/*
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
+ Copyright (C) 2015-2016 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
#include <algorithm>
#include <cassert>
-#include <cstring>
+#include <cstring> // For std::memset, std::memcmp
#include <iomanip>
#include <sstream>
#include "bitcount.h"
+#include "misc.h"
#include "movegen.h"
#include "position.h"
-#include "psqtab.h"
-#include "rkiss.h"
#include "thread.h"
#include "tt.h"
#include "uci.h"
Key exclusion;
}
-Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion;}
+Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion; }
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.
-template<int Pt> FORCE_INLINE
-PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers,
+template<int Pt>
+PieceType min_attacker(const Bitboard* bb, Square to, Bitboard stmAttackers,
Bitboard& occupied, Bitboard& attackers) {
Bitboard b = stmAttackers & bb[Pt];
return (PieceType)Pt;
}
-template<> FORCE_INLINE
-PieceType min_attacker<KING>(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) {
+template<>
+PieceType min_attacker<KING>(const Bitboard*, Square, Bitboard, Bitboard&, Bitboard&) {
return KING; // No need to update bitboards: it is the last cycle
}
} // namespace
-/// CheckInfo c'tor
+/// CheckInfo constructor
CheckInfo::CheckInfo(const Position& pos) {
Color them = ~pos.side_to_move();
- ksq = pos.king_square(them);
+ ksq = pos.square<KING>(them);
pinned = pos.pinned_pieces(pos.side_to_move());
dcCandidates = pos.discovered_check_candidates();
- checkSq[PAWN] = pos.attacks_from<PAWN>(ksq, them);
- checkSq[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
- checkSq[BISHOP] = pos.attacks_from<BISHOP>(ksq);
- checkSq[ROOK] = pos.attacks_from<ROOK>(ksq);
- checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK];
- checkSq[KING] = 0;
+ checkSq
uares[PAWN] = pos.attacks_from<PAWN>(ksq, them);
+ checkSquares[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
+ checkSquares[BISHOP] = pos.attacks_from<BISHOP>(ksq);
+ checkSquares[ROOK] = pos.attacks_from<ROOK>(ksq);
+ checkSquares[QUEEN] = checkSquares[BISHOP] | checkSquares[ROOK];
+ checkSquares[KING] = 0;
}
}
os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
- << std::setfill('0') << std::setw(16) << pos.st->key << std::dec << "\nCheckers: ";
+ << std::setfill('0') << std::setw(16) << pos.key() << std::dec << "\nCheckers: ";
for (Bitboard b = pos.checkers(); b; )
- os << UCI::format_square(pop_lsb(&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.
-/// Secondly, the black halves of the tables are initialized by flipping and
-/// changing the sign of the white scores.
+/// hash keys.
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 cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr)
{
+ Zobrist::castling[cr] = 0;
Bitboard b = cr;
while (b)
{
Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
- Zobrist::castling[cr] ^= k ? k : rk.rand<Key>();
+ Zobrist::castling[cr] ^= k ? k : rng.rand<Key>();
}
}
- Zobrist::side = rk.rand<Key>();
- Zobrist::exclusion = rk.rand<Key>();
-
- for (PieceType pt = PAWN; pt <= KING; ++pt)
- {
- PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt];
- PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt];
-
- Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]);
-
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
- psq[WHITE][pt][ s] = (v + PSQT[pt][s]);
- psq[BLACK][pt][~s] = -(v + PSQT[pt][s]);
- }
- }
+ Zobrist::side = rng.rand<Key>();
