Fix a MSVC warning

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 9c960409c5d514dd1512ff11c933da272b84457e..8e5a7f82042d7d88a22ca39f013e3b9473793e40 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)

-  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad

 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by


@@ -17,891 +17,889 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 

-
-////
-//// Includes
-////
-
+#include <algorithm>

 #include <cassert>
 #include <cassert>

-#include <cstring>
+#include <cstring>   // For std::memset
+#include <iomanip>
+#include <sstream>

 
 #include "bitcount.h"
 #include "evaluate.h"
 #include "material.h"
 #include "pawns.h"
 
 #include "bitcount.h"
 #include "evaluate.h"
 #include "material.h"
 #include "pawns.h"

-#include "thread.h"
-#include "ucioption.h"
-
-
-////
-//// Local definitions
-////

 
 namespace {
 
 
 namespace {
 

-  const int Sign[2] = { 1, -1 };
+  // Struct EvalInfo contains various information computed and collected
+  // by the evaluation functions.
+  struct EvalInfo {
+
+    // Pointers to material and pawn hash table entries
+    Material::Entry* mi;
+    Pawns::Entry* pi;
+
+    // attackedBy[color][piece type] is a bitboard representing all squares
+    // attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
+    // contains all squares attacked by the given color.
+    Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
+
+    // kingRing[color] is the zone around the king which is considered
+    // by the king safety evaluation. This consists of the squares directly
+    // adjacent to the king, and the three (or two, for a king on an edge file)
+    // squares two ranks in front of the king. For instance, if black's king
+    // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
+    // f7, g7, h7, f6, g6 and h6.
+    Bitboard kingRing[COLOR_NB];
+
+    // kingAttackersCount[color] is the number of pieces of the given color
+    // which attack a square in the kingRing of the enemy king.
+    int kingAttackersCount[COLOR_NB];
+
+    // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
+    // given color which attack a square in the kingRing of the enemy king. The
+    // weights of the individual piece types are given by the elements in the
+    // KingAttackWeights array.
+    int kingAttackersWeight[COLOR_NB];
+
+    // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
+    // directly adjacent to the king of the given color. Pieces which attack
+    // more than one square are counted multiple times. For instance, if black's
+    // king is on g8 and there's a white knight on g5, this knight adds
+    // 2 to kingAdjacentZoneAttacksCount[BLACK].
+    int kingAdjacentZoneAttacksCount[COLOR_NB];
+
+    Bitboard pinnedPieces[COLOR_NB];
+  };

 
 

-  // Evaluation grain size, must be a power of 2
-  const int GrainSize = 8;
+  namespace Tracing {

 
 

-  // Evaluation weights, initialized from UCI options
-  enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
-  Score Weights[6];
+    enum Terms { // First 8 entries are for PieceType
+      MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
+    };

 
 

-  typedef Value V;
-  #define S(mg, eg) make_score(mg, eg)
+    Score scores[COLOR_NB][TERMS_NB];
+    EvalInfo ei;
+    ScaleFactor sf;

 
 

-  // Internal evaluation weights. These are applied on top of the evaluation
-  // weights read from UCI parameters. The purpose is to be able to change
-  // the evaluation weights while keeping the default values of the UCI
-  // parameters at 100, which looks prettier.
-  //
-  // Values modified by Joona Kiiski
-  const Score WeightsInternal[] = {
-      S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
+    double to_cp(Value v);
+    void write(int idx, Color c, Score s);
+    void write(int idx, Score w, Score b = SCORE_ZERO);
+    void print(std::stringstream& ss, const char* name, int idx);
+    std::string do_trace(const Position& pos);
+  }
+
+  // Evaluation weights, indexed by evaluation term
+  enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety };
+  const struct Weight { int mg, eg; } Weights[] = {
+    {289, 344}, {233, 201}, {221, 273}, {46, 0}, {324, 0}

   };
 
   };
 

-  // MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
-  // end game, indexed by piece type and number of attacked squares not occupied
-  // by friendly pieces.
+  #define V(v) Value(v)
+  #define S(mg, eg) make_score(mg, eg)
+
+  // MobilityBonus[PieceType][attacked] contains bonuses for middle and end
+  // game, indexed by piece type and number of attacked squares not occupied by
+  // friendly pieces.

   const Score MobilityBonus[][32] = {
   const Score MobilityBonus[][32] = {

-     {}, {},
-     { S(-38,-33), S(-25,-23), S(-12,-13), S( 0, -3), S(12,  7), S(25, 17), // Knights
-       S( 31, 22), S( 38, 27), S( 38, 27) },
-     { S(-25,-30), S(-11,-16), S(  3, -2), S(17, 12), S(31, 26), S(45, 40), // Bishops
-       S( 57, 52), S( 65, 60), S( 71, 65), S(74, 69), S(76, 71), S(78, 73),
-       S( 79, 74), S( 80, 75), S( 81, 76), S(81, 76) },
-     { S(-20,-36), S(-14,-19), S( -8, -3), S(-2, 13), S( 4, 29), S(10, 46), // Rooks
-       S( 14, 62), S( 19, 79), S( 23, 95), S(26,106), S(27,111), S(28,114),
-       S( 29,116), S( 30,117), S( 31,118), S(32,118) },
-     { S(-10,-18), S( -8,-13), S( -6, -7), S(-3, -2), S(-1,  3), S( 1,  8), // Queens
-       S(  3, 13), S(  5, 19), S(  8, 23), S(10, 27), S(12, 32), S(15, 34),
-       S( 16, 35), S( 17, 35), S( 18, 35), S(20, 35), S(20, 35), S(20, 35),
-       S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
-       S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
-       S( 20, 35), S( 20, 35) }
+    {}, {},
+    { S(-65,-50), S(-42,-30), S(-9,-10), S( 3,  0), S(15, 10), S(27, 20), // Knights
+      S( 37, 28), S( 42, 31), S(44, 33) },
+    { S(-52,-47), S(-28,-23), 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(-47,-53), S(-31,-26), 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(-42,-40), S(-28,-23), S(-5, -7), S( 0,  0), S( 6, 10), S(11, 19), // Queens
+      S( 13, 29), S( 18, 38), S(20, 40), S(21, 41), S(22, 41), S(22, 41),
+      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) }

   };
 
   };
 

-  // OutpostBonus[PieceType][Square] contains outpost bonuses of knights and
-  // bishops, indexed by piece type and square (from white's point of view).
-  const Value OutpostBonus[][64] = {
-  {
-  //  A     B     C     D     E     F     G     H
+  // Outpost[PieceType][Square] contains bonuses for knights and bishops outposts,
+  // indexed by piece type and square (from white's point of view).
+  const Value Outpost[][SQUARE_NB] = {
+  {// A     B     C     D     E     F     G     H

     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
     V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
     V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
     V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
     V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
     V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
     V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),

-    V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0),
-    V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
-    V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) },
+    V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },

   {
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
     V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
     V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
     V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
   {
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
     V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
     V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
     V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),

-    V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0),
-    V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
-    V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }
+    V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }

   };
 
   };
 

-  // ThreatBonus[attacking][attacked] contains threat bonuses according to
-  // which piece type attacks which one.
-  const Score ThreatBonus[][8] = {
-    {}, {},
-    { S(0, 0), S( 7, 39), S( 0,  0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
-    { S(0, 0), S( 7, 39), S(24, 49), S( 0,  0), S(41,100), S(41,100) }, // BISHOP
-    { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0,  0), S(24, 49) }, // ROOK
-    { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0,  0) }  // QUEEN
+  // Threat[defended/weak][minor/major attacking][attacked PieceType] contains
+  // bonuses according to which piece type attacks which one.
+  const Score Threat[][2][PIECE_TYPE_NB] = {
+  { { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) },   // Defended Minor
+    { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) } }, // Defended Major
+  { { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) },   // Weak Minor
+    { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } }  // Weak Major

