assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < ActiveThreads);
- // Initialize, and make an early exit in case of an aborted search,
- // an instant draw, maximum ply reached, etc.
- if (AbortSearch || thread_should_stop(threadID))
- return Value(0);
-
if (depth < OnePly)
return qsearch(pos, ss, alpha, beta, Depth(0), ply, threadID);
+ // Initialize, and make an early exit in case of an aborted search,
+ // an instant draw, maximum ply reached, etc.
init_node(pos, ss, ply, threadID);
+ // After init_node() that calls poll()
+ if (AbortSearch || thread_should_stop(threadID))
+ return Value(0);
+
if (pos.is_draw())
return VALUE_DRAW;
movesSearched[moveCount++] = ss[ply].currentMove = move;
if (moveIsCapture)
- ss[ply].currentMoveCaptureValue = pos.midgame_value_of_piece_on(move_to(move));
- else if (move_is_ep(move))
- ss[ply].currentMoveCaptureValue = PawnValueMidgame;
+ ss[ply].currentMoveCaptureValue =
+ move_is_ep(move)? PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
else
ss[ply].currentMoveCaptureValue = Value(0);
assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < ActiveThreads);
- EvalInfo ei;
+ if (depth < OnePly)
+ return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
+ init_node(pos, ss, ply, threadID);
+
+ // After init_node() that calls poll()
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (depth < OnePly)
- return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
-
- init_node(pos, ss, ply, threadID);
-
if (pos.is_draw())
return VALUE_DRAW;
+ EvalInfo ei;
+
if (ply >= PLY_MAX - 1)
return evaluate(pos, ei, threadID);
Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
// Check for a null capture artifact, if the value without the null capture
- // is above beta then there is a good possibility that this is a cut-node.
- // We will do an IID later to find a ttMove.
+ // is above beta then mark the node as a suspicious failed low. We will verify
+ // later if we are really under threat.
if ( UseNullDrivenIID
&& nullValue < beta
&& depth > 6 * OnePly
}
}
// Null move search not allowed, try razoring
- else if ( !isCheck
- && !value_is_mate(beta)
- && ( (approximateEval < beta - RazorMargin && depth < RazorDepth)
- ||(approximateEval < beta - PawnValueMidgame && depth <= OnePly)))
+ else if ( !value_is_mate(beta)
+ && approximateEval < beta - RazorMargin
+ && depth < RazorDepth)
{
Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
- if (v < beta)
+ if (v < beta - RazorMargin / 2)
return v;
}
{
// The null move failed low due to a suspicious capture. Perhaps we
// are facing a null capture artifact due to the side to move change
- // and this is a cut-node. So it's a good time to search for a ttMove.
+ // and this position should fail high. So do a normal search with a
+ // reduced depth to get a good ttMove to use in the following full
+ // depth search.
Move tm = ss[ply].threatMove;
assert(tm != MOVE_NONE);
assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < ActiveThreads);
- EvalInfo ei;
-
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
+ init_node(pos, ss, ply, threadID);
+
+ // After init_node() that calls poll()
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- init_node(pos, ss, ply, threadID);
-
if (pos.is_draw())
return VALUE_DRAW;
return value_from_tt(tte->value(), ply);
// Evaluate the position statically
- Value staticValue = evaluate(pos, ei, threadID);
+ EvalInfo ei;
+ bool isCheck = pos.is_check();
+ Value staticValue = (isCheck ? -VALUE_INFINITE : evaluate(pos, ei, threadID));
if (ply == PLY_MAX - 1)
- return staticValue;
+ return evaluate(pos, ei, threadID);
// Initialize "stand pat score", and return it immediately if it is
// at least beta.
- Value bestValue = (pos.is_check() ? -VALUE_INFINITE : staticValue);
+ Value bestValue = staticValue;
if (bestValue >= beta)
return bestValue;
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth == 0) will be generated.
bool pvNode = (beta - alpha != 1);
- MovePicker mp = MovePicker(pos, pvNode, MOVE_NONE, EmptySearchStack, depth, &ei);
+ MovePicker mp = MovePicker(pos, pvNode, MOVE_NONE, EmptySearchStack, depth, isCheck ? NULL : &ei);
Move move;
int moveCount = 0;
Bitboard dcCandidates = mp.discovered_check_candidates();
- bool isCheck = pos.is_check();
bool enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame;
// Loop through the moves until no moves remain or a beta cutoff
Value futilityValue = staticValue
+ Max(pos.midgame_value_of_piece_on(move_to(move)),
pos.endgame_value_of_piece_on(move_to(move)))
+ + (move_is_ep(move) ? PawnValueEndgame : Value(0))
+ FutilityMargin0
+ ei.futilityMargin;
assert(move_is_ok(move));
- ss[sp->ply].currentMoveCaptureValue = move_is_ep(move)?
- PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
+ if (moveIsCapture)
+ ss[sp->ply].currentMoveCaptureValue =
+ move_is_ep(move)? PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
+ else
+ ss[sp->ply].currentMoveCaptureValue = Value(0);
lock_grab(&(sp->lock));
int moveCount = ++sp->moves;
Depth extension(const Position &pos, Move m, bool pvNode, bool check,
bool singleReply, bool mateThreat, bool* dangerous) {
+ assert(m != MOVE_NONE);
+
Depth result = Depth(0);
*dangerous = check || singleReply || mateThreat;
*dangerous = true;
}
- if ( pos.midgame_value_of_piece_on(move_to(m)) >= RookValueMidgame
+ if ( pos.move_is_capture(m)
+ && pos.type_of_piece_on(move_to(m)) != PAWN
&& ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
- pos.midgame_value_of_piece_on(move_to(m)) == Value(0))
- && !move_promotion(m))
+ && !move_promotion(m)
+ && !move_is_ep(m))
{
result += PawnEndgameExtension[pvNode];
*dangerous = true;
// value of the threatening piece, don't prune move which defend it.
if ( !PruneDefendingMoves
&& threat != MOVE_NONE
- && pos.type_of_piece_on(tto) != NO_PIECE_TYPE
+ && pos.move_is_capture(threat)
&& ( pos.midgame_value_of_piece_on(tfrom) >= pos.midgame_value_of_piece_on(tto)
|| pos.type_of_piece_on(tfrom) == KING)
&& pos.move_attacks_square(m, tto))
if ( !PruneBlockingMoves
&& threat != MOVE_NONE
&& piece_is_slider(pos.piece_on(tfrom))
- && bit_is_set(squares_between(tfrom, tto), mto) && pos.see(m) >= 0)
+ && bit_is_set(squares_between(tfrom, tto), mto)
+ && pos.see(m) >= 0)
return false;
return true;