+ Zobrist::exclusion = rng.rand<Key>();
}
-/// 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) {
std::memcpy(this, &pos, sizeof(Position));
- startState = *st;
+ std::memcpy(&startState, st, sizeof(StateInfo));
st = &startState;
nodes = 0;
else if ((idx = PieceToChar.find(token)) != string::npos)
{
- put_piece(sq, color_of(Piece(idx)), type_of(Piece(idx)));
+ put_piece(color_of(Piece(idx)), type_of(Piece(idx)), sq);
++sq;
}
}
{
Square rsq;
Color c = islower(token) ? BLACK : WHITE;
+ Piece rook = make_piece(c, ROOK);
token = char(toupper(token));
if (token == 'K')
- for (rsq = relative_square(c, SQ_H1); type_of(piece_on(rsq)) != ROOK; --rsq) {}
+ for (rsq = relative_square(c, SQ_H1); piece_on(rsq) != rook; --rsq) {}
else if (token == 'Q')
- for (rsq = relative_square(c, SQ_A1); type_of(piece_on(rsq)) != ROOK; ++rsq) {}
+ for (rsq = relative_square(c, SQ_A1); piece_on(rsq) != rook; ++rsq) {}
else if (token >= 'A' && token <= 'H')
rsq = make_square(File(token - 'A'), relative_rank(c, RANK_1));
void Position::set_castling_right(Color c, Square rfrom) {
- Square kfrom = king_square(c);
+ Square kfrom = square<KING>(c);
CastlingSide cs = kfrom < rfrom ? KING_SIDE : QUEEN_SIDE;
CastlingRight cr = (c | cs);
si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
si->psq = SCORE_ZERO;
- si->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
+ si->checkersBB = attackers_to(square<KING>(sideToMove)) & pieces(~sideToMove);
for (Bitboard b = pieces(); b; )
{
Square s = pop_lsb(&b);
Piece pc = piece_on(s);
si->key ^= Zobrist::psq[color_of(pc)][type_of(pc)][s];
- si->psq += psq[color_of(pc)][type_of(pc)][s];
+ si->psq += PSQT::psq[color_of(pc)][type_of(pc)][s];
}
- if (ep_square() != SQ_NONE)
- si->key ^= Zobrist::enpassant[file_of(ep_square())];
+ if (si->epSquare != SQ_NONE)
+ si->key ^= Zobrist::enpassant[file_of(si->epSquare)];
if (sideToMove == BLACK)
si->key ^= Zobrist::side;
- si->key ^= Zobrist::castling[st->castlingRights];
+ si->key ^= Zobrist::castling[si->castlingRights];
for (Bitboard b = pieces(PAWN); b; )
{
if (!can_castle(WHITE) && !can_castle(BLACK))
ss << '-';
- ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::format_square(ep_square()) + " ")
+ ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::square(ep_square()) + " ")
<< st->rule50 << " " << 1 + (gamePly - (sideToMove == BLACK)) / 2;
return ss.str();
Bitboard Position::check_blockers(Color c, Color kingColor) const {
Bitboard b, pinners, result = 0;
- Square ksq = king_square(kingColor);
+ Square ksq = square<KING>(kingColor);
// Pinners are sliders that give check when a pinned piece is removed
pinners = ( (pieces( ROOK, QUEEN) & PseudoAttacks[ROOK ][ksq])
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<ROOK >(s, occupied) & pieces(ROOK, QUEEN))
| (attacks_bb<BISHOP>(s, occupied) & pieces(BISHOP, QUEEN))
| (attacks_from<KING>(s) & pieces(KING));
}
Square from = from_sq(m);
assert(color_of(moved_piece(m)) == us);
- assert(piece_on(king_square(us)) == make_piece(us, KING));
+ assert(piece_on(square<KING>(us)) == make_piece(us, KING));
// En passant captures are a tricky special case. Because they are rather
// uncommon, we do it simply by testing whether the king is attacked after
// the move is made.
if (type_of(m) == ENPASSANT)
{
- Square ksq = king_square(us);
+ Square ksq = square<KING>(us);
Square to = to_sq(m);
Square capsq = to - pawn_push(us);
Bitboard occupied = (pieces() ^ from ^ capsq) | to;
// is moving along the ray towards or away from the king.