   };
 
   };
 

-  // ThreatedByPawnPenalty[PieceType] contains a penalty according to which
-  // piece type is attacked by an enemy pawn.
-  const Score ThreatedByPawnPenalty[] = {
-    S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
+  // ThreatenedByPawn[PieceType] contains a penalty according to which piece
+  // type is attacked by an enemy pawn.
+  const Score ThreatenedByPawn[] = {
+    S(0, 0), S(0, 0), S(87, 118), S(84, 122), S(114, 203), S(121, 217)

   };
 
   };
 

-  #undef S
-
-  // Rooks and queens on the 7th rank (modified by Joona Kiiski)
-  const Score RookOn7thBonus  = make_score(47, 98);
-  const Score QueenOn7thBonus = make_score(27, 54);
-
-  // Rooks on open files (modified by Joona Kiiski)
-  const Score RookOpenFileBonus = make_score(43, 43);
-  const Score RookHalfOpenFileBonus = make_score(19, 19);
+  // Assorted bonuses and penalties used by evaluation
+  const Score KingOnOne          = S( 2, 58);
+  const Score KingOnMany         = S( 6,125);
+  const Score RookOnPawn         = S( 7, 27);
+  const Score RookOnOpenFile     = S(43, 21);
+  const Score RookOnSemiOpenFile = S(19, 10);
+  const Score BishopPawns        = S( 8, 12);
+  const Score MinorBehindPawn    = S(16,  0);
+  const Score TrappedRook        = S(92,  0);
+  const Score Unstoppable        = S( 0, 20);
+  const Score Hanging            = S(31, 26);
+
+  // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
+  // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
+  // happen in Chess960 games.
+  const Score TrappedBishopA1H1 = S(50, 50);

 
 

-  // Penalty for rooks trapped inside a friendly king which has lost the
-  // right to castle.
-  const Value TrappedRookPenalty = Value(180);
+  #undef S
+  #undef V

 
 

-  // The SpaceMask[Color] contains the area of the board which is considered
-  // by the space evaluation. In the middle game, each side is given a bonus
+  // SpaceMask[Color] contains the area of the board which is considered
+  // by the space evaluation. In the middlegame, each side is given a bonus

   // based on how many squares inside this area are safe and available for
   // friendly minor pieces.
   // based on how many squares inside this area are safe and available for
   // friendly minor pieces.

-  const Bitboard SpaceMask[2] = {
-    (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)
+  const Bitboard SpaceMask[] = {
+    (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
-  // from the KingDangerTable[]. Various little "meta-bonuses" measuring
-  // the strength of the enemy attack are added up into an integer, which
-  // is used as an index to KingDangerTable[].
+  // King danger constants and variables. The king danger scores are looked-up
+  // in KingDanger[]. Various little "meta-bonuses" measuring the strength
+  // of the enemy attack are added up into an integer, which is used as an
+  // index to KingDanger[].

   //
   // KingAttackWeights[PieceType] contains king attack weights by piece type
   //
   // KingAttackWeights[PieceType] contains king attack weights by piece type

-  const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
+  const int KingAttackWeights[] = { 0, 0, 8, 4, 4, 1 };

 
   // Bonuses for enemy's safe checks
 
   // Bonuses for enemy's safe checks

-  const int QueenContactCheckBonus = 3;
-  const int QueenCheckBonus        = 2;
-  const int RookCheckBonus         = 1;
-  const int BishopCheckBonus       = 1;
-  const int KnightCheckBonus       = 1;
-
-  // InitKingDanger[Square] contains penalties based on the position of the
-  // defending king, indexed by king's square (from white's point of view).
-  const int InitKingDanger[] = {
-     2,  0,  2,  5,  5,  2,  0,  2,
-     2,  2,  4,  8,  8,  4,  2,  2,
-     7, 10, 12, 12, 12, 12, 10,  7,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15
-  };
-
-  // KingDangerTable[Color][attackUnits] contains the actual king danger
-  // weighted scores, indexed by color and by a calculated integer number.
-  Score KingDangerTable[2][128];
-
-  // Pawn and material hash tables, indexed by the current thread id.
-  // Note that they will be initialized at 0 being global variables.
-  MaterialInfoTable* MaterialTable[MAX_THREADS];
-  PawnInfoTable* PawnTable[MAX_THREADS];
-
-  // Function prototypes
-  template<bool HasPopCnt>
-  Value do_evaluate(const Position& pos, EvalInfo& ei);
-
-  template<Color Us, bool HasPopCnt>
-  void init_attack_tables(const Position& pos, EvalInfo& ei);
+  const int QueenContactCheck = 89;
+  const int RookContactCheck  = 72;
+  const int QueenCheck        = 51;
+  const int RookCheck         = 38;
+  const int BishopCheck       = 5;
+  const int KnightCheck       = 16;
+
+  // KingDanger[attackUnits] contains the actual king danger weighted
+  // scores, indexed by a calculated integer number.
+  Score KingDanger[512];
+
+  // apply_weight() weighs score 's' by weight 'w' trying to prevent overflow
+  Score apply_weight(Score s, const Weight& w) {
+    return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256);
+  }

 
 

-  template<Color Us, bool HasPopCnt>
-  Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);

 
 

-  template<Color Us, bool HasPopCnt>
-  void evaluate_king(const Position& pos, EvalInfo& ei);
+  // init_eval_info() initializes king bitboards for given color adding
+  // pawn attacks. To be done at the beginning of the evaluation.

 
   template<Color Us>
 
   template<Color Us>

-  void evaluate_threats(const Position& pos, EvalInfo& ei);
+  void init_eval_info(const Position& pos, EvalInfo& ei) {

 
 

-  template<Color Us, bool HasPopCnt>
-  int evaluate_space(const Position& pos, EvalInfo& ei);
+    const Color  Them = (Us == WHITE ? BLACK : WHITE);
+    const Square Down = (Us == WHITE ? DELTA_S : DELTA_N);

 
 

-  template<Color Us>
-  void evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+    ei.pinnedPieces[Us] = pos.pinned_pieces(Us);

 
 

-  inline Score apply_weight(Score v, Score weight);
-  Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]);
-  Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
-  void init_safety();
-}
+    Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
+    ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);

 
 

+    // Init king safety tables only if we are going to use them
+    if (pos.non_pawn_material(Us) >= QueenValueMg)
+    {
+        ei.kingRing[Them] = b | shift_bb<Down>(b);
+        b &= ei.attackedBy[Us][PAWN];
+        ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) : 0;
+        ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
+    }
+    else
+        ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
+  }

 
 

-////
-//// Functions
-////

 
 

+  // evaluate_outpost() evaluates bishop and knight outpost squares

 
 

-/// Prefetches in pawn hash tables
+  template<PieceType Pt, Color Us>
+  Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) {

 
 

-void prefetchPawn(Key key, int threadID) {
+    const Color Them = (Us == WHITE ? BLACK : WHITE);

 
 

-    PawnTable[threadID]->prefetch(key);
-}
+    assert (Pt == BISHOP || Pt == KNIGHT);

 
 

-/// evaluate() is the main evaluation function. It always computes two
-/// values, an endgame score and a middle game score, and interpolates
-/// between them based on the remaining material.
-Value evaluate(const Position& pos, EvalInfo& ei) {
+    // Initial bonus based on square
+    Value bonus = Outpost[Pt == BISHOP][relative_square(Us, s)];

 
 

