along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
#include <cassert>
#include <iostream>
#include <iomanip>
#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)
};
// TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
// evaluation terms, used when tracing.
- Score TracedTerms[2][16];
+ Score TracedScores[2][16];
std::stringstream TraceStream;
enum TracedType {
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();
+ 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, false>(pos, margin)
- : do_evaluate<false, false>(pos, margin);
+ return CpuHasPOPCNT ? do_evaluate<true, false>(pos, margin)
+ : do_evaluate<false, false>(pos, margin);
}
namespace {
-double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
-
-void trace_add(int idx, Score term_w, Score term_b = Score(0)) {
-
- TracedTerms[WHITE][idx] = term_w;
- TracedTerms[BLACK][idx] = term_b;
-}
-
template<bool HasPopCnt, bool Trace>
Value do_evaluate(const Position& pos, Value& margin) {
EvalInfo ei;
Value margins[2];
- Score mobilityWhite, mobilityBlack;
+ Score score, mobilityWhite, mobilityBlack;
assert(pos.is_ok());
assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
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();
// 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 = Threads[pos.thread()].materialTable.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())
+ if (ei.mi->specialized_eval_exists())
{
margin = VALUE_ZERO;
- return mi->evaluate(pos);
+ return ei.mi->evaluate(pos);
}
// Probe the pawn hash table
ei.pi = Threads[pos.thread()].pawnTable.get_pawn_info(pos);
- bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+ 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, Trace>(pos, ei, mobilityWhite)
+ 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, Trace>(pos, ei, margins)
+ 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))
- bonus += evaluate_unstoppable_pawns<HasPopCnt>(pos, ei);
+ 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_w = evaluate_space<WHITE, HasPopCnt>(pos, ei);
- int s_b = evaluate_space<BLACK, HasPopCnt>(pos, ei);
- bonus += apply_weight(make_score((s_w - s_b) * mi->space_weight(), 0), Weights[Space]);
-
- if (Trace)
- trace_add(SPACE, apply_weight(make_score(s_w * mi->space_weight(), make_score(0, 0)), Weights[Space]),
- apply_weight(make_score(s_b * mi->space_weight(), make_score(0, 0)), Weights[Space]));
+ int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
+ 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_DRAW ? 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
margin = margins[pos.side_to_move()];
- Value v = scale_by_game_phase(bonus, phase, sf);
+ Value v = scale_by_game_phase(score, ei.mi->game_phase(), sf);
+ // In case of tracing add all single evaluation contributions for both white and black
if (Trace)
{
trace_add(PST, pos.value());
- trace_add(IMBALANCE, mi->material_value());
- trace_add(PAWN, apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]));
+ 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<HasPopCnt>(pos, ei));
- trace_add(TOTAL, bonus);
+ 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 * phase/128.0 << "% MG, "
- << std::setw(6) << 100.0 * (1.0 - phase/128.0) << "% * "
+ << 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);
}
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]);
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 (pos.piece_on(s + d) == make_piece(Us, PAWN))
{
if (!pos.square_is_empty(s + d + pawn_push(Us)))
- bonus -= 2*TrappedBishopA1H1Penalty;
+ score -= 2*TrappedBishopA1H1Penalty;
else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
- bonus -= TrappedBishopA1H1Penalty;
+ score -= TrappedBishopA1H1Penalty;
else
- bonus -= TrappedBishopA1H1Penalty / 2;
+ score -= TrappedBishopA1H1Penalty / 2;
}
}
}
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);
}
}
}
if (Trace)
- TracedTerms[Us][Piece] = bonus;
+ TracedScores[Us][Piece] = score;
- return bonus;
+ 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;
}
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, Trace>(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces<BISHOP, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces<ROOK, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces<QUEEN, Us, HasPopCnt, Trace>(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;
}
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];
+ score -= KingDangerTable[Us][attackUnits];
margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
}
if (Trace)
- TracedTerms[Us][KING] = bonus;
+ TracedScores[Us][KING] = score;
- return bonus;
+ 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))
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
+ // 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 b1, b2, queeningPath, candidates, supBB, sacBB;
- Square s1, s2, queeningSquare, supSq, sacSq;
+ Bitboard b, b2, blockers, supporters, queeningPath, candidates;
+ Square s, blockSq, queeningSquare;
Color c, winnerSide, loserSide;
bool pathDefended, opposed;
- int pliesToGo, movesToGo, oppMovesToGo;
+ int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
int pliesToQueen[] = { 256, 256 };
- // Step 1. Hunt for unstoppable pawns. If we find at least one, record how many plies
- // are required for promotion
+ // 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;
- b1 = ei.pi->passed_pawns(c);
+ b = ei.pi->passed_pawns(c);
- while (b1)
+ while (b)
{
- s1 = pop_1st_bit(&b1);
- queeningSquare = relative_square(c, make_square(square_file(s1), RANK_8));
- queeningPath = squares_in_front_of(c, s1);
+ 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 from queening and check direct advancement
- movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(c, s1) == RANK_2);
+ // 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);
// 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));
+ 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));
continue;
pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
-
- if (pliesToGo < pliesToQueen[c])
- pliesToQueen[c] = pliesToGo;
+ pliesToQueen[c] = Min(pliesToQueen[c], pliesToGo);
}
}
loserSide = opposite_color(winnerSide);
// Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
- // We collect the potential candidates in potentialBB.
