/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
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 <cstring> // For std::memset, std::memcmp
#include <iomanip>
#include <sstream>
+#include <string_view>
#include "bitboard.h"
#include "misc.h"
namespace {
-const string PieceToChar(" PNBRQK pnbrqk");
+constexpr std::string_view PieceToChar(" PNBRQK pnbrqk");
constexpr Piece Pieces[] = { W_PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING,
B_PAWN, B_KNIGHT, B_BISHOP, B_ROOK, B_QUEEN, B_KING };
// Marcel van Kervinck's cuckoo algorithm for fast detection of "upcoming repetition"
// situations. Description of the algorithm in the following paper:
-// https://marcelk.net/2013-04-06/paper/upcoming-rep-v2.pdf
+// http://web.archive.org/web/20201107002606/https://marcelk.net/2013-04-06/paper/upcoming-rep-v2.pdf
// First and second hash functions for indexing the cuckoo tables
inline int H1(Key h) { return h & 0x1fff; }
// Prepare the cuckoo tables
std::memset(cuckoo, 0, sizeof(cuckoo));
std::memset(cuckooMove, 0, sizeof(cuckooMove));
- int count = 0;
+ [[maybe_unused]] int count = 0;
for (Piece pc : Pieces)
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
for (Square s2 = Square(s1 + 1); s2 <= SQ_H8; ++s2)
chess960 = isChess960;
thisThread = th;
- set_state(st);
+ set_state();
assert(pos_is_ok());
/// Position::set_check_info() sets king attacks to detect if a move gives check
-void Position::set_check_info(StateInfo* si) const {
+void Position::set_check_info() const {
- si->blockersForKing[WHITE] = slider_blockers(pieces(BLACK), square<KING>(WHITE), si->pinners[BLACK]);
- si->blockersForKing[BLACK] = slider_blockers(pieces(WHITE), square<KING>(BLACK), si->pinners[WHITE]);
+ st->blockersForKing[WHITE] = slider_blockers(pieces(BLACK), square<KING>(WHITE), st->pinners[BLACK]);
+ st->blockersForKing[BLACK] = slider_blockers(pieces(WHITE), square<KING>(BLACK), st->pinners[WHITE]);
Square ksq = square<KING>(~sideToMove);
- si->checkSquares[PAWN] = pawn_attacks_bb(~sideToMove, ksq);
- si->checkSquares[KNIGHT] = attacks_bb<KNIGHT>(ksq);
- si->checkSquares[BISHOP] = attacks_bb<BISHOP>(ksq, pieces());
- si->checkSquares[ROOK] = attacks_bb<ROOK>(ksq, pieces());
- si->checkSquares[QUEEN] = si->checkSquares[BISHOP] | si->checkSquares[ROOK];
- si->checkSquares[KING] = 0;
+ st->checkSquares[PAWN] = pawn_attacks_bb(~sideToMove, ksq);
+ st->checkSquares[KNIGHT] = attacks_bb<KNIGHT>(ksq);
+ st->checkSquares[BISHOP] = attacks_bb<BISHOP>(ksq, pieces());
+ st->checkSquares[ROOK] = attacks_bb<ROOK>(ksq, pieces());
+ st->checkSquares[QUEEN] = st->checkSquares[BISHOP] | st->checkSquares[ROOK];
+ st->checkSquares[KING] = 0;
}
/// Position::set_state() computes the hash keys of the position, and other
/// data that once computed is updated incrementally as moves are made.
-/// The function is only used when a new position is set up, and to verify
-/// the correctness of the StateInfo data when running in debug mode.
+/// The function is only used when a new position is set up
-void Position::set_state(StateInfo* si) const {
+void Position::set_state() const {
- si->key = si->materialKey = 0;
- si->pawnKey = Zobrist::noPawns;
- si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
- si->checkersBB = attackers_to(square<KING>(sideToMove)) & pieces(~sideToMove);
+ st->key = st->materialKey = 0;
+ st->pawnKey = Zobrist::noPawns;
+ st->nonPawnMaterial[WHITE] = st->nonPawnMaterial[BLACK] = VALUE_ZERO;
+ st->checkersBB = attackers_to(square<KING>(sideToMove)) & pieces(~sideToMove);
- set_check_info(si);
+ set_check_info();
for (Bitboard b = pieces(); b; )
{
Square s = pop_lsb(b);
Piece pc = piece_on(s);
- si->key ^= Zobrist::psq[pc][s];
+ st->key ^= Zobrist::psq[pc][s];
if (type_of(pc) == PAWN)
- si->pawnKey ^= Zobrist::psq[pc][s];
+ st->pawnKey ^= Zobrist::psq[pc][s];
else if (type_of(pc) != KING)
- si->nonPawnMaterial[color_of(pc)] += PieceValue[MG][pc];
+ st->nonPawnMaterial[color_of(pc)] += PieceValue[MG][pc];
}
- if (si->epSquare != SQ_NONE)
- si->key ^= Zobrist::enpassant[file_of(si->epSquare)];
+ if (st->epSquare != SQ_NONE)
+ st->key ^= Zobrist::enpassant[file_of(st->epSquare)];
if (sideToMove == BLACK)
- si->key ^= Zobrist::side;
+ st->key ^= Zobrist::side;
- si->key ^= Zobrist::castling[si->castlingRights];
