along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
#include <cassert>
+#include <iostream>
+#include <iomanip>
+#include <sstream>
#include "bitcount.h"
#include "evaluate.h"
#include "thread.h"
#include "ucioption.h"
-
-////
-//// Local definitions
-////
-
namespace {
// Struct EvalInfo contains various information computed and collected
// by the evaluation functions.
struct EvalInfo {
- // Pointer to pawn hash table entry
+ // Pointers to material and pawn hash table entries
+ MaterialInfo* mi;
PawnInfo* pi;
// attackedBy[color][piece type] is a bitboard representing all squares
const int GrainSize = 8;
// Evaluation weights, initialized from UCI options
- enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
+ enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem };
Score Weights[6];
typedef Value V;
//
// Values modified by Joona Kiiski
const Score WeightsInternal[] = {
- S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
+ S(284, 229), S(252, 259), S(46, 0), S(209, 0), S(349, 0)
};
// MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
{ S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
};
- // ThreatedByPawnPenalty[PieceType] contains a penalty according to which
+ // ThreatenedByPawnPenalty[PieceType] contains a penalty according to which
// piece type is attacked by an enemy pawn.
- const Score ThreatedByPawnPenalty[] = {
+ const Score ThreatenedByPawnPenalty[] = {
S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
};
// right to castle.
const Value TrappedRookPenalty = Value(180);
+ // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
+ // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
+ // happen in Chess960 games.
+ const Score TrappedBishopA1H1Penalty = make_score(100, 100);
+
// The SpaceMask[Color] contains the area of the board which is considered
// by the space evaluation. In the middle game, each side is given a bonus
// based on how many squares inside this area are safe and available for
// weighted scores, indexed by color and by a calculated integer number.
Score KingDangerTable[2][128];
- // Pawn and material hash tables, indexed by the current thread id.
- // Note that they will be initialized at 0 being global variables.
- MaterialInfoTable* MaterialTable[MAX_THREADS];
- PawnInfoTable* PawnTable[MAX_THREADS];
+ // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
+ // evaluation terms, used when tracing.
+ Score TracedScores[2][16];
+ std::stringstream TraceStream;
+
+ enum TracedType {
+ PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
+ PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
+ };
// Function prototypes
- template<bool HasPopCnt>
+ template<bool HasPopCnt, bool Trace>
Value do_evaluate(const Position& pos, Value& margin);
template<Color Us, bool HasPopCnt>
void init_eval_info(const Position& pos, EvalInfo& ei);
- template<Color Us, bool HasPopCnt>
+ template<Color Us, bool HasPopCnt, bool Trace>
Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
- template<Color Us, bool HasPopCnt>
- Score evaluate_king(const Position& pos, EvalInfo& ei, Value& margin);
+ template<Color Us, bool HasPopCnt, bool Trace>
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
template<Color Us>
Score evaluate_threats(const Position& pos, EvalInfo& ei);
template<Color Us>
Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
- Score apply_weight(Score v, Score weight);
+ template<bool HasPopCnt>
+ Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
+
+ inline Score apply_weight(Score v, Score weight);
Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
void init_safety();
-}
-
-
-////
-//// Functions
-////
-
-
-/// Prefetches in pawn hash tables
-
-void prefetchPawn(Key key, int threadID) {
-
- PawnTable[threadID]->prefetch(key);
+ double to_cp(Value v);
+ void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
}
/// between them based on the remaining material.
Value evaluate(const Position& pos, Value& margin) {
- return CpuHasPOPCNT ? do_evaluate<true>(pos, margin)
- : do_evaluate<false>(pos, margin);
+ return CpuHasPOPCNT ? do_evaluate<true, false>(pos, margin)
+ : do_evaluate<false, false>(pos, margin);
}
namespace {
-template<bool HasPopCnt>
+template<bool HasPopCnt, bool Trace>
Value do_evaluate(const Position& pos, Value& margin) {
EvalInfo ei;
- Score mobilityWhite, mobilityBlack;
+ Value margins[2];
+ Score score, mobilityWhite, mobilityBlack;
assert(pos.is_ok());
assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
- assert(!pos.is_check());
+ assert(!pos.in_check());
- // Initialize value by reading the incrementally updated scores included
+ // Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables).