-    return CpuHasPOPCNT ? do_evaluate<true>(pos, ei)
-                        : do_evaluate<false>(pos, ei);
-}
+    // Increase bonus if supported by pawn, especially if the opponent has
+    // no minor piece which can trade with the outpost piece.
+    if (bonus && (ei.attackedBy[Us][PAWN] & s))
+    {
+        if (   !pos.pieces(Them, KNIGHT)
+            && !(squares_of_color(s) & pos.pieces(Them, BISHOP)))
+            bonus += bonus + bonus / 2;
+        else
+            bonus += bonus / 2;
+    }

 
 

-namespace {
+    return make_score(bonus * 2, bonus / 2);
+  }

 
 

-template<bool HasPopCnt>
-Value do_evaluate(const Position& pos, EvalInfo& ei) {

 
 

-  ScaleFactor factor[2];
-  Score mobility;
+  // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color

 
 

-  assert(pos.is_ok());
-  assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
-  assert(!pos.is_check());
+  template<PieceType Pt, Color Us, bool Trace>
+  Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) {

 
 

-  memset(&ei, 0, sizeof(EvalInfo));
+    Bitboard b;
+    Square s;
+    Score score = SCORE_ZERO;

 
 

-  // Initialize by reading the incrementally updated scores included in the
-  // position object (material + piece square tables).
-  ei.value = pos.value();
+    const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
+    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    const Square* pl = pos.list<Pt>(Us);

 
 

-  // Probe the material hash table
-  ei.mi = MaterialTable[pos.thread()]->get_material_info(pos);
-  ei.value += ei.mi->material_value();
+    ei.attackedBy[Us][Pt] = 0;

 
 

-  // If we have a specialized evaluation function for the current material
-  // configuration, call it and return.
-  if (ei.mi->specialized_eval_exists())
-      return ei.mi->evaluate(pos);
+    while ((s = *pl++) != SQ_NONE)
+    {
+        // Find attacked squares, including x-ray attacks for bishops and rooks
+        b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN))
+          : Pt ==   ROOK ? attacks_bb<  ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
+                         : pos.attacks_from<Pt>(s);

 
 

-  // After get_material_info() call that modifies them
-  factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
-  factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
+        if (ei.pinnedPieces[Us] & s)
+            b &= LineBB[pos.king_square(Us)][s];

 
 

-  // Probe the pawn hash table
-  ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
-  ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+        ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b;

 
 

-  // Initialize attack bitboards with pawns evaluation
-  init_attack_tables<WHITE, HasPopCnt>(pos, ei);
-  init_attack_tables<BLACK, HasPopCnt>(pos, ei);
+        if (b & ei.kingRing[Them])
+        {
+            ei.kingAttackersCount[Us]++;
+            ei.kingAttackersWeight[Us] += KingAttackWeights[Pt];
+            Bitboard bb = b & ei.attackedBy[Them][KING];
+            if (bb)
+                ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
+        }

 
 

-  // Evaluate pieces and mobility
-  mobility =   evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei)
-             - evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei);
-  ei.value += apply_weight(mobility, Weights[Mobility]);
+        if (Pt == QUEEN)
+            b &= ~(  ei.attackedBy[Them][KNIGHT]
+                   | ei.attackedBy[Them][BISHOP]
+                   | ei.attackedBy[Them][ROOK]);

 
 

-  // Kings. Kings are evaluated after all other pieces for both sides,
-  // because we need complete attack information for all pieces when computing
-  // the king safety evaluation.
-  evaluate_king<WHITE, HasPopCnt>(pos, ei);
-  evaluate_king<BLACK, HasPopCnt>(pos, ei);
+        int mob = Pt != QUEEN ? popcount<Max15>(b & mobilityArea[Us])
+                              : popcount<Full >(b & mobilityArea[Us]);

 
 

-  // Evaluate tactical threats, we need full attack info including king
-  evaluate_threats<WHITE>(pos, ei);
-  evaluate_threats<BLACK>(pos, ei);
+        mobility[Us] += MobilityBonus[Pt][mob];

 
 

-  // Evaluate passed pawns, we need full attack info including king
-  evaluate_passed_pawns<WHITE>(pos, ei);
-  evaluate_passed_pawns<BLACK>(pos, ei);
+        // Decrease score if we are attacked by an enemy pawn. The remaining part
+        // of threat evaluation must be done later when we have full attack info.
+        if (ei.attackedBy[Them][PAWN] & s)
+            score -= ThreatenedByPawn[Pt];

 
 

-  Phase phase = ei.mi->game_phase();
+        if (Pt == BISHOP || Pt == KNIGHT)
+        {
+            // Bonus for outpost square
+            if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
+                score += evaluate_outpost<Pt, Us>(pos, ei, s);
+
+            // Bonus when behind a pawn
+            if (    relative_rank(Us, s) < RANK_5
+                && (pos.pieces(PAWN) & (s + pawn_push(Us))))
+                score += MinorBehindPawn;
+
+            // Penalty for pawns on same color square of bishop
+            if (Pt == BISHOP)
+                score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
+
+            // An important Chess960 pattern: A cornered bishop blocked by a friendly
+            // pawn diagonally in front of it is a very serious problem, especially
+            // when that pawn is also blocked.
+            if (   Pt == BISHOP
+                && pos.is_chess960()
+                && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
+            {
+                Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
+                if (pos.piece_on(s + d) == make_piece(Us, PAWN))
+                    score -= !pos.empty(s + d + pawn_push(Us))                ? TrappedBishopA1H1 * 4
+                            : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
+                                                                              : TrappedBishopA1H1;
+            }
+        }

 
 

-  // Middle-game specific evaluation terms
-  if (phase > PHASE_ENDGAME)
-  {
-      // Evaluate pawn storms in positions with opposite castling
-      if (   square_file(pos.king_square(WHITE)) >= FILE_E
-          && square_file(pos.king_square(BLACK)) <= FILE_D)
+        if (Pt == ROOK)
+        {
+            // Bonus for aligning with enemy pawns on the same rank/file
+            if (relative_rank(Us, s) >= RANK_5)
+            {
+                Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
+                if (alignedPawns)
+                    score += popcount<Max15>(alignedPawns) * RookOnPawn;
+            }

 
 

-          ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
+            // Bonus when on an open or semi-open file
+            if (ei.pi->semiopen_file(Us, file_of(s)))
+                score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOnOpenFile : RookOnSemiOpenFile;

 
 

-      else if (   square_file(pos.king_square(WHITE)) <= FILE_D
-               && square_file(pos.king_square(BLACK)) >= FILE_E)
+            // Penalize when trapped by the king, even more if king cannot castle
+            if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(s)))
+            {
+                Square ksq = pos.king_square(Us);

 
 

-          ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
+                if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
+                    && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
+                    && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
+                    score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
+            }
+        }
+    }

 
 

-      // Evaluate space for both sides
-      if (ei.mi->space_weight() > 0)
-      {
-          int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
-          ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
-      }
-  }
+    if (Trace)
+        Tracing::write(Pt, Us, score);

 
 

-  // If we don't already have an unusual scale factor, check for opposite
-  // colored bishop endgames, and use a lower scale for those
-  if (   phase < PHASE_MIDGAME
-      && pos.opposite_colored_bishops()
-      && (   (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(ei.value) > VALUE_ZERO)
-          || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < VALUE_ZERO)))
-  {
-      ScaleFactor sf;
-
-      // Only the two bishops ?
-      if (   pos.non_pawn_material(WHITE) == BishopValueMidgame
-          && pos.non_pawn_material(BLACK) == BishopValueMidgame)
-      {
-          // Check for KBP vs KB with only a single pawn that is almost
-          // certainly a draw or at least two pawns.
-          bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
-          sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
-      }
-      else
-          // Endgame with opposite-colored bishops, but also other pieces. Still
-          // a bit drawish, but not as drawish as with only the two bishops.
-           sf = ScaleFactor(50);
-
-      if (factor[WHITE] == SCALE_FACTOR_NORMAL)
-          factor[WHITE] = sf;
-      if (factor[BLACK] == SCALE_FACTOR_NORMAL)
-          factor[BLACK] = sf;
+    // Recursively call evaluate_pieces() of next piece type until KING excluded
+    return score - evaluate_pieces<NextPt, Them, Trace>(pos, ei, mobility, mobilityArea);