return !pinned
|| !(pinned & from)
- || aligned(from, to_sq(m), king_square(us));
+ || aligned(from, to_sq(m), square<KING>(us));
}
return MoveList<LEGAL>(*this).contains(m);
// Is not a promotion, so promotion piece must be empty
- if (promotion_type(m) - 2 != NO_PIECE_TYPE)
+ if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE)
return false;
// If the 'from' square is not occupied by a piece belonging to the side to
return false;
if ( !(attacks_from<PAWN>(from, us) & pieces(~us) & to) // Not a capture
-
&& !((from + pawn_push(us) == to) && empty(to)) // Not a single push
-
&& !( (from + 2 * pawn_push(us) == to) // Not a double push
&& (rank_of(from) == relative_rank(us, RANK_2))
&& empty(to)
return false;
// Our move must be a blocking evasion or a capture of the checking piece
- if (!((between_bb(lsb(checkers()), king_square(us)) | checkers()) & to))
+ if (!((between_bb(lsb(checkers()), square<KING>(us)) | checkers()) & to))
return false;
}
// In case of king moves under check we have to remove king so as to catch
Square from = from_sq(m);
Square to = to_sq(m);
- PieceType pt = type_of(piece_on(from));
// Is there a direct check?
- if (ci.checkSq[pt] & to)
+ if (ci.checkSquares[type_of(piece_on(from))] & to)
return true;
// Is there a discovered check?
- if ( unlikely(ci.dcCandidates)
+ if ( ci.dcCandidates
&& (ci.dcCandidates & from)
&& !aligned(from, to, ci.ksq))
return true;
/// to a StateInfo object. The move is assumed to be legal. Pseudo-legal
/// moves should be filtered out before this function is called.
-void Position::do_move(Move m, StateInfo& newSt) {
-
- CheckInfo ci(*this);
- do_move(m, newSt, ci, gives_check(m, ci));
-}
-
-void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
+void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
assert(is_ok(m));
assert(&newSt != st);
++nodes;
- Key k = st->key;
+ Key k = st->key ^ Zobrist::side;
// Copy some fields of the old state to our new StateInfo object except the
// ones which are going to be recalculated from scratch anyway and then switch
// our state pointer to point to the new (ready to be updated) state.
- std::memcpy(&newSt, st, StateCopySize64 * sizeof(uint64_t));
-
+ std::memcpy(&newSt, st, offsetof(StateInfo, key));
newSt.previous = st;
st = &newSt;
- // Update side to move
- k ^= Zobrist::side;
-
// Increment ply counters. In particular, rule50 will be reset to zero later on
// in case of a capture or a pawn move.
++gamePly;
Color them = ~us;
Square from = from_sq(m);
Square to = to_sq(m);
- Piece pc = piece_on(from);
- PieceType pt = type_of(pc);
+ PieceType pt = type_of(piece_on(from));
PieceType captured = type_of(m) == ENPASSANT ? PAWN : type_of(piece_on(to));
- assert(color_of(pc) == us);
- assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == them || type_of(m) == CASTLING);
+ assert(color_of(piece_on(from)) == us);
+ assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == (type_of(m) != CASTLING ? them : us));
assert(captured != KING);
if (type_of(m) == CASTLING)
{
- assert(pc == make_piece(us, KING));
+ assert(pt == KING);
Square rfrom, rto;
- do_castling<true>(from, to, rfrom, rto);
+ do_castling<true>(us, from, to, rfrom, rto);
captured = NO_PIECE_TYPE;
- st->psq += psq[us][ROOK][rto] - psq[us][ROOK][rfrom];
+ st->psq += PSQT::psq[us][ROOK][rto] - PSQT::psq[us][ROOK][rfrom];
k ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto];
}
{
if (type_of(m) == ENPASSANT)
{
- capsq += pawn_push(them);
+ capsq -= pawn_push(us);
assert(pt == PAWN);
assert(to == st->epSquare);
assert(piece_on(to) == NO_PIECE);
assert(piece_on(capsq) == make_piece(them, PAWN));
- board[capsq] = NO_PIECE;
+ board[capsq] = NO_PIECE; // Not done by remove_piece()
}
st->pawnKey ^= Zobrist::psq[them][PAWN][capsq];
st->nonPawnMaterial[them] -= PieceValue[MG][captured];
// Update board and piece lists
- remove_piece(capsq, them, captured);
+ remove_piece(them, captured, capsq);
// Update material hash key and prefetch access to materialTable