- Score bonus = pos.value();
+ score = pos.value();
- // margin is the uncertainty estimation of position's evaluation
- // and typically is used by the search for pruning decisions.
- margin = VALUE_ZERO;
+ // margins[] store the uncertainty estimation of position's evaluation
+ // that typically is used by the search for pruning decisions.
+ margins[WHITE] = margins[BLACK] = VALUE_ZERO;
// Probe the material hash table
- MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos);
- bonus += mi->material_value();
+ ei.mi = Threads[pos.thread()].materialTable.get_material_info(pos);
+ score += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
- if (mi->specialized_eval_exists())
- return mi->evaluate(pos);
+ if (ei.mi->specialized_eval_exists())
+ {
+ margin = VALUE_ZERO;
+ return ei.mi->evaluate(pos);
+ }
// Probe the pawn hash table
- ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
- bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+ ei.pi = Threads[pos.thread()].pawnTable.get_pawn_info(pos);
+ score += ei.pi->pawns_value();
// Initialize attack and king safety bitboards
init_eval_info<WHITE, HasPopCnt>(pos, ei);
init_eval_info<BLACK, HasPopCnt>(pos, ei);
// Evaluate pieces and mobility
- bonus += evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei, mobilityWhite)
- - evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei, mobilityBlack);
+ score += evaluate_pieces_of_color<WHITE, HasPopCnt, Trace>(pos, ei, mobilityWhite)
+ - evaluate_pieces_of_color<BLACK, HasPopCnt, Trace>(pos, ei, mobilityBlack);
- bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
+ score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
- bonus += evaluate_king<WHITE, HasPopCnt>(pos, ei, margin)
- - evaluate_king<BLACK, HasPopCnt>(pos, ei, margin);
+ score += evaluate_king<WHITE, HasPopCnt, Trace>(pos, ei, margins)
+ - evaluate_king<BLACK, HasPopCnt, Trace>(pos, ei, margins);
// Evaluate tactical threats, we need full attack information including king
- bonus += evaluate_threats<WHITE>(pos, ei)
+ score += evaluate_threats<WHITE>(pos, ei)
- evaluate_threats<BLACK>(pos, ei);
// Evaluate passed pawns, we need full attack information including king
- bonus += evaluate_passed_pawns<WHITE>(pos, ei)
+ score += evaluate_passed_pawns<WHITE>(pos, ei)
- evaluate_passed_pawns<BLACK>(pos, ei);
+ // If one side has only a king, check whether exists any unstoppable passed pawn
+ if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
+ score += evaluate_unstoppable_pawns<HasPopCnt>(pos, ei);
+
// Evaluate space for both sides, only in middle-game.
- if (mi->space_weight())
+ if (ei.mi->space_weight())
{
int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
- bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]);
+ score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
}
// Scale winning side if position is more drawish that what it appears
- ScaleFactor sf = eg_value(bonus) > VALUE_ZERO ? mi->scale_factor(pos, WHITE)
- : mi->scale_factor(pos, BLACK);
- Phase phase = mi->game_phase();
+ ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
+ : ei.mi->scale_factor(pos, BLACK);
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
- if ( phase < PHASE_MIDGAME
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
&& pos.opposite_colored_bishops()
&& sf == SCALE_FACTOR_NORMAL)
{
}
// Interpolate between the middle game and the endgame score
- Value v = scale_by_game_phase(bonus, phase, sf);
- return pos.side_to_move() == WHITE ? v : -v;
-}
-
-} // namespace
+ margin = margins[pos.side_to_move()];
+ Value v = scale_by_game_phase(score, ei.mi->game_phase(), sf);
-
-/// init_eval() initializes various tables used by the evaluation function
-
-void init_eval(int threads) {
-
- assert(threads <= MAX_THREADS);
-
- for (int i = 0; i < MAX_THREADS; i++)
+ // In case of tracing add all single evaluation contributions for both white and black
+ if (Trace)
{
- if (i >= threads)
- {
- delete PawnTable[i];
- delete MaterialTable[i];
- PawnTable[i] = NULL;
- MaterialTable[i] = NULL;
- continue;
- }
- if (!PawnTable[i])
- PawnTable[i] = new PawnInfoTable();