- b1 = candidates = pos.pieces(PAWN, loserSide);
+ b = candidates = pos.pieces(PAWN, loserSide);
- while (b1)
+ while (b)
{
- s1 = pop_1st_bit(&b1);
+ s = pop_1st_bit(&b);
// Compute plies from queening
- queeningSquare = relative_square(loserSide, make_square(square_file(s1), RANK_8));
- movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(loserSide, s1) == RANK_2);
+ 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, s1) & pos.pieces(PAWN, loserSide)))
- clear_bit(&candidates, s1);
+ || (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 sacrifices
- b1 = candidates;
+ // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
+ b = candidates;
- while (b1)
+ while (b)
{
- s1 = pop_1st_bit(&b1);
+ s = pop_1st_bit(&b);
+ sacptg = blockersCount = 0;
+ minKingDist = kingptg = 256;
// Compute plies from queening
- queeningSquare = relative_square(loserSide, make_square(square_file(s1), RANK_8));
- movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(loserSide, s1) == RANK_2);
+ 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 obstacles
- opposed = squares_in_front_of(loserSide, s1) & pos.pieces(PAWN, winnerSide);
- b2 = passed_pawn_mask(loserSide, s1) & pos.pieces(PAWN, winnerSide);
-
- assert(b2);
+ // 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);
- // How many plies does it take to remove all the obstacles?
- int sacptg = 0;
- int realObsCount = 0;
- int minKingDist = 256;
- int kingptg = 256;
+ assert(blockers);
- while (b2)
+ // How many plies does it take to remove all the blocking pawns?
+ while (blockers)
{
- s2 = pop_1st_bit(&b2);
+ 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 && square_file(s1) != square_file(s2))
+ if (!opposed)
{
- supBB = in_front_bb(winnerSide, s2 + pawn_push(winnerSide)) & neighboring_files_bb(s1) & candidates;
+ b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
- while (supBB) // This while-loop could be replaced with supSq = LSB/MSB(supBB) (depending on color)
+ while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
{
- supSq = pop_1st_bit(&supBB);
- movesToGo = Min(movesToGo, square_distance(s2, supSq) - 2);
+ d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
+ movesToGo = Min(movesToGo, d);
}
}
- // Check pawns that can be sacrificed
- sacBB = passed_pawn_mask(winnerSide, s2) & neighboring_files_bb(s2) & candidates & ~(1ULL << s1);
+ // Check pawns that can be sacrificed against the blocking pawn
+ b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
- while (sacBB) // This while-loop could be replaced with sacSq = LSB/MSB(sacBB) (depending on color)
+ while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
{
- sacSq = pop_1st_bit(&sacBB);
- movesToGo = Min(movesToGo, square_distance(s2, sacSq) - 2);
+ d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
+ movesToGo = Min(movesToGo, d);
}
- // Good, obstacle can be destroyed with an immediate pawn sacrifice,
+ // 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 the pawn
+ // Plies needed to sacrifice against all the blocking pawns
sacptg += movesToGo * 2;
- realObsCount++;
+ blockersCount++;
- // Plies needed for the king to capture opposing pawn
- minKingDist = Min(minKingDist, square_distance(pos.king_square(loserSide), s2));
- kingptg = (minKingDist + realObsCount) * 2;
+ // 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
// 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);
}
}
+ // 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 term_w = TracedTerms[WHITE][idx];
- Score term_b = TracedTerms[BLACK][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(term_w)) << " "
- << std::setw(6) << to_cp(eg_value(term_w)) << " \n";
+ << 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(term_w)) << " "
- << std::setw(5) << to_cp(eg_value(term_w)) << " | "
- << std::setw(5) << to_cp(mg_value(term_b)) << " "
- << std::setw(5) << to_cp(eg_value(term_b)) << " | "
+ << 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(term_w - term_b)) << " "
- << std::setw(6) << to_cp(eg_value(term_w - term_b)) << " \n";
+ << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";
}
}
}
TraceStream.str("");
TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
- memset(TracedTerms, 0, 2 * 16 * sizeof(Score));
+ memset(TracedScores, 0, 2 * 16 * sizeof(Score));
do_evaluate<false, true>(pos, margin);
projects / stockfish / blobdiff