A small code simplification

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 3ac52f8c0f9cbd0910b00ab1a05532c198c291b1..8037e6e74f29300065618b16a435e29201a9488e 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -341,7 +341,7 @@ namespace {
     Move easyMove = EasyMove.get(pos.key());
     EasyMove.clear();
 
-    std::memset(ss-2, 0, 5 * sizeof(Stack));
+    std::memset(stack, 0, 5 * sizeof(Stack));
 
     depth = DEPTH_ZERO;
     BestMoveChanges = 0;
@@ -531,7 +531,7 @@ namespace {
     Depth extension, newDepth, predictedDepth;
     Value bestValue, value, ttValue, eval, nullValue, futilityValue;
     bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
-    bool captureOrPromotion, dangerous, doFullDepthSearch;
+    bool captureOrPromotion, doFullDepthSearch;
     int moveCount, quietCount;
 
     // Step 1. Initialize node
@@ -769,9 +769,9 @@ namespace {
         && !ttMove
         && (PvNode || ss->staticEval + 256 >= beta))
     {
-        Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2);
+        Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
         ss->skipEarlyPruning = true;
-        search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d / 2, true);
+        search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d, true);
         ss->skipEarlyPruning = false;
 
         tte = TT.probe(posKey, ttHit);
@@ -821,13 +821,11 @@ moves_loop: // When in check and at SpNode search starts from here
           if (!pos.legal(move, ci.pinned))
               continue;
 
-          moveCount = ++splitPoint->moveCount;
+          ss->moveCount = moveCount = ++splitPoint->moveCount;
           splitPoint->spinlock.release();
       }
       else
-          ++moveCount;
-      
-      ss->moveCount = moveCount;
+          ss->moveCount = ++moveCount;
 
       if (RootNode)
       {
@@ -849,10 +847,6 @@ moves_loop: // When in check and at SpNode search starts from here
                   ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move)
                   : pos.gives_check(move, ci);
 
-      dangerous =   givesCheck
-                 || type_of(move) != NORMAL
-                 || pos.advanced_pawn_push(move);
-
       // Step 12. Extend checks
       if (givesCheck && pos.see_sign(move) >= VALUE_ZERO)
           extension = ONE_PLY;
@@ -885,7 +879,8 @@ moves_loop: // When in check and at SpNode search starts from here
       if (   !RootNode
           && !captureOrPromotion
           && !inCheck
-          && !dangerous
+          && !givesCheck
+          && !pos.advanced_pawn_push(move)
           &&  bestValue > VALUE_MATED_IN_MAX_PLY)
       {
           // Move count based pruning
@@ -935,8 +930,7 @@ moves_loop: // When in check and at SpNode search starts from here
       // Check for legality just before making the move
       if (!RootNode && !SpNode && !pos.legal(move, ci.pinned))
       {
-          moveCount--;
-          ss->moveCount = moveCount;
+          ss->moveCount = --moveCount;
           continue;
       }
 
@@ -1429,7 +1423,7 @@ moves_loop: // When in check and at SpNode search starts from here
     }
 
     // Extra penalty for PV move in previous ply when it gets refuted
-    if (is_ok((ss-2)->currentMove) && (ss-1)->moveCount==1 && !pos.captured_piece_type())
+    if (is_ok((ss-2)->currentMove) && (ss-1)->moveCount == 1 && !pos.captured_piece_type())
     {
         Square prevPrevSq = to_sq((ss-2)->currentMove);
         HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];