   }
 
   }
 

-  // Interpolate between the middle game and the endgame score
-  return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor);
-}
+  template<>
+  Score evaluate_pieces<KING, WHITE, false>(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; }
+  template<>
+  Score evaluate_pieces<KING, WHITE,  true>(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; }

 
 

-} // namespace

 
 

-/// init_eval() initializes various tables used by the evaluation function
+  // evaluate_king() assigns bonuses and penalties to a king of a given color

 
 

-void init_eval(int threads) {
+  template<Color Us, bool Trace>
+  Score evaluate_king(const Position& pos, const EvalInfo& ei) {

 
 

-  assert(threads <= MAX_THREADS);
+    const Color Them = (Us == WHITE ? BLACK : WHITE);

 
 

-  for (int i = 0; i < MAX_THREADS; i++)
-  {
-    if (i >= threads)
-    {
-        delete PawnTable[i];
-        delete MaterialTable[i];
-        PawnTable[i] = NULL;
-        MaterialTable[i] = NULL;
-        continue;
-    }
-    if (!PawnTable[i])
-        PawnTable[i] = new PawnInfoTable();
-    if (!MaterialTable[i])
-        MaterialTable[i] = new MaterialInfoTable();
-  }
-}
+    Bitboard undefended, b, b1, b2, safe;
+    int attackUnits;
+    const Square ksq = pos.king_square(Us);

 
 

+    // King shelter and enemy pawns storm
+    Score score = ei.pi->king_safety<Us>(pos, ksq);

 
 

-/// quit_eval() releases heap-allocated memory at program termination
+    // Main king safety evaluation
+    if (ei.kingAttackersCount[Them])
+    {
+        // Find the attacked squares around the king which have no defenders
+        // apart from the king itself
+        undefended =  ei.attackedBy[Them][ALL_PIECES]
+                    & ei.attackedBy[Us][KING]
+                    & ~(  ei.attackedBy[Us][PAWN]   | ei.attackedBy[Us][KNIGHT]
+                        | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
+                        | ei.attackedBy[Us][QUEEN]);

 
 

-void quit_eval() {
+        // Initialize the 'attackUnits' variable, which is used later on as an
+        // index into the KingDanger[] array. The initial value is based on the
+        // number and types of the enemy's attacking pieces, the number of
+        // attacked and undefended squares around our king and the quality of
+        // the pawn shelter (current 'score' value).
+        attackUnits =  std::min(74, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+                     + 9 * ei.kingAdjacentZoneAttacksCount[Them]
+                     + 25 * popcount<Max15>(undefended)
+                     +  10 * (ei.pinnedPieces[Us] != 0)
+                     - mg_value(score) / 8
+                     - !pos.count<QUEEN>(Them) * 60;
+
+        // Analyse the enemy's safe queen contact checks. Firstly, find the
+        // undefended squares around the king reachable by the enemy queen...
+        b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
+        if (b)
+        {
+            // ...and then remove squares not supported by another enemy piece
+            b &=  ei.attackedBy[Them][PAWN]   | ei.attackedBy[Them][KNIGHT]
+                | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK];

 
 

-  for (int i = 0; i < MAX_THREADS; i++)
-  {
-      delete PawnTable[i];
-      delete MaterialTable[i];
-      PawnTable[i] = NULL;
-      MaterialTable[i] = NULL;
-  }
-}
+            if (b)
+                attackUnits += QueenContactCheck * popcount<Max15>(b);
+        }

 
 

+        // Analyse the enemy's safe rook contact checks. Firstly, find the
+        // undefended squares around the king reachable by the enemy rooks...
+        b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);

 
 

-/// read_weights() reads evaluation weights from the corresponding UCI parameters
+        // Consider only squares where the enemy's rook gives check
+        b &= PseudoAttacks[ROOK][ksq];

 
 

-void read_weights(Color us) {
+        if (b)
+        {
+            // ...and then remove squares not supported by another enemy piece
+            b &= (  ei.attackedBy[Them][PAWN]   | ei.attackedBy[Them][KNIGHT]
+                  | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);

 
 

-  // King safety is asymmetrical. Our king danger level is weighted by
-  // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
-  const int kingDangerUs   = (us == WHITE ? KingDangerUs   : KingDangerThem);
-  const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
+            if (b)
+                attackUnits += RookContactCheck * popcount<Max15>(b);
+        }

 
 

-  Weights[Mobility]       = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
-  Weights[PawnStructure]  = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
-  Weights[PassedPawns]    = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
-  Weights[Space]          = weight_option("Space", "Space", WeightsInternal[Space]);
-  Weights[kingDangerUs]   = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
-  Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
+        // Analyse the enemy's safe distance checks for sliders and knights
+        safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them));

 
 

-  // If running in analysis mode, make sure we use symmetrical king safety. We do this
-  // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
-  if (get_option_value_bool("UCI_AnalyseMode"))
-      Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
+        b1 = pos.attacks_from<ROOK  >(ksq) & safe;
+        b2 = pos.attacks_from<BISHOP>(ksq) & safe;

 
 

-  init_safety();
-}
+        // Enemy queen safe checks
+        b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
+        if (b)
+            attackUnits += QueenCheck * popcount<Max15>(b);

 
 

+        // Enemy rooks safe checks
+        b = b1 & ei.attackedBy[Them][ROOK];
+        if (b)
+            attackUnits += RookCheck * popcount<Max15>(b);

 
 

-namespace {
+        // Enemy bishops safe checks
+        b = b2 & ei.attackedBy[Them][BISHOP];
+        if (b)
+            attackUnits += BishopCheck * popcount<Max15>(b);

 
 

-  // init_attack_tables() initializes king bitboards for both sides adding
-  // pawn attacks. To be done before other evaluations.
+        // Enemy knights safe checks
+        b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
+        if (b)
+            attackUnits += KnightCheck * popcount<Max15>(b);

 
 

-  template<Color Us, bool HasPopCnt>
-  void init_attack_tables(const Position& pos, EvalInfo& ei) {
+        // Finally, extract the king danger score from the KingDanger[]
+        // array and subtract the score from evaluation.
+        score -= KingDanger[std::max(std::min(attackUnits, 399), 0)];
+    }

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    if (Trace)
+        Tracing::write(KING, Us, score);

 
 

-    Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
-    ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
-    ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
-    b &= ei.attackedBy[Us][PAWN];
-    if (b)
-        ei.kingAttackersCount[Us] = count_1s_max_15<HasPopCnt>(b) / 2;
+    return score;

   }
 
 
   }
 
 

-  // evaluate_outposts() evaluates bishop and knight outposts squares
+  // evaluate_threats() assigns bonuses according to the type of attacking piece
+  // and the type of attacked one.