-
- if (!MaterialTable[i])
- MaterialTable[i] = new MaterialInfoTable();
+ trace_add(PST, pos.value());
+ trace_add(IMBALANCE, ei.mi->material_value());
+ trace_add(PAWN, ei.pi->pawns_value());
+ trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
+ trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
+ trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
+ trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns<false>(pos, ei));
+ Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE, false>(pos, ei), 0);
+ Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK, false>(pos, ei), 0);
+ trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ trace_add(TOTAL, score);
+ TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
+ << ", Black: " << to_cp(margins[BLACK])
+ << "\nScaling: " << std::noshowpos
+ << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
+ << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
+ << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
+ << "Total evaluation: " << to_cp(v);
}
-}
-
-/// quit_eval() releases heap-allocated memory at program termination
-
-void quit_eval() {
-
- init_eval(0);
+ return pos.side_to_move() == WHITE ? v : -v;
}
+} // namespace
+
/// read_weights() reads evaluation weights from the corresponding UCI parameters
-void read_weights(Color us) {
+void read_evaluation_uci_options(Color us) {
// King safety is asymmetrical. Our king danger level is weighted by
// "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
// If running in analysis mode, make sure we use symmetrical king safety. We do this
// by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
- if (get_option_value_bool("UCI_AnalyseMode"))
+ if (Options["UCI_AnalyseMode"].value<bool>())
Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
init_safety();
// evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
- template<PieceType Piece, Color Us, bool HasPopCnt>
+ template<PieceType Piece, Color Us, bool HasPopCnt, bool Trace>
Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
Bitboard b;
Square s, ksq;
int mob;
File f;
- Score bonus = SCORE_ZERO;
+ Score score = SCORE_ZERO;
const BitCountType Full = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64 : CNT32;
const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
// Decrease score if we are attacked by an enemy pawn. Remaining part
// of threat evaluation must be done later when we have full attack info.
if (bit_is_set(ei.attackedBy[Them][PAWN], s))
- bonus -= ThreatedByPawnPenalty[Piece];
+ score -= ThreatenedByPawnPenalty[Piece];
// Bishop and knight outposts squares
if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
-
bonus += evaluate_outposts<Piece, Us>(pos, ei, s);
+
score += evaluate_outposts<Piece, Us>(pos, ei, s);
// Queen or rook on 7th rank
if ( (Piece == ROOK || Piece == QUEEN)
&& relative_rank(Us, s) == RANK_7
&& relative_rank(Us, pos.king_square(Them)) == RANK_8)
{
- bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ }
+
+ // Special extra evaluation for bishops
+ if (Piece == BISHOP && pos.is_chess960())
+ {
+ // An important Chess960 pattern: A cornered bishop blocked by
+ // a friendly pawn diagonally in front of it is a very serious
+ // problem, especially when that pawn is also blocked.
+ if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
+ {
+ Square d = pawn_push(Us) + (square_file(s) == FILE_A ? DELTA_E : DELTA_W);
+ if (pos.piece_on(s + d) == make_piece(Us, PAWN))
+ {
+ if (!pos.square_is_empty(s + d + pawn_push(Us)))
+ score -= 2*TrappedBishopA1H1Penalty;
+ else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
+ score -= TrappedBishopA1H1Penalty;
+ else
+ score -= TrappedBishopA1H1Penalty / 2;
+ }
+ }
}
// Special extra evaluation for rooks
if (ei.pi->file_is_half_open(Us, f))
{
if (ei.pi->file_is_half_open(Them, f))
- bonus += RookOpenFileBonus;
+ score += RookOpenFileBonus;
else
- bonus += RookHalfOpenFileBonus;
+ score += RookHalfOpenFileBonus;
}
// Penalize rooks which are trapped inside a king. Penalize more if
{
// Is there a half-open file between the king and the edge of the board?