+ st->key ^= Zobrist::castling[st->castlingRights];
for (Piece pc : Pieces)
for (int cnt = 0; cnt < pieceCount[pc]; ++cnt)
- si->materialKey ^= Zobrist::psq[pc][cnt];
+ st->materialKey ^= Zobrist::psq[pc][cnt];
}
: MoveList<NON_EVASIONS>(*this).contains(m);
// Is not a promotion, so promotion piece must be empty
- if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE)
- return false;
+ assert(promotion_type(m) - KNIGHT == NO_PIECE_TYPE);
// If the 'from' square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
// Update board and piece lists
remove_piece(capsq);
- if (type_of(m) == EN_PASSANT)
- board[capsq] = NO_PIECE;
-
// Update material hash key and prefetch access to materialTable
k ^= Zobrist::psq[captured][capsq];
st->materialKey ^= Zobrist::psq[captured][pieceCount[captured]];
sideToMove = ~sideToMove;
// Update king attacks used for fast check detection
- set_check_info(st);
+ set_check_info();
// Calculate the repetition info. It is the ply distance from the previous
// occurrence of the same position, negative in the 3-fold case, or zero
sideToMove = ~sideToMove;
- set_check_info(st);
+ set_check_info();
st->repetition = 0;
if (captured)
k ^= Zobrist::psq[captured][to];
- return k ^ Zobrist::psq[pc][to] ^ Zobrist::psq[pc][from];
+ k ^= Zobrist::psq[pc][to] ^ Zobrist::psq[pc][from];
+
+ return (captured || type_of(pc) == PAWN)
+ ? k : adjust_key50<true>(k);
}
/// SEE value of move is greater or equal to the given threshold. We'll use an
/// algorithm similar to alpha-beta pruning with a null window.
-bool Position::see_ge(Move m, Value threshold) const {
+bool Position::see_ge(Move m, Bitboard& occupied, Value threshold) const {
assert(is_ok(m));
return true;
assert(color_of(piece_on(from)) == sideToMove);
- Bitboard occupied = pieces() ^ from ^ to;
+ occupied = pieces() ^ from ^ to; // xoring to is important for pinned piece logic
Color stm = sideToMove;
Bitboard attackers = attackers_to(to, occupied);
Bitboard stmAttackers, bb;
// Don't allow pinned pieces to attack as long as there are
// pinners on their original square.
if (pinners(~stm) & occupied)
+ {
stmAttackers &= ~blockers_for_king(stm);
- if (!stmAttackers)
- break;
+ if (!stmAttackers)
+ break;
+ }
res ^= 1;
// the bitboard 'attackers' any X-ray attackers behind it.
if ((bb = stmAttackers & pieces(PAWN)))
{
+ occupied ^= least_significant_square_bb(bb);
if ((swap = PawnValueMg - swap) < res)
break;
- occupied ^= least_significant_square_bb(bb);
attackers |= attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN);
}
else if ((bb = stmAttackers & pieces(KNIGHT)))
{
+ occupied ^= least_significant_square_bb(bb);
if ((swap = KnightValueMg - swap) < res)
break;
-
- occupied ^= least_significant_square_bb(bb);
}
else if ((bb = stmAttackers & pieces(BISHOP)))
{
+ occupied ^= least_significant_square_bb(bb);
if ((swap = BishopValueMg - swap) < res)
break;
- occupied ^= least_significant_square_bb(bb);
attackers |= attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN);
}
else if ((bb = stmAttackers & pieces(ROOK)))
{
+ occupied ^= least_significant_square_bb(bb);
if ((swap = RookValueMg - swap) < res)
break;
- occupied ^= least_significant_square_bb(bb);
attackers |= attacks_bb<ROOK>(to, occupied) & pieces(ROOK, QUEEN);
}
else if ((bb = stmAttackers & pieces(QUEEN)))
{
+ occupied ^= least_significant_square_bb(bb);
if ((swap = QueenValueMg - swap) < res)
break;
- occupied ^= least_significant_square_bb(bb);
attackers |= (attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN))
| (attacks_bb<ROOK >(to, occupied) & pieces(ROOK , QUEEN));
}
return bool(res);
}
+bool Position::see_ge(Move m, Value threshold) const {
+ Bitboard occupied;
+ return see_ge(m, occupied, threshold);
+}
+
/// Position::is_draw() tests whether the position is drawn by 50-move rule
/// or by repetition. It does not detect stalemates.
if (p1 != p2 && (pieces(p1) & pieces(p2)))
assert(0 && "pos_is_ok: Bitboards");
- StateInfo si = *st;
- ASSERT_ALIGNED(&si, Eval::NNUE::CacheLineSize);
-
- set_state(&si);
- if (std::memcmp(&si, st, sizeof(StateInfo)))
- assert(0 && "pos_is_ok: State");
for (Piece pc : Pieces)
if ( pieceCount[pc] != popcount(pieces(color_of(pc), type_of(pc)))
projects / stockfish / blobdiff