X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=1bae6843df5303d3d7379e335debd7c02946b898;hp=321055e826dba25609ab2ce00e0f5743080fcca7;hb=caef31921900e092616c56193e37201b08baa875;hpb=37fa8adc2b4aeba95c10531b9bb834b0fcb47c42

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 321055e8..1bae6843 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -45,7 +45,7 @@ Bitboard ThisAndAdjacentFilesBB[8];
 Bitboard InFrontBB[2][8];
 Bitboard StepAttacksBB[16][64];
 Bitboard BetweenBB[64][64];
-Bitboard SquaresInFrontMask[2][64];
+Bitboard ForwardBB[2][64];
 Bitboard PassedPawnMask[2][64];
 Bitboard AttackSpanMask[2][64];
 Bitboard PseudoAttacks[6][64];
@@ -92,33 +92,13 @@ Square first_1(Bitboard b) {
   return Square(BSFTable[(fold * 0x783A9B23) >> 26]);
 }
 
-// Use type-punning
-union b_union {
-
-    Bitboard dummy;
-    struct {
-#if defined (BIGENDIAN)
-        uint32_t h;
-        uint32_t l;
-#else
-        uint32_t l;
-        uint32_t h;
-#endif
-    } b;
-};
-
 Square pop_1st_bit(Bitboard* b) {
 
-   const b_union u = *((b_union*)b);
-
-   if (u.b.l)
-   {
-       ((b_union*)b)->b.l = u.b.l & (u.b.l - 1);
-       return Square(BSFTable[((u.b.l ^ (u.b.l - 1)) * 0x783A9B23) >> 26]);
-   }
-
-   ((b_union*)b)->b.h = u.b.h & (u.b.h - 1);
-   return Square(BSFTable[((~(u.b.h ^ (u.b.h - 1))) * 0x783A9B23) >> 26]);
+  Bitboard bb = *b;
+  *b = bb & (bb - 1);
+  bb ^= (bb - 1);
+  uint32_t fold = unsigned(bb) ^ unsigned(bb >> 32);
+  return Square(BSFTable[(fold * 0x783A9B23) >> 26]);
 }
 
 Square last_1(Bitboard b) {
@@ -188,30 +168,27 @@ void Bitboards::init() {
   FileBB[FILE_A] = FileABB;
   RankBB[RANK_1] = Rank1BB;
 
-  for (int f = FILE_B; f <= FILE_H; f++)
+  for (int i = 1; i < 8; i++)
   {
-      FileBB[f] = FileBB[f - 1] << 1;
-      RankBB[f] = RankBB[f - 1] << 8;
+      FileBB[i] = FileBB[i - 1] << 1;
+      RankBB[i] = RankBB[i - 1] << 8;
   }
 
-  for (int f = FILE_A; f <= FILE_H; f++)
+  for (File f = FILE_A; f <= FILE_H; f++)
   {
       AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
       ThisAndAdjacentFilesBB[f] = FileBB[f] | AdjacentFilesBB[f];
   }
 
-  for (int rw = RANK_7, rb = RANK_2; rw >= RANK_1; rw--, rb++)
-  {
-      InFrontBB[WHITE][rw] = InFrontBB[WHITE][rw + 1] | RankBB[rw + 1];
-      InFrontBB[BLACK][rb] = InFrontBB[BLACK][rb - 1] | RankBB[rb - 1];
-  }
+  for (Rank r = RANK_1; r < RANK_8; r++)
+      InFrontBB[WHITE][r] = ~(InFrontBB[BLACK][r + 1] = InFrontBB[BLACK][r] | RankBB[r]);
 
   for (Color c = WHITE; c <= BLACK; c++)
       for (Square s = SQ_A1; s <= SQ_H8; s++)
       {
-          SquaresInFrontMask[c][s] = in_front_bb(c, s) & file_bb(s);
-          PassedPawnMask[c][s]     = in_front_bb(c, s) & this_and_adjacent_files_bb(file_of(s));
-          AttackSpanMask[c][s]     = in_front_bb(c, s) & adjacent_files_bb(file_of(s));
+          ForwardBB[c][s]      = InFrontBB[c][rank_of(s)] & FileBB[file_of(s)];
+          PassedPawnMask[c][s] = InFrontBB[c][rank_of(s)] & ThisAndAdjacentFilesBB[file_of(s)];
+          AttackSpanMask[c][s] = InFrontBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
       }
 
   for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
@@ -251,9 +228,8 @@ void Bitboards::init() {
 
   for (Square s = SQ_A1; s <= SQ_H8; s++)
   {
-      PseudoAttacks[BISHOP][s] = attacks_bb<BISHOP>(s, 0);
-      PseudoAttacks[ROOK][s]   = attacks_bb<ROOK>(s, 0);
-      PseudoAttacks[QUEEN][s]  = PseudoAttacks[BISHOP][s] | PseudoAttacks[ROOK][s];
+      PseudoAttacks[QUEEN][s]  = PseudoAttacks[BISHOP][s] = attacks_bb<BISHOP>(s, 0);
+      PseudoAttacks[QUEEN][s] |= PseudoAttacks[  ROOK][s] = attacks_bb<  ROOK>(s, 0);
   }
 
   for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)