// Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
- // The main transposition table
- TranspositionTable TT;
-
/// Variables initialized by UCI options
// Make and search the move
StateInfo st;
pos.do_move(move, st, dcCandidates);
- TT.prefetch(pos.get_key());
if (moveCount == 1) // The first move in list is the PV
value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
bool mateThreat = false;
bool isCheck = pos.is_check();
+ bool useNullMove = ( allowNullmove
+ && depth > OnePly
+ && !isCheck
+ && !value_is_mate(beta)
+ && ok_to_do_nullmove(pos)
+ && approximateEval >= beta - NullMoveMargin);
+
// Null move search
- if ( allowNullmove
- && depth > OnePly
- && !isCheck
- && !value_is_mate(beta)
- && ok_to_do_nullmove(pos)
- && approximateEval >= beta - NullMoveMargin)
+ if (useNullMove)
{
ss[ply].currentMove = MOVE_NULL;
StateInfo st;
pos.do_null_move(st);
- TT.prefetch(pos.get_key());
-
int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction
Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
}
}
// Null move search not allowed, try razoring
- else if ( !value_is_mate(beta)
- && depth < RazorDepth
- && approximateEval < beta - RazorApprMargins[int(depth) - 2]
- && ss[ply - 1].currentMove != MOVE_NULL
- && ttMove == MOVE_NONE
- && !pos.has_pawn_on_7th(pos.side_to_move()))
+ if ( !useNullMove
+ && !value_is_mate(beta)
+ && depth < RazorDepth
+ && approximateEval < beta - RazorApprMargins[int(depth) - 2]
+ && ss[ply - 1].currentMove != MOVE_NULL
+ && ttMove == MOVE_NONE
+ && !pos.has_pawn_on_7th(pos.side_to_move()))
{
Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
if (v < beta - RazorMargins[int(depth) - 2])
// Make and search the move
StateInfo st;
pos.do_move(move, st, dcCandidates);
- TT.prefetch(pos.get_key());
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
// Make and search the move.
StateInfo st;
pos.do_move(move, st, dcCandidates);
- TT.prefetch(pos.get_key());
Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
pos.undo_move(move);
if (pos.type_of_piece_on(move_from(m)) == PAWN)
{
- if (pos.move_is_pawn_push_to_7th(m))
+ Color c = pos.side_to_move();
+ if (relative_rank(c, move_to(m)) == RANK_7)
{
result += PawnPushTo7thExtension[pvNode];
*dangerous = true;
}
- if (pos.move_is_passed_pawn_push(m))
+ if (pos.pawn_is_passed(c, move_to(m)))
{
result += PassedPawnExtension[pvNode];
*dangerous = true;