Fixed a sliding attack bitboard bug in 32-bit mode

[stockfish] / src / bitboard.cpp

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 89065c49fe81eb11d0328e08b121cb0018c23f77..5c5211e565756d9572efc156991da9fc0ced76ab 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -1,13 +1,14 @@
 /*
-  Glaurung, a UCI chess playing engine.
-  Copyright (C) 2004-2008 Tord Romstad
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+  Copyright (C) 2008 Marco Costalba
 
-  Glaurung is free software: you can redistribute it and/or modify
+  Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
-  Glaurung is distributed in the hope that it will be useful,
+  Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
@@ -37,64 +38,6 @@
 #include "direction.h"
 
 
-////
-//// Constants and variables
-////
-
-const Bitboard SquaresByColorBB[2] = {BlackSquaresBB, WhiteSquaresBB};
-
-const Bitboard FileBB[8] = {
-  FileABB, FileBBB, FileCBB, FileDBB, FileEBB, FileFBB, FileGBB, FileHBB
-};
-
-const Bitboard NeighboringFilesBB[8] = {
-  FileBBB, FileABB|FileCBB, FileBBB|FileDBB, FileCBB|FileEBB,
-  FileDBB|FileFBB, FileEBB|FileGBB, FileFBB|FileHBB, FileGBB
-};
-
-const Bitboard ThisAndNeighboringFilesBB[8] = {
-  FileABB|FileBBB, FileABB|FileBBB|FileCBB,
-  FileBBB|FileCBB|FileDBB, FileCBB|FileDBB|FileEBB,
-  FileDBB|FileEBB|FileFBB, FileEBB|FileFBB|FileGBB,
-  FileFBB|FileGBB|FileHBB, FileGBB|FileHBB
-};
-
-const Bitboard RankBB[8] = {
-  Rank1BB, Rank2BB, Rank3BB, Rank4BB, Rank5BB, Rank6BB, Rank7BB, Rank8BB
-};
-
-const Bitboard RelativeRankBB[2][8] = {
-  {
-    Rank1BB, Rank2BB, Rank3BB, Rank4BB, Rank5BB, Rank6BB, Rank7BB, Rank8BB
-  },
-  {
-    Rank8BB, Rank7BB, Rank6BB, Rank5BB, Rank4BB, Rank3BB, Rank2BB, Rank1BB
-  }
-};
-
-const Bitboard InFrontBB[2][8] = {
-  {
-    Rank2BB | Rank3BB | Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
-    Rank3BB | Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
-    Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
-    Rank5BB | Rank6BB | Rank7BB | Rank8BB,
-    Rank6BB | Rank7BB | Rank8BB,
-    Rank7BB | Rank8BB,
-    Rank8BB,
-    EmptyBoardBB
-  },
-  {
-    EmptyBoardBB,
-    Rank1BB,
-    Rank2BB | Rank1BB,
-    Rank3BB | Rank2BB | Rank1BB,
-    Rank4BB | Rank3BB | Rank2BB | Rank1BB,
-    Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB,
-    Rank6BB | Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB,
-    Rank7BB | Rank6BB | Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB
-  }
-};
-
 #if defined(USE_COMPACT_ROOK_ATTACKS)
 
 Bitboard RankAttacks[8][64], FileAttacks[8][64];
@@ -249,8 +192,8 @@ Bitboard BMask[64];
 int BAttackIndex[64];
 Bitboard BAttacks[0x1480];
 
-Bitboard SetMaskBB[64];
-Bitboard ClearMaskBB[64];
+Bitboard SetMaskBB[65];
+Bitboard ClearMaskBB[65];
 
 Bitboard StepAttackBB[16][64];
 Bitboard RayBB[64][8];
@@ -269,6 +212,7 @@ Bitboard QueenPseudoAttacks[64];
 ////
 
 namespace {
+
   void init_masks();
   void init_ray_bitboards();
   void init_attacks();
@@ -432,6 +376,8 @@ namespace {
   // be necessary to touch any of them.
 
   void init_masks() {
+    SetMaskBB[SQ_NONE] = 0ULL;
+    ClearMaskBB[SQ_NONE] = ~SetMaskBB[SQ_NONE];
     for(Square s = SQ_A1; s <= SQ_H8; s++) {
       SetMaskBB[s] = (1ULL << s);
       ClearMaskBB[s] = ~SetMaskBB[s];
@@ -447,7 +393,7 @@ namespace {
 
   void init_ray_bitboards() {
     int d[8] = {1, -1, 16, -16, 17, -17, 15, -15};
-    for(int i = 0; i < 128; i = i + 9 & ~8) {
+    for(int i = 0; i < 128; i = (i + 9) & ~8) {
       for(int j = 0; j < 8; j++) {
         RayBB[(i&7)|((i>>4)<<3)][j] = EmptyBoardBB;
         for(int k = i + d[j]; (k & 0x88) == 0; k += d[j])
@@ -533,8 +479,15 @@ namespace {
     for(i = 0; i < 64; i++) {
       attackIndex[i] = index;
       mask[i] = sliding_attacks(i, 0ULL, 4, deltas, 1, 6, 1, 6);
+
+#if defined(USE_32BIT_ATTACKS)
+      j = (1 << (32 - shift[i]));
+#else
       j = (1 << (64 - shift[i]));
+#endif
+
       for(k = 0; k < j; k++) {
+
 #if defined(USE_32BIT_ATTACKS)
         b = index_to_bitboard(k, mask[i]);
         attacks[index +