kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-30 00:33:09 +00:00
Code Issues Releases Wiki Activity

Aspiration window rewrite

Browse source 
Joona new aspiration window. Main idea is to always
research aspiration fail highs/low at the same
ply and use much smaller aspiration window than previously.

Testing result is very positive.

1CPU:
953-1149

4CPU:
545 - 656

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2010-01-27 19:46:57 +01:00
parent 62b43130e2
commit c83fd08fd4
1 changed files with 72 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

78
src/search.cpp
View file

@ -214,6 +214,9 @@ namespace {
IterationInfoType IterationInfo[PLY_MAX_PLUS_2];
int BestMoveChangesByIteration[PLY_MAX_PLUS_2];
// Search window management
int AspirationDelta;
// MultiPV mode
int MultiPV;
@ -266,7 +269,7 @@ namespace {
/// Functions
Value id_loop(const Position& pos, Move searchMoves[]);
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value alpha, Value beta);
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta);
Value search_pv(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
Value search(Position& pos, SearchStack ss[], Value beta, Depth depth, int ply, bool allowNullmove, int threadID, Move excludedMove = MOVE_NONE);
Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
@ -730,7 +733,10 @@ namespace {
int prevDelta1 = IterationInfo[Iteration - 1].speculatedValue - IterationInfo[Iteration - 2].speculatedValue;
int prevDelta2 = IterationInfo[Iteration - 2].speculatedValue - IterationInfo[Iteration - 3].speculatedValue;
int delta = Max(2 * abs(prevDelta1) + abs(prevDelta2), ProblemMargin);
int delta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16);
delta = (delta + 7) / 8 * 8; // Round to match grainSize
AspirationDelta = delta;
alpha = Max(IterationInfo[Iteration - 1].value - delta, -VALUE_INFINITE);
beta = Min(IterationInfo[Iteration - 1].value + delta, VALUE_INFINITE);
@ -886,11 +892,12 @@ namespace {
// similar to search_pv except that it uses a different move ordering
// scheme and prints some information to the standard output.
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value alpha, Value beta) {
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta) {
Value oldAlpha = alpha;
Value value = -VALUE_INFINITE;
Value alpha = oldAlpha;
Value value;
CheckInfo ci(pos);
int researchCount = 0;
bool isCheck = pos.is_check();
// Evaluate the position statically
@ -900,6 +907,9 @@ namespace {
else
ss[0].eval = VALUE_NONE;
while(1) // Fail low loop
{
// Loop through all the moves in the root move list
for (int i = 0; i < rml.move_count() && !AbortSearch; i++)
{
@ -941,10 +951,15 @@ namespace {
ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, false, false, &dangerous);
newDepth = depth + ext;
value = - VALUE_INFINITE;
while (1) // Fail high loop
{
// Make the move, and search it
pos.do_move(move, st, ci, moveIsCheck);
if (i < MultiPV)
if (i < MultiPV || value > alpha)
{
// Aspiration window is disabled in multi-pv case
if (MultiPV > 1)
@ -1000,6 +1015,46 @@ namespace {
pos.undo_move(move);
if (AbortSearch || value < beta)
break; // We are not failing high
// We are failing high and going to do a research. It's important to update score
// before research in case we run out of time while researching.
rml.set_move_score(i, value);
update_pv(ss, 0);
TT.extract_pv(pos, ss[0].pv, PLY_MAX);
rml.set_move_pv(i, ss[0].pv);
// Print search information to the standard output
cout << "info depth " << Iteration
<< " score " << value_to_string(value)
<< ((value >= beta) ? " lowerbound" :
((value <= alpha)? " upperbound" : ""))
<< " time " << current_search_time()
<< " nodes " << nodes_searched()
<< " nps " << nps()
<< " pv ";
for (int j = 0; ss[0].pv[j] != MOVE_NONE && j < PLY_MAX; j++)
cout << ss[0].pv[j] << " ";
cout << endl;
if (UseLogFile)
{
ValueType type = (value >= beta ? VALUE_TYPE_LOWER
: (value <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT));
LogFile << pretty_pv(pos, current_search_time(), Iteration,
nodes_searched(), value, type, ss[0].pv) << endl;
}
// Prepare for research
researchCount++;
beta = Min(beta + AspirationDelta * (1 << researchCount), VALUE_INFINITE);
} // End of fail high loop
// Finished searching the move. If AbortSearch is true, the search
// was aborted because the user interrupted the search or because we
// ran out of time. In this case, the return value of the search cannot
@ -1094,6 +1149,17 @@ namespace {
FailLow = (alpha == oldAlpha);
}
if (AbortSearch || alpha > oldAlpha)
break; // End search, we are not failing low
// Prepare for research
researchCount++;
alpha = Max(alpha - AspirationDelta * (1 << researchCount), -VALUE_INFINITE);
oldAlpha = alpha;
} // Fail low loop
return alpha;
}