Assorted trivial cleanups (#1894)

To address https://github.com/official-stockfish/Stockfish/issues/1862

No functional change.

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 398c6bf77858a5bfb79635ba732a1952b54896bf..8079b783b6d004178a77644130f9340f2ee00758 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -184,8 +184,8 @@ namespace {
 
   // init_magics() computes all rook and bishop attacks at startup. Magic
   // bitboards are used to look up attacks of sliding pieces. As a reference see
-  // chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we
-  // use the so called "fancy" approach.
+  // www.chessprogramming.org/Magic_Bitboards. In particular, here we use the so
+  // called "fancy" approach.
 
   void init_magics(Bitboard table[], Magic magics[], Direction directions[]) {
 

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 66ee54d846044c90d03ec4dcaf9699e07aae13ee..835173c468b68bed46b7159dfafe5e32d74c9b0a 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -131,7 +131,7 @@ Value Endgame<KBNK>::operator()(const Position& pos) const {
   Square loserKSq = pos.square<KING>(weakSide);
   Square bishopSq = pos.square<BISHOP>(strongSide);
 
-  // If our Bishop does not attack A1/H8, we flip the enemy king square 
+  // If our Bishop does not attack A1/H8, we flip the enemy king square
   // to drive to opposite corners (A8/H1).
 
   Value result =  VALUE_KNOWN_WIN
@@ -724,6 +724,9 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
 template<>
 ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
 
+  assert(verify_material(pos, strongSide, KnightValueMg, 1));
+  assert(verify_material(pos, weakSide, BishopValueMg, 0));
+
   Square pawnSq = pos.square<PAWN>(strongSide);
   Square bishopSq = pos.square<BISHOP>(weakSide);
   Square weakKingSq = pos.square<KING>(weakSide);

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 0a7d0af9ae5b68af2f2519870b3579de9368d2fb..725ea49ce05ba1d6981ca15f460afae8535169c0 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -213,7 +213,7 @@ namespace {
     // kingRing[color] are the squares adjacent to the king, plus (only for a
     // king on its first rank) the squares two ranks in front. For instance,
     // if black's king is on g8, kingRing[BLACK] is f8, h8, f7, g7, h7, f6, g6
-    // and h6. It is set to 0 when king safety evaluation is skipped.
+    // and h6.
     Bitboard kingRing[COLOR_NB];
 
     // kingAttackersCount[color] is the number of pieces of the given color
@@ -505,7 +505,7 @@ namespace {
     Score score = SCORE_ZERO;
 
     // Non-pawn enemies
-    nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(Them, PAWN);
+    nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(PAWN);
 
     // Squares strongly protected by the enemy, either because they defend the
     // square with a pawn, or because they defend the square twice and we don't.
@@ -717,8 +717,8 @@ namespace {
     behind |= (Us == WHITE ? behind >> 16 : behind << 16);
 
     int bonus = popcount(safe) + popcount(behind & safe);
-    int weight = pos.count<ALL_PIECES>(Us)
-               - 2 * popcount(pe->semiopenFiles[WHITE] & pe->semiopenFiles[BLACK]);
+    int weight =  pos.count<ALL_PIECES>(Us)
+                - 2 * popcount(pe->semiopenFiles[WHITE] & pe->semiopenFiles[BLACK]);
 
     Score score = make_score(bonus * weight * weight / 16, 0);
 

diff --git a/src/movegen.cpp b/src/movegen.cpp
index e7678979f42450029c78d70cb0afe0d01358139e..c3cff08dab598b98872f2faf3785e271018ebd9d 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -28,6 +28,7 @@ namespace {
   template<Color Us, CastlingSide Cs, bool Checks, bool Chess960>
   ExtMove* generate_castling(const Position& pos, ExtMove* moveList) {
 
+    constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
     constexpr CastlingRight Cr = Us | Cs;
     constexpr bool KingSide = (Cs == KING_SIDE);
 
@@ -39,7 +40,7 @@ namespace {
     Square kfrom = pos.square<KING>(Us);
     Square rfrom = pos.castling_rook_square(Cr);
     Square kto = relative_square(Us, KingSide ? SQ_G1 : SQ_C1);
-    Bitboard enemies = pos.pieces(~Us);
+    Bitboard enemies = pos.pieces(Them);
 
     assert(!pos.checkers());
 