k ^= Zobrist::psq[them][captured][capsq];
st->materialKey ^= Zobrist::psq[them][captured][pieceCount[them][captured]];
- prefetch((char*)thisThread->materialTable[st->materialKey]);
+ prefetch(thisThread->materialTable[st->materialKey]);
// Update incremental scores
- st->psq -= psq[them][captured][capsq];
+ st->psq -= PSQT::psq[them][captured][capsq];
// Reset rule 50 counter
st->rule50 = 0;
// Move the piece. The tricky Chess960 castling is handled earlier
if (type_of(m) != CASTLING)
- move_piece(from, to, us, pt);
+ move_piece(us, pt, from, to);
// If the moving piece is a pawn do some special extra work
if (pt == PAWN)
{
// Set en-passant square if the moved pawn can be captured
if ( (int(to) ^ int(from)) == 16
- && (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(them, PAWN)))
+ && (attacks_from<PAWN>(to - pawn_push(us), us) & pieces(them, PAWN)))
{
- st->epSquare = Square((from + to) / 2);
+ st->epSquare = (from + to) / 2;
k ^= Zobrist::enpassant[file_of(st->epSquare)];
}
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
- remove_piece(to, us, PAWN);
- put_piece(to, us, promotion);
+ remove_piece(us, PAWN, to);
+ put_piece(us, promotion, to);
// Update hash keys
k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to];
^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]];
// Update incremental score
- st->psq += psq[us][promotion][to] - psq[us][PAWN][to];
+ st->psq += PSQT::psq[us][promotion][to] - PSQT::psq[us][PAWN][to];
// Update material
st->nonPawnMaterial[us] += PieceValue[MG][promotion];
// Update pawn hash key and prefetch access to pawnsTable
st->pawnKey ^= Zobrist::psq[us][PAWN][from] ^ Zobrist::psq[us][PAWN][to];
- prefetch((char*)thisThread->pawnsTable[st->pawnKey]);
+ prefetch(thisThread->pawnsTable[st->pawnKey]);
// Reset rule 50 draw counter
st->rule50 = 0;
}
// Update incremental scores
- st->psq += psq[us][pt][to] - psq[us][pt][from];
+ st->psq += PSQT::psq[us][pt][to] - PSQT::psq[us][pt][from];
// Set capture piece
st->capturedType = captured;
// Update the key with the final value
st->key = k;
- // Update checkers bitboard: piece must be already moved due to attacks_from()
- st->checkersBB = 0;
-
- if (moveIsCheck)
- {
- if (type_of(m) != NORMAL)
- st->checkersBB = attackers_to(king_square(them)) & pieces(us);
- else
- {
- // Direct checks
- if (ci.checkSq[pt] & to)
- st->checkersBB |= to;
-
- // Discovered checks
- if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from))
- {
- if (pt != ROOK)
- st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
-
- if (pt != BISHOP)
- st->checkersBB |= attacks_from<BISHOP>(king_square(them)) & pieces(us, QUEEN, BISHOP);
- }
- }
- }
+ // Calculate checkers bitboard (if move gives check)
+ st->checkersBB = givesCheck ? attackers_to(square<KING>(them)) & pieces(us) : 0;
sideToMove = ~sideToMove;
if (type_of(m) == PROMOTION)
{
- assert(pt == promotion_type(m));
assert(relative_rank(us, to) == RANK_8);
- assert(promotion_type(m) >= KNIGHT && promotion_type(m) <= QUEEN);
+ assert(pt == promotion_type(m));
+ assert(pt >= KNIGHT && pt <= QUEEN);
- remove_piece(to, us, promotion_type(m));
- put_piece(to, us, PAWN);
+ remove_piece(us, pt, to);
+ put_piece(us, PAWN, to);
pt = PAWN;
}
if (type_of(m) == CASTLING)
{
Square rfrom, rto;
- do_castling<false>(from, to, rfrom, rto);
+ do_castling<false>(us, from, to, rfrom, rto);
}
else
{
- move_piece(to, from, us, pt); // Put the piece back at the source square
+ move_piece(us, pt, to, from); // Put the piece back at the source square
if (st->capturedType)
{
assert(to == st->previous->epSquare);
assert(relative_rank(us, to) == RANK_6);
assert(piece_on(capsq) == NO_PIECE);
+ assert(st->capturedType == PAWN);
}
- put_piece(capsq, ~us, st->capturedType); // Restore the captured piece
+ put_piece(~us, st->capturedType, capsq); // Restore the captured piece
}
}
/// Position::do_castling() is a helper used to do/undo a castling move. This
/// is a bit tricky, especially in Chess960.
