Speed up updateShelter()

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/bitboard.h

@@ -38,7 +38,7 @@
 
 const Bitboard EmptyBoardBB = 0;
 
-const Bitboard FileABB = 0x0101010101010101;
+const Bitboard FileABB = 0x0101010101010101ULL;
 const Bitboard FileBBB = FileABB << 1;
 const Bitboard FileCBB = FileABB << 2;
 const Bitboard FileDBB = FileABB << 3;

src/evaluate.cpp

@@ -677,7 +677,7 @@ namespace {
     const Square ksq = pos.king_square(Us);
 
     // King shelter
-    Score bonus = ei.pi->king_shelter(pos, Us, ksq);
+    Score bonus = ei.pi->king_shelter<Us>(pos, ksq);
 
     // King safety. This is quite complicated, and is almost certainly far
     // from optimally tuned.
@@ -701,7 +701,7 @@ namespace {
         attackUnits =  Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
                      + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
                      + InitKingDanger[relative_square(Us, ksq)]
-                     - mg_value(ei.pi->king_shelter(pos, Us, ksq)) / 32;
+                     - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
 
         // Analyse enemy's safe queen contact checks. First find undefended
         // squares around the king attacked by enemy queen...

src/pawns.cpp

@@ -320,27 +320,3 @@ int PawnInfoTable::evaluate_pawn_storm(Square s, Rank r, File f, Bitboard theirP
   }
   return bonus;
 }
-
-
-/// PawnInfo::updateShelter calculates and caches king shelter. It is called
-/// only when king square changes, about 20% of total king_shelter() calls.
-Score PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) {
-
-  Bitboard pawns;
-  unsigned r, k, shelter = 0;
-
-  if (relative_rank(c, ksq) <= RANK_4)
-  {
-      pawns = pos.pieces(PAWN, c) & this_and_neighboring_files_bb(ksq);
-      r = ksq & (7 << 3);
-      k = (c ? -8 : 8);
-      for (int i = 1; i < 4; i++)
-      {
-          r += k;
-          shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (128 >> i);
-      }
-  }
-  kingSquares[c] = ksq;
-  kingShelters[c] = make_score(shelter, 0);
-  return kingShelters[c];
-}

src/pawns.h

@@ -26,6 +26,7 @@
 ////
 
 #include "bitboard.h"
+#include "position.h"
 #include "value.h"
 
 ////
@@ -40,8 +41,6 @@ const int PawnTableSize = 16384;
 /// to add further information in the future. A lookup to the pawn hash table
 /// (performed by calling the get_pawn_info method in a PawnInfoTable object)
 /// returns a pointer to a PawnInfo object.
-class Position;
-
 class PawnInfo {
 
   friend class PawnInfoTable;
@@ -55,10 +54,13 @@ public:
   int file_is_half_open(Color c, File f) const;
   int has_open_file_to_left(Color c, File f) const;
   int has_open_file_to_right(Color c, File f) const;
-  Score king_shelter(const Position& pos, Color c, Square ksq);
+
+  template<Color Us>
+  Score king_shelter(const Position& pos, Square ksq);
 
 private:
-  Score updateShelter(const Position& pos, Color c, Square ksq);
+  template<Color Us>
+  Score updateShelter(const Position& pos, Square ksq);
 
   Key key;
   Bitboard passedPawns[2];
@@ -140,8 +142,34 @@ inline int PawnInfo::has_open_file_to_right(Color c, File f) const {
   return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
 }
 
-inline Score PawnInfo::king_shelter(const Position& pos, Color c, Square ksq) {
-  return kingSquares[c] == ksq ? kingShelters[c] : updateShelter(pos, c, ksq);
+/// PawnInfo::updateShelter() calculates and caches king shelter. It is called
+/// only when king square changes, about 20% of total king_shelter() calls.
+template<Color Us>
+Score PawnInfo::updateShelter(const Position& pos, Square ksq) {
+
+  const int Shift = (Us == WHITE ? 8 : -8);
+
+  Bitboard pawns;
+  int r, shelter = 0;
+
+  if (relative_rank(Us, ksq) <= RANK_4)
+  {
+      pawns = pos.pieces(PAWN, Us) & this_and_neighboring_files_bb(ksq);
+      r = square_rank(ksq) * 8;
+      for (int i = 1; i < 4; i++)
+      {
+          r += Shift;
+          shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (128 >> i);
+      }
+  }
+  kingSquares[Us] = ksq;
+  kingShelters[Us] = make_score(shelter, 0);
+  return kingShelters[Us];
+}
+
+template<Color Us>
+inline Score PawnInfo::king_shelter(const Position& pos, Square ksq) {
+  return kingSquares[Us] == ksq ? kingShelters[Us] : updateShelter<Us>(pos, ksq);
 }
 
 #endif // !defined(PAWNS_H_INCLUDED)