Introduce SimpleHash class

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 658a570079509e1aee2efad52bef96c887705e8f..0846344223137f93a2372c737b6a553609e8c5a4 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -81,27 +81,6 @@ namespace {
 //// Functions
 ////
 
-/// PawnInfoTable c'tor and d'tor instantiated one each thread
-
-PawnInfoTable::PawnInfoTable() {
-
-  entries = new PawnInfo[PawnTableSize];
-
-  if (!entries)
-  {
-      std::cerr << "Failed to allocate " << (PawnTableSize * sizeof(PawnInfo))
-                << " bytes for pawn hash table." << std::endl;
-      Application::exit_with_failure();
-  }
-  memset(entries, 0, PawnTableSize * sizeof(PawnInfo));
-}
-
-
-PawnInfoTable::~PawnInfoTable() {
-
-  delete [] entries;
-}
-
 
 /// PawnInfoTable::get_pawn_info() takes a position object as input, computes
 /// a PawnInfo object, and returns a pointer to it. The result is also stored
@@ -113,8 +92,7 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) const {
   assert(pos.is_ok());
 
   Key key = pos.get_pawn_key();
-  unsigned index = unsigned(key & (PawnTableSize - 1));
-  PawnInfo* pi = entries + index;
+  PawnInfo* pi = find(key);
 
   // If pi->key matches the position's pawn hash key, it means that we
   // have analysed this pawn structure before, and we can simply return
@@ -172,7 +150,7 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
       // Passed, isolated, doubled or member of a pawn
       // chain (but not the backward one) ?
       passed   = !(theirPawns & passed_pawn_mask(Us, s));
-      doubled  =   ourPawns   & squares_behind(Us, s);
+      doubled  =   ourPawns   & squares_in_front_of(Us, s);
       opposed  =   theirPawns & squares_in_front_of(Us, s);
       isolated = !(ourPawns   & neighboring_files_bb(f));
       chain    =   ourPawns   & neighboring_files_bb(f) & b;
@@ -212,15 +190,10 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
                  && (b = attack_span_mask(opposite_color(Us), s + pawn_push(Us)) & ourPawns) != EmptyBoardBB
                  &&  count_1s<Max15>(b) >= count_1s<Max15>(attack_span_mask(Us, s) & theirPawns);
 
-      // In order to prevent doubled passed pawns from receiving a too big
-      // bonus, only the frontmost passed pawn on each file is considered as
-      // a true passed pawn.
-      if (passed && (ourPawns & squares_in_front_of(Us, s)))
-          passed = false;
-
       // Mark the pawn as passed. Pawn will be properly scored in evaluation
-      // because we need full attack info to evaluate passed pawns.
-      if (passed)
+      // because we need full attack info to evaluate passed pawns. Only the
+      // frontmost passed pawn on each file is considered a true passed pawn.
+      if (passed && !doubled)
           set_bit(&(pi->passedPawns[Us]), s);
 
       // Score this pawn
@@ -239,6 +212,5 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
       if (candidate)
           value += CandidateBonus[relative_rank(Us, s)];
   }
-
   return value;
 }