Simplify Weak Lever

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 33e859e5a3d49b769b1ae0500393842399a8f2c9..1ae65bf181bcb74dac8755704776bf95a31a3a4c 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -71,10 +71,10 @@ namespace {
     constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
     constexpr Direction Up   = (Us == WHITE ? NORTH : SOUTH);
 
-    Bitboard neighbours, stoppers, doubled, support, phalanx;
+    Bitboard neighbours, stoppers, support, phalanx;
     Bitboard lever, leverPush;
     Square s;
-    bool opposed, backward, passed;
+    bool opposed, backward, passed, doubled;
     Score score = SCORE_ZERO;
     const Square* pl = pos.squares<PAWN>(Us);
 
@@ -137,20 +137,16 @@ namespace {
         }
 
         else if (!neighbours)
-            score -= Isolated + WeakUnopposed * int(!opposed);
+            score -= Isolated + WeakUnopposed * !opposed;
 
         else if (backward)
-            score -= Backward + WeakUnopposed * int(!opposed);
+            score -= Backward + WeakUnopposed * !opposed;
 
-        if (doubled && !support)
-            score -= Doubled;
+        if (!support)
+            score -=   Doubled * doubled
+                     + WeakLever * more_than_one(lever);
     }
 
-    // Penalize our unsupported pawns attacked twice by enemy pawns
-    score -= WeakLever * popcount(  ourPawns
-                                  & doubleAttackThem
-                                  & ~e->pawnAttacks[Us]);
-
     return score;
   }