Templetize sliding attacks

[stockfish] / src / bitboard.h

diff --git a/src/bitboard.h b/src/bitboard.h
index e6abd39fa8697a77f352d0e56674330790b5b2ad..7a39a5009c5571ccf0ef68b5d90792acc353de9b 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -23,15 +23,17 @@
 
 #include "types.h"
 
+CACHE_LINE_ALIGNMENT
+
 extern Bitboard RMasks[64];
 extern Bitboard RMagics[64];
 extern Bitboard* RAttacks[64];
-extern int RShifts[64];
+extern unsigned RShifts[64];
 
 extern Bitboard BMasks[64];
 extern Bitboard BMagics[64];
 extern Bitboard* BAttacks[64];
-extern int BShifts[64];
+extern unsigned BShifts[64];
 
 extern Bitboard SquareBB[64];
 extern Bitboard FileBB[8];
@@ -47,31 +49,19 @@ extern Bitboard AttackSpanMask[2][64];
 extern Bitboard PseudoAttacks[6][64];
 
 
-/// Functions for testing whether a given bit is set in a bitboard, and for
-/// setting and clearing bits.
+/// Overloads of bitwise operators between a Bitboard and a Square for testing
+/// whether a given bit is set in a bitboard, and for setting and clearing bits.
 
-inline Bitboard bit_is_set(Bitboard b, Square s) {
+inline Bitboard operator&(Bitboard b, Square s) {
   return b & SquareBB[s];
 }
 
-inline void set_bit(Bitboard* b, Square s) {
-  *b |= SquareBB[s];
+inline Bitboard& operator|=(Bitboard& b, Square s) {
+  return b |= SquareBB[s], b;
 }
 
-inline void xor_bit(Bitboard* b, Square s) {
-  *b ^= SquareBB[s];
-}
-
-
-/// Functions used to update a bitboard after a move. This is faster
-/// then calling a sequence of clear_bit() + set_bit()
-
-inline Bitboard make_move_bb(Square from, Square to) {
-  return SquareBB[from] | SquareBB[to];
-}
-
-inline void do_move_bb(Bitboard* b, Bitboard move_bb) {
-  *b ^= move_bb;
+inline Bitboard& operator^=(Bitboard& b, Square s) {
+  return b ^= SquareBB[s], b;
 }
 
 
@@ -126,41 +116,28 @@ inline Bitboard in_front_bb(Color c, Square s) {
 }
 
 
-/// Functions for computing sliding attack bitboards. rook_attacks_bb(),
-/// bishop_attacks_bb() and queen_attacks_bb() all take a square and a
-/// bitboard of occupied squares as input, and return a bitboard representing
-/// all squares attacked by a rook, bishop or queen on the given square.
+/// Functions for computing sliding attack bitboards. Function attacks_bb() takes
+/// a square and a bitboard of occupied squares as input, and returns a bitboard
+/// representing all squares attacked by Pt (bishop or rook) on the given square.
+template<PieceType Pt>
+FORCE_INLINE unsigned magic_index(Square s, Bitboard occ) {
 
-#if defined(IS_64BIT)
-
-FORCE_INLINE unsigned r_index(Square s, Bitboard occ) {
-  return unsigned(((occ & RMasks[s]) * RMagics[s]) >> RShifts[s]);
-}
+  Bitboard* const Masks  = Pt == ROOK ? RMasks  : BMasks;
+  Bitboard* const Magics = Pt == ROOK ? RMagics : BMagics;
+  unsigned* const Shifts = Pt == ROOK ? RShifts : BShifts;
 
-FORCE_INLINE unsigned b_index(Square s, Bitboard occ) {
-  return unsigned(((occ & BMasks[s]) * BMagics[s]) >> BShifts[s]);
-}
-
-#else // if !defined(IS_64BIT)
-
-FORCE_INLINE unsigned r_index(Square s, Bitboard occ) {
-  Bitboard b = occ & RMasks[s];
-  return unsigned(int(b) * int(RMagics[s]) ^ int(b >> 32) * int(RMagics[s] >> 32)) >> RShifts[s];
-}
-
-FORCE_INLINE unsigned b_index(Square s, Bitboard occ) {
-  Bitboard b = occ & BMasks[s];
-  return unsigned(int(b) * int(BMagics[s]) ^ int(b >> 32) * int(BMagics[s] >> 32)) >> BShifts[s];
-}
-
-#endif
+  if (Is64Bit)
+      return unsigned(((occ & Masks[s]) * Magics[s]) >> Shifts[s]);
 
-inline Bitboard rook_attacks_bb(Square s, Bitboard occ) {
-  return RAttacks[s][r_index(s, occ)];
+  unsigned lo = unsigned(occ) & unsigned(Masks[s]);
+  unsigned hi = unsigned(occ >> 32) & unsigned(Masks[s] >> 32);
+  return (lo * unsigned(Magics[s]) ^ hi * unsigned(Magics[s] >> 32)) >> Shifts[s];
 }
 
-inline Bitboard bishop_attacks_bb(Square s, Bitboard occ) {
-  return BAttacks[s][b_index(s, occ)];
+template<PieceType Pt>
+inline Bitboard attacks_bb(Square s, Bitboard occ) {
+  Bitboard** const Attacks = Pt == ROOK ? RAttacks : BAttacks;
+  return Attacks[s][magic_index<Pt>(s, occ)];
 }
 
 
@@ -217,8 +194,8 @@ inline bool squares_aligned(Square s1, Square s2, Square s3) {
 /// the same color of the given square.
 
 inline Bitboard same_color_squares(Square s) {
-  return bit_is_set(0xAA55AA55AA55AA55ULL, s) ?  0xAA55AA55AA55AA55ULL
-                                              : ~0xAA55AA55AA55AA55ULL;
+  return Bitboard(0xAA55AA55AA55AA55ULL) & s ?  0xAA55AA55AA55AA55ULL
+                                             : ~0xAA55AA55AA55AA55ULL;
 }