X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=c4fc26e1eefb1787b35ebb6090d271e53404c53b;hp=2ad8773634dce967e6cc6b223e68eeb3d4d66f05;hb=2dd24dc4e618dc7b83799890fe7e84b09b6456b4;hpb=db4b0d8b7db8db15c16a71212990354094f00b0d

diff --git a/src/bitboard.h b/src/bitboard.h
index 2ad87736..c4fc26e1 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -61,16 +61,6 @@ const Bitboard Rank8BB = Rank1BB << (8 * 7);
 
 extern int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-extern Bitboard  RookMasks  [SQUARE_NB];
-extern Bitboard  RookMagics [SQUARE_NB];
-extern Bitboard* RookAttacks[SQUARE_NB];
-extern unsigned  RookShifts [SQUARE_NB];
-
-extern Bitboard  BishopMasks  [SQUARE_NB];
-extern Bitboard  BishopMagics [SQUARE_NB];
-extern Bitboard* BishopAttacks[SQUARE_NB];
-extern unsigned  BishopShifts [SQUARE_NB];
-
 extern Bitboard SquareBB[SQUARE_NB];
 extern Bitboard FileBB[FILE_NB];
 extern Bitboard RankBB[RANK_NB];
@@ -225,6 +215,13 @@ template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_
 template<PieceType Pt>
 inline unsigned magic_index(Square s, Bitboard occupied) {
 
+  extern Bitboard RookMasks[SQUARE_NB];
+  extern Bitboard RookMagics[SQUARE_NB];
+  extern unsigned RookShifts[SQUARE_NB];
+  extern Bitboard BishopMasks[SQUARE_NB];
+  extern Bitboard BishopMagics[SQUARE_NB];
+  extern unsigned BishopShifts[SQUARE_NB];
+
   Bitboard* const Masks  = Pt == ROOK ? RookMasks  : BishopMasks;
   Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics;
   unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts;
@@ -242,6 +239,10 @@ inline unsigned magic_index(Square s, Bitboard occupied) {
 
 template<PieceType Pt>
 inline Bitboard attacks_bb(Square s, Bitboard occupied) {
+
+  extern Bitboard* RookAttacks[SQUARE_NB];
+  extern Bitboard* BishopAttacks[SQUARE_NB];
+
   return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
 }
 
@@ -257,22 +258,57 @@ inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) {
 }
 
 
+/// popcount() counts the number of non-zero bits in a bitboard
+
+inline int popcount(Bitboard b) {
+
+#ifndef USE_POPCNT
+
+  extern uint8_t PopCnt16[1 << 16];
+  union { Bitboard bb; uint16_t u[4]; } v = { b };
+  return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];
+
+#elif defined(_MSC_VER) || defined(__INTEL_COMPILER)
+
+  return _mm_popcnt_u64(b);
+
+#elif defined(_MSC_VER)
+
+  return (int)__popcnt64(b);
+
+#else // Assumed gcc or compatible compiler
+
+  return __builtin_popcountll(b);
+
+#endif
+}
+
+
 /// lsb() and msb() return the least/most significant bit in a non-zero bitboard
 
 #if defined(__GNUC__)
 
-inline Square lsb(Bitboard b) { return Square(__builtin_ctzll(b)); }
-inline Square msb(Bitboard b) { return Square(63 - __builtin_clzll(b)); }
+inline Square lsb(Bitboard b) {
+  assert(b);
+  return Square(__builtin_ctzll(b));
+}
+
+inline Square msb(Bitboard b) {
+  assert(b);
+  return Square(63 - __builtin_clzll(b));
+}
 
 #elif defined(_WIN64) && defined(_MSC_VER)
 
 inline Square lsb(Bitboard b) {
+  assert(b);
   unsigned long idx;
   _BitScanForward64(&idx, b);
   return (Square) idx;
 }
 
 inline Square msb(Bitboard b) {
+  assert(b);
   unsigned long idx;
   _BitScanReverse64(&idx, b);
   return (Square) idx;