 
 

-  template<PieceType Piece, Color Us>
-  void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+  template<Color Us, bool Trace>
+  Score evaluate_threats(const Position& pos, const EvalInfo& ei) {

 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 

-    assert (Piece == BISHOP || Piece == KNIGHT);
+    enum { Defended, Weak };
+    enum { Minor, Major };

 
 

-    // Initial bonus based on square
-    Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
+    Bitboard b, weak, defended;
+    Score score = SCORE_ZERO;

 
 

-    // Increase bonus if supported by pawn, especially if the opponent has
-    // no minor piece which can exchange the outpost piece
-    if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s))
+    // Non-pawn enemies defended by a pawn
+    defended =  (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
+              &  ei.attackedBy[Them][PAWN];
+
+    // Add a bonus according to the kind of attacking pieces
+    if (defended)

     {
     {

-        if (    pos.pieces(KNIGHT, Them) == EmptyBoardBB
-            && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB)
-            bonus += bonus + bonus / 2;
-        else
-            bonus += bonus / 2;
+        b = defended & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+        while (b)
+            score += Threat[Defended][Minor][type_of(pos.piece_on(pop_lsb(&b)))];
+
+        b = defended & (ei.attackedBy[Us][ROOK]);
+        while (b)
+            score += Threat[Defended][Major][type_of(pos.piece_on(pop_lsb(&b)))];

     }
     }

-    ei.value += Sign[Us] * make_score(bonus, bonus);
-  }

 
 

+    // Enemies not defended by a pawn and under our attack
+    weak =   pos.pieces(Them)
+          & ~ei.attackedBy[Them][PAWN]
+          &  ei.attackedBy[Us][ALL_PIECES];

 
 

-  // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
+    // Add a bonus according to the kind of attacking pieces
+    if (weak)
+    {
+        b = weak & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+        while (b)
+            score += Threat[Weak][Minor][type_of(pos.piece_on(pop_lsb(&b)))];

 
 

-  template<PieceType Piece, Color Us, bool HasPopCnt>
-  Score evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) {
+        b = weak & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
+        while (b)
+            score += Threat[Weak][Major][type_of(pos.piece_on(pop_lsb(&b)))];

 
 

-    Bitboard b;
-    Square s, ksq;
-    int mob;
-    File f;
-    Score mobility = SCORE_ZERO;
+        b = weak & ~ei.attackedBy[Them][ALL_PIECES];
+        if (b)
+            score += Hanging * popcount<Max15>(b);

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
-    const Square* ptr = pos.piece_list_begin(Us, Piece);
+        b = weak & ei.attackedBy[Us][KING];
+        if (b)
+            score += more_than_one(b) ? KingOnMany : KingOnOne;
+    }

 
 

-    while ((s = *ptr++) != SQ_NONE)
-    {
-        // Find attacked squares, including x-ray attacks for bishops and rooks
-        if (Piece == KNIGHT || Piece == QUEEN)
-            b = pos.attacks_from<Piece>(s);
-        else if (Piece == BISHOP)
-            b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
-        else if (Piece == ROOK)
-            b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
-        else
-            assert(false);
+    if (Trace)
+        Tracing::write(Tracing::THREAT, Us, score);

 
 

-        // Update attack info
-        ei.attackedBy[Us][Piece] |= b;
+    return score;
+  }

 
 

-        // King attacks
-        if (b & ei.kingZone[Us])
-        {
-            ei.kingAttackersCount[Us]++;
-            ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
-            Bitboard bb = (b & ei.attackedBy[Them][KING]);
-            if (bb)
-                ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
-        }

 
 

-        // Mobility
-        mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b & no_mob_area)
-                              : count_1s<HasPopCnt>(b & no_mob_area));
+  // evaluate_passed_pawns() evaluates the passed pawns of the given color

 
 

-        mobility += MobilityBonus[Piece][mob];
+  template<Color Us, bool Trace>
+  Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) {

 
 

-        // Decrease score if we are attacked by an enemy pawn. Remaining part
-        // of threat evaluation must be done later when we have full attack info.
-        if (bit_is_set(ei.attackedBy[Them][PAWN], s))
-            ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece];
+    const Color Them = (Us == WHITE ? BLACK : WHITE);

 
 

-        // Bishop and knight outposts squares
-        if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
-            evaluate_outposts<Piece, Us>(pos, ei, s);
+    Bitboard b, squaresToQueen, defendedSquares, unsafeSquares;
+    Score score = SCORE_ZERO;

 
 

-        // Queen or rook on 7th rank
-        if (  (Piece == ROOK || Piece == QUEEN)
-            && relative_rank(Us, s) == RANK_7
-            && relative_rank(Us, pos.king_square(Them)) == RANK_8)
-        {
-            ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
-        }
+    b = ei.pi->passed_pawns(Us);
+
+    while (b)
+    {
+        Square s = pop_lsb(&b);
+
+        assert(pos.pawn_passed(Us, s));

 
 

-        // Special extra evaluation for rooks
-        if (Piece == ROOK)
+        int r = relative_rank(Us, s) - RANK_2;
+        int rr = r * (r - 1);
+
+        // Base bonus based on rank
+        Value mbonus = Value(17 * rr), ebonus = Value(7 * (rr + r + 1));
+
+        if (rr)

         {
         {

-            // Open and half-open files
-            f = square_file(s);
-            if (ei.pi->file_is_half_open(Us, f))
-            {
-                if (ei.pi->file_is_half_open(Them, f))
-                    ei.value += Sign[Us] * RookOpenFileBonus;
-                else
-                    ei.value += Sign[Us] * RookHalfOpenFileBonus;
-            }
+            Square blockSq = s + pawn_push(Us);

 
 

-            // Penalize rooks which are trapped inside a king. Penalize more if
-            // king has lost right to castle.
-            if (mob > 6 || ei.pi->file_is_half_open(Us, f))
-                continue;
+            // Adjust bonus based on the king's proximity
+            ebonus +=  distance(pos.king_square(Them), blockSq) * 5 * rr
+                     - distance(pos.king_square(Us  ), blockSq) * 2 * rr;

 
 

-            ksq = pos.king_square(Us);
+            // If blockSq is not the queening square then consider also a second push
+            if (relative_rank(Us, blockSq) != RANK_8)
+                ebonus -= distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr;

 
 

-            if (    square_file(ksq) >= FILE_E
-                &&  square_file(s) > square_file(ksq)
-                && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
-            {
-                // Is there a half-open file between the king and the edge of the board?
-                if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
-                    ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
-                                                                         : (TrappedRookPenalty - mob * 16), 0);
-            }
-            else if (    square_file(ksq) <= FILE_D
-                     &&  square_file(s) < square_file(ksq)
-                     && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
+            // If the pawn is free to advance, then increase the bonus
+            if (pos.empty(blockSq))

             {
             {

-                // Is there a half-open file between the king and the edge of the board?
-                if (!ei.pi->has_open_file_to_left(Us, square_file(ksq)))
-                    ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
-                                                                         : (TrappedRookPenalty - mob * 16), 0);
-            }
-        }
-    }
-    return mobility;
-  }
+                // If there is a rook or queen attacking/defending the pawn from behind,
+                // consider all the squaresToQueen. Otherwise consider only the squares
+                // in the pawn's path attacked or occupied by the enemy.
+                defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s);

 
 

+                Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);

 
 

-  // evaluate_threats<>() assigns bonuses according to the type of attacking piece
-  // and the type of attacked one.
+                if (!(pos.pieces(Us) & bb))
+                    defendedSquares &= ei.attackedBy[Us][ALL_PIECES];

 
 

-  template<Color Us>
-  void evaluate_threats(const Position& pos, EvalInfo& ei) {
+                if (!(pos.pieces(Them) & bb))
+                    unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them);

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+                // If there aren't any enemy attacks, assign a big bonus. Otherwise
+                // assign a smaller bonus if the block square isn't attacked.
+                int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 0;

 
 