if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
- bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
: (TrappedRookPenalty - mob * 16), 0);
}
else if ( square_file(ksq) <= FILE_D
{
// Is there a half-open file between the king and the edge of the board?
if (!ei.pi->has_open_file_to_left(Us, square_file(ksq)))
- bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
: (TrappedRookPenalty - mob * 16), 0);
}
}
}
- return bonus;
+
+ if (Trace)
+ TracedScores[Us][Piece] = score;
+
+ return score;
}
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b;
- Score bonus = SCORE_ZERO;
+ Score score = SCORE_ZERO;
// Enemy pieces not defended by a pawn and under our attack
Bitboard weakEnemies = pos.pieces_of_color(Them)
if (b)
for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
if (b & pos.pieces(pt2))
- bonus += ThreatBonus[pt1][pt2];
+ score += ThreatBonus[pt1][pt2];
}
- return bonus;
+ return score;
}
// evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
// pieces of a given color.
- template<Color Us, bool HasPopCnt>
+ template<Color Us, bool HasPopCnt, bool Trace>
Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score bonus = mobility = SCORE_ZERO;
+ Score score = mobility = SCORE_ZERO;
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
- bonus += evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<KNIGHT, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<BISHOP, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<ROOK, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<QUEEN, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
// Sum up all attacked squares
ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
- return bonus;
+ return score;
}
// evaluate_king<>() assigns bonuses and penalties to a king of a given color
- template<Color Us, bool HasPopCnt>
- Score evaluate_king(const Position& pos, EvalInfo& ei, Value& margin) {
+ template<Color Us, bool HasPopCnt, bool Trace>
+ Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square ksq = pos.king_square(Us);
// King shelter
- Score bonus = ei.pi->king_shelter<Us>(pos, ksq);
+ Score score = ei.pi->king_shelter<Us>(pos, ksq);
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
// value that will be used for pruning because this value can sometimes
// be very big, and so capturing a single attacking piece can therefore
// result in a score change far bigger than the value of the captured piece.
- bonus -= KingDangerTable[Us][attackUnits];
- if (pos.side_to_move() == Us)
- margin += mg_value(KingDangerTable[Us][attackUnits]);
+ score -= KingDangerTable[Us][attackUnits];
+ margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
}
- return bonus;
+
+ if (Trace)
+ TracedScores[Us][KING] = score;
+
+ return score;
}
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score bonus = SCORE_ZERO;
- Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
- Bitboard b = ei.pi->passed_pawns(Us);
+ Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
+ Score score = SCORE_ZERO;
+
+ b = ei.pi->passed_pawns(Us);
if (!b)
return SCORE_ZERO;
Square blockSq = s + pawn_push(Us);
// Adjust bonus based on kings proximity
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr);
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
+
+ // If blockSq is not the queening square then consider also a second push
+ if (square_rank(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
// If the pawn is free to advance, increase bonus
if (pos.square_is_empty(blockSq))
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen. Otherwise consider only
// the squares in the pawn's path attacked or occupied by the enemy.
- if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
- && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
+ if ( (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them))
+ && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
unsafeSquares = squaresToQueen;
else
unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them));
else if (pos.pieces(ROOK, QUEEN, Them))
ebonus -= ebonus / 4;
}
- bonus += make_score(mbonus, ebonus);
+ score += make_score(mbonus, ebonus);
} while (b);
// Add the scores to the middle game and endgame eval
- return apply_weight(bonus, Weights[PassedPawns]);
+ return apply_weight(score, Weights[PassedPawns]);
+ }
+
+
+ // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
+ // conservative and returns a winning score only when we are very sure that the pawn is winning.
+
+ template<bool HasPopCnt>
+ Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
+
+ const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
+
+ Bitboard b, b2, blockers, supporters, queeningPath, candidates;
+ Square s, blockSq, queeningSquare;
+ Color c, winnerSide, loserSide;
+ bool pathDefended, opposed;
+ int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
+ int pliesToQueen[] = { 256, 256 };
+
+ // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
+ // record how many plies are required for promotion.
