Introduce distance() and unify some API

[stockfish] / src / bitboard.h

diff --git a/src/bitboard.h b/src/bitboard.h
index 888e96905469b1c907340a79beaca613d2b90c41..7c4a55f00f4a98b9d864b5c924d3a837951d476c 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -21,6 +21,8 @@
 #ifndef BITBOARD_H_INCLUDED
 #define BITBOARD_H_INCLUDED
 
+#include <string>
+
 #include "types.h"
 
 namespace Bitboards {
@@ -55,8 +57,6 @@ const Bitboard Rank6BB = Rank1BB << (8 * 5);
 const Bitboard Rank7BB = Rank1BB << (8 * 6);
 const Bitboard Rank8BB = Rank1BB << (8 * 7);
 
-CACHE_LINE_ALIGNMENT
-
 extern Bitboard RMasks[SQUARE_NB];
 extern Bitboard RMagics[SQUARE_NB];
 extern Bitboard* RAttacks[SQUARE_NB];
@@ -112,17 +112,12 @@ inline bool more_than_one(Bitboard b) {
   return b & (b - 1);
 }
 
-inline int square_distance(Square s1, Square s2) {
-  return SquareDistance[s1][s2];
-}
-
-inline int file_distance(Square s1, Square s2) {
-  return abs(file_of(s1) - file_of(s2));
-}
+template<typename T> inline int distance(T x, T y) { return x < y ? y - x : x - y; }
+template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
 
-inline int rank_distance(Square s1, Square s2) {
-  return abs(rank_of(s1) - rank_of(s2));
-}
+template<typename T1, typename T2> inline int distance(T2 x, T2 y);
+template<> inline int distance<File>(Square x, Square y) { return distance(file_of(x), file_of(y)); }
+template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_of(x), rank_of(y)); }
 
 
 /// shift_bb() moves bitboard one step along direction Delta. Mainly for pawns.
@@ -130,9 +125,10 @@ inline int rank_distance(Square s1, Square s2) {
 template<Square Delta>
 inline Bitboard shift_bb(Bitboard b) {
 
-  return  Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
+  return  Delta == DELTA_N  ?  b             << 8 : Delta == DELTA_S  ?  b             >> 8
+        : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
         : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
-        : Delta > 0 ? b << Delta : b >> -Delta;
+        : 0;
 }