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stockfish
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Retire ss->bestMove 

And introduce SPlitPoint bestMove to pass back the
best move after a split point.

This allow to define as const the search stack passed
to split.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
sf_2.3.1_base
Marco Costalba 2012-02-20 14:21:25 +01:00
parent 43f84efa15
commit 2608b9249d
4 changed files with 33 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
src/search.cpp
View File

@ -548,7 +548,7 @@ namespace {
StateInfo st;
const TTEntry *tte;
Key posKey;
Move ttMove, move, excludedMove, threatMove;
Move ttMove, move, excludedMove, bestMove, threatMove;
Depth ext, newDepth;
Bound bt;
Value bestValue, value, oldAlpha;
@ -574,6 +574,7 @@ namespace {
tte = NULL;
ttMove = excludedMove = MOVE_NONE;
sp = ss->sp;
bestMove = sp->bestMove;
threatMove = sp->threatMove;
bestValue = sp->bestValue;
moveCount = sp->moveCount; // Lock must be held here
@ -584,7 +585,7 @@ namespace {
}
else
{
ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE;
ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
(ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
@ -630,16 +631,16 @@ namespace {
: can_return_tt(tte, depth, beta, ss->ply)))
{
TT.refresh(tte);
ss->bestMove = move = ttMove; // Can be MOVE_NONE
ss->currentMove = ttMove; // Can be MOVE_NONE
value = value_from_tt(tte->value(), ss->ply);
if ( value >= beta
&& move
&& !pos.is_capture_or_promotion(move)
&& move != ss->killers[0])
&& ttMove
&& !pos.is_capture_or_promotion(ttMove)
&& ttMove != ss->killers[0])
{
ss->killers[1] = ss->killers[0];
ss->killers[0] = move;
ss->killers[0] = ttMove;
}
return value;
}
@ -752,7 +753,7 @@ namespace {
// move which was reduced. If a connection is found, return a fail
// low score (which will cause the reduced move to fail high in the
// parent node, which will trigger a re-search with full depth).
threatMove = (ss+1)->bestMove;
threatMove = (ss+1)->currentMove;
if ( depth < ThreatDepth
&& (ss-1)->reduction
@ -778,6 +779,7 @@ namespace {
assert(rdepth >= ONE_PLY);
assert((ss-1)->currentMove != MOVE_NONE);
assert((ss-1)->currentMove != MOVE_NULL);
MovePicker mp(pos, ttMove, H, pos.captured_piece_type());
CheckInfo ci(pos);
@ -813,7 +815,6 @@ split_point_start: // At split points actual search starts from here
MovePickerExt<SpNode> mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta);
CheckInfo ci(pos);
ss->bestMove = MOVE_NONE;
futilityBase = ss->eval + ss->evalMargin;
singularExtensionNode = !RootNode
&& !SpNode
@ -896,7 +897,6 @@ split_point_start: // At split points actual search starts from here
value = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
ss->bestMove = MOVE_NONE;
if (value < rBeta)
ext = ONE_PLY;
}
@ -1045,7 +1045,7 @@ split_point_start: // At split points actual search starts from here
if (value > bestValue)
{
bestValue = value;
ss->bestMove = move;
bestMove = move;
if ( PvNode
&& value > alpha
@ -1055,7 +1055,7 @@ split_point_start: // At split points actual search starts from here
if (SpNode && !thread.cutoff_occurred())
{
sp->bestValue = value;
sp->ss->bestMove = move;
sp->bestMove = move;
sp->alpha = alpha;
if (value >= beta)
@ -1070,8 +1070,8 @@ split_point_start: // At split points actual search starts from here
&& Threads.available_slave_exists(pos.thread())
&& !Signals.stop
&& !thread.cutoff_occurred())
bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, depth,
threatMove, moveCount, &mp, NT);
bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, &bestMove,
depth, threatMove, moveCount, &mp, NT);
}
// Step 20. Check for mate and stalemate
@ -1088,14 +1088,14 @@ split_point_start: // At split points actual search starts from here
{
assert(!playedMoveCount);
bestValue = alpha;
bestValue = oldAlpha;
}
// Step 21. Update tables
// Update transposition table entry, killers and history
if (!SpNode && !Signals.stop && !thread.cutoff_occurred())
{
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
move = bestValue <= oldAlpha ? MOVE_NONE : bestMove;
bt = bestValue <= oldAlpha ? BOUND_UPPER
: bestValue >= beta ? BOUND_LOWER : BOUND_EXACT;
@ -1147,7 +1147,7 @@ split_point_start: // At split points actual search starts from here
assert(pos.thread() >= 0 && pos.thread() < Threads.size());
StateInfo st;
Move ttMove, move;
Move ttMove, move, bestMove;
Value bestValue, value, evalMargin, futilityValue, futilityBase;
bool inCheck, enoughMaterial, givesCheck, evasionPrunable;
const TTEntry* tte;
@ -1155,7 +1155,7 @@ split_point_start: // At split points actual search starts from here
Bound bt;
Value oldAlpha = alpha;
ss->bestMove = ss->currentMove = MOVE_NONE;
ss->currentMove = bestMove = MOVE_NONE;
ss->ply = (ss-1)->ply + 1;
// Check for an instant draw or maximum ply reached
@ -1175,7 +1175,7 @@ split_point_start: // At split points actual search starts from here
if (!PvNode && tte && can_return_tt(tte, ttDepth, beta, ss->ply))
{
ss->bestMove = ttMove; // Can be MOVE_NONE
ss->currentMove = ttMove; // Can be MOVE_NONE
return value_from_tt(tte->value(), ss->ply);
}
@ -1299,7 +1299,7 @@ split_point_start: // At split points actual search starts from here
if (value > bestValue)
{
bestValue = value;
ss->bestMove = move;
bestMove = move;
if ( PvNode
&& value > alpha
@ -1314,7 +1314,7 @@ split_point_start: // At split points actual search starts from here
return mated_in(ss->ply); // Plies to mate from the root
// Update transposition table
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
move = bestValue <= oldAlpha ? MOVE_NONE : bestMove;
bt = bestValue <= oldAlpha ? BOUND_UPPER
: bestValue >= beta ? BOUND_LOWER : BOUND_EXACT;

