X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=15a9cde5b706914ffe1904ca74d060769ff892c2;hp=bf33a136b6f8364ead77831d46e399ae4c0837f5;hb=6fbe027da05d6de0b7f03e8696bbde2e33baad98;hpb=b8930d0c267d9d01ea1f854122e663c34bf5fce2

diff --git a/src/search.cpp b/src/search.cpp
index bf33a136..15a9cde5 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -296,9 +296,12 @@ namespace {
     Value bestValue, alpha, beta, delta;
 
     memset(ss-1, 0, 4 * sizeof(Stack));
-    depth = BestMoveChanges = 0;
-    bestValue = delta = -VALUE_INFINITE;
     (ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains
+
+    depth = BestMoveChanges = 0;
+    bestValue = delta = alpha = -VALUE_INFINITE;
+    beta = VALUE_INFINITE;
+
     TT.new_search();
     History.clear();
     Gains.clear();
@@ -328,17 +331,12 @@ namespace {
         // MultiPV loop. We perform a full root search for each PV line
         for (PVIdx = 0; PVIdx < PVSize; PVIdx++)
         {
-            // Set aspiration window default width
-            if (depth >= 5 && abs(RootMoves[PVIdx].prevScore) < VALUE_KNOWN_WIN)
+            // Reset aspiration window starting size
+            if (depth >= 5)
             {
                 delta = Value(16);
-                alpha = RootMoves[PVIdx].prevScore - delta;
-                beta  = RootMoves[PVIdx].prevScore + delta;
-            }
-            else
-            {
-                alpha = -VALUE_INFINITE;
-                beta  =  VALUE_INFINITE;
+                alpha = std::max(RootMoves[PVIdx].prevScore - delta,-VALUE_INFINITE);
+                beta  = std::min(RootMoves[PVIdx].prevScore + delta, VALUE_INFINITE);
             }
 
             // Start with a small aspiration window and, in case of fail high/low,
@@ -366,35 +364,28 @@ namespace {
                 if (Signals.stop)
                     return;
 
-                // In case of failing high/low increase aspiration window and
+                // In case of failing low/high increase aspiration window and
                 // research, otherwise exit the loop.
-                if (bestValue > alpha && bestValue < beta)
-                    break;
-
-                // Give some update (without cluttering the UI) before to research
-                if (Time::now() - SearchTime > 3000)
-                    sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
-
-                if (abs(bestValue) >= VALUE_KNOWN_WIN)
+                if (bestValue <= alpha)
                 {
-                    alpha = -VALUE_INFINITE;
-                    beta  =  VALUE_INFINITE;
+                    alpha = std::max(bestValue - delta, -VALUE_INFINITE);
+
+                    Signals.failedLowAtRoot = true;
+                    Signals.stopOnPonderhit = false;
                 }
                 else if (bestValue >= beta)
-                {
-                    beta += delta;
-                    delta += delta / 2;
-                }
+                    beta = std::min(bestValue + delta, VALUE_INFINITE);
+
                 else
-                {
-                    Signals.failedLowAtRoot = true;
-                    Signals.stopOnPonderhit = false;
+                    break;
 
-                    alpha -= delta;
-                    delta += delta / 2;
-                }
+                delta += delta / 2;
 
                 assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+
+                // Give some update (without cluttering the UI) before to research
+                if (Time::now() - SearchTime > 3000)
+                    sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
             }
 
             // Sort the PV lines searched so far and update the GUI
@@ -820,12 +811,7 @@ split_point_start: // At split points actual search starts from here
       givesCheck = pos.move_gives_check(move, ci);
       dangerous =   givesCheck
                  || pos.is_passed_pawn_push(move)
-                 || type_of(move) == CASTLE
-                 || (   captureOrPromotion // Entering a pawn endgame?
-                     && type_of(pos.piece_on(to_sq(move))) != PAWN
-                     && type_of(move) == NORMAL
-                     && (  pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
-                         - PieceValue[MG][pos.piece_on(to_sq(move))] == VALUE_ZERO));
+                 || type_of(move) == CASTLE;
 
       // Step 12. Extend checks and, in PV nodes, also dangerous moves
       if (PvNode && dangerous)