Small cleanups (march 2021)

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index af7f801ffe2da43e713f8213972ce9ce12d2dd69..ff8764d8a808313da7d5650845c13496f45556f7 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -612,12 +612,12 @@ namespace {
 
     // Step 1. Initialize node
     Thread* thisThread = pos.this_thread();
-    ss->inCheck = pos.checkers();
-    priorCapture = pos.captured_piece();
-    Color us = pos.side_to_move();
-    moveCount = captureCount = quietCount = ss->moveCount = 0;
-    bestValue = -VALUE_INFINITE;
-    maxValue = VALUE_INFINITE;
+    ss->inCheck        = pos.checkers();
+    priorCapture       = pos.captured_piece();
+    Color us           = pos.side_to_move();
+    moveCount          = captureCount = quietCount = ss->moveCount = 0;
+    bestValue          = -VALUE_INFINITE;
+    maxValue           = VALUE_INFINITE;
     ss->distanceFromPv = (PvNode ? 0 : ss->distanceFromPv);
 
     // Check for the available remaining time
@@ -917,6 +917,7 @@ namespace {
             return probCutBeta;
 
         assert(probCutBeta < VALUE_INFINITE);
+
         MovePicker mp(pos, ttMove, probCutBeta - ss->staticEval, &captureHistory);
         int probCutCount = 0;
         bool ttPv = ss->ttPv;
@@ -1121,6 +1122,7 @@ moves_loop: // When in check, search starts from here
       {
           Value singularBeta = ttValue - ((formerPv + 4) * depth) / 2;
           Depth singularDepth = (depth - 1 + 3 * formerPv) / 2;
+
           ss->excludedMove = move;
           value = search<NonPV>(pos, ss, singularBeta - 1, singularBeta, singularDepth, cutNode);
           ss->excludedMove = MOVE_NONE;
@@ -1205,15 +1207,19 @@ moves_loop: // When in check, search starts from here
 
           // Decrease reduction if position is or has been on the PV
           // and node is not likely to fail low. (~10 Elo)
-          if (ss->ttPv && !likelyFailLow)
+          if (   ss->ttPv
+              && !likelyFailLow)
               r -= 2;
 
           // Increase reduction at root and non-PV nodes when the best move does not change frequently
-          if ((rootNode || !PvNode) && thisThread->rootDepth > 10 && thisThread->bestMoveChanges <= 2)
+          if (   (rootNode || !PvNode)
+              && thisThread->rootDepth > 10
+              && thisThread->bestMoveChanges <= 2)
               r++;
 
           // More reductions for late moves if position was not in previous PV
-          if (moveCountPruning && !formerPv)
+          if (   moveCountPruning
+              && !formerPv)
               r++;
 
           // Decrease reduction if opponent's move count is high (~5 Elo)
@@ -1226,7 +1232,7 @@ moves_loop: // When in check, search starts from here
 
           if (captureOrPromotion)
           {
-              // Unless giving check, this capture is likely bad
+              // Increase reduction for non-checking captures likely to be bad
               if (   !givesCheck
                   && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 210 * depth <= alpha)
                   r++;
@@ -1246,7 +1252,7 @@ moves_loop: // When in check, search starts from here
 
               // Decrease reduction for moves that escape a capture. Filter out
               // castling moves, because they are coded as "king captures rook" and
-              // hence break make_move(). (~2 Elo)
+              // hence break reverse_move() (~2 Elo)
               else if (    type_of(move) == NORMAL
                        && !pos.see_ge(reverse_move(move)))
                   r -= 2 + ss->ttPv - (type_of(movedPiece) == PAWN);
@@ -1408,8 +1414,9 @@ moves_loop: // When in check, search starts from here
     assert(moveCount || !ss->inCheck || excludedMove || !MoveList<LEGAL>(pos).size());
 
     if (!moveCount)
-        bestValue = excludedMove ? alpha
-                   :     ss->inCheck ? mated_in(ss->ply) : VALUE_DRAW;
+        bestValue = excludedMove ? alpha :
+                    ss->inCheck  ? mated_in(ss->ply)
+                                 : VALUE_DRAW;
 
     // If there is a move which produces search value greater than alpha we update stats of searched moves
     else if (bestMove)