@@ -53,7 +54,7 @@ namespace {
     // Because we generate only legal castling moves we need to verify that
     // when moving the castling rook we do not discover some hidden checker.
     // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
-    if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~Us, ROOK, QUEEN)))
+    if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(Them, ROOK, QUEEN)))
         return moveList;
 
     Move m = make<CASTLING>(kfrom, rfrom);
@@ -93,8 +94,7 @@ namespace {
   template<Color Us, GenType Type>
   ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
 
-    // Compute our parametrized parameters at compile time, named according to
-    // the point of view of white side.
+    // Compute some compile time parameters relative to the white side
     constexpr Color     Them     = (Us == WHITE ? BLACK      : WHITE);
     constexpr Bitboard  TRank7BB = (Us == WHITE ? Rank7BB    : Rank2BB);
     constexpr Bitboard  TRank3BB = (Us == WHITE ? Rank3BB    : Rank6BB);

diff --git a/src/movepick.h b/src/movepick.h
index 7a55e21c63cb8e38b1ccb187dc463ba5c85cdebb..d9ecba99d8e3043f47c7c7981b69d37de9b386dc 100644 (file)
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -85,11 +85,11 @@ enum StatsParams { NOT_USED = 0 };
 /// ButterflyHistory records how often quiet moves have been successful or
 /// unsuccessful during the current search, and is used for reduction and move
 /// ordering decisions. It uses 2 tables (one for each color) indexed by
-/// the move's from and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
+/// the move's from and to squares, see www.chessprogramming.org/Butterfly_Boards
 typedef Stats<int16_t, 10692, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
 
 /// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
-/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
+/// move, see www.chessprogramming.org/Countermove_Heuristic
 typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
 
 /// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]

diff --git a/src/pawns.cpp b/src/pawns.cpp
index a9fc92b25b937b51ca429764a3d30660049db143..c581c8e72e90fa7ef4ac64408b1fa56405b1d21b 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -115,7 +115,7 @@ namespace {
         // not attacked more times than defended.
         if (   !(stoppers ^ lever ^ leverPush)
             && popcount(support) >= popcount(lever) - 1
-            && popcount(phalanx)   >= popcount(leverPush))
+            && popcount(phalanx) >= popcount(leverPush))
             e->passedPawns[Us] |= s;
 
         else if (   stoppers == SquareBB[s + Up]

diff --git a/src/position.cpp b/src/position.cpp
index bd5daa6dcb0268be338f753750cdb945ecdc0faf..0396eb9f5b9e09244952ad52d40c473f1d88e523 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -183,7 +183,7 @@ void Position::init() {
                   {
                       std::swap(cuckoo[i], key);
                       std::swap(cuckooMove[i], move);
-                      if (move == 0)   // Arrived at empty slot ?
+                      if (move == MOVE_NONE) // Arrived at empty slot?
                           break;
                       i = (i == H1(key)) ? H2(key) : H1(key); // Push victim to alternative slot
                   }
@@ -465,16 +465,16 @@ const string Position::fen() const {
   ss << (sideToMove == WHITE ? " w " : " b ");
 
   if (can_castle(WHITE_OO))
-      ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE |  KING_SIDE))) : 'K');
+      ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE_OO ))) : 'K');
 
   if (can_castle(WHITE_OOO))
-      ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE | QUEEN_SIDE))) : 'Q');
+      ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE_OOO))) : 'Q');
 
   if (can_castle(BLACK_OO))
-      ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK |  KING_SIDE))) : 'k');
+      ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK_OO ))) : 'k');
 
   if (can_castle(BLACK_OOO))
-      ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK | QUEEN_SIDE))) : 'q');
+      ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK_OOO))) : 'q');
 
   if (!can_castle(ANY_CASTLING))
       ss << '-';

diff --git a/src/psqt.cpp b/src/psqt.cpp
index a4a5e0a04dc60ef50840da1ec80ebb23e9908cb5..bc3e53928cb25faa6874acaf6f3cebb8845ad9df 100644 (file)
--- a/src/psqt.cpp
+++ b/src/psqt.cpp
@@ -90,15 +90,15 @@ constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
   }
 };
 
