X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=dc488c2b8922df283d51ba1c525e452b83cab7e4;hp=72711b6909f7d4b2715dfe0440edfe5574e2b8c3;hb=24dac5ccd309837c6767dcf6b145be385eea2e21;hpb=c13052f344e1de69bd824256427fd7e723a79e14

diff --git a/src/search.cpp b/src/search.cpp
index 72711b69..dc488c2b 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -179,8 +179,6 @@ namespace {
 
 void Search::init() {
 
-  const bool PV=true;
-
   for (int imp = 0; imp <= 1; ++imp)
       for (int d = 1; d < 64; ++d)
           for (int mc = 1; mc < 64; ++mc)
@@ -189,12 +187,12 @@ void Search::init() {
               if (r < 0.80)
                 continue;
 
-              Reductions[!PV][imp][d][mc] = int(std::round(r)) * ONE_PLY;
-              Reductions[PV][imp][d][mc] = std::max(Reductions[!PV][imp][d][mc] - ONE_PLY, DEPTH_ZERO);
-              
+              Reductions[NonPV][imp][d][mc] = int(std::round(r)) * ONE_PLY;
+              Reductions[PV][imp][d][mc] = std::max(Reductions[NonPV][imp][d][mc] - ONE_PLY, DEPTH_ZERO);
+
               // Increase reduction for non-PV nodes when eval is not improving
-              if (!imp && Reductions[!PV][imp][d][mc] >= 2 * ONE_PLY)
-                Reductions[!PV][imp][d][mc] += ONE_PLY;
+              if (!imp && Reductions[NonPV][imp][d][mc] >= 2 * ONE_PLY)
+                Reductions[NonPV][imp][d][mc] += ONE_PLY;
           }
 
   for (int d = 0; d < 16; ++d)
@@ -870,10 +868,12 @@ namespace {
 moves_loop: // When in check search starts from here
 
     Square prevSq = to_sq((ss-1)->currentMove);
+    Square ownPrevSq = to_sq((ss-2)->currentMove);
     Move cm = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
     const CounterMoveStats& cmh = CounterMoveHistory[pos.piece_on(prevSq)][prevSq];
+    const CounterMoveStats& fmh = CounterMoveHistory[pos.piece_on(ownPrevSq)][ownPrevSq];
 
-    MovePicker mp(pos, ttMove, depth, thisThread->history, cmh, cm, ss);
+    MovePicker mp(pos, ttMove, depth, thisThread->history, cmh, fmh, cm, ss);
     CheckInfo ci(pos);
     value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
     improving =   ss->staticEval >= (ss-2)->staticEval
@@ -1427,8 +1427,8 @@ moves_loop: // When in check search starts from here
   }
 
 
-  // update_stats() updates killers, history, countermove and countermove
-  // history when a new quiet best move is found.
+  // update_stats() updates killers, history, countermove and countermove plus
+  // follow-up move history when a new quiet best move is found.
 
   void update_stats(const Position& pos, Stack* ss, Move move,
                     Depth depth, Move* quiets, int quietsCnt) {
@@ -1442,7 +1442,9 @@ moves_loop: // When in check search starts from here
     Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
 
     Square prevSq = to_sq((ss-1)->currentMove);
+    Square ownPrevSq = to_sq((ss-2)->currentMove);
     CounterMoveStats& cmh = CounterMoveHistory[pos.piece_on(prevSq)][prevSq];
+    CounterMoveStats& fmh = CounterMoveHistory[pos.piece_on(ownPrevSq)][ownPrevSq];
     Thread* thisThread = pos.this_thread();
 
     thisThread->history.update(pos.moved_piece(move), to_sq(move), bonus);
@@ -1453,6 +1455,9 @@ moves_loop: // When in check search starts from here
         cmh.update(pos.moved_piece(move), to_sq(move), bonus);
     }
 
+    if (is_ok((ss-2)->currentMove))
+        fmh.update(pos.moved_piece(move), to_sq(move), bonus);
+
     // Decrease all the other played quiet moves
     for (int i = 0; i < quietsCnt; ++i)
     {
@@ -1460,6 +1465,9 @@ moves_loop: // When in check search starts from here
 
         if (is_ok((ss-1)->currentMove))
             cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+
+        if (is_ok((ss-2)->currentMove))
+            fmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
     }
 
     // Extra penalty for a quiet TT move in previous ply when it gets refuted