-    Bitboard b;
-    Score bonus = SCORE_ZERO;
-
-    // Enemy pieces not defended by a pawn and under our attack
-    Bitboard weakEnemies =  pos.pieces_of_color(Them)
-                          & ~ei.attackedBy[Them][PAWN]
-                          & ei.attackedBy[Us][0];
-    if (!weakEnemies)
-        return;
-
-    // Add bonus according to type of attacked enemy pieces and to the
-    // type of attacking piece, from knights to queens. Kings are not
-    // considered because are already special handled in king evaluation.
-    for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
-    {
-        b = ei.attackedBy[Us][pt1] & weakEnemies;
-        if (b)
-            for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
-                if (b & pos.pieces(pt2))
-                    bonus += ThreatBonus[pt1][pt2];
-    }
-    ei.value += Sign[Us] * bonus;
-  }
+                // If the path to queen is fully defended, assign a big bonus.
+                // Otherwise assign a smaller bonus if the block square is defended.
+                if (defendedSquares == squaresToQueen)
+                    k += 6;

 
 

+                else if (defendedSquares & blockSq)
+                    k += 4;

 
 

-  // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
-  // pieces of a given color.
+                mbonus += k * rr, ebonus += k * rr;
+            }
+            else if (pos.pieces(Us) & blockSq)
+                mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2;
+        } // rr != 0

 
 

-  template<Color Us, bool HasPopCnt>
-  Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) {
+        if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
+            ebonus += ebonus / 4;

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+        score += make_score(mbonus, ebonus);
+    }

 
 

-    Score mobility = SCORE_ZERO;
+    if (Trace)
+        Tracing::write(Tracing::PASSED, Us, apply_weight(score, Weights[PassedPawns]));

 
 

-    // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
-    const Bitboard no_mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+    // Add the scores to the middlegame and endgame eval
+    return apply_weight(score, Weights[PassedPawns]);
+  }

 
 

-    mobility += evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei, no_mob_area);
-    mobility += evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, no_mob_area);
-    mobility += evaluate_pieces<ROOK,   Us, HasPopCnt>(pos, ei, no_mob_area);
-    mobility += evaluate_pieces<QUEEN,  Us, HasPopCnt>(pos, ei, no_mob_area);

 
 

-    // Sum up all attacked squares
-    ei.attackedBy[Us][0] =   ei.attackedBy[Us][PAWN]   | ei.attackedBy[Us][KNIGHT]
-                           | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
-                           | ei.attackedBy[Us][QUEEN]  | ei.attackedBy[Us][KING];
-    return mobility;
-  }
+  // evaluate_space() computes the space evaluation for a given side. The
+  // space evaluation is a simple bonus based on the number of safe squares
+  // available for minor pieces on the central four files on ranks 2--4. Safe
+  // squares one, two or three squares behind a friendly pawn are counted
+  // twice. Finally, the space bonus is multiplied by a weight. The aim is to
+  // improve play on game opening.
+  template<Color Us>
+  Score evaluate_space(const Position& pos, const EvalInfo& ei) {

 
 

+    const Color Them = (Us == WHITE ? BLACK : WHITE);

 
 

-  // evaluate_king<>() assigns bonuses and penalties to a king of a given color
+    // 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.
+    Bitboard safe =   SpaceMask[Us]
+                   & ~pos.pieces(Us, PAWN)
+                   & ~ei.attackedBy[Them][PAWN]
+                   & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);

 
 

-  template<Color Us, bool HasPopCnt>
-  void evaluate_king(const Position& pos, EvalInfo& ei) {
+    // Find all squares which are at most three squares behind some friendly pawn
+    Bitboard behind = pos.pieces(Us, PAWN);
+    behind |= (Us == WHITE ? behind >>  8 : behind <<  8);
+    behind |= (Us == WHITE ? behind >> 16 : behind << 16);

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    // Since SpaceMask[Us] is fully on our half of the board
+    assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);

 
 

-    Bitboard undefended, b, b1, b2, safe;
-    bool sente;
-    int attackUnits;
-    const Square ksq = pos.king_square(Us);
+    // Count safe + (behind & safe) with a single popcount
+    int bonus = popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
+    int weight =  pos.count<KNIGHT>(Us) + pos.count<BISHOP>(Us)
+                + pos.count<KNIGHT>(Them) + pos.count<BISHOP>(Them);

 
 

-    // King shelter
-    ei.value += Sign[Us] * ei.pi->king_shelter(pos, Us, ksq);
+    return make_score(bonus * weight * weight, 0);
+  }

 
 

-    // King safety. This is quite complicated, and is almost certainly far
-    // from optimally tuned.
-    if (   pos.piece_count(Them, QUEEN) >= 1
-        && ei.kingAttackersCount[Them]  >= 2
-        && pos.non_pawn_material(Them)  >= QueenValueMidgame + RookValueMidgame
-        && ei.kingAdjacentZoneAttacksCount[Them])
-    {
-        // Is it the attackers turn to move?
-        sente = (Them == pos.side_to_move());

 
 

-        // Find the attacked squares around the king which has no defenders
-        // apart from the king itself
-        undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING);
-        undefended &= ~(  ei.attacked_by(Us, PAWN)   | ei.attacked_by(Us, KNIGHT)
-                        | ei.attacked_by(Us, BISHOP) | ei.attacked_by(Us, ROOK)
-                        | ei.attacked_by(Us, QUEEN));
+  // do_evaluate() is the evaluation entry point, called directly from evaluate()

 
 

-        // Initialize the 'attackUnits' variable, which is used later on as an
-        // index to the KingDangerTable[] array. The initial value is based on
-        // the number and types of the enemy's attacking pieces, the number of
-        // attacked and undefended squares around our king, the square of the
-        // king, and the quality of the pawn shelter.
-        attackUnits =  Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
-                     + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
-                     + InitKingDanger[relative_square(Us, ksq)]
-                     - mg_value(ei.pi->king_shelter(pos, Us, ksq)) / 32;
-
-        // Analyse enemy's safe queen contact checks. First find undefended
-        // squares around the king attacked by enemy queen...
-        b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them);
-        if (b)
-        {
-            // ...then remove squares not supported by another enemy piece
-            b &= (  ei.attacked_by(Them, PAWN)   | ei.attacked_by(Them, KNIGHT)
-                  | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK));
-            if (b)
-                attackUnits += QueenContactCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
-        }
+  template<bool Trace>
+  Value do_evaluate(const Position& pos) {

 
 

-        // Analyse enemy's safe distance checks for sliders and knights
-        safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us));
+    assert(!pos.checkers());

 
 

-        b1 = pos.attacks_from<ROOK>(ksq) & safe;
-        b2 = pos.attacks_from<BISHOP>(ksq) & safe;
+    EvalInfo ei;
+    Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };

 
 

-        // Enemy queen safe checks
-        b = (b1 | b2) & ei.attacked_by(Them, QUEEN);
-        if (b)
-            attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b);
+    // Initialize score by reading the incrementally updated scores included
+    // in the position object (material + piece square tables).
+    // Score is computed from the point of view of white.
+    score = pos.psq_score();

 
 

-        // Enemy rooks safe checks
-        b = b1 & ei.attacked_by(Them, ROOK);
-        if (b)
-            attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b);
+    // Probe the material hash table
+    ei.mi = Material::probe(pos);
+    score += ei.mi->imbalance();

 
 

-        // Enemy bishops safe checks
-        b = b2 & ei.attacked_by(Them, BISHOP);
-        if (b)
-            attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b);
+    // If we have a specialized evaluation function for the current material
+    // configuration, call it and return.
+    if (ei.mi->specialized_eval_exists())
+        return ei.mi->evaluate(pos);

 
 