-constexpr Score PBonus[RANK_NB][FILE_NB] =\r
-  { // Pawn\r
-   { S(  0,  0), S(  0,  0), S(  0,  0), S(  0,  0), S(  0,  0), S(  0,  0), S(  0,  0), S(  0,  0) },\r
-   { S(  0,-11), S( -3, -4), S( 13, -1), S( 19, -4), S( 16, 17), S( 13,  7), S(  4,  4), S( -4,-13) },\r
-   { S(-16, -8), S(-12, -6), S( 20, -3), S( 21,  0), S( 25,-11), S( 29,  3), S(  0,  0), S(-27, -1) },\r
-   { S(-11,  3), S(-17,  6), S( 11,-10), S( 21,  1), S( 32, -6), S( 19,-11), S( -5,  0), S(-14, -2) },\r
-   { S(  4, 13), S(  6,  7), S( -8,  3), S(  3, -5), S(  8,-15), S( -2, -1), S(-19,  9), S( -5, 13) },\r
-   { S( -5, 25), S(-19, 20), S(  7, 16), S(  8, 12), S( -7, 21), S( -2,  3), S(-10, -4), S(-16, 15) },\r
-   { S(-10,  6), S(  9, -5), S( -7, 16), S(-12, 27), S( -7, 15), S( -8, 11), S( 16, -7), S( -8,  4) }\r
+constexpr Score PBonus[RANK_NB][FILE_NB] =
+  { // Pawn (asymmetric distribution)
+   { },
+   { S(  0,-11), S( -3,-4), S(13, -1), S( 19, -4), S(16, 17), S(13,  7), S(  4,  4), S( -4,-13) },
+   { S(-16, -8), S(-12,-6), S(20, -3), S( 21,  0), S(25,-11), S(29,  3), S(  0,  0), S(-27, -1) },
+   { S(-11,  3), S(-17, 6), S(11,-10), S( 21,  1), S(32, -6), S(19,-11), S( -5,  0), S(-14, -2) },
+   { S(  4, 13), S(  6, 7), S(-8,  3), S(  3, -5), S( 8,-15), S(-2, -1), S(-19,  9), S( -5, 13) },
+   { S( -5, 25), S(-19,20), S( 7, 16), S(  8, 12), S(-7, 21), S(-2,  3), S(-10, -4), S(-16, 15) },
+   { S(-10,  6), S(  9,-5), S(-7, 16), S(-12, 27), S(-7, 15), S(-8, 11), S( 16, -7), S( -8,  4) }
   };
 
 #undef S

diff --git a/src/search.cpp b/src/search.cpp
index 4a541c5b90697137371c47cfb53662d066472e27..fe9b446e42d61b15b98212b3d05fa237e0701543 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -113,8 +113,8 @@ namespace {
   Value value_from_tt(Value v, int ply);
   void update_pv(Move* pv, Move move, Move* childPv);
   void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus);
-  void update_quiet_stats(const Position& pos, Stack* ss, Move move, Move* quiets, int quietsCnt, int bonus);
-  void update_capture_stats(const Position& pos, Move move, Move* captures, int captureCnt, int bonus);
+  void update_quiet_stats(const Position& pos, Stack* ss, Move move, Move* quiets, int quietCount, int bonus);
+  void update_capture_stats(const Position& pos, Move move, Move* captures, int captureCount, int bonus);
 
