void SearchStack::init() {
currentMove = threatMove = bestMove = MOVE_NONE;
- reduction = Depth(0);
- eval = VALUE_NONE;
}
// SearchStack::initKillers() initializes killers for a search stack entry
void SearchStack::initKillers() {
- mateKiller = MOVE_NONE;
- for (int i = 0; i < KILLER_MAX; i++)
- killers[i] = MOVE_NONE;
+ killers[0] = killers[1] = mateKiller = MOVE_NONE;
}
beta = *betaPtr;
isCheck = pos.is_check();
- // Step 1. Initialize node and poll (omitted at root, init_ss_array() has already initialized root node)
+ // Step 1. Initialize node (polling is omitted at root)
+ ss->init();
+
// Step 2. Check for aborted search (omitted at root)
// Step 3. Mate distance pruning (omitted at root)
// Step 4. Transposition table lookup (omitted at root)
// Step 5. Evaluate the position statically
// At root we do this only to get reference value for child nodes
- if (!isCheck)
- ss->eval = evaluate(pos, ei);
+ ss->eval = isCheck ? VALUE_NONE : evaluate(pos, ei);
// Step 6. Razoring (omitted at root)
// Step 7. Static null move pruning (omitted at root)
refinedValue = refine_eval(tte, ss->eval, ply); // Enhance accuracy with TT value if possible
update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval);
}
+ else
+ ss->eval = VALUE_NONE;
// Step 6. Razoring (is omitted in PV nodes)
if ( !PvNode
TM.incrementNodeCounter(pos.thread());
ss->bestMove = ss->currentMove = MOVE_NONE;
- ss->eval = VALUE_NONE;
// Check for an instant draw or maximum ply reached
if (pos.is_draw() || ply >= PLY_MAX - 1)
if (isCheck)
{
bestValue = futilityBase = -VALUE_INFINITE;
+ ss->eval = VALUE_NONE;
deepChecks = enoughMaterial = false;
}
else
bool move_is_killer(Move m, SearchStack* ss) {
- const Move* k = ss->killers;
- for (int i = 0; i < KILLER_MAX; i++, k++)
- if (*k == m)
- return true;
+ if (ss->killers[0] == m || ss->killers[1] == m)
+ return true;
return false;
}
if (m == ss->killers[0])
return;
- for (int i = KILLER_MAX - 1; i > 0; i--)
- ss->killers[i] = ss->killers[i - 1];
-
+ ss->killers[1] = ss->killers[0];
ss->killers[0] = m;
}
{
ss->excludedMove = MOVE_NONE;
ss->skipNullMove = false;
+ ss->reduction = Depth(0);
if (i < 3)
- {
- ss->init();
ss->initKillers();
- }
}
}
// Find a quick score for the move
init_ss_array(ss, PLY_MAX_PLUS_2);
+ ss[0].init();
+ ss[0].eval = VALUE_NONE;
+ ss[0].currentMove = cur->move;
pos.do_move(cur->move, st);
moves[count].move = cur->move;
moves[count].score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1);