-        // Enemy knights safe checks
-        b = pos.attacks_from<KNIGHT>(ksq) & ei.attacked_by(Them, KNIGHT) & safe;
-        if (b)
-            attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
-
-        // To index KingDangerTable[] attackUnits must be in [0, 99] range
-        attackUnits = Min(99, Max(0, attackUnits));
-
-        // Finally, extract the king danger score from the KingDangerTable[]
-        // array and subtract the score from evaluation. Set also ei.kingDanger[]
-        // value that will be used for pruning because this value can sometimes
-        // be very big, and so capturing a single attacking piece can therefore
-        // result in a score change far bigger than the value of the captured piece.
-        ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits];
-        ei.kingDanger[Us] = mg_value(KingDangerTable[Us][attackUnits]);
-    }
-  }
+    // Probe the pawn hash table
+    ei.pi = Pawns::probe(pos);
+    score += apply_weight(ei.pi->pawns_score(), Weights[PawnStructure]);

 
 

+    // Initialize attack and king safety bitboards
+    init_eval_info<WHITE>(pos, ei);
+    init_eval_info<BLACK>(pos, ei);

 
 

-  // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
+    ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING];
+    ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING];

 
 

-  template<Color Us>
-  void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+    // Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king
+    Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)),
+                                ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) };

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+    // Evaluate pieces and mobility
+    score += evaluate_pieces<KNIGHT, WHITE, Trace>(pos, ei, mobility, mobilityArea);
+    score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]);

 
 

-    Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
-    Bitboard b = ei.pi->passed_pawns(Us);
+    // Evaluate kings after all other pieces because we need complete attack
+    // information when computing the king safety evaluation.
+    score +=  evaluate_king<WHITE, Trace>(pos, ei)
+            - evaluate_king<BLACK, Trace>(pos, ei);

 
 

-    while (b)
-    {
-        Square s = pop_1st_bit(&b);
+    // Evaluate tactical threats, we need full attack information including king
+    score +=  evaluate_threats<WHITE, Trace>(pos, ei)
+            - evaluate_threats<BLACK, Trace>(pos, ei);

 
 

-        assert(pos.pawn_is_passed(Us, s));
+    // Evaluate passed pawns, we need full attack information including king
+    score +=  evaluate_passed_pawns<WHITE, Trace>(pos, ei)
+            - evaluate_passed_pawns<BLACK, Trace>(pos, ei);

 
 

-        int r = int(relative_rank(Us, s) - RANK_2);
-        int tr = r * (r - 1);
+    // If both sides have only pawns, score for potential unstoppable pawns
+    if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK))
+    {
+        Bitboard b;
+        if ((b = ei.pi->passed_pawns(WHITE)) != 0)
+            score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable;

 
 

-        // Base bonus based on rank
-        Value mbonus = Value(20 * tr);
-        Value ebonus = Value(10 + r * r * 10);
+        if ((b = ei.pi->passed_pawns(BLACK)) != 0)
+            score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable;
+    }

 
 

-        if (tr)
-        {
-            Square blockSq = s + pawn_push(Us);
+    // Evaluate space for both sides, only during opening
+    if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
+    {
+        Score s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
+        score += apply_weight(s, Weights[Space]);
+    }

 
 

-            // Adjust bonus based on kings proximity
-            ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * tr);
-            ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * 1 * tr);
-            ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * tr);
+    // Scale winning side if position is more drawish than it appears
+    Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK;
+    ScaleFactor sf = ei.mi->scale_factor(pos, strongSide);

 
 

-            // If the pawn is free to advance, increase bonus
-            if (pos.square_is_empty(blockSq))
-            {
-                squaresToQueen = squares_in_front_of(Us, s);
-                defendedSquares = squaresToQueen & ei.attacked_by(Us);
-
-                // 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
-                // the squares in the pawn's path attacked or occupied by the enemy.
-                if (   (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
-                    && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
-                    unsafeSquares = squaresToQueen;
-                else
-                    unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
-
-                // If there aren't enemy attacks or pieces along the path to queen give
-                // huge bonus. Even bigger if we protect the pawn's path.
-                if (!unsafeSquares)
-                    ebonus += Value(tr * (squaresToQueen == defendedSquares ? 17 : 15));
-                else
-                    // OK, there are enemy attacks or pieces (but not pawns). Are those
-                    // squares which are attacked by the enemy also attacked by us ?
-                    // If yes, big bonus (but smaller than when there are no enemy attacks),
-                    // if no, somewhat smaller bonus.
-                    ebonus += Value(tr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
-
-                // At last, add a small bonus when there are no *friendly* pieces
-                // in the pawn's path.
-                if (!(squaresToQueen & pos.pieces_of_color(Us)))
-                    ebonus += Value(tr);
-            }
-        } // tr != 0
-
-        // Increase the bonus if the passed pawn is supported by a friendly pawn
-        // on the same rank and a bit smaller if it's on the previous rank.
-        supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
-        if (supportingPawns & rank_bb(s))
-            ebonus += Value(r * 20);
-        else if (supportingPawns & rank_bb(s - pawn_push(Us)))
-            ebonus += Value(r * 12);
-
-        // Rook pawns are a special case: They are sometimes worse, and
-        // sometimes better than other passed pawns. It is difficult to find
-        // good rules for determining whether they are good or bad. For now,
-        // we try the following: Increase the value for rook pawns if the
-        // other side has no pieces apart from a knight, and decrease the
-        // value if the other side has a rook or queen.
-        if (square_file(s) == FILE_A || square_file(s) == FILE_H)
+    // If we don't already have an unusual scale factor, check for certain
+    // types of endgames, and use a lower scale for those.
+    if (    ei.mi->game_phase() < PHASE_MIDGAME
+        && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
+    {
+        if (pos.opposite_bishops())

         {
         {

-            if (pos.non_pawn_material(Them) <= KnightValueMidgame)
-                ebonus += ebonus / 4;
-            else if (pos.pieces(ROOK, QUEEN, Them))
-                ebonus -= ebonus / 4;
+            // Endgame with opposite-colored bishops and no other pieces (ignoring pawns)
+            // is almost a draw, in case of KBP vs KB is even more a draw.
+            if (   pos.non_pawn_material(WHITE) == BishopValueMg
+                && pos.non_pawn_material(BLACK) == BishopValueMg)
+                sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8);
+
+            // Endgame with opposite-colored bishops, but also other pieces. Still
+            // a bit drawish, but not as drawish as with only the two bishops.
+            else
+                 sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);

         }
         }

+        // Endings where weaker side can place his king in front of the opponent's
+        // pawns are drawish.
+        else if (    abs(eg_value(score)) <= BishopValueEg
+                 &&  ei.pi->pawn_span(strongSide) <= 1
+                 && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide)))
+                 sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(56) : ScaleFactor(38);
+    }
+
+    // Interpolate between a middlegame and a (scaled by 'sf') endgame score
+    Value v =  mg_value(score) * int(ei.mi->game_phase())
+             + eg_value(score) * int(PHASE_MIDGAME - ei.mi->game_phase()) * sf / SCALE_FACTOR_NORMAL;

 
 

-        // Add the scores for this pawn to the middle game and endgame eval
-        ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), Weights[PassedPawns]);
+    v /= int(PHASE_MIDGAME);
+
+    // In case of tracing add all single evaluation contributions for both white and black
+    if (Trace)
+    {
+        Tracing::write(Tracing::MATERIAL, pos.psq_score());
+        Tracing::write(Tracing::IMBALANCE, ei.mi->imbalance());
+        Tracing::write(PAWN, ei.pi->pawns_score());
+        Tracing::write(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
+                                        , apply_weight(mobility[BLACK], Weights[Mobility]));
+        Tracing::write(Tracing::SPACE, apply_weight(evaluate_space<WHITE>(pos, ei), Weights[Space])
+                                     , apply_weight(evaluate_space<BLACK>(pos, ei), Weights[Space]));
+        Tracing::write(Tracing::TOTAL, score);
+        Tracing::ei = ei;
+        Tracing::sf = sf;
+    }

