]> git.sesse.net Git - stockfish/blobdiff - src/material.cpp
Zero more redundant coefficients
[stockfish] / src / material.cpp
index 208227e5223b87665377ea2395df11c76f055340..4fd125de25bc5e1740f774e2eff0e07a7871a05f 100644 (file)
@@ -35,18 +35,18 @@ namespace {
   const int NoPawnsSF[4] = { 6, 12, 32 };
 
   // Polynomial material balance parameters
-  const Value RedundantQueenPenalty = Value(320);
-  const Value RedundantRookPenalty  = Value(554);
+  const Value RedundantQueen = Value(320);
+  const Value RedundantRook  = Value(554);
 
   //                                  pair  pawn knight bishop rook queen
-  const int LinearCoefficients[6] = { 1617, -162, -1172, -190,  105,  26 };
+  const int LinearCoefficients[6] = { 1852, -162, -1122, -183,  105,  26 };
 
   const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = {
     // pair pawn knight bishop rook queen
-    {   7                               }, // Bishop pair
+    {   0                               }, // Bishop pair
     {  39,    2                         }, // Pawn
     {  35,  271,  -4                    }, // Knight
-    {   7,  105,   4,    7              }, // Bishop
+    {   0,  105,   4,    0              }, // Bishop
     { -27,   -2,  46,   100,   56       }, // Rook
     {  58,   29,  83,   148,   -3,  -25 }  // Queen
   };
@@ -54,12 +54,12 @@ namespace {
   const int QuadraticCoefficientsOppositeColor[][PIECE_TYPE_NB] = {
     //           THEIR PIECES
     // pair pawn knight bishop rook queen
-    {  41                               }, // Bishop pair
-    {  37,   41                         }, // Pawn
-    {  10,   62,  41                    }, // Knight      OUR PIECES
-    {  57,   64,  39,    41             }, // Bishop
-    {  50,   40,  23,   -22,   41       }, // Rook
-    { 106,  101,   3,   151,  171,   41 }  // Queen
+    {   0                               }, // Bishop pair
+    {  37,    0                         }, // Pawn
+    {  10,   62,   0                    }, // Knight      OUR PIECES
+    {  57,   64,  39,     0             }, // Bishop
+    {  50,   40,  23,   -22,    0       }, // Rook
+    { 106,  101,   3,   151,  171,    0 }  // Queen
   };
 
   // Endgame evaluation and scaling functions accessed direcly and not through
@@ -75,24 +75,24 @@ namespace {
   // Helper templates used to detect a given material distribution
   template<Color Us> bool is_KXK(const Position& pos) {
     const Color Them = (Us == WHITE ? BLACK : WHITE);
-    return   pos.non_pawn_material(Them) == VALUE_ZERO
-          && pos.piece_count(Them, PAWN) == 0
-          && pos.non_pawn_material(Us)   >= RookValueMg;
+    return  !pos.count<PAWN>(Them)
+          && pos.non_pawn_material(Them) == VALUE_ZERO
+          && pos.non_pawn_material(Us) >= RookValueMg;
   }
 
   template<Color Us> bool is_KBPsKs(const Position& pos) {
-    return   pos.non_pawn_material(Us)   == BishopValueMg
-          && pos.piece_count(Us, BISHOP) == 1
-          && pos.piece_count(Us, PAWN)   >= 1;
+    return   pos.non_pawn_material(Us) == BishopValueMg
+          && pos.count<BISHOP>(Us) == 1
+          && pos.count<PAWN  >(Us) >= 1;
   }
 
   template<Color Us> bool is_KQKRPs(const Position& pos) {
     const Color Them = (Us == WHITE ? BLACK : WHITE);
-    return   pos.piece_count(Us, PAWN)    == 0
-          && pos.non_pawn_material(Us)    == QueenValueMg
-          && pos.piece_count(Us, QUEEN)   == 1
-          && pos.piece_count(Them, ROOK)  == 1
-          && pos.piece_count(Them, PAWN)  >= 1;
+    return  !pos.count<PAWN>(Us)
+          && pos.non_pawn_material(Us) == QueenValueMg
+          && pos.count<QUEEN>(Us)  == 1
+          && pos.count<ROOK>(Them) == 1
+          && pos.count<PAWN>(Them) >= 1;
   }
 
   /// imbalance() calculates imbalance comparing piece count of each
@@ -109,11 +109,11 @@ namespace {
     // Redundancy of major pieces, formula based on Kaufman's paper
     // "The Evaluation of Material Imbalances in Chess"
     if (pieceCount[Us][ROOK] > 0)
-        value -=  RedundantRookPenalty * (pieceCount[Us][ROOK] - 1)
-                + RedundantQueenPenalty * pieceCount[Us][QUEEN];
+        value -=  RedundantRook * (pieceCount[Us][ROOK] - 1)
+                + RedundantQueen * pieceCount[Us][QUEEN];
 
