X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=20aaabbdde0288a28743ea230706dc2905cc281f;hp=43f30f7709565e22502e6e94438a0aa91ac663d1;hb=c6d62b7da5b9bb0e8c987596d1c6a304b337ca32;hpb=75d001adddfaa7a2eb57af99cf6c57a12913d2d1

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 43f30f77..20aaabbd 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -71,7 +71,7 @@ MovePicker::MovePicker(const Position& p, bool pv, Move ttm,
   ttMove = ttm;
   mateKiller = (ss.mateKiller == ttm)? MOVE_NONE : ss.mateKiller;
   killer1 = ss.killers[0];
-  killer2 = ss.killers[0];
+  killer2 = ss.killers[1];
   depth = d;
   movesPicked = 0;
   numOfMoves = 0;
@@ -270,10 +270,11 @@ void MovePicker::score_noncaptures() {
       else
           hs = H.move_ordering_score(pos.piece_on(move_from(m)), m);
 
-      // Ensure moves in history are always sorted as first
+      // Ensure history is always preferred to pst
       if (hs > 0)
           hs += 1000;
 
+      // pst based scoring
       moves[i].score = hs + pos.mg_pst_delta(m);
   }
 }
@@ -292,7 +293,6 @@ void MovePicker::score_evasions() {
       } else
           moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m);
   }
-  // FIXME try psqt also here
 }
 
 void MovePicker::score_qcaptures() {
@@ -310,17 +310,19 @@ void MovePicker::score_qcaptures() {
 }
 
 
-/// find_best_index() loops across the moves and returns index of
-/// the highest scored one. There is also a second version that
-/// lowers the priority of moves that attack the same square,
-/// so that if the best move that attack a square fails the next
+/// find_best_index() loops across the moves and returns index of
+/// the highest scored one. There is also a second version that
+/// lowers the priority of moves that attack the same square,
+/// so that if the best move that attack a square fails the next
 /// move picked attacks a different square if any, not the same one.
 
 int MovePicker::find_best_index() {
 
-  int bestScore = -10000000, bestIndex = -1;
+  assert(movesPicked < numOfMoves);
 
-  for (int i = movesPicked; i < numOfMoves; i++)
+  int bestIndex = movesPicked, bestScore = moves[movesPicked].score;
+
+  for (int i = movesPicked + 1; i < numOfMoves; i++)
       if (moves[i].score > bestScore)
       {
           bestIndex = i;
@@ -329,41 +331,43 @@ int MovePicker::find_best_index() {
   return bestIndex;
 }
 
-int MovePicker::find_best_index(Bitboard* squares, int values[]) {
-
-  int hs;
-  Move m;
-  Square to;
-  int bestScore = -10000000, bestIndex = -1;
-
-  for (int i = movesPicked; i < numOfMoves; i++)
-  {
-      m = moves[i].move;
-      to = move_to(m);
-      
-      if (!bit_is_set(*squares, to))
-      {
-          // Init at first use
-          set_bit(squares, to);
-          values[to] = 0;
-      }
-
-      hs = moves[i].score - values[to];
-      if (hs > bestScore)
-      {
-          bestIndex = i;
-          bestScore = hs;
-      }
-  }
-
-  if (bestIndex != -1)
-  {
-      // Raise value of the picked square, so next attack
-      // to the same square will get low priority.
-      to = move_to(moves[bestIndex].move);
-      values[to] += 0xB00;
-  }
-  return bestIndex;
+int MovePicker::find_best_index(Bitboard* squares, int values[]) {
+
+  assert(movesPicked < numOfMoves);
+
+  int hs;
+  Move m;
+  Square to;
+  int bestScore = -10000000, bestIndex = -1;
+
+  for (int i = movesPicked; i < numOfMoves; i++)
+  {
+      m = moves[i].move;
+      to = move_to(m);
+
+      if (!bit_is_set(*squares, to))
+      {
+          // Init at first use
+          set_bit(squares, to);
+          values[to] = 0;
+      }
+
+      hs = moves[i].score - values[to];
+      if (hs > bestScore)
+      {
+          bestIndex = i;
+          bestScore = hs;
+      }
+  }
+
+  if (bestIndex != -1)
+  {
+      // Raise value of the picked square, so next attack
+      // to the same square will get low priority.
+      to = move_to(moves[bestIndex].move);
+      values[to] += 0xB00;
+  }
+  return bestIndex;
 }
 
 
@@ -378,6 +382,7 @@ Move MovePicker::pick_move_from_list() {
   Move move;
 
   switch (PhaseTable[phaseIndex]) {
+
   case PH_GOOD_CAPTURES:
       assert(!pos.is_check());
       assert(movesPicked >= 0);
@@ -385,16 +390,12 @@ Move MovePicker::pick_move_from_list() {
       while (movesPicked < numOfMoves)
       {
           bestIndex = find_best_index();
-
-          if (bestIndex != -1) // Found a good capture
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              if (   move != ttMove
-                  && move != mateKiller
-                  && pos.pl_move_is_legal(move, pinned))
-                  return move;
-          }
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          if (   move != ttMove
+              && move != mateKiller
+              && pos.pl_move_is_legal(move, pinned))
+              return move;
       }
       break;
 
@@ -409,16 +410,12 @@ Move MovePicker::pick_move_from_list() {
           // been searched and it is not a PV node, we are probably failing low
           // anyway, so we just pick the first move from the list.
           bestIndex = (pvNode || movesPicked < 12) ? find_best_index() : movesPicked;
-
-          if (bestIndex != -1)
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              if (   move != ttMove
-                  && move != mateKiller
-                  && pos.pl_move_is_legal(move, pinned))
-                  return move;
-          }
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          if (   move != ttMove
+              && move != mateKiller
+              && pos.pl_move_is_legal(move, pinned))
+              return move;
       }
       break;
 
@@ -429,13 +426,9 @@ Move MovePicker::pick_move_from_list() {
       while (movesPicked < numOfMoves)
       {
           bestIndex = find_best_index();
-
-          if (bestIndex != -1)
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              return move;
-          }
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          return move;
     }
     break;
 
@@ -460,16 +453,12 @@ Move MovePicker::pick_move_from_list() {
       while (movesPicked < numOfMoves)
       {
           bestIndex = (movesPicked < 4 ? find_best_index() : movesPicked);
-
-          if (bestIndex != -1)
-          {
-              move = moves[bestIndex].move;
-              moves[bestIndex] = moves[movesPicked++];
-              // Remember to change the line below if we decide to hash the qsearch!
-              // Maybe also postpone the legality check until after futility pruning?
-              if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned))
-                  return move;
-          }
+          move = moves[bestIndex].move;
+          moves[bestIndex] = moves[movesPicked++];
+          // Remember to change the line below if we decide to hash the qsearch!
+          // Maybe also postpone the legality check until after futility pruning?
+          if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned))
+              return move;
       }
       break;