template<bool Do>
-void Position::do_castling(Square from, Square& to, Square& rfrom, Square& rto) {
+void Position::do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto) {
bool kingSide = to > from;
rfrom = to; // Castling is encoded as "king captures friendly rook"
- rto = relative_square(sideToMove, kingSide ? SQ_F1 : SQ_D1);
- to = relative_square(sideToMove, kingSide ? SQ_G1 : SQ_C1);
+ rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
+ to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
// Remove both pieces first since squares could overlap in Chess960
- remove_piece(Do ? from : to, sideToMove, KING);
- remove_piece(Do ? rfrom : rto, sideToMove, ROOK);
+ remove_piece(us, KING, Do ? from : to);
+ remove_piece(us, ROOK, Do ? rfrom : rto);
board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do it for us
- put_piece(Do ? to : from, sideToMove, KING);
- put_piece(Do ? rto : rfrom, sideToMove, ROOK);
+ put_piece(us, KING, Do ? to : from);
+ put_piece(us, ROOK, Do ? rto : rfrom);
}
void Position::do_null_move(StateInfo& newSt) {
assert(!checkers());
+ assert(&newSt != st);
- std::memcpy(&newSt, st, sizeof(StateInfo)); // Fully copy here
-
+ std::memcpy(&newSt, st, sizeof(StateInfo));
newSt.previous = st;
st = &newSt;
}
st->key ^= Zobrist::side;
- prefetch((char*)TT.first_entry(st->key));
+ prefetch(TT.first_entry(st->key));
++st->rule50;
st->pliesFromNull = 0;
stm = color_of(piece_on(from));
occupied = pieces() ^ from;
- // Castling moves are implemented as king capturing the rook so cannot be
- // handled correctly. Simply return 0 that is always the correct value
+ // Castling moves are implemented as king capturing the rook so cannot
+ // be handled correctly. Simply return VALUE_ZERO that is always correct
// unless in the rare case the rook ends up under attack.
if (type_of(m) == CASTLING)
return VALUE_ZERO;
// Locate and remove the next least valuable attacker
captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
-
- // Stop before processing a king capture
- if (captured == KING)
- {
- if (stmAttackers == attackers)
- ++slIndex;
-
- break;
- }
-
stm = ~stm;
stmAttackers = attackers & pieces(stm);
++slIndex;
- } while (stmAttackers);
+ } while (stmAttackers && (captured != KING || (--slIndex, false))); // Stop before a king capture
// Having built the swap list, we negamax through it to find the best
// achievable score from the point of view of the side to move.
}
-/// Position::is_draw() tests whether the position is drawn by material, 50 moves
-/// rule or repetition. It does not detect stalemates.
+/// Position::is_draw() tests whether the position is drawn by 50-move rule
+/// or by repetition. It does not detect stalemates.
bool Position::is_draw() const {
/// Position::flip() flips position with the white and black sides reversed. This
/// is only useful for debugging e.g. for finding evaluation symmetry bugs.
-static char toggle_case(char c) {
- return char(islower(c) ? toupper(c) : tolower(c));
-}
-
void Position::flip() {
string f, token;
ss >> token; // Castling availability
f += token + " ";
- std::transform(f.begin(), f.end(), f.begin(), toggle_case);
+ std::transform(f.begin(), f.end(), f.begin(),
+ [](char c) { return char(islower(c) ? toupper(c) : tolower(c)); });
ss >> token; // En passant square
f += (token == "-" ? token : token.replace(1, 1, token[1] == '3' ? "6" : "3"));
/// 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* step) const {
-
- // Which parts of the position should be verified?
