std::ofstream LogFile;
// Natural logarithmic lookup table and its getter function
- double lnArray[512];
- inline double ln(int i) { return lnArray[i]; }
+ float lnArray[512];
+ inline float ln(int i) { return lnArray[i]; }
// MP related variables
int ActiveThreads = 1;
bool ok_to_prune(const Position& pos, Move m, Move threat);
bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply);
Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
- void reduction_parameters(double base, double Inhibitor, Depth depth, double& logLimit, double& gradient);
- Depth reduction(int moveCount, const double LogLimit, const double BaseRed, const double Gradient);
+ void reduction_parameters(float base, float Inhibitor, Depth depth, float& logLimit, float& gradient);
+ Depth reduction(int moveCount, const float LogLimit, const float BaseRed, const float Gradient);
void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
void update_killers(Move m, SearchStack& ss);
void update_gains(const Position& pos, Move move, Value before, Value after);
// Init our logarithmic lookup table
for (i = 0; i < 512; i++)
- lnArray[i] = log(double(i)); // log() returns base-e logarithm
+ lnArray[i] = float(log(double(i))); // log() returns base-e logarithm
for (i = 0; i < THREAD_MAX; i++)
Threads[i].activeSplitPoints = 0;
value = - VALUE_INFINITE;
// Precalculate reduction parameters
- double LogLimit, Gradient, BaseReduction = 0.5;
+ float LogLimit, Gradient, BaseReduction = 0.5;
reduction_parameters(BaseReduction, 6.0, depth, LogLimit, Gradient);
while (1) // Fail high loop
MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
// Precalculate reduction parameters
- double LogLimit, Gradient, BaseReduction = 0.5;
+ float LogLimit, Gradient, BaseReduction = 0.5;
reduction_parameters(BaseReduction, 6.0, depth, LogLimit, Gradient);
// Loop through all legal moves until no moves remain or a beta cutoff
// Do a "stand pat". If we are above beta by a good margin then
// return immediately.
- // FIXME: test with added condition 'allowNullmove || depth <= OnePly' and !value_is_mate(beta)
- // FIXME: test with modified condition 'depth < RazorDepth'
if ( !isCheck
- && depth < SelectiveDepth
+ && allowNullmove
+ && depth < RazorDepth
&& staticValue - FutilityMargins[int(depth)] >= beta)
return staticValue - FutilityMargins[int(depth)];
CheckInfo ci(pos);
// Precalculate reduction parameters
- double LogLimit, Gradient, BaseReduction = 0.5;
+ float LogLimit, Gradient, BaseReduction = 0.5;
reduction_parameters(BaseReduction, 3.0, depth, LogLimit, Gradient);
// Loop through all legal moves until no moves remain or a beta cutoff occurs
// Update current move
movesSearched[moveCount++] = ss[ply].currentMove = move;
- // Futility pruning for captures
- // FIXME: test disabling 'Futility pruning for captures'
- // FIXME: test with 'newDepth < RazorDepth'
- Color them = opposite_color(pos.side_to_move());
-
- if ( !isCheck
- && newDepth < SelectiveDepth
- && !dangerous
- && pos.move_is_capture(move)
- && !pos.move_is_check(move, ci)
- && !move_is_promotion(move)
- && move != ttMove
- && !move_is_ep(move)
- && (pos.type_of_piece_on(move_to(move)) != PAWN || !pos.pawn_is_passed(them, move_to(move)))) // Do not prune passed pawn captures
- {
- int preFutilityValueMargin = 0;
-
- if (newDepth >= OnePly)
- preFutilityValueMargin = FutilityMargins[int(newDepth)];
-
- Value futilityCaptureValue = ss[ply].eval + pos.endgame_value_of_piece_on(move_to(move)) + preFutilityValueMargin + ei.futilityMargin + 90;
-
- if (futilityCaptureValue < beta)
- {
- if (futilityCaptureValue > bestValue)
- bestValue = futilityCaptureValue;
- continue;
- }
- }
-
// Futility pruning
if ( !isCheck
&& !dangerous
const TTEntry* tte = NULL;
int moveCount = 0;
bool pvNode = (beta - alpha != 1);
+ Value oldAlpha = alpha;
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
// Update transposition table
Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
- if (bestValue < beta)
+ if (bestValue <= oldAlpha)
{
// If bestValue isn't changed it means it is still the static evaluation
// of the node, so keep this info to avoid a future evaluation() call.
ValueType type = (bestValue == staticValue && !ei.futilityMargin ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE);
}
- else
+ else if (bestValue >= beta)
{
move = ss[ply].pv[ply];
TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move);
if (!pos.move_is_capture_or_promotion(move))
update_killers(move, ss[ply]);
}
+ else
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, d, ss[ply].pv[ply]);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8));
// Precalculate reduction parameters
- double LogLimit, Gradient, BaseReduction = 0.5;
+ float LogLimit, Gradient, BaseReduction = 0.5;
reduction_parameters(BaseReduction, 3.0, sp->depth, LogLimit, Gradient);
while ( lock_grab_bool(&(sp->lock))
Move move;
// Precalculate reduction parameters
- double LogLimit, Gradient, BaseReduction = 0.5;
+ float LogLimit, Gradient, BaseReduction = 0.5;
reduction_parameters(BaseReduction, 6.0, sp->depth, LogLimit, Gradient);
while ( lock_grab_bool(&(sp->lock))
// floating point operations are involved we try to recalculate reduction at each move, but
// we do the most consuming computation only once per node.
- void reduction_parameters(double baseReduction, double reductionInhibitor, Depth depth, double& logLimit, double& gradient)
+ void reduction_parameters(float baseReduction, float reductionInhibitor, Depth depth, float& logLimit, float& gradient)
{
// Precalculate some parameters to avoid to calculate the following formula for each move:
//
// red = baseReduction + ln(moveCount) * ln(depth / 2) / reductionInhibitor;
//
- logLimit = depth > OnePly ? (1.0 - baseReduction) * reductionInhibitor / ln(depth / 2) : 1000.0;
- gradient = ln(depth / 2) / reductionInhibitor;
+ logLimit = depth > OnePly ? (1 - baseReduction) * reductionInhibitor / ln(depth / 2) : 1000;
+ gradient = depth > OnePly ? ln(depth / 2) / reductionInhibitor : 0;
}
// reduction() returns reduction in plies based on moveCount and depth.
// Reduction is always at least one ply.
- Depth reduction(int moveCount, double logLimit, double baseReduction, double gradient) {
+ Depth reduction(int moveCount, float logLimit, float baseReduction, float gradient) {
if (ln(moveCount) < logLimit)
return Depth(0);
- double red = baseReduction + ln(moveCount) * gradient;
+ float red = baseReduction + ln(moveCount) * gradient;
return Depth(int(floor(red * int(OnePly))));
}
projects / stockfish / blobdiff