//// Functions
////
+
/// Constructor
-History::History() {
- this->clear();
-}
+History::History() { clear(); }
-/// History::clear() clears the history tables.
+/// History::clear() clears the history tables
void History::clear() {
memset(history, 0, 2 * 8 * 64 * sizeof(int));
}
-/// History::success() registers a move as being successful. This is done
+/// History::success() registers a move as being successful. This is done
/// whenever a non-capturing move causes a beta cutoff in the main search.
-/// The three parameters are the moving piece, the move itself, and the
-/// search depth.
+/// The three parameters are the moving piece, the destination square, and
+/// the search depth.
+
+void History::success(Piece p, Square to, Depth d) {
-void History::success(Piece p, Move m, Depth d) {
assert(piece_is_ok(p));
- assert(move_is_ok(m));
+ assert(square_is_ok(to));
- history[p][move_to(m)] += int(d) * int(d);
- successCount[p][move_to(m)]++;
+ history[p][to] += int(d) * int(d);
+ successCount[p][to]++;
- // Prevent history overflow:
- if(history[p][move_to(m)] >= HistoryMax)
- for(int i = 0; i < 16; i++)
- for(int j = 0; j < 64; j++)
- history[i][j] /= 2;
+ // Prevent history overflow
+ if (history[p][to] >= HistoryMax)
+ for (int i = 0; i < 16; i++)
+ for (int j = 0; j < 64; j++)
+ history[i][j] /= 4;
}
-/// History::failure() registers a move as being unsuccessful. The function is
+/// History::failure() registers a move as being unsuccessful. The function is
/// called for each non-capturing move which failed to produce a beta cutoff
/// at a node where a beta cutoff was finally found.
-void History::failure(Piece p, Move m) {
+void History::failure(Piece p, Square to) {
+
assert(piece_is_ok(p));
- assert(move_is_ok(m));
+ assert(square_is_ok(to));
- failureCount[p][move_to(m)]++;
+ failureCount[p][to]++;
}
/// History::move_ordering_score() returns an integer value used to order the
/// non-capturing moves in the MovePicker class.
-int History::move_ordering_score(Piece p, Move m) const {
+int History::move_ordering_score(Piece p, Square to) const {
+
assert(piece_is_ok(p));
- assert(move_is_ok(m));
+ assert(square_is_ok(to));
- return history[p][move_to(m)];
+ return history[p][to];
}
/// History::ok_to_prune() decides whether a move has been sufficiently
/// unsuccessful that it makes sense to prune it entirely.
-bool History::ok_to_prune(Piece p, Move m, Depth d) const {
+bool History::ok_to_prune(Piece p, Square to, Depth d) const {
+
assert(piece_is_ok(p));
- assert(move_is_ok(m));
+ assert(square_is_ok(to));
- return (int(d) * successCount[p][move_to(m)] < failureCount[p][move_to(m)]);
+ return (int(d) * successCount[p][to] < failureCount[p][to]);
}