X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitboard.cpp;h=bb03dfebf289d3e099420a56528f2fc418654a81;hb=fbc7a328c67092799547f93e684323e2c1a6226e;hp=f66d971b675987f720d305e5d009193dbabfae25;hpb=b8efa0daac897e1b8f3efb9ca09ec4151492f1e0;p=stockfish

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index f66d971b..bb03dfeb 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, 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
@@ -28,19 +28,10 @@ uint8_t PopCnt16[1 << 16];
 uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
 Bitboard SquareBB[SQUARE_NB];
-Bitboard ForwardRanksBB[COLOR_NB][RANK_NB];
-Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
-Bitboard DistanceRingBB[SQUARE_NB][8];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
 
-Bitboard KingFlank[FILE_NB] = {
-  QueenSide ^ FileDBB, QueenSide, QueenSide,
-  CenterFiles, CenterFiles,
-  KingSide, KingSide, KingSide ^ FileEBB
-};
-
 Magic RookMagics[SQUARE_NB];
 Magic BishopMagics[SQUARE_NB];
 
@@ -85,28 +76,7 @@ void Bitboards::init() {
 
   for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
       for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
-          {
-              SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
-              DistanceRingBB[s1][SquareDistance[s1][s2]] |= s2;
-          }
-
-  int steps[][5] = { {}, { 7, 9 }, { 6, 10, 15, 17 }, {}, {}, {}, { 1, 7, 8, 9 } };
-
-  for (Color c = WHITE; c <= BLACK; ++c)
-      for (PieceType pt : { PAWN, KNIGHT, KING })
-          for (Square s = SQ_A1; s <= SQ_H8; ++s)
-              for (int i = 0; steps[pt][i]; ++i)
-              {
-                  Square to = s + Direction(c == WHITE ? steps[pt][i] : -steps[pt][i]);
-
-                  if (is_ok(to) && distance(s, to) < 3)
-                  {
-                      if (pt == PAWN)
-                          PawnAttacks[c][s] |= to;
-                      else
-                          PseudoAttacks[pt][s] |= to;
-                  }
-              }
+          SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
 
   Direction RookDirections[] = { NORTH, EAST, SOUTH, WEST };
   Direction BishopDirections[] = { NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST };
@@ -114,18 +84,31 @@ void Bitboards::init() {
   init_magics(RookTable, RookMagics, RookDirections);
   init_magics(BishopTable, BishopMagics, BishopDirections);
 
+  // Helper returning the target bitboard of a step from a square
+  auto landing_square_bb = [&](Square s, int step)
+  {
+      Square to = Square(s + step);
+      return is_ok(to) && distance(s, to) <= 2 ? square_bb(to) : Bitboard(0);
+  };
+
   for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
   {
+      PawnAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
+      PawnAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
+
+      for (int step : {-9, -8, -7, -1, 1, 7, 8, 9} )
+         PseudoAttacks[KING][s1] |= landing_square_bb(s1, step);
+
+      for (int step : {-17, -15, -10, -6, 6, 10, 15, 17} )
+         PseudoAttacks[KNIGHT][s1] |= landing_square_bb(s1, step);
+
       PseudoAttacks[QUEEN][s1]  = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
       PseudoAttacks[QUEEN][s1] |= PseudoAttacks[  ROOK][s1] = attacks_bb<  ROOK>(s1, 0);
 
       for (PieceType pt : { BISHOP, ROOK })
           for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
               if (PseudoAttacks[pt][s1] & s2)
-              {
                   LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
-                  BetweenBB[s1][s2] = attacks_bb(pt, s1, SquareBB[s2]) & attacks_bb(pt, s2, SquareBB[s1]);
-              }
   }
 }