Speedup sliders attacks for 32bit CPU

[stockfish] / src / bitboard.h

diff --git a/src/bitboard.h b/src/bitboard.h
index e6abd39fa8697a77f352d0e56674330790b5b2ad..24ae794b68b0f4183087a882cb94ca1bd64cc29c 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 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 Bitboard& operator|=(Bitboard& b, Square s) {
+  return b |= SquareBB[s], b;
 }
 
-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;
 }
 
 
@@ -144,13 +134,15 @@ FORCE_INLINE unsigned b_index(Square s, Bitboard occ) {
 #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];
+  unsigned lo = unsigned(occ) & unsigned(RMasks[s]);
+  unsigned hi = unsigned(occ >> 32) & unsigned(RMasks[s] >> 32);
+  return (lo * unsigned(RMagics[s]) ^ hi * unsigned(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];
+  unsigned lo = unsigned(occ) & unsigned(BMasks[s]);
+  unsigned hi = unsigned(occ >> 32) & unsigned(BMasks[s] >> 32);
+  return (lo * unsigned(BMagics[s]) ^ hi * unsigned(BMagics[s] >> 32)) >> BShifts[s];
 }
 
 #endif
@@ -217,8 +209,8 @@ 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;
 }