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Re-add "Pass evalMargin through SearchStack as eval"

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It has more sense to treat the two evaluation metrics
in the same way.

As a side effect now we use the correct eval margin when
pruning in a SplitPoint node.

No functional change in single thread.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2010-10-23 07:52:17 +01:00
parent f6e11ee2a3
commit c81bf3743f
2 changed files with 14 additions and 13 deletions
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26
src/search.cpp
View file

@ -700,7 +700,7 @@ namespace {
int64_t nodes;
Move move;
Depth depth, ext, newDepth;
Value value, evalMargin, alpha, beta;
Value value, alpha, beta;
bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
int researchCountFH, researchCountFL;
@ -719,7 +719,8 @@ namespace {
// Step 5. Evaluate the position statically
// At root we do this only to get reference value for child nodes
ss->eval = isCheck ? VALUE_NONE : evaluate(pos, evalMargin);
ss->evalMargin = VALUE_NONE;
ss->eval = isCheck ? VALUE_NONE : evaluate(pos, ss->evalMargin);
// Step 6. Razoring (omitted at root)
// Step 7. Static null move pruning (omitted at root)
@ -965,7 +966,7 @@ namespace {
Key posKey;
Move ttMove, move, excludedMove, threatMove;
Depth ext, newDepth;
Value bestValue, value, evalMargin, oldAlpha;
Value bestValue, value, oldAlpha;
Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific
bool isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
@ -980,7 +981,6 @@ namespace {
{
sp = ss->sp;
tte = NULL;
evalMargin = VALUE_ZERO;
ttMove = excludedMove = MOVE_NONE;
threatMove = sp->threatMove;
mateThreat = sp->mateThreat;
@ -1041,19 +1041,19 @@ namespace {
// Step 5. Evaluate the position statically and
// update gain statistics of parent move.
if (isCheck)
ss->eval = evalMargin = VALUE_NONE;
ss->eval = ss->evalMargin = VALUE_NONE;
else if (tte)
{
assert(tte->static_value() != VALUE_NONE);
ss->eval = tte->static_value();
evalMargin = tte->static_value_margin();
ss->evalMargin = tte->static_value_margin();
refinedValue = refine_eval(tte, ss->eval, ply);
}
else
{
refinedValue = ss->eval = evaluate(pos, evalMargin);
TT.store(posKey, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
refinedValue = ss->eval = evaluate(pos, ss->evalMargin);
TT.store(posKey, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, ss->evalMargin);
}
// Save gain for the parent non-capture move
@ -1174,12 +1174,12 @@ split_point_start: // At split points actual search starts from here
// Initialize a MovePicker object for the current position
// FIXME currently MovePicker() c'tor is needless called also in SplitPoint
MovePicker mpBase = MovePicker(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
MovePicker mpBase(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
MovePicker& mp = SpNode ? *sp->mp : mpBase;
CheckInfo ci(pos);
ss->bestMove = MOVE_NONE;
singleEvasion = !SpNode && isCheck && mp.number_of_evasions() == 1;
futilityBase = ss->eval + evalMargin;
futilityBase = ss->eval + ss->evalMargin;
singularExtensionNode = !SpNode
&& depth >= SingularExtensionDepth[PvNode]
&& tte
@ -1383,7 +1383,7 @@ split_point_start: // At split points actual search starts from here
sp->alpha = value;
}
if (!SpNode && value == value_mate_in(ply + 1))
if (value == value_mate_in(ply + 1))
ss->mateKiller = move;
ss->bestMove = move;
@ -1429,7 +1429,7 @@ split_point_start: // At split points actual search starts from here
ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
move = (bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove);
TT.store(posKey, value_to_tt(bestValue, ply), vt, depth, move, ss->eval, evalMargin);
TT.store(posKey, value_to_tt(bestValue, ply), vt, depth, move, ss->eval, ss->evalMargin);
// Update killers and history only for non capture moves that fails high
if ( bestValue >= beta
@ -2583,7 +2583,7 @@ split_point_start: // At split points actual search starts from here
// Initialize search stack
init_ss_array(ss, PLY_MAX_PLUS_2);
ss[0].eval = VALUE_NONE;
ss[0].eval = ss[0].evalMargin = VALUE_NONE;
count = 0;
// Generate all legal moves

1
src/search.h
View file

@ -57,6 +57,7 @@ struct SearchStack {
Move killers[2];
Depth reduction;
Value eval;
Value evalMargin;
bool skipNullMove;
SplitPoint* sp;
};