Remove DistanceRing #2107

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 7edaa6e1bb786bfa42ff341352f3d153b280e417..095126d451964942b26b6a79d5118e606d524b31 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -36,7 +36,7 @@ namespace {
   constexpr Score Isolated = S( 5, 15);
 
   // Connected pawn bonus
-  constexpr int Connected[RANK_NB] = { 0, 13, 24, 18, 65, 100, 175, 330 };
+  constexpr int Connected[RANK_NB] = { 0, 13, 17, 24, 59, 96, 171 };
 
   // 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.
@@ -77,11 +77,8 @@ namespace {
     Bitboard theirPawns = pos.pieces(Them, PAWN);
 
     e->passedPawns[Us] = e->pawnAttacksSpan[Us] = e->weakUnopposed[Us] = 0;
-    e->semiopenFiles[Us] = 0xFF;
     e->kingSquares[Us]   = SQ_NONE;
     e->pawnAttacks[Us]   = pawn_attacks_bb<Us>(ourPawns);
-    e->pawnsOnSquares[Us][BLACK] = popcount(ourPawns & DarkSquares);
-    e->pawnsOnSquares[Us][WHITE] = pos.count<PAWN>(Us) - e->pawnsOnSquares[Us][BLACK];
 
     // Loop through all pawns of the current color and score each pawn
     while ((s = *pl++) != SQ_NONE)
@@ -89,8 +86,8 @@ namespace {
         assert(pos.piece_on(s) == make_piece(Us, PAWN));
 
         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
@@ -117,8 +114,7 @@ namespace {
             && popcount(phalanx) >= popcount(leverPush))
             e->passedPawns[Us] |= s;
 
-        else if (   stoppers == square_bb(s + Up)
-                 && relative_rank(Us, s) >= RANK_5)
+        else if (stoppers == square_bb(s + Up) && r >= RANK_5)
         {
             b = shift<Up>(support) & ~theirPawns;
             while (b)
@@ -129,8 +125,7 @@ namespace {
         // Score this pawn
         if (support | phalanx)
         {
-            int r = relative_rank(Us, s);
-            int v = phalanx ? Connected[r] + Connected[r + 1] : 2 * Connected[r];
+            int v = (phalanx ? 3 : 2) * Connected[r];
             v = 17 * popcount(support) + (v >> (opposed + 1));
             score += make_score(v, v * (r - 2) / 4);
         }
@@ -167,7 +162,6 @@ Entry* probe(const Position& pos) {
   e->key = key;
   e->scores[WHITE] = evaluate<WHITE>(pos, e);
   e->scores[BLACK] = evaluate<BLACK>(pos, e);
-  e->passedCount= popcount(e->passedPawns[WHITE] | e->passedPawns[BLACK]);
 
   return e;
 }
@@ -218,11 +212,15 @@ Score Entry::do_king_safety(const Position& pos) {
   Square ksq = pos.square<KING>(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<Us>(pos, ksq);
 
@@ -233,7 +231,7 @@ Score Entry::do_king_safety(const Position& pos) {
   if (pos.can_castle(Us | QUEEN_SIDE))
       bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_C1)));
 
-  return make_score(bonus, -16 * minKingPawnDistance);
+  return make_score(bonus, -16 * minPawnDist);
 }
 
 // Explicit template instantiation