More readable space mask

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index daa911e682fefaa4d2753e2077e4b0837261b58d..e693b2a8e3f4fb6ae9724ad62ee5d65a72ccdb86 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -114,16 +114,15 @@ namespace {
        S( 37, 28), S( 42, 31), S(44, 33) },
      { S(-22,-27), S( -8,-13), S( 6,  1), S(20, 15), S(34, 29), S(48, 43), // Bishops
        S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77),
-       S( 84, 79), S( 86, 81), S(87, 82), S(87, 82) },
+       S( 84, 79), S( 86, 81) },
      { S(-17,-33), S(-11,-16), S(-5,  0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks
        S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119),
-       S( 35,122), S( 36,123), S(37,124), S(38,124) },
+       S( 35,122), S( 36,123), S(37,124) },
      { S(-12,-20), S( -8,-13), S(-5, -7), S(-2, -1), S( 1,  5), S( 4, 11), // Queens
        S(  7, 17), S( 10, 23), S(13, 29), S(16, 34), S(18, 38), S(20, 40),
        S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41),
        S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41),
-       S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41),
-       S( 25, 41), S( 25, 41) }
+       S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) }
   };
 
   // Outpost[PieceType][Square] contains bonuses of knights and bishops, indexed
@@ -173,6 +172,7 @@ namespace {
   const Score RookOpenFile     = make_score(43, 21);
   const Score RookSemiopenFile = make_score(19, 10);
   const Score BishopPawns      = make_score( 8, 12);
+  const Score MinorBehindPawn  = make_score(16,  0);
   const Score UndefendedMinor  = make_score(25, 10);
   const Score TrappedRook      = make_score(90,  0);
 
@@ -186,12 +186,8 @@ namespace {
   // based on how many squares inside this area are safe and available for
   // friendly minor pieces.
   const Bitboard SpaceMask[] = {
-    (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
-    (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
-    (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
-    (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
-    (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
-    (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
+    (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB),
+    (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB)
   };
 
   // King danger constants and variables. The king danger scores are taken
@@ -536,10 +532,10 @@ Value do_evaluate(const Position& pos, Value& margin) {
             if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
                 score += evaluate_outposts<Piece, Us>(pos, ei, s);
 
-            // Pawn in front of knight/bishop
+            // Bishop or knight behind a pawn
             if (    relative_rank(Us, s) < RANK_5
                 && (pos.pieces(PAWN) & (s + pawn_push(Us))))
-                score += make_score(16, 0);
+                score += MinorBehindPawn;
         }
 
         if (  (Piece == ROOK || Piece == QUEEN)
@@ -818,14 +814,13 @@ Value do_evaluate(const Position& pos, Value& margin) {
             ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
 
             // If blockSq is not the queening square then consider also a second push
-            if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
+            if (relative_rank(Us, blockSq) != RANK_8)
                 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
 
             // If the pawn is free to advance, increase bonus
             if (pos.is_empty(blockSq))
             {
                 squaresToQueen = forward_bb(Us, s);
-                defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
 
                 // If there is an enemy rook or queen attacking the pawn from behind,
                 // add all X-ray attacks by the rook or queen. Otherwise consider only
@@ -836,6 +831,12 @@ Value do_evaluate(const Position& pos, Value& margin) {
                 else
                     unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
 
+                if (    unlikely(forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN))
+                    && (forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
+                    defendedSquares = squaresToQueen;
+                else
+                    defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
+
                 // If there aren't enemy attacks huge bonus, a bit smaller if at
                 // least block square is not attacked, otherwise smallest bonus.
                 int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 3;
@@ -1088,9 +1089,9 @@ Value do_evaluate(const Position& pos, Value& margin) {
     assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
     assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
 
-    int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
-    int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
-    return Value((result / GrainSize) * GrainSize); // Sign independent
+    int e = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
+    int r = (mg_value(v) * int(ph) + e * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME;
+    return Value((r / GrainSize) * GrainSize); // Sign independent
   }
 
   // apply_weight() weights score v by score w trying to prevent overflow