 
 

-    } // while
+    return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo;

   }
 
 
   }
 
 

-  // evaluate_space() computes the space evaluation for a given side. The
-  // space evaluation is a simple bonus based on the number of safe squares
-  // available for minor pieces on the central four files on ranks 2--4. Safe
-  // squares one, two or three squares behind a friendly pawn are counted
-  // twice. Finally, the space bonus is scaled by a weight taken from the
-  // material hash table.
-  template<Color Us, bool HasPopCnt>
-  int evaluate_space(const Position& pos, EvalInfo& ei) {
+  // Tracing function definitions

 
 

-    const Color Them = (Us == WHITE ? BLACK : WHITE);
+  double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; }

 
 

-    // Find the safe squares for our pieces inside the area defined by
-    // SpaceMask[us]. A square is unsafe if it is attacked by an enemy
-    // pawn, or if it is undefended and attacked by an enemy piece.
-    Bitboard safe =   SpaceMask[Us]
-                   & ~pos.pieces(PAWN, Us)
-                   & ~ei.attacked_by(Them, PAWN)
-                   & (ei.attacked_by(Us) | ~ei.attacked_by(Them));
+  void Tracing::write(int idx, Color c, Score s) { scores[c][idx] = s; }

 
 

-    // Find all squares which are at most three squares behind some friendly pawn
-    Bitboard behind = pos.pieces(PAWN, Us);
-    behind |= (Us == WHITE ? behind >>  8 : behind <<  8);
-    behind |= (Us == WHITE ? behind >> 16 : behind << 16);
+  void Tracing::write(int idx, Score w, Score b) {

 
 

-    return count_1s_max_15<HasPopCnt>(safe) + count_1s_max_15<HasPopCnt>(behind & safe);
+    write(idx, WHITE, w);
+    write(idx, BLACK, b);

   }
 
   }
 

+  void Tracing::print(std::stringstream& ss, const char* name, int idx) {
+
+    Score wScore = scores[WHITE][idx];
+    Score bScore = scores[BLACK][idx];
+
+    switch (idx) {
+    case MATERIAL: case IMBALANCE: case PAWN: case TOTAL:
+        ss << std::setw(15) << name << " |   ---   --- |   ---   --- | "
+           << std::setw(5)  << to_cp(mg_value(wScore - bScore)) << " "
+           << std::setw(5)  << to_cp(eg_value(wScore - bScore)) << " \n";
+        break;
+    default:
+        ss << std::setw(15) << name << " | " << std::noshowpos
+           << std::setw(5)  << to_cp(mg_value(wScore)) << " "
+           << std::setw(5)  << to_cp(eg_value(wScore)) << " | "
+           << std::setw(5)  << to_cp(mg_value(bScore)) << " "
+           << std::setw(5)  << to_cp(eg_value(bScore)) << " | "
+           << std::setw(5)  << to_cp(mg_value(wScore - bScore)) << " "
+           << std::setw(5)  << to_cp(eg_value(wScore - bScore)) << " \n";
+    }
+  }

 
 

-  // apply_weight() applies an evaluation weight to a value trying to prevent overflow
+  std::string Tracing::do_trace(const Position& pos) {

 
 

-  inline Score apply_weight(Score v, Score w) {
-      return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, (int(eg_value(v)) * eg_value(w)) / 0x100);
-  }
+    std::memset(scores, 0, sizeof(scores));

 
 

+    Value v = do_evaluate<true>(pos);
+    v = pos.side_to_move() == WHITE ? v : -v; // White's point of view

 
 

-  // scale_by_game_phase() interpolates between a middle game and an endgame score,
-  // based on game phase. It also scales the return value by a ScaleFactor array.
+    std::stringstream ss;
+    ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2)
+       << "      Eval term |    White    |    Black    |    Total    \n"
+       << "                |   MG    EG  |   MG    EG  |   MG    EG  \n"
+       << "----------------+-------------+-------------+-------------\n";

 
 

-  Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) {
+    print(ss, "Material", MATERIAL);
+    print(ss, "Imbalance", IMBALANCE);
+    print(ss, "Pawns", PAWN);
+    print(ss, "Knights", KNIGHT);
+    print(ss, "Bishops", BISHOP);
+    print(ss, "Rooks", ROOK);
+    print(ss, "Queens", QUEEN);
+    print(ss, "Mobility", MOBILITY);
+    print(ss, "King safety", KING);
+    print(ss, "Threats", THREAT);
+    print(ss, "Passed pawns", PASSED);
+    print(ss, "Space", SPACE);

 
 

-    assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
-    assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
-    assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
+    ss << "----------------+-------------+-------------+-------------\n";
+    print(ss, "Total", TOTAL);

 
 

-    Value eg = eg_value(v);
-    ScaleFactor f = sf[eg > VALUE_ZERO ? WHITE : BLACK];
-    Value ev = Value((eg * int(f)) / SCALE_FACTOR_NORMAL);
+    ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n";

 
 

-    int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
-    return Value(result & ~(GrainSize - 1));
+    return ss.str();

   }
 
   }
 

+} // namespace

 
 

-  // weight_option() computes the value of an evaluation weight, by combining
-  // two UCI-configurable weights (midgame and endgame) with an internal weight.

 
 

-  Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
+namespace Eval {

 
 

-    // Scale option value from 100 to 256
-    int mg = get_option_value_int(mgOpt) * 256 / 100;
-    int eg = get_option_value_int(egOpt) * 256 / 100;
+  /// evaluate() is the main evaluation function. It returns a static evaluation
+  /// of the position always from the point of view of the side to move.

 
 

-    return apply_weight(make_score(mg, eg), internalWeight);
+  Value evaluate(const Position& pos) {
+    return do_evaluate<false>(pos);

   }
 
   }
 

-  // init_safety() initizes the king safety evaluation, based on UCI
-  // parameters. It is called from read_weights().

 
 

-  void init_safety() {
+  /// trace() is like evaluate(), but instead of returning a value, it returns
+  /// a string (suitable for outputting to stdout) that contains the detailed
+  /// descriptions and values of each evaluation term. It's mainly used for
+  /// debugging.
+  std::string trace(const Position& pos) {
+    return Tracing::do_trace(pos);
+  }

 
 

-    const Value MaxSlope = Value(30);
-    const Value Peak = Value(1280);
-    Value t[100];

 
 

-    // First setup the base table
-    for (int i = 0; i < 100; i++)
-    {
-        t[i] = Value(int(0.4 * i * i));
+  /// init() computes evaluation weights, usually at startup

 
 

-        if (i > 0)
-            t[i] = Min(t[i], t[i - 1] + MaxSlope);
+  void init() {

 
 

-        t[i] = Min(t[i], Peak);
-    }
+    const double MaxSlope = 8.5;
+    const double Peak = 1280;
+    double t = 0.0;

 
 

-    // Then apply the weights and get the final KingDangerTable[] array
-    for (Color c = WHITE; c <= BLACK; c++)
-        for (int i = 0; i < 100; i++)
-            KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
+    for (int i = 1; i < 400; ++i)
+    {
+        t = std::min(Peak, std::min(0.027 * i * i, t + MaxSlope));
+        KingDanger[i] = apply_weight(make_score(int(t), 0), Weights[KingSafety]);
+    }

   }
   }

-}
+
+} // namespace Eval