static int history_prob(int move, const board_t * board, int ThreadId) {
int value;
unsigned int index;
ASSERT(move_is_ok(move));
ASSERT(board!=NULL);
ASSERT(!move_is_tactical(move,board) || see_move(move,board) < 0 || move_is_under_promote(move));
index = history_index(move,board);
ASSERT(HistHit[index]<=HistTot[index]);
ASSERT(HistTot[index]<HistTotMax);
// int * int assumed to be int by C++, large values and overflows need to use double on the interim product.
value = int(double(double(HistHit[index]) * HistoryMax) / HistTot[index]);
// // for uint16 or short or unsigned short the simple formula is OK.
// value = ( ( (HistHit[index]) * HistoryMax) / HistTot[index]); // HistoryMax instead
ASSERT(value>=1 && value<=16384);
return value;
}
static bool capture_is_good(int move, const board_t * board) {
int piece, capture;
ASSERT(move_is_ok(move));
ASSERT(board!=NULL);
ASSERT(move_is_tactical(move,board));
// special cases
if (MOVE_IS_EN_PASSANT(move)) return true;
if (move_is_under_promote(move)) return false; // REMOVE ME?
// captures and queen promotes
capture = board->square[MOVE_TO(move)];
if (capture != Empty) {
// capture
ASSERT(move_is_capture(move,board));
if (MOVE_IS_PROMOTE(move)) return true; // promote-capture
piece = board->square[MOVE_FROM(move)];
if (VALUE_PIECE(capture) >= VALUE_PIECE(piece)) return true;
}
return see_move(move,board) >= 0;
}
bool capture_is_good(int move, const board_t * board, bool in_pv) {
#else
static bool capture_is_good(int move, const board_t * board, bool in_pv) {
#endif
int piece, capture;
int see_value; // WHM 11/22/08
ASSERT(move_is_ok(move));
ASSERT(board!=NULL);
ASSERT(move_is_tactical(move,board));
// special cases
if (MOVE_IS_EN_PASSANT(move)) return true;
if (move_is_under_promote(move)) return false; // REMOVE ME? Keep, looks good to me. WHM;
// if (MOVE_IS_PROMOTE(move)) return true; // WHM; promote-to-queen, measures a little weaker
// too many garbage lines going nuts.
// captures and queen promotes
capture = board->square[MOVE_TO(move)];
piece = board->square[MOVE_FROM(move)];
if (capture != Empty) {
// capture
ASSERT(move_is_capture(move,board));
if (MOVE_IS_PROMOTE(move)) return true; // capture a piece on Rank8 and promote to queen
if (VALUE_PIECE(capture) >= VALUE_PIECE(piece)) return true;
}
// return see_move(move,board) >= 0; WHM 11/22/08
// WHM 11/22/08 START
see_value = see_move(move,board);
if (see_value >= 0) return true;
if (TryNodePVQueenPromotes) {
if (in_pv && MOVE_IS_PROMOTE(move)) {
ASSERT(!move_is_under_promote(move));
return true; // WHM:
}
}
if (TryKingAttackSacs || TryKingBoxSacs || TryPasserSacs) {
if (in_pv && see_value > -ValueBishop && capture != Empty) {
ASSERT(COLOUR_IS(capture,COLOUR_OPP(board->turn)));
// king attack sacs.
if (TryKingAttackSacs) {
if (narrow_piece_attack_king(board, piece, MOVE_TO(move), KING_POS(board,COLOUR_OPP(board->turn)))) {
return true;
}
}
// sacrifice attacks around the narrow/close king box can be examined more fully. Rybka lessons.
if (TryKingBoxSacs) {
if (DISTANCE(MOVE_TO(move),KING_POS(board,COLOUR_OPP(board->turn))) <= 1) {
return true;
}
}
// passer sacrifices...
if (TryPasserSacs) {
if (PIECE_IS_PAWN(capture) && PAWN_RANK(MOVE_TO(move),COLOUR_OPP(board->turn)) >= Rank6) {
return true;
}
}
}
} // WHM 11/22/08 END
return false;
}