Fix a crash with depth 1 perft

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index fc94f4f79347dfc14dc6fe5e186c90ca3a1d0fac..c7798c873d6286980983440f9ddfb3142f83c327 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -153,7 +153,7 @@ void Search::init() {
 /// Search::perft() is our utility to verify move generation. All the leaf nodes
 /// up to the given depth are generated and counted and the sum returned.
 
-size_t Search::perft(Position& pos, Depth depth) {
+static size_t perft(Position& pos, Depth depth) {
 
   StateInfo st;
   size_t cnt = 0;
@@ -163,12 +163,15 @@ size_t Search::perft(Position& pos, Depth depth) {
   for (MoveList<LEGAL> it(pos); *it; ++it)
   {
       pos.do_move(*it, st, ci, pos.move_gives_check(*it, ci));
-      cnt += leaf ? MoveList<LEGAL>(pos).size() : perft(pos, depth - ONE_PLY);
+      cnt += leaf ? MoveList<LEGAL>(pos).size() : ::perft(pos, depth - ONE_PLY);
       pos.undo_move(*it);
   }
   return cnt;
 }
 
+size_t Search::perft(Position& pos, Depth depth) {
+  return depth > ONE_PLY ? ::perft(pos, depth) : MoveList<LEGAL>(pos).size();
+}
 
 /// Search::think() is the external interface to Stockfish's search, and is
 /// called by the main thread when the program receives the UCI 'go' command. It
@@ -364,8 +367,6 @@ namespace {
                 if (Signals.stop)
                     return;
 
-                delta += delta / 2;
-
                 // In case of failing low/high increase aspiration window and
                 // research, otherwise exit the loop.
                 if (bestValue <= alpha)
@@ -381,6 +382,8 @@ namespace {
                 else
                     break;
 
+                delta += delta / 2;
+
                 assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
 
                 // Give some update (without cluttering the UI) before to research
@@ -512,7 +515,7 @@ namespace {
 
         assert(splitPoint->bestValue > -VALUE_INFINITE && splitPoint->moveCount > 0);
 
-        goto split_point_start;
+        goto moves_loop;
     }
 
     bestValue = -VALUE_INFINITE;
@@ -581,7 +584,10 @@ namespace {
 
     // Step 5. Evaluate the position statically and update parent's gain statistics
     if (inCheck)
+    {
         ss->staticEval = ss->evalMargin = eval = VALUE_NONE;
+        goto moves_loop;
+    }
 
     else if (tte)
     {
@@ -618,7 +624,6 @@ namespace {
     // Step 6. Razoring (is omitted in PV nodes)
     if (   !PvNode
         &&  depth < 4 * ONE_PLY
-        && !inCheck
         &&  eval + razor_margin(depth) < beta
         &&  ttMove == MOVE_NONE
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
@@ -638,7 +643,6 @@ namespace {
     if (   !PvNode
         && !ss->skipNullMove
         &&  depth < 4 * ONE_PLY
-        && !inCheck
         &&  eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  abs(eval) < VALUE_KNOWN_WIN
@@ -649,7 +653,6 @@ namespace {
     if (   !PvNode
         && !ss->skipNullMove
         &&  depth > ONE_PLY
-        && !inCheck
         &&  eval >= beta
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  pos.non_pawn_material(pos.side_to_move()))
@@ -711,7 +714,6 @@ namespace {
     // prune the previous move.
     if (   !PvNode
         &&  depth >= 5 * ONE_PLY
-        && !inCheck
         && !ss->skipNullMove
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY)
     {
@@ -740,7 +742,7 @@ namespace {
     // Step 10. Internal iterative deepening
     if (   depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
         && ttMove == MOVE_NONE
-        && (PvNode || (!inCheck && ss->staticEval + Value(256) >= beta)))
+        && (PvNode || ss->staticEval + Value(256) >= beta))
     {
         Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
 
@@ -752,7 +754,7 @@ namespace {
         ttMove = tte ? tte->move() : MOVE_NONE;
     }
 
-split_point_start: // At split points actual search starts from here
+moves_loop: // When in check and at SpNode search starts from here
 
     Square prevMoveSq = to_sq((ss-1)->currentMove);
     Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first,
@@ -811,12 +813,7 @@ 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)