROOK))
+ && !(attacks_bb<BISHOP>(ksq, occupied) & pieces(~us, QUEEN, BISHOP));
}
// If the moving piece is a king, check whether the destination
return true;
// Is there a discovered check?
- if ( unlikely(ci.dcCandidates)
+ if ( ci.dcCandidates
&& (ci.dcCandidates & from)
&& !aligned(from, to, ci.ksq))
return true;
// the captured pawn.
case ENPASSANT:
{
- Square capsq = file_of(to) | rank_of(from);
+ Square capsq = make_square(file_of(to), rank_of(from));
Bitboard b = (pieces() ^ from ^ capsq) | to;
return (attacks_bb< ROOK>(ci.ksq, b) & pieces(sideToMove, QUEEN, ROOK))
st->pawnKey ^= Zobrist::psq[them][PAWN][capsq];
}
else
- st->npMaterial[them] -= PieceValue[MG][captured];
+ st->nonPawnMaterial[them] -= PieceValue[MG][captured];
// Update board and piece lists
remove_piece(capsq, them, captured);
st->castlingRights &= ~cr;
}
- // Prefetch TT access as soon as we know the new hash key
- prefetch((char*)TT.first_entry(k));
-
// Move the piece. The tricky Chess960 castling is handled earlier
if (type_of(m) != CASTLING)
move_piece(from, to, us, pt);
k ^= Zobrist::enpassant[file_of(st->epSquare)];
}
- if (type_of(m) == PROMOTION)
+ else if (type_of(m) == PROMOTION)
{
PieceType promotion = promotion_type(m);
st->psq += psq[us][promotion][to] - psq[us][PAWN][to];
// Update material
- st->npMaterial[us] += PieceValue[MG][promotion];
+ st->nonPawnMaterial[us] += PieceValue[MG][promotion];
}
// Update pawn hash key and prefetch access to pawnsTable
st->checkersBB |= to;
// Discovered checks
- if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from))
+ if (ci.dcCandidates && (ci.dcCandidates & from))
{
if (pt != ROOK)
st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
}
+/// Position::key_after() computes the new hash key after the given move. Needed
+/// for speculative prefetch. It doesn't recognize special moves like castling,
+/// en-passant and promotions.
+
+Key Position::key_after(Move m) const {
+
+ Color us = sideToMove;
+ Square from = from_sq(m);
+ Square to = to_sq(m);
+ PieceType pt = type_of(piece_on(from));
+ PieceType captured = type_of(piece_on(to));
+ Key k = st->key ^ Zobrist::side;
+
+ if (captured)
+ k ^= Zobrist::psq[~us][captured][to];
+
+ return k ^ Zobrist::psq[us][pt][to] ^ Zobrist::psq[us][pt][from];
+}
+
+
/// Position::see() is a static exchange evaluator: It tries to estimate the
/// material gain or loss resulting from a move.
bool Position::is_draw() const {
- if ( !pieces(PAWN)
- && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
- return true;
-
if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
return true;
string f, token;
std::stringstream ss(fen());
- for (Rank rank = RANK_8; rank >= RANK_1; --rank) // Piece placement
+ for (Rank r = RANK_8; r >= RANK_1; --r) // Piece placement
{
- std::getline(ss, token, rank > RANK_1 ? '/' : ' ');
+ std::getline(ss, token, r > RANK_1 ? '/' : ' ');
f.insert(0, token + (f.empty() ? " " : "/"));
}
/// Position::pos_is_ok() performs some consistency checks for the position object.
/// This is meant to be helpful when debugging.
-bool Position::pos_is_ok(int* failedStep) const {
-
- int dummy, *step = failedStep ? failedStep : &dummy;
+bool Position::pos_is_ok(int* step) const {
// Which parts of the position should be verified?
const bool all = false;
const bool testPieceList = all || false;
const bool testCastlingSquares = all || false;
- if (*step = 1, sideToMove != WHITE && sideToMove != BLACK)
- return false;
-
- if ((*step)++, piece_on(king_square(WHITE)) != W_KING)
- return false;
-
- if ((*step)++, piece_on(king_square(BLACK)) != B_KING)
- return false;
+ if (step)
+ *step = 1;
- if ((*step)++, ep_square() != SQ_NONE && relative_rank(sideToMove, ep_square()) != RANK_6)
+ if ( (sideToMove != WHITE && sideToMove != BLACK)
+ || piece_on(king_square(WHITE)) != W_KING
+ || piece_on(king_square(BLACK)) != B_KING
+ || ( ep_square() != SQ_NONE
+ && relative_rank(sideToMove, ep_square()) != RANK_6))
return false;
- if ((*step)++, testBitboards)
+ if (step && ++*step, testBitboards)
{
// The intersection of the white and black pieces must be empty
if (pieces(WHITE) & pieces(BLACK))
return false;
}
- if ((*step)++, testState)
+ if (step && ++*step, testState)
{
StateInfo si;
set_state(&si);
if ( st->key != si.key
|| st->pawnKey != si.pawnKey
|| st->materialKey != si.materialKey
- || st->npMaterial[WHITE] != si.npMaterial[WHITE]
- || st->npMaterial[BLACK] != si.npMaterial[BLACK]
+ || st->nonPawnMaterial[WHITE] != si.nonPawnMaterial[WHITE]
+ || st->nonPawnMaterial[BLACK] != si.nonPawnMaterial[BLACK]
|| st->psq != si.psq
|| st->checkersBB != si.checkersBB)
return false;
}
- if ((*step)++, testKingCount)
+ if (step && ++*step, testKingCount)
if ( std::count(board, board + SQUARE_NB, W_KING) != 1
|| std::count(board, board + SQUARE_NB, B_KING) != 1)
return false;
- if ((*step)++, testKingCapture)
+ if (step && ++*step, testKingCapture)
if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
return false;
- if ((*step)++, testPieceCounts)
+ if (step && ++*step, testPieceCounts)
for (Color c = WHITE; c <= BLACK; ++c)
for (PieceType pt = PAWN; pt <= KING; ++pt)
if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
return false;
- if ((*step)++, testPieceList)
+ if (step && ++*step, testPieceList)
for (Color c = WHITE; c <= BLACK; ++c)
for (PieceType pt = PAWN; pt <= KING; ++pt)
for (int i = 0; i < pieceCount[c][pt]; ++i)
|| index[pieceList[c][pt][i]] != i)
return false;
- if ((*step)++, testCastlingSquares)
+ if (step && ++*step, testCastlingSquares)
for (Color c = WHITE; c <= BLACK; ++c)
for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
{
return false;
}
- *step = 0;
return true;
}
projects / stockfish / blobdiff