+ for (c = WHITE; c <= BLACK; c++)
+ {
+ // Skip if other side has non-pawn pieces
+ if (pos.non_pawn_material(opposite_color(c)))
+ continue;
+
+ b = ei.pi->passed_pawns(c);
+
+ while (b)
+ {
+ s = pop_1st_bit(&b);
+ queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
+ queeningPath = squares_in_front_of(c, s);
+
+ // Compute plies to queening and check direct advancement
+ movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
+ oppMovesToGo = square_distance(pos.king_square(opposite_color(c)), queeningSquare) - int(c != pos.side_to_move());
+ pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
+
+ if (movesToGo >= oppMovesToGo && !pathDefended)
+ continue;
+
+ // Opponent king cannot block because path is defended and position
+ // is not in check. So only friendly pieces can be blockers.
+ assert(!pos.in_check());
+ assert((queeningPath & pos.occupied_squares()) == (queeningPath & pos.pieces_of_color(c)));
+
+ // Add moves needed to free the path from friendly pieces and retest condition
+ movesToGo += count_1s<Max15>(queeningPath & pos.pieces_of_color(c));
+
+ if (movesToGo >= oppMovesToGo && !pathDefended)
+ continue;
+
+ pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
+ pliesToQueen[c] = Min(pliesToQueen[c], pliesToGo);
+ }
+ }
+
+ // Step 2. If either side cannot promote at least three plies before the other side then situation
+ // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
+ if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
+ return SCORE_ZERO;
+
+ winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
+ loserSide = opposite_color(winnerSide);
+
+ // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
+ b = candidates = pos.pieces(PAWN, loserSide);
+
+ while (b)
+ {
+ s = pop_1st_bit(&b);
+
+ // Compute plies from queening
+ queeningSquare = relative_square(loserSide, make_square(square_file(s), RANK_8));
+ movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
+ pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
+
+ // Check if (without even considering any obstacles) we're too far away or doubled
+ if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
+ || (squares_in_front_of(loserSide, s) & pos.pieces(PAWN, loserSide)))
+ clear_bit(&candidates, s);
+ }
+
+ // If any candidate is already a passed pawn it _may_ promote in time. We give up.
+ if (candidates & ei.pi->passed_pawns(loserSide))
+ return SCORE_ZERO;
+
+ // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
+ b = candidates;
+
+ while (b)
+ {
+ s = pop_1st_bit(&b);
+ sacptg = blockersCount = 0;
+ minKingDist = kingptg = 256;
+
+ // Compute plies from queening
+ queeningSquare = relative_square(loserSide, make_square(square_file(s), RANK_8));
+ movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
+ pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
+
+ // Generate list of blocking pawns and supporters
+ supporters = neighboring_files_bb(s) & candidates;
+ opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
+ blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
+
+ assert(blockers);
+
+ // How many plies does it take to remove all the blocking pawns?
+ while (blockers)
+ {
+ blockSq = pop_1st_bit(&blockers);
+ movesToGo = 256;
+
+ // Check pawns that can give support to overcome obstacle, for instance
+ // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
+ if (!opposed)
+ {
+ b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
+
+ while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
+ {
+ d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
+ movesToGo = Min(movesToGo, d);
+ }
+ }
+
+ // Check pawns that can be sacrificed against the blocking pawn
+ b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
+
+ while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
+ {
+ d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
+ movesToGo = Min(movesToGo, d);
+ }
+
+ // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
+ // it's not a real obstacle and we have nothing to add to pliesToGo.