1
src/search.h
View File

@ -39,7 +39,6 @@ struct Stack {
int ply;
Move currentMove;
Move excludedMove;
Move bestMove;
Move killers[2];
Depth reduction;
Value eval;

10
src/thread.cpp
View File

@ -299,8 +299,8 @@ bool ThreadsManager::available_slave_exists(int master) const {
template <bool Fake>
Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
Value bestValue, Depth depth, Move threatMove,
int moveCount, MovePicker* mp, int nodeType) {
Value bestValue, Move* bestMove, Depth depth,
Move threatMove, int moveCount, MovePicker *mp, int nodeType) {
assert(pos.pos_is_ok());
assert(bestValue > -VALUE_INFINITE);
assert(bestValue <= alpha);
@ -324,6 +324,7 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
sp->cutoff = false;
sp->slavesMask = 1ULL << master;
sp->depth = depth;
sp->bestMove = *bestMove;
sp->threatMove = threatMove;
sp->alpha = alpha;
sp->beta = beta;
@ -387,6 +388,7 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
masterThread.splitPointsCnt--;
masterThread.curSplitPoint = sp->parent;
pos.set_nodes_searched(pos.nodes_searched() + sp->nodes);
*bestMove = sp->bestMove;
lock_release(splitLock);
lock_release(sp->lock);
@ -395,8 +397,8 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
}
// Explicit template instantiations
template Value ThreadsManager::split<false>(Position&, Stack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
template Value ThreadsManager::split<true>(Position&, Stack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
template Value ThreadsManager::split<false>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
template Value ThreadsManager::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
// ThreadsManager::set_timer() is used to set the timer to trigger after msec

10
src/thread.h
View File

@ -34,9 +34,9 @@ const int MAX_SPLITPOINTS_PER_THREAD = 8;
struct SplitPoint {
// Const data after splitPoint has been setup
SplitPoint* parent;
// Const data after split point has been setup
const Position* pos;
const Search::Stack* ss;
Depth depth;
Value beta;
int nodeType;
@ -45,7 +45,8 @@ struct SplitPoint {
// Const pointers to shared data
MovePicker* mp;
Search::Stack* ss;
SplitPoint* parent;
// Shared data
Lock lock;
@ -53,6 +54,7 @@ struct SplitPoint {
volatile int64_t nodes;
volatile Value alpha;
volatile Value bestValue;
volatile Move bestMove;
volatile int moveCount;
volatile bool cutoff;
};
@ -116,7 +118,7 @@ public:
const std::set<Move>& = std::set<Move>(), bool async = false);
template <bool Fake>
Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue,
Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
private:
friend struct Thread;