     // Second-degree polynomial material imbalance by Tord Romstad
-    for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+    for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
     {
         pc = pieceCount[Us][pt1];
         if (!pc)
@@ -121,7 +121,7 @@ namespace {
 
         v = LinearCoefficients[pt1];
 
-        for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+        for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
             v +=  QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
                 + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
 
@@ -150,7 +150,7 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
   if (e->key == key)
       return e;
 
-  memset(e, 0, sizeof(Entry));
+  std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
   e->gamePhase = game_phase(pos);
@@ -180,8 +180,8 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
       assert((pos.pieces(WHITE, KNIGHT) | pos.pieces(WHITE, BISHOP)));
       assert((pos.pieces(BLACK, KNIGHT) | pos.pieces(BLACK, BISHOP)));
 
-      if (   pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
-          && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
+      if (   pos.count<BISHOP>(WHITE) + pos.count<KNIGHT>(WHITE) <= 2
+          && pos.count<BISHOP>(BLACK) + pos.count<KNIGHT>(BLACK) <= 2)
       {
           e->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()];
           return e;
@@ -221,17 +221,17 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
 
   if (npm_w + npm_b == VALUE_ZERO)
   {
-      if (pos.piece_count(BLACK, PAWN) == 0)
+      if (!pos.count<PAWN>(BLACK))
       {
-          assert(pos.piece_count(WHITE, PAWN) >= 2);
+          assert(pos.count<PAWN>(WHITE) >= 2);
           e->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
       }
-      else if (pos.piece_count(WHITE, PAWN) == 0)
+      else if (!pos.count<PAWN>(WHITE))
       {
-          assert(pos.piece_count(BLACK, PAWN) >= 2);
+          assert(pos.count<PAWN>(BLACK) >= 2);
           e->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
       }
-      else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
+      else if (pos.count<PAWN>(WHITE) == 1 && pos.count<PAWN>(BLACK) == 1)
       {
           // This is a special case because we set scaling functions
           // for both colors instead of only one.
@@ -240,36 +240,37 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
       }
   }
 
-  // No pawns makes it difficult to win, even with a material advantage
-  if (pos.piece_count(WHITE, PAWN) == 0 && npm_w - npm_b <= BishopValueMg)
+  // No pawns makes it difficult to win, even with a material advantage. This
+  // catches some trivial draws like KK, KBK and KNK
+  if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
   {
       e->factor[WHITE] = (uint8_t)
-      (npm_w == npm_b || npm_w < RookValueMg ? 0 : NoPawnsSF[std::min(pos.piece_count(WHITE, BISHOP), 2)]);
+      (npm_w == npm_b || npm_w < RookValueMg ? 0 : NoPawnsSF[std::min(pos.count<BISHOP>(WHITE), 2)]);
   }
 
-  if (pos.piece_count(BLACK, PAWN) == 0 && npm_b - npm_w <= BishopValueMg)
+  if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
   {
       e->factor[BLACK] = (uint8_t)
-      (npm_w == npm_b || npm_b < RookValueMg ? 0 : NoPawnsSF[std::min(pos.piece_count(BLACK, BISHOP), 2)]);
+      (npm_w == npm_b || npm_b < RookValueMg ? 0 : NoPawnsSF[std::min(pos.count<BISHOP>(BLACK), 2)]);
   }
 
   // Compute the space weight
   if (npm_w + npm_b >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
   {
-      int minorPieceCount =  pos.piece_count(WHITE, KNIGHT) + pos.piece_count(WHITE, BISHOP)
-                           + pos.piece_count(BLACK, KNIGHT) + pos.piece_count(BLACK, BISHOP);
+      int minorPieceCount =  pos.count<KNIGHT>(WHITE) + pos.count<BISHOP>(WHITE)
+                           + pos.count<KNIGHT>(BLACK) + pos.count<BISHOP>(BLACK);
 
-      e->spaceWeight = minorPieceCount * minorPieceCount;
+      e->spaceWeight = make_score(minorPieceCount * minorPieceCount, 0);
   }
 
   // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
   // for the bishop pair "extended piece", this allow us to be more flexible
   // in defining bishop pair bonuses.
   const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
-  { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
-    pos.piece_count(WHITE, BISHOP)    , pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
-  { pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
-    pos.piece_count(BLACK, BISHOP)    , pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
+  { pos.count<BISHOP>(WHITE) > 1, pos.count<PAWN>(WHITE), pos.count<KNIGHT>(WHITE),
+    pos.count<BISHOP>(WHITE)    , pos.count<ROOK>(WHITE), pos.count<QUEEN >(WHITE) },
+  { pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
+    pos.count<BISHOP>(BLACK)    , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
 
   e->value = (int16_t)((imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16);
   return e;