X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=47c89ed4c076c73d6be4647ba1cd16f960438cec;hp=b034f478bede4e4456bd4ee3c741992c2ef6ef5d;hb=5935daf8a5b6925a6af2084f87e3831b3bb17dac;hpb=a2cdb6e5d2b33deedfe09baa43708151c45c802a
diff --git a/src/pawns.cpp b/src/pawns.cpp
index b034f478..47c89ed4 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -18,6 +18,7 @@
along with this program. If not, see .
*/
+#include
#include
#include "bitboard.h"
@@ -34,9 +35,10 @@ namespace {
constexpr Score Backward = S( 9, 24);
constexpr Score Doubled = S(11, 56);
constexpr Score Isolated = S( 5, 15);
+ constexpr Score WeakUnopposed = S( 13, 27);
// Connected pawn bonus
- constexpr int Connected[RANK_NB] = { 0, 13, 17, 24, 59, 96, 171 };
+ constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
// Strength of pawn shelter for our king by [distance from edge][rank].
// RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
@@ -76,12 +78,9 @@ namespace {
Bitboard ourPawns = pos.pieces( Us, PAWN);
Bitboard theirPawns = pos.pieces(Them, PAWN);
- e->passedPawns[Us] = e->pawnAttacksSpan[Us] = e->weakUnopposed[Us] = 0;
- e->semiopenFiles[Us] = 0xFF;
+ e->passedPawns[Us] = e->pawnAttacksSpan[Us] = 0;
e->kingSquares[Us] = SQ_NONE;
e->pawnAttacks[Us] = pawn_attacks_bb(ourPawns);
- e->pawnsOnSquares[Us][BLACK] = popcount(ourPawns & DarkSquares);
- e->pawnsOnSquares[Us][WHITE] = pos.count(Us) - e->pawnsOnSquares[Us][BLACK];
// Loop through all pawns of the current color and score each pawn
while ((s = *pl++) != SQ_NONE)
@@ -91,7 +90,6 @@ namespace {
File f = file_of(s);
Rank r = relative_rank(Us, s);
- e->semiopenFiles[Us] &= ~(1 << f);
e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s);
// Flag the pawn
@@ -129,15 +127,16 @@ namespace {
// Score this pawn
if (support | phalanx)
{
- int v = (phalanx ? 3 : 2) * Connected[r];
- v = 17 * popcount(support) + (v >> (opposed + 1));
+ int v = Connected[r] * (phalanx ? 3 : 2) / (opposed ? 2 : 1)
+ + 17 * popcount(support);
+
score += make_score(v, v * (r - 2) / 4);
}
else if (!neighbours)
- score -= Isolated, e->weakUnopposed[Us] += !opposed;
+ score -= Isolated + WeakUnopposed * int(!opposed);
else if (backward)
- score -= Backward, e->weakUnopposed[Us] += !opposed;
+ score -= Backward + WeakUnopposed * int(!opposed);
if (doubled && !support)
score -= Doubled;
@@ -166,7 +165,6 @@ Entry* probe(const Position& pos) {
e->key = key;
e->scores[WHITE] = evaluate(pos, e);
e->scores[BLACK] = evaluate(pos, e);
- e->passedCount= popcount(e->passedPawns[WHITE] | e->passedPawns[BLACK]);
return e;
}
@@ -176,18 +174,19 @@ Entry* probe(const Position& pos) {
/// penalty for a king, looking at the king file and the two closest files.
template
-Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
+void Entry::evaluate_shelter(const Position& pos, Square ksq, Score& shelter) {
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
- constexpr Bitboard BlockRanks = (Us == WHITE ? Rank1BB | Rank2BB : Rank8BB | Rank7BB);
+ constexpr Bitboard BlockSquares = (Rank1BB | Rank2BB | Rank7BB | Rank8BB)
+ & (FileABB | FileHBB);
Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
Bitboard ourPawns = b & pos.pieces(Us);
Bitboard theirPawns = b & pos.pieces(Them);
- Value safety = (shift(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) ?
- Value(374) : Value(5);
+ Value bonus[] = { (shift(theirPawns) & BlockSquares & ksq) ? Value(374) : Value(5),
+ VALUE_ZERO };
File center = clamp(file_of(ksq), FILE_B, FILE_G);
for (File f = File(center - 1); f <= File(center + 1); ++f)
@@ -199,12 +198,16 @@ Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
Rank theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
int d = std::min(f, ~f);
- safety += ShelterStrength[d][ourRank];
- safety -= (ourRank && (ourRank == theirRank - 1)) ? 66 * (theirRank == RANK_3)
- : UnblockedStorm[d][theirRank];
+ bonus[MG] += ShelterStrength[d][ourRank];
+
+ if (ourRank && (ourRank == theirRank - 1))
+ bonus[MG] -= 82 * (theirRank == RANK_3), bonus[EG] -= 82 * (theirRank == RANK_3);
+ else
+ bonus[MG] -= UnblockedStorm[d][theirRank];
}
- return safety;
+ if (bonus[MG] > mg_value(shelter))
+ shelter = make_score(bonus[MG], bonus[EG]);
}
@@ -217,22 +220,27 @@ Score Entry::do_king_safety(const Position& pos) {
Square ksq = pos.square(Us);
kingSquares[Us] = ksq;
castlingRights[Us] = pos.castling_rights(Us);
- int minKingPawnDistance = 0;
Bitboard pawns = pos.pieces(Us, PAWN);
- if (pawns)
- while (!(DistanceRingBB[ksq][++minKingPawnDistance] & pawns)) {}
+ int minPawnDist = pawns ? 8 : 0;
+
+ if (pawns & PseudoAttacks[KING][ksq])
+ minPawnDist = 1;
+
+ else while (pawns)
+ minPawnDist = std::min(minPawnDist, distance(ksq, pop_lsb(&pawns)));
- Value bonus = evaluate_shelter(pos, ksq);
+ Score shelter = make_score(-VALUE_INFINITE, VALUE_ZERO);
+ evaluate_shelter(pos, ksq, shelter);
// If we can castle use the bonus after the castling if it is bigger
if (pos.can_castle(Us | KING_SIDE))
- bonus = std::max(bonus, evaluate_shelter(pos, relative_square(Us, SQ_G1)));
+ evaluate_shelter(pos, relative_square(Us, SQ_G1), shelter);
if (pos.can_castle(Us | QUEEN_SIDE))
- bonus = std::max(bonus, evaluate_shelter(pos, relative_square(Us, SQ_C1)));
+ evaluate_shelter(pos, relative_square(Us, SQ_C1), shelter);
- return make_score(bonus, -16 * minKingPawnDistance);
+ return shelter - make_score(VALUE_ZERO, 16 * minPawnDist);
}
// Explicit template instantiation