Simplify endgame functions handling

[stockfish] / src / bitboard.h

diff --git a/src/bitboard.h b/src/bitboard.h
index 54ed50538a2d3b960a37f48eb65a73ffca4e7ea3..0064fb26d83bf42decc3db7d9eb3102b47e4ce8a 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -22,37 +22,6 @@
 #if !defined(BITBOARD_H_INCLUDED)
 #define BITBOARD_H_INCLUDED
 
-////
-//// Defines
-////
-
-// Comment following define if you prefer manually adjust
-// platform macros defined below
-#define AUTO_CONFIGURATION
-
-// Quiet a warning on Intel compiler
-#if !defined(__SIZEOF_INT__ )
-#define __SIZEOF_INT__ 0
-#endif
-
-// Check for 64 bits for different compilers: Intel, MSVC and gcc
-#if defined(__x86_64) || defined(_WIN64) || (__SIZEOF_INT__ > 4)
-#define IS_64BIT
-#endif
-
-#if !defined(AUTO_CONFIGURATION) || defined(IS_64BIT)
-
-//#define USE_COMPACT_ROOK_ATTACKS
-//#define USE_32BIT_ATTACKS
-#define USE_FOLDED_BITSCAN
-
-#else
-
-#define USE_32BIT_ATTACKS
-#define USE_FOLDED_BITSCAN
-
-#endif
-
 ////
 //// Includes
 ////
@@ -63,13 +32,6 @@
 #include "types.h"
 
 
-////
-//// Types
-////
-
-typedef uint64_t Bitboard;
-
-
 ////
 //// Constants and variables
 ////
@@ -154,20 +116,12 @@ extern Bitboard BetweenBB[64][64];
 extern Bitboard PassedPawnMask[2][64];
 extern Bitboard OutpostMask[2][64];
 
-#if defined(USE_COMPACT_ROOK_ATTACKS)
-
-extern Bitboard RankAttacks[8][64], FileAttacks[8][64];
-
-#else
-
 extern const uint64_t RMult[64];
 extern const int RShift[64];
 extern Bitboard RMask[64];
 extern int RAttackIndex[64];
 extern Bitboard RAttacks[0x19000];
 
-#endif // defined(USE_COMPACT_ROOK_ATTACKS)
-
 extern const uint64_t BMult[64];
 extern const int BShift[64];
 extern Bitboard BMask[64];
@@ -303,29 +257,24 @@ inline Bitboard ray_bb(Square s, SignedDirection d) {
 }
 
 
-/// Functions for computing sliding attack bitboards.  rook_attacks_bb(),
+/// 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.
 
-#if defined(USE_COMPACT_ROOK_ATTACKS)
+#if defined(IS_64BIT)
 
-inline Bitboard file_attacks_bb(Square s, Bitboard blockers) {
-  Bitboard b = (blockers >> square_file(s)) & 0x01010101010100ULL;
-  return
-    FileAttacks[square_rank(s)][(b*0xd6e8802041d0c441ULL)>>58] & file_bb(s);
-}
-
-inline Bitboard rank_attacks_bb(Square s, Bitboard blockers) {
-  Bitboard b = (blockers >> ((s & 56) + 1)) & 63;
-  return RankAttacks[square_file(s)][b] & rank_bb(s);
+inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
+  Bitboard b = blockers & RMask[s];
+  return RAttacks[RAttackIndex[s] + ((b * RMult[s]) >> RShift[s])];
 }
 
-inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
-  return file_attacks_bb(s, blockers) | rank_attacks_bb(s, blockers);
+inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
+  Bitboard b = blockers & BMask[s];
+  return BAttacks[BAttackIndex[s] + ((b * BMult[s]) >> BShift[s])];
 }
 
-#elif defined(USE_32BIT_ATTACKS)
+#else // if !defined(IS_64BIT)
 
 inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
   Bitboard b = blockers & RMask[s];
@@ -335,17 +284,6 @@ inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
                    >> RShift[s])];
 }
 
-#else
-
-inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
-  Bitboard b = blockers & RMask[s];
-  return RAttacks[RAttackIndex[s] + ((b * RMult[s]) >> RShift[s])];
-}
-
-#endif
-
-#if defined(USE_32BIT_ATTACKS)
-
 inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
   Bitboard b = blockers & BMask[s];
   return BAttacks[BAttackIndex[s] +
@@ -354,14 +292,7 @@ inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
                    >> BShift[s])];
 }
 
-#else // defined(USE_32BIT_ATTACKS)
-
-inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
-  Bitboard b = blockers & BMask[s];
-  return BAttacks[BAttackIndex[s] + ((b * BMult[s]) >> BShift[s])];
-}
-
-#endif // defined(USE_32BIT_ATTACKS)
+#endif
 
 inline Bitboard queen_attacks_bb(Square s, Bitboard blockers) {
   return rook_attacks_bb(s, blockers) | bishop_attacks_bb(s, blockers);
@@ -423,14 +354,38 @@ inline Bitboard isolated_pawn_mask(Square s) {
 }
 
 
+/// first_1() finds the least significant nonzero bit in a nonzero bitboard.
+/// pop_1st_bit() finds and clears the least significant nonzero bit in a
+/// nonzero bitboard.
+
+#if defined(USE_BSFQ) // Assembly code by Heinz van Saanen
+
+inline Square __attribute__((always_inline)) first_1(Bitboard b) {
+  Bitboard dummy;
+  __asm__("bsfq %1, %0": "=r"(dummy): "rm"(b) );
+  return (Square)(dummy);
+}
+
+inline Square __attribute__((always_inline)) pop_1st_bit(Bitboard* b) {
+  const Square s = first_1(*b);
+  *b &= ~(1ULL<<s);
+  return s;
+}
+
+#else // if !defined(USE_BSFQ)
+
+extern Square first_1(Bitboard b);
+extern Square pop_1st_bit(Bitboard* b);
+
+#endif
+
+
 ////
 //// Prototypes
 ////
 
 extern void print_bitboard(Bitboard b);
 extern void init_bitboards();
-extern Square first_1(Bitboard b);
-extern Square pop_1st_bit(Bitboard *b);
 
 
 #endif // !defined(BITBOARD_H_INCLUDED)