   inline bool gives_check(const Position& pos, Move move) {
     Color us = pos.side_to_move();
@@ -498,32 +498,32 @@ void Thread::search() {
       if (    Limits.use_time_management()
           && !Threads.stop
           && !Threads.stopOnPonderhit)
+      {
+          double fallingEval = (306 + 119 * failedLow + 6 * (mainThread->previousScore - bestValue)) / 581.0;
+          fallingEval        = std::max(0.5, std::min(1.5, fallingEval));
+
+          // If the bestMove is stable over several iterations, reduce time accordingly
+          timeReduction = 1.0;
+          for (int i : {3, 4, 5})
+              if (lastBestMoveDepth * i < completedDepth)
+                  timeReduction *= 1.25;
+
+          // Use part of the gained time from a previous stable move for the current move
+          double bestMoveInstability = 1.0 + mainThread->bestMoveChanges;
+          bestMoveInstability *= std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
+
+          // Stop the search if we have only one legal move, or if available time elapsed
+          if (   rootMoves.size() == 1
+              || Time.elapsed() > Time.optimum() * bestMoveInstability * fallingEval)
           {
-              double fallingEval = (306 + 119 * failedLow + 6 * (mainThread->previousScore - bestValue)) / 581.0;
-              fallingEval        = std::max(0.5, std::min(1.5, fallingEval));
-
-              // If the bestMove is stable over several iterations, reduce time accordingly
-              timeReduction = 1.0;
-              for (int i : {3, 4, 5})
-                  if (lastBestMoveDepth * i < completedDepth)
-                     timeReduction *= 1.25;
-
-              // Use part of the gained time from a previous stable move for the current move
-              double bestMoveInstability = 1.0 + mainThread->bestMoveChanges;
-              bestMoveInstability *= std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
-
-              // Stop the search if we have only one legal move, or if available time elapsed
-              if (   rootMoves.size() == 1
-                  || Time.elapsed() > Time.optimum() * bestMoveInstability * fallingEval)
-              {
-                  // If we are allowed to ponder do not stop the search now but
-                  // keep pondering until the GUI sends "ponderhit" or "stop".
-                  if (Threads.ponder)
-                      Threads.stopOnPonderhit = true;
-                  else
-                      Threads.stop = true;
-              }
+              // If we are allowed to ponder do not stop the search now but
+              // keep pondering until the GUI sends "ponderhit" or "stop".
+              if (Threads.ponder)
+                  Threads.stopOnPonderhit = true;
+              else
+                  Threads.stop = true;
           }
+      }
   }
 
   if (!mainThread)
@@ -1481,7 +1481,7 @@ moves_loop: // When in check, search starts from here
   // update_capture_stats() updates move sorting heuristics when a new capture best move is found
 
   void update_capture_stats(const Position& pos, Move move,
-                            Move* captures, int captureCnt, int bonus) {
+                            Move* captures, int captureCount, int bonus) {
 
       CapturePieceToHistory& captureHistory =  pos.this_thread()->captureHistory;
       Piece moved_piece = pos.moved_piece(move);
@@ -1491,7 +1491,7 @@ moves_loop: // When in check, search starts from here
           captureHistory[moved_piece][to_sq(move)][captured] << bonus;
 
       // Decrease all the other played capture moves
-      for (int i = 0; i < captureCnt; ++i)
+      for (int i = 0; i < captureCount; ++i)
       {
           moved_piece = pos.moved_piece(captures[i]);
           captured = type_of(pos.piece_on(to_sq(captures[i])));
@@ -1503,7 +1503,7 @@ moves_loop: // When in check, search starts from here
   // update_quiet_stats() updates move sorting heuristics when a new quiet best move is found
 
   void update_quiet_stats(const Position& pos, Stack* ss, Move move,
-                          Move* quiets, int quietsCnt, int bonus) {
+                          Move* quiets, int quietCount, int bonus) {
 
     if (ss->killers[0] != move)
     {
@@ -1523,7 +1523,7 @@ moves_loop: // When in check, search starts from here
     }
 
     // Decrease all the other played quiet moves
-    for (int i = 0; i < quietsCnt; ++i)
+    for (int i = 0; i < quietCount; ++i)
     {
         thisThread->mainHistory[us][from_to(quiets[i])] << -bonus;
         update_continuation_histories(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
@@ -1666,7 +1666,7 @@ bool RootMove::extract_ponder_from_tt(Position& pos) {
 
     assert(pv.size() == 1);
 
-    if (!pv[0])
+    if (pv[0] == MOVE_NONE)
         return false;
 
     pos.do_move(pv[0], st);

diff --git a/tests/perft.sh b/tests/perft.sh
index d4022211607a8617e3ddb6afe5da2c1a73088be2..545e750fec037142c82ae110b93583a32a906a24 100755 (executable)
--- a/tests/perft.sh
+++ b/tests/perft.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# verify perft numbers (positions from https://chessprogramming.wikispaces.com/Perft+Results)
+# verify perft numbers (positions from www.chessprogramming.org/Perft_Results)
 
 error()
 {