+ if (movesToGo <= 0)
+ continue;
+
+ // Plies needed to sacrifice against all the blocking pawns
+ sacptg += movesToGo * 2;
+ blockersCount++;
+
+ // Plies needed for the king to capture all the blocking pawns
+ d = square_distance(pos.king_square(loserSide), blockSq);
+ minKingDist = Min(minKingDist, d);
+ kingptg = (minKingDist + blockersCount) * 2;
+ }
+
+ // Check if pawn sacrifice plan _may_ save the day
+ if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
+ return SCORE_ZERO;
+
+ // Check if king capture plan _may_ save the day (contains some false positives)
+ if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
+ return SCORE_ZERO;
+ }
+
+ // Winning pawn is unstoppable and will promote as first, return big score
+ Score score = make_score(0, (Value) 0x500 - 0x20 * pliesToQueen[winnerSide]);
+ return winnerSide == WHITE ? score : -score;
}
// apply_weight() applies an evaluation weight to a value trying to prevent overflow
inline Score apply_weight(Score v, Score w) {
- return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
- (int(eg_value(v)) * eg_value(w)) / 0x100);
+ return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
+ (int(eg_value(v)) * eg_value(w)) / 0x100);
}
assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
- Value eg = eg_value(v);
- Value ev = Value((eg * int(sf)) / SCALE_FACTOR_NORMAL);
-
+ int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
- return Value(result & ~(GrainSize - 1));
+ return Value((result + GrainSize / 2) & ~(GrainSize - 1));
}
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
// Scale option value from 100 to 256
- int mg = get_option_value_int(mgOpt) * 256 / 100;
- int eg = get_option_value_int(egOpt) * 256 / 100;
+ int mg = Options[mgOpt].value<int>() * 256 / 100;
+ int eg = Options[egOpt].value<int>() * 256 / 100;
return apply_weight(make_score(mg, eg), internalWeight);
}
for (int i = 0; i < 100; i++)
KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
}
+
+
+ // A couple of little helpers used by tracing code, to_cp() converts a value to
+ // a double in centipawns scale, trace_add() stores white and black scores.
+
+ double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
+
+ void trace_add(int idx, Score wScore, Score bScore) {
+
+ TracedScores[WHITE][idx] = wScore;
+ TracedScores[BLACK][idx] = bScore;
+ }
+
+ // trace_row() is an helper function used by tracing code to register the
+ // values of a single evaluation term.
+
+ void trace_row(const char *name, int idx) {
+
+ Score wScore = TracedScores[WHITE][idx];
+ Score bScore = TracedScores[BLACK][idx];
+
+ switch (idx) {
+ case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
+ TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
+ << std::setw(6) << to_cp(mg_value(wScore)) << " "
+ << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
+ break;
+ default:
+ TraceStream << std::setw(20) << name << " | " << std::noshowpos
+ << std::setw(5) << to_cp(mg_value(wScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore)) << " | "
+ << std::setw(5) << to_cp(mg_value(bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(bScore)) << " | "
+ << std::showpos
+ << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";
+ }
+ }
+}
+
+
+/// trace_evaluate() is like evaluate() but instead of a value returns a string
+/// suitable to be print on stdout with the detailed descriptions and values of
+/// each evaluation term. Used mainly for debugging.
+
+std::string trace_evaluate(const Position& pos) {
+
+ Value margin;
+ std::string totals;
+
+ TraceStream.str("");
+ TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
+ memset(TracedScores, 0, 2 * 16 * sizeof(Score));
+
+ do_evaluate<false, true>(pos, margin);
+
+ totals = TraceStream.str();
+ TraceStream.str("");
+
+ TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
+ << " | MG EG | MG EG | MG EG \n"
+ << "---------------------+-------------+-------------+---------------\n";
+
+ trace_row("Material, PST, Tempo", PST);
+ trace_row("Material imbalance", IMBALANCE);
+ trace_row("Pawns", PAWN);
+ trace_row("Knights", KNIGHT);
+ trace_row("Bishops", BISHOP);
+ trace_row("Rooks", ROOK);
+ trace_row("Queens", QUEEN);
+ trace_row("Mobility", MOBILITY);
+ trace_row("King safety", KING);
+ trace_row("Threats", THREAT);
+ trace_row("Passed pawns", PASSED);
+ trace_row("Unstoppable pawns", UNSTOPPABLE);
+ trace_row("Space", SPACE);
+
+ TraceStream << "---------------------+-------------+-------------+---------------\n";
+ trace_row("Total", TOTAL);
+ TraceStream << totals;
+
+ return TraceStream.str();
}
projects / stockfish / blobdiff