Assorted trivial cleanups June 2019

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index c85d4fd942b907cd6de1b0241c1bb49a763d57da..45c404712a200b949dbc0e3b515ebc81f4475bae 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -32,9 +32,9 @@ namespace {
   #define S(mg, eg) make_score(mg, eg)
 
   // Pawn penalties
-  constexpr Score Backward = S( 9, 24);
-  constexpr Score Doubled  = S(11, 56);
-  constexpr Score Isolated = S( 5, 15);
+  constexpr Score Backward      = S( 9, 24);
+  constexpr Score Doubled       = S(11, 56);
+  constexpr Score Isolated      = S( 5, 15);
   constexpr Score WeakUnopposed = S( 13, 27);
   constexpr Score Attacked2Unsupported = S( 0, 20);
 
@@ -108,17 +108,18 @@ namespace {
         phalanx    = neighbours & rank_bb(s);
         support    = neighbours & rank_bb(s - Up);
 
-        // A pawn is backward when it is behind all pawns of the same color
-        // on the adjacent files and cannot be safely advanced.
-        backward =  !(ourPawns & pawn_attack_span(Them, s + Up))
+        // A pawn is backward when it is behind all pawns of the same color on
+        // the adjacent files and cannot safely advance. Phalanx and isolated
+        // pawns will be excluded when the pawn is scored.
+        backward =  !(neighbours & forward_ranks_bb(Them, s))
                   && (stoppers & (leverPush | (s + Up)));
 
         // Passed pawns will be properly scored in evaluation because we need
         // full attack info to evaluate them. Include also not passed pawns
         // which could become passed after one or two pawn pushes when are
         // not attacked more times than defended.
-        if (   !(stoppers ^ lever) ||
-              (!(stoppers ^ leverPush) && popcount(phalanx) >= popcount(leverPush)))
+        if ( !(stoppers ^ lever) ||
+            (!(stoppers ^ leverPush) && popcount(phalanx) >= popcount(leverPush)))
             e->passedPawns[Us] |= s;
 
         else if (stoppers == square_bb(s + Up) && r >= RANK_5)
@@ -137,6 +138,7 @@ namespace {
 
             score += make_score(v, v * (r - 2) / 4);
         }
+
         else if (!neighbours)
             score -= Isolated + WeakUnopposed * int(!opposed);
 
@@ -181,13 +183,13 @@ Entry* probe(const Position& pos) {
 template<Color Us>
 void Entry::evaluate_shelter(const Position& pos, Square ksq, Score& shelter) {
 
-  constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
+  constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
 
   Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
   Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);
 
-  Value bonus[] = { Value(5), Value(5) };
+  Score bonus = make_score(5, 5);
 
   File center = clamp(file_of(ksq), FILE_B, FILE_G);
   for (File f = File(center - 1); f <= File(center + 1); ++f)
@@ -199,16 +201,16 @@ void Entry::evaluate_shelter(const Position& pos, Square ksq, Score& shelter) {
       Rank theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
 
       int d = std::min(f, ~f);
-      bonus[MG] += ShelterStrength[d][ourRank];
+      bonus += make_score(ShelterStrength[d][ourRank], 0);
 
       if (ourRank && (ourRank == theirRank - 1))
-          bonus[MG] -= 82 * (theirRank == RANK_3), bonus[EG] -= 82 * (theirRank == RANK_3);
+          bonus -= make_score(82 * (theirRank == RANK_3), 82 * (theirRank == RANK_3));
       else
-          bonus[MG] -= UnblockedStorm[d][theirRank];
+          bonus -= make_score(UnblockedStorm[d][theirRank], 0);
   }
 
-  if (bonus[MG] > mg_value(shelter))
-      shelter = make_score(bonus[MG], bonus[EG]);
+  if (mg_value(bonus) > mg_value(shelter))
+      shelter = bonus;
 }