int MvvLva(POS *p, int move) {
// Captures
if (p->pc[Tsq(move)] != NO_PC)
return TpOnSq(p, Tsq(move)) * 6 + 5 - TpOnSq(p, Fsq(move));
// Non-capturing promotions
if (IsProm(move)) return PromType(move) - 5;
return 5;
}
void sManipulator::DoMove(sPosition *p, int move, UNDO *u)
{
int side = p->side; // moving side
int fsq = Fsq(move); // start square
int tsq = Tsq(move); // target square
int ftp = TpOnSq(p, fsq); // moving piece
int ttp = TpOnSq(p, tsq); // captured piece
U64 bbMove = SqBb(fsq) | SqBb(tsq); // optimization from Stockfish
// save data for undoing a move
u->ttp = ttp;
u->castleFlags = p->castleFlags;
u->epSquare = p->epSquare;
u->reversibleMoves = p->reversibleMoves;
u->hashKey = p->hashKey;
u->pawnKey = p->pawnKey;
p->repetitionList[p->head++] = p->hashKey;
// update reversible move counter (zeroing is done on captures and pawn moves)
p->reversibleMoves++;
p->hashKey ^= zobCastle[p->castleFlags];
p->castleFlags &= castleMask[fsq] & castleMask[tsq];
p->hashKey ^= zobCastle[p->castleFlags];
// clear en passant square
if (p->epSquare != NO_SQ) {
p->hashKey ^= zobEp[File(p->epSquare)];
p->epSquare = NO_SQ;
}
// move a piece from start square
p->pc[fsq] = NO_PC;
p->pc[tsq] = Pc(side, ftp);
p->hashKey ^= zobPiece[Pc(side, ftp)][fsq] ^ zobPiece[Pc(side, ftp)][tsq];
if (ftp == P) {
p->reversibleMoves = 0;
p->pawnKey ^= zobPiece[Pc(side, ftp)][fsq] ^ zobPiece[Pc(side, ftp)][tsq];
}
p->bbCl[side] ^= bbMove;
p->bbTp[ftp] ^= bbMove;
p->pstMg[side] += Data.pstMg[side][ftp][tsq] - Data.pstMg[side][ftp][fsq];
p->pstEg[side] += Data.pstEg[side][ftp][tsq] - Data.pstEg[side][ftp][fsq];
// on a king move update king location data
if (ftp == K) p->kingSquare[side] = tsq;
// capture
if (ttp != NO_TP) {
p->reversibleMoves = 0;
p->hashKey ^= zobPiece[Pc(Opp(side), ttp)][tsq];
if (ttp == P)
p->pawnKey ^= zobPiece[Pc(Opp(side), ttp)][tsq];
p->bbCl[Opp(side)] ^= SqBb(tsq);
p->bbTp[ttp] ^= SqBb(tsq);
p->pcCount[Opp(side)][ttp]--;
p->pieceMat[Opp(side)] -= Data.matValue[ttp];
p->phase -= Data.phaseValue[ttp];
p->pstMg[Opp(side)] -= Data.pstMg[Opp(side)][ttp][tsq];
p->pstEg[Opp(side)] -= Data.pstEg[Opp(side)][ttp][tsq];
}
switch (MoveType(move)) {
case NORMAL:
break;
case CASTLE:
if (tsq > fsq) {
fsq += 3;
tsq -= 1;
} else {
fsq -= 4;
tsq += 1;
}
p->pc[fsq] = NO_PC;
p->pc[tsq] = Pc(side, R);
p->hashKey ^= zobPiece[Pc(side, R)][fsq] ^ zobPiece[Pc(side, R)][tsq];
p->bbCl[side] ^= SqBb(fsq) | SqBb(tsq);
p->bbTp[R] ^= SqBb(fsq) | SqBb(tsq);
p->pstMg[side] += Data.pstMg[side][R][tsq] - Data.pstMg[side][R][fsq];
p->pstEg[side] += Data.pstEg[side][R][tsq] - Data.pstEg[side][R][fsq];
break;
case EP_CAP:
tsq ^= 8;
p->pc[tsq] = NO_PC;
p->hashKey ^= zobPiece[Pc(Opp(side), P)][tsq];
p->pawnKey ^= zobPiece[Pc(Opp(side), P)][tsq];
p->bbCl[Opp(side)] ^= SqBb(tsq);
p->bbTp[P] ^= SqBb(tsq);
p->pcCount[Opp(side)][P]--;
p->phase -= Data.phaseValue[P];
p->pstMg[Opp(side)] -= Data.pstMg[Opp(side)][P][tsq];
p->pstEg[Opp(side)] -= Data.pstEg[Opp(side)][P][tsq];
break;
case EP_SET:
tsq ^= 8;
if (bbPawnAttacks[side][tsq] & bbPc(p, Opp(side), P)) {
p->epSquare = tsq;
p->hashKey ^= zobEp[File(tsq)];
}
break;
// promotion: (1) add promoted piece and add values associated with it
case N_PROM: // (2) remove promoted pawn and substract values associated with it
case B_PROM:
case R_PROM:
case Q_PROM:
ftp = PromType(move);
p->pc[tsq] = Pc(side, ftp);
p->hashKey ^= zobPiece[Pc(side, P)][tsq] ^ zobPiece[Pc(side, ftp)][tsq];
p->pawnKey ^= zobPiece[Pc(side, P)][tsq];
p->bbTp[P] ^= SqBb(tsq);
p->bbTp[ftp]^= SqBb(tsq);
p->pcCount[side][ftp]++;
p->pcCount[side][P]--;
p->pieceMat[side] += Data.matValue[ftp];
p->phase += Data.phaseValue[ftp] - Data.phaseValue[P];
p->pstMg[side] += Data.pstMg[side][ftp][tsq] - Data.pstMg[side][P][tsq];
p->pstEg[side] += Data.pstEg[side][ftp][tsq] - Data.pstEg[side][P][tsq];
break;
}
p->side ^= 1;
p->hashKey ^= SIDE_RANDOM;
}
