X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitboard.cpp;h=45d5150408751a078be90973559d79cfbe1b40ba;hb=09bef14c76e119103cc1a9404cbde7e249205deb;hp=d90201d3e10aebb5edb76fe295402ab9edff5fdd;hpb=2bceba7f5162198834ca9f3dca0258e7eac1f797;p=stockfish

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index d90201d3..45d51504 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
@@ -19,6 +19,7 @@
 */
 
 #include <algorithm>
+#include <bitset>
 
 #include "bitboard.h"
 #include "misc.h"
@@ -27,19 +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];
 
@@ -49,14 +41,6 @@ namespace {
   Bitboard BishopTable[0x1480]; // To store bishop attacks
 
   void init_magics(Bitboard table[], Magic magics[], Direction directions[]);
-
-  // popcount16() counts the non-zero bits using SWAR-Popcount algorithm
-  unsigned popcount16(unsigned u) {
-    u -= (u >> 1) & 0x5555U;
-    u = ((u >> 2) & 0x3333U) + (u & 0x3333U);
-    u = ((u >> 4) + u) & 0x0F0FU;
-    return (u * 0x0101U) >> 8;
-  }
 }
 
 
@@ -85,21 +69,18 @@ const std::string Bitboards::pretty(Bitboard b) {
 void Bitboards::init() {
 
   for (unsigned i = 0; i < (1 << 16); ++i)
-      PopCnt16[i] = (uint8_t)popcount16(i);
+      PopCnt16[i] = std::bitset<16>(i).count();
 
   for (Square s = SQ_A1; s <= SQ_H8; ++s)
       SquareBB[s] = (1ULL << s);
 
   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 (Color c : { WHITE, BLACK })
       for (PieceType pt : { PAWN, KNIGHT, KING })
           for (Square s = SQ_A1; s <= SQ_H8; ++s)
               for (int i = 0; steps[pt][i]; ++i)
@@ -129,10 +110,7 @@ void Bitboards::init() {
       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]);
-              }
   }
 }