kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-29 16:23:09 +00:00
Code Issues Releases Wiki Activity

Sync search() and qsearch() alpha update

Browse source 
Change qsearch() to reflect alpha update logic
of search().

To be consistent changed also moves loop condition and
futility pruning condition.

No regression after 5072 games at TC 10"+0.1

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2011-08-07 10:29:47 +01:00
parent 4a71c86270
commit 06e0d48794
1 changed files with 22 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

36
src/search.cpp
View file

@ -712,7 +712,7 @@ namespace {
Depth ext, newDepth;
ValueType vt;
Value bestValue, value, oldAlpha;
Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific
Value refinedValue, nullValue, futilityBase, futilityValue;
bool isPvMove, inCheck, singularExtensionNode, givesCheck, captureOrPromotion, dangerous;
int moveCount = 0, playedMoveCount = 0;
Thread& thread = Threads[pos.thread()];
@ -1070,19 +1070,19 @@ split_point_start: // At split points actual search starts from here
// We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth,
// but fixing this made program slightly weaker.
Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
futilityValueScaled = futilityBase + futility_margin(predictedDepth, moveCount)
futilityValue = futilityBase + futility_margin(predictedDepth, moveCount)
+ H.gain(pos.piece_on(move_from(move)), move_to(move));
if (futilityValueScaled < beta)
if (futilityValue < beta)
{
if (SpNode)
{
lock_grab(&(sp->lock));
if (futilityValueScaled > sp->bestValue)
sp->bestValue = bestValue = futilityValueScaled;
if (futilityValue > sp->bestValue)
sp->bestValue = bestValue = futilityValue;
}
else if (futilityValueScaled > bestValue)
bestValue = futilityValueScaled;
else if (futilityValue > bestValue)
bestValue = futilityValue;
continue;
}
@ -1298,6 +1298,7 @@ split_point_start: // At split points actual search starts from here
bool inCheck, enoughMaterial, givesCheck, evasionPrunable;
const TTEntry* tte;
Depth ttDepth;
ValueType vt;
Value oldAlpha = alpha;
ss->bestMove = ss->currentMove = MOVE_NONE;
@ -1368,7 +1369,7 @@ split_point_start: // At split points actual search starts from here
CheckInfo ci(pos);
// Loop through the moves until no moves remain or a beta cutoff occurs
while ( alpha < beta
while ( bestValue < beta
&& (move = mp.get_next_move()) != MOVE_NONE)
{
assert(move_is_ok(move));
@ -1388,10 +1389,11 @@ split_point_start: // At split points actual search starts from here
+ piece_value_endgame(pos.piece_on(move_to(move)))
+ (move_is_ep(move) ? PawnValueEndgame : VALUE_ZERO);
if (futilityValue < alpha)
if (futilityValue < beta)
{
if (futilityValue > bestValue)
bestValue = futilityValue;
continue;
}
@ -1450,11 +1452,12 @@ split_point_start: // At split points actual search starts from here
if (value > bestValue)
{
bestValue = value;
if (value > alpha)
{
alpha = value;
ss->bestMove = move;
}
if ( PvNode
&& value > alpha
&& value < beta) // We want always alpha < beta
alpha = value;
}
}
@ -1464,8 +1467,11 @@ split_point_start: // At split points actual search starts from here
return value_mated_in(ss->ply);
// Update transposition table
ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, ss->bestMove, ss->eval, evalMargin);
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
: bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT;
TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);