X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=2adf27794209a4e89d175eca412453a2beda2f48;hp=d90201d3e10aebb5edb76fe295402ab9edff5fdd;hb=82ad9ce9cfb0eff33f1d781f329f7c5dc0b277eb;hpb=2bceba7f5162198834ca9f3dca0258e7eac1f797

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index d90201d3..2adf2779 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -18,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <bitset>
 #include <algorithm>
 
 #include "bitboard.h"
@@ -26,13 +27,12 @@
 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 SquareBB[SQUARE_NB];
 
 Bitboard KingFlank[FILE_NB] = {
   QueenSide ^ FileDBB, QueenSide, QueenSide,
@@ -49,14 +49,6 @@ 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;
-  }
 }
 
 
@@ -85,7 +77,7 @@ 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);
@@ -131,7 +123,7 @@ void Bitboards::init() {
               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]);
+                  BetweenBB[s1][s2] = attacks_bb(pt, s1, square_bb(s2)) & attacks_bb(pt, s2, square_bb(s1));
               }
   }
 }