Remove skipEarlyPruning argument to search()

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index ad63e21630126499e168dba7fef10a550909e8ec..275d7ae16ae33681013ab6fc76f6fab23c39a1c5 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -162,7 +162,7 @@ namespace {
   constexpr Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
 
   // Assorted bonuses and penalties
-  constexpr Score BishopPawns        = S(  8, 12);
+  constexpr Score BishopPawns        = S(  3,  5);
   constexpr Score CloseEnemies       = S(  7,  0);
   constexpr Score Connectivity       = S(  3,  1);
   constexpr Score CorneredBishop     = S( 50, 50);
@@ -293,7 +293,8 @@ namespace {
   template<Tracing T> template<Color Us, PieceType Pt>
   Score Evaluation<T>::pieces() {
 
-    constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
     constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
                                                    : Rank5BB | Rank4BB | Rank3BB);
     const Square* pl = pos.squares<Pt>(Us);
@@ -349,8 +350,12 @@ namespace {
 
             if (Pt == BISHOP)
             {
-                // Penalty according to number of pawns on the same color square as the bishop
-                score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s);
+                // Penalty according to number of pawns on the same color square as the
+                // bishop, bigger when the center files are blocked with pawns.
+                Bitboard blocked = pos.pieces(Us, PAWN) & shift<Down>(pos.pieces());
+
+                score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s)
+                                     * (1 + popcount(blocked & CenterFiles));
 
                 // Bonus for bishop on a long diagonal which can "see" both center squares
                 if (more_than_one(Center & (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) | s)))
@@ -698,7 +703,7 @@ namespace {
         } // w != 0
 
         // Scale down bonus for candidate passers which need more than one
-        // pawn push to become passed or have a pawn in front of them.
+        // pawn push to become passed, or have a pawn in front of them.
         if (   !pos.pawn_passed(Us, s + Up)
             || (pos.pieces(PAWN) & forward_file_bb(Us, s)))
             bonus = bonus / 2;
@@ -731,9 +736,7 @@ namespace {
     if (pos.non_pawn_material() < SpaceThreshold)
         return SCORE_ZERO;
 
-    // Find the safe squares for our pieces inside the area defined by
-    // SpaceMask. A square is unsafe if it is attacked by an enemy
-    // pawn, or if it is undefended and attacked by an enemy piece.
+    // Find the available squares for our pieces inside the area defined by SpaceMask
     Bitboard safe =   SpaceMask
                    & ~pos.pieces(Us, PAWN)
                    & ~attackedBy[Them][PAWN];
@@ -796,9 +799,8 @@ namespace {
     Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
     int sf = me->scale_factor(pos, strongSide);
 
-    // If we don't already have an unusual scale factor, check for certain
-    // types of endgames, and use a lower scale for those.
-    if (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)
+    // If scale is not already specific, scale down the endgame via general heuristics
+    if (sf == SCALE_FACTOR_NORMAL)
     {
         if (pos.opposite_bishops())
         {
@@ -812,12 +814,8 @@ namespace {
             else
                 sf = 46;
         }
-        // Endings where weaker side can place his king in front of the enemy's
-        // pawns are drawish.
-        else if (    abs(eg) <= BishopValueEg
-                 &&  pos.count<PAWN>(strongSide) <= 2
-                 && !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
-            sf = 37 + 7 * pos.count<PAWN>(strongSide);
+        else
+            sf = std::min(40 + 7 * pos.count<PAWN>(strongSide), sf);
     }
 
     return ScaleFactor(sf);