#include "book.h"
#include "evaluate.h"
#include "history.h"
+#include "maxgain.h"
#include "misc.h"
#include "movegen.h"
#include "movepick.h"
// History table
History H;
+ // MaxGain table
+ MaxGain MG;
/// Functions
// Initialize
TT.new_search();
H.clear();
+ MG.clear();
init_ss_array(ss);
IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0));
Iteration = 1;
// If we are pondering or in infinite search, we shouldn't print the
// best move before we are told to do so.
- if (!AbortSearch && !ExactMaxTime && (PonderSearch || InfiniteSearch))
+ if (!AbortSearch && (PonderSearch || InfiniteSearch))
wait_for_stop_or_ponderhit();
else
// Print final search statistics
Value oldAlpha = alpha;
Value value = -VALUE_INFINITE;
CheckInfo ci(pos);
+ bool isCheck = pos.is_check();
+
+ // Evaluate the position statically
+ EvalInfo ei;
+ if (!isCheck)
+ ss[0].eval = evaluate(pos, ei, 0);
+ else
+ ss[0].eval = VALUE_NONE;
// Loop through all the moves in the root move list
for (int i = 0; i < rml.move_count() && !AbortSearch; i++)
tte = TT.retrieve(pos.get_key());
}
+ // Evaluate the position statically
+ isCheck = pos.is_check();
+ EvalInfo ei;
+ if (!isCheck)
+ {
+ ss[ply].eval = evaluate(pos, ei, threadID);
+
+ // Store gain statistics
+ Move m = ss[ply - 1].currentMove;
+ if ( m != MOVE_NULL
+ && pos.captured_piece() == NO_PIECE_TYPE
+ && !move_is_castle(m)
+ && !move_is_promotion(m))
+ MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
+
+ }
+
// Initialize a MovePicker object for the current position, and prepare
// to search all moves
- isCheck = pos.is_check();
mateThreat = pos.has_mate_threat(opposite_color(pos.side_to_move()));
CheckInfo ci(pos);
MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
Move ttMove, move;
Depth ext, newDepth;
Value bestValue, staticValue, nullValue, value, futilityValue, futilityValueScaled;
- bool isCheck, useFutilityPruning, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
+ bool isCheck, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0;
futilityValue = staticValue = bestValue = value = -VALUE_INFINITE;
// Calculate depth dependant futility pruning parameters
const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8));
- const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
+ const int PostFutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
// Evaluate the position statically
if (!isCheck)
}
ss[ply].eval = staticValue;
- futilityValue = staticValue + FutilityValueMargin;
+ futilityValue = staticValue + PostFutilityValueMargin; //FIXME: Remove me, only for split
staticValue = refine_eval(tte, staticValue, ply); // Enhance accuracy with TT value if possible
+
+ // Store gain statistics
+ Move m = ss[ply - 1].currentMove;
+ if ( m != MOVE_NULL
+ && pos.captured_piece() == NO_PIECE_TYPE
+ && !move_is_castle(m)
+ && !move_is_promotion(m))
+ MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
}
+ // Post futility pruning
+ if (depth < SelectiveDepth && staticValue - PostFutilityValueMargin >= beta)
+ return (staticValue - PostFutilityValueMargin);
+
// Null move search
if ( allowNullmove
&& depth > OnePly
// to search all moves.
MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
CheckInfo ci(pos);
- useFutilityPruning = depth < SelectiveDepth && !isCheck;
// Loop through all legal moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
// Update current move
movesSearched[moveCount++] = ss[ply].currentMove = move;
+ // Futility pruning for captures
+ 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 = 112 * bitScanReverse32(int(newDepth) * int(newDepth) / 2);
+
+ if (ss[ply].eval + pos.endgame_value_of_piece_on(move_to(move)) + preFutilityValueMargin + ei.futilityMargin + 90 < beta)
+ continue;
+ }
+
+
// Futility pruning
- if ( useFutilityPruning
+ if ( !isCheck
&& !dangerous
&& !captureOrPromotion
+ && !move_is_castle(move)
&& move != ttMove)
{
// Move count based pruning
continue;
// Value based pruning
- futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin;
+ Depth predictedDepth = newDepth;
- if (futilityValueScaled < beta)
+ //FIXME HACK: awful code duplication
+ double red = 0.5 + ln(moveCount) * ln(depth / 2) / 3.0;
+ if (red >= 1.0)
+ predictedDepth -= int(floor(red * int(OnePly)));
+
+ if (predictedDepth < SelectiveDepth)
{
- if (futilityValueScaled > bestValue)
- bestValue = futilityValueScaled;
- continue;
+ int preFutilityValueMargin = 0;
+ if (predictedDepth >= OnePly)
+ preFutilityValueMargin = 112 * bitScanReverse32(int(predictedDepth) * int(predictedDepth) / 2);
+
+ preFutilityValueMargin += MG.retrieve(pos.piece_on(move_from(move)), move_from(move), move_to(move)) + 45;
+
+ futilityValueScaled = ss[ply].eval + preFutilityValueMargin - moveCount * IncrementalFutilityMargin;
+
+ if (futilityValueScaled < beta)
+ {
+ if (futilityValueScaled > bestValue)
+ bestValue = futilityValueScaled;
+ continue;
+ }
}
}
&& idle_thread_exists(threadID)
&& !AbortSearch
&& !thread_should_stop(threadID)
- && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue,
+ && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, //FIXME: SMP & futilityValue
depth, &moveCount, &mp, threadID, false))
break;
}
else
staticValue = evaluate(pos, ei, threadID);
+ if (!isCheck)
+ {
+ ss[ply].eval = staticValue;
+ // Store gain statistics
+ Move m = ss[ply - 1].currentMove;
+ if ( m != MOVE_NULL
+ && pos.captured_piece() == NO_PIECE_TYPE
+ && !move_is_castle(m)
+ && !move_is_promotion(m))
+ MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
+ }
+
+
// Initialize "stand pat score", and return it immediately if it is
// at least beta.
bestValue = staticValue;
Square mfrom, mto, tfrom, tto;
- // Prune if there isn't any threat move and
- // is not a castling move (common case).
- if (threat == MOVE_NONE && !move_is_castle(m))
+ // Prune if there isn't any threat move
+ if (threat == MOVE_NONE)
return true;
mfrom = move_from(m);
tfrom = move_from(threat);
tto = move_to(threat);
- // Case 1: Castling moves are never pruned
- if (move_is_castle(m))
- return false;
-
- // Case 2: Don't prune moves which move the threatened piece
+ // Case 1: Don't prune moves which move the threatened piece
if (mfrom == tto)
return false;
- // Case 3: If the threatened piece has value less than or equal to the
+ // Case 2: If the threatened piece has value less than or equal to the
// value of the threatening piece, don't prune move which defend it.
if ( pos.move_is_capture(threat)
&& ( pos.midgame_value_of_piece_on(tfrom) >= pos.midgame_value_of_piece_on(tto)
&& pos.move_attacks_square(m, tto))
return false;
- // Case 4: If the moving piece in the threatened move is a slider, don't
+ // Case 3: If the moving piece in the threatened move is a slider, don't
// prune safe moves which block its ray.
if ( piece_is_slider(pos.piece_on(tfrom))
&& bit_is_set(squares_between(tfrom, tto), mto)
projects / stockfish / blobdiff