- const bool all = false;
-
- const bool testBitboards = all || false;
- const bool testState = all || false;
- const bool testKingCount = all || false;
- const bool testKingCapture = all || false;
- const bool testPieceCounts = all || false;
- const bool testPieceList = all || false;
- const bool testCastlingSquares = all || false;
+bool Position::pos_is_ok(int* failedStep) const {
- if (step)
- *step = 1;
+ const bool Fast = true; // Quick (default) or full check?
- 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;
+ enum { Default, King, Bitboards, State, Lists, Castling };
- if (step && ++*step, testBitboards)
+ for (int step = Default; step <= (Fast ? Default : Castling); step++)
{
- // The intersection of the white and black pieces must be empty
- if (pieces(WHITE) & pieces(BLACK))
- return false;
-
- // The union of the white and black pieces must be equal to all
- // occupied squares
- if ((pieces(WHITE) | pieces(BLACK)) != pieces())
- return false;
+ if (failedStep)
+ *failedStep = step;
+
+ if (step == Default)
+ if ( (sideToMove != WHITE && sideToMove != BLACK)
+ || piece_on(square<KING>(WHITE)) != W_KING
+ || piece_on(square<KING>(BLACK)) != B_KING
+ || ( ep_square() != SQ_NONE
+ && relative_rank(sideToMove, ep_square()) != RANK_6))
+ return false;
- // Separate piece type bitboards must have empty intersections
- for (PieceType p1 = PAWN; p1 <= KING; ++p1)
- for (PieceType p2 = PAWN; p2 <= KING; ++p2)
- if (p1 != p2 && (pieces(p1) & pieces(p2)))
- return false;
- }
+ if (step == King)
+ if ( std::count(board, board + SQUARE_NB, W_KING) != 1
+ || std::count(board, board + SQUARE_NB, B_KING) != 1
+ || attackers_to(square<KING>(~sideToMove)) & pieces(sideToMove))
+ return false;
- if (step && ++*step, testState)
- {
- StateInfo si;
- set_state(&si);
- if ( st->key != si.key
- || st->pawnKey != si.pawnKey
- || st->materialKey != si.materialKey
- || st->nonPawnMaterial[WHITE] != si.nonPawnMaterial[WHITE]
- || st->nonPawnMaterial[BLACK] != si.nonPawnMaterial[BLACK]
- || st->psq != si.psq
- || st->checkersBB != si.checkersBB)
- return false;
- }
+ if (step == Bitboards)
+ {
+ if ( (pieces(WHITE) & pieces(BLACK))
+ ||(pieces(WHITE) | pieces(BLACK)) != pieces())
+ return false;
- 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;
+ for (PieceType p1 = PAWN; p1 <= KING; ++p1)
+ for (PieceType p2 = PAWN; p2 <= KING; ++p2)
+ if (p1 != p2 && (pieces(p1) & pieces(p2)))
+ return false;
+ }
- if (step && ++*step, testKingCapture)
- if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
- return false;
+ if (step == State)
+ {
+ StateInfo si = *st;
+ set_state(&si);
+ if (std::memcmp(&si, st, sizeof(StateInfo)))
+ return false;
+ }
- 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 && ++*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)
- if ( board[pieceList[c][pt][i]] != make_piece(c, pt)
- || index[pieceList[c][pt][i]] != i)
+ if (step == Lists)
+ 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 && ++*step, testCastlingSquares)
- for (Color c = WHITE; c <= BLACK; ++c)
- for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
- {
- if (!can_castle(c | s))
- continue;
-
- if ( (castlingRightsMask[king_square(c)] & (c | s)) != (c | s)
- || piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
- || castlingRightsMask[castlingRookSquare[c | s]] != (c | s))
- return false;
- }
+ for (int i = 0; i < pieceCount[c][pt]; ++i)
+ if ( board[pieceList[c][pt][i]] != make_piece(c, pt)
+ || index[pieceList[c][pt][i]] != i)
+ return false;
+ }
+
+ if (step == Castling)
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
+ {
+ if (!can_castle(c | s))
+ continue;
+
+ if ( piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
+ || castlingRightsMask[castlingRookSquare[c | s]] != (c | s)
+ ||(castlingRightsMask[square<KING>(c)] & (c | s)) != (c | s))
+ return false;
+ }
+ }
return true;
}
projects / stockfish / blobdiff