// best move from the previous iteration, Problem is set back to false.
const Value NoProblemMargin = Value(0x14);
- // Null move margin. A null move search will not be done if the approximate
+ // Null move margin. A null move search will not be done if the static
// evaluation of the position is more than NullMoveMargin below beta.
- const Value NullMoveMargin = Value(0x300);
+ const Value NullMoveMargin = Value(0x200);
// If the TT move is at least SingleReplyMargin better then the
// remaining ones we will extend it.
// Depth limit for razoring
const Depth RazorDepth = 4 * OnePly;
- // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
- const Value RazorMargins[6] = { Value(0x180), Value(0x300), Value(0x300), Value(0x3C0), Value(0x3C0), Value(0x3C0) };
-
- // 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) };
-
-
/// Variables initialized by UCI options
// Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV nodes
pv[ply] = pv[ply + 1] = MOVE_NONE;
currentMove = threatMove = MOVE_NONE;
reduction = Depth(0);
+ eval = VALUE_NONE;
}
void SearchStack::initKillers() {
assert(threadID >= 0 && threadID < ActiveThreads);
Move movesSearched[256];
- EvalInfo ei;
StateInfo st;
const TTEntry* tte;
Move ttMove, move;
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (pos.is_draw())
+ if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
- if (ply >= PLY_MAX - 1)
- return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
-
// Mate distance pruning
oldAlpha = alpha;
alpha = Max(value_mated_in(ply), alpha);
const TTEntry* tte;
Move ttMove, move;
Depth ext, newDepth;
- Value staticValue, nullValue, value, futilityValue, futilityValueScaled;
+ Value bestValue, staticValue, nullValue, value, futilityValue, futilityValueScaled;
bool isCheck, useFutilityPruning, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0;
- Value bestValue = -VALUE_INFINITE;
+ futilityValue = staticValue = bestValue = -VALUE_INFINITE;
if (depth < OnePly)
return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (pos.is_draw())
+ if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
- if (ply >= PLY_MAX - 1)
- return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
-
// Mate distance pruning
if (value_mated_in(ply) >= beta)
return beta;
}
isCheck = pos.is_check();
- ei.futilityMargin = Value(0); // Manually initialize futilityMargin
-
- // Evaluate the position statically
- if (isCheck)
- staticValue = quick_evaluate(pos);
- else if (tte && (tte->type() & VALUE_TYPE_EVAL))
- staticValue = value_from_tt(tte->value(), ply);
- else
- staticValue = evaluate(pos, ei, threadID);
// Calculate depth dependant futility pruning parameters
const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8));
const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
- // Enhance score accuracy with TT value if possible
- futilityValue = staticValue + FutilityValueMargin;
- staticValue = refine_eval(tte, staticValue, ply);
+ // Evaluate the position statically
+ if (isCheck)
+ ss[ply].eval = VALUE_NONE;
+ else
+ {
+ if (tte && (tte->type() & VALUE_TYPE_EVAL))
+ staticValue = value_from_tt(tte->value(), ply);
+ else
+ staticValue = evaluate(pos, ei, threadID);
+
+ ss[ply].eval = staticValue;
+ futilityValue = staticValue + FutilityValueMargin;
+ staticValue = refine_eval(tte, staticValue, ply); // Enhance accuracy with TT value if possible
+ }
// Null move search
if ( allowNullmove
}
// Null move search not allowed, try razoring
else if ( !value_is_mate(beta)
+ && !isCheck
&& depth < RazorDepth
- && staticValue < beta - RazorApprMargins[int(depth) - 2]
+ && staticValue < beta - (NullMoveMargin + 16 * depth)
&& ss[ply - 1].currentMove != MOVE_NULL
&& ttMove == MOVE_NONE
&& !pos.has_pawn_on_7th(pos.side_to_move()))
{
- Value rbeta = beta - RazorMargins[int(depth) - 2];
+ Value rbeta = beta - (NullMoveMargin + 16 * depth);
Value v = qsearch(pos, ss, rbeta-1, rbeta, Depth(0), ply, threadID);
if (v < rbeta)
return v;
if (AbortSearch || thread_should_stop(threadID))
return Value(0);
- if (pos.is_draw())
+ if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
- if (ply >= PLY_MAX - 1)
- return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
-
// Transposition table lookup. At PV nodes, we don't use the TT for
// pruning, but only for move ordering.
tte = TT.retrieve(pos.get_key());
}
isCheck = pos.is_check();
- ei.futilityMargin = Value(0); // Manually initialize futilityMargin
// Evaluate the position statically
if (isCheck)
&& !isCheck;
const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8));
- const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2);
while ( sp->bestValue < sp->beta
&& !thread_should_stop(threadID)
continue;
// Value based pruning
- if (sp->futilityValue == VALUE_NONE)
- {
- EvalInfo ei;
- sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
- }
-
Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin;
if (futilityValueScaled < sp->beta)