A useless assignment found by Clang’s static analyzer

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 220fff5e10d03e50e74e4052c2f3c9f97bbfd380..be9f108a3a0e2ce90769200d89dfb97757c3f63e 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
@@ -212,7 +215,7 @@ void Search::think() {
   else
       DrawValue[WHITE] = DrawValue[BLACK] = VALUE_DRAW;
 
-  if (Options["Use Search Log"])
+  if (Options["Write Search Log"])
   {
       Log log(Options["Search Log Filename"]);
       log << "\nSearching: "  << RootPos.fen()
@@ -228,7 +231,7 @@ void Search::think() {
   for (size_t i = 0; i < Threads.size(); i++)
       Threads[i]->maxPly = 0;
 
-  Threads.sleepWhileIdle = Options["Use Sleeping Threads"];
+  Threads.sleepWhileIdle = Options["Idle Threads Sleep"];
 
   // Set best timer interval to avoid lagging under time pressure. Timer is
   // used to check for remaining available thinking time.
@@ -244,7 +247,7 @@ void Search::think() {
   Threads.timer->msec = 0; // Stop the timer
   Threads.sleepWhileIdle = true; // Send idle threads to sleep
 
-  if (Options["Use Search Log"])
+  if (Options["Write Search Log"])
   {
       Time::point elapsed = Time::now() - SearchTime + 1;
 
@@ -364,6 +367,12 @@ namespace {
                 if (Signals.stop)
                     return;
 
+                // When failing high/low give some update (without cluttering
+                // the UI) before to research.
+                if (  (bestValue <= alpha || bestValue >= beta)
+                    && Time::now() - SearchTime > 3000)
+                    sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
+
                 // In case of failing low/high increase aspiration window and
                 // research, otherwise exit the loop.
                 if (bestValue <= alpha)
@@ -382,10 +391,6 @@ namespace {
                 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
@@ -399,7 +404,7 @@ namespace {
         if (skill.enabled() && skill.time_to_pick(depth))
             skill.pick_move();
 
-        if (Options["Use Search Log"])
+        if (Options["Write Search Log"])
         {
             RootMove& rm = RootMoves[0];
             if (skill.best != MOVE_NONE)
@@ -497,7 +502,6 @@ namespace {
 
     // Step 1. Initialize node
     Thread* thisThread = pos.this_thread();
-    moveCount = quietCount = 0;
     inCheck = pos.checkers();
 
     if (SpNode)
@@ -512,9 +516,10 @@ namespace {
 
         assert(splitPoint->bestValue > -VALUE_INFINITE && splitPoint->moveCount > 0);
 
-        goto split_point_start;
+        goto moves_loop;
     }
 
+    moveCount = quietCount = 0;
     bestValue = -VALUE_INFINITE;
     ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
     ss->ply = (ss-1)->ply + 1;
@@ -583,7 +588,7 @@ namespace {
     if (inCheck)
     {
         ss->staticEval = ss->evalMargin = eval = VALUE_NONE;
-        goto iid_start;
+        goto moves_loop;
     }
 
     else if (tte)
@@ -736,12 +741,10 @@ namespace {
             }
     }
 
-iid_start: // When in check we skip early cut tests
-
     // 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);
 
@@ -753,7 +756,7 @@ iid_start: // When in check we skip early cut tests
         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,
@@ -1240,8 +1243,7 @@ split_point_start: // At split points actual search starts from here
       }
 
       // Detect non-capture evasions that are candidate to be pruned
-      evasionPrunable =   !PvNode
-                       &&  InCheck
+      evasionPrunable =    InCheck
                        &&  bestValue > VALUE_MATED_IN_MAX_PLY
                        && !pos.is_capture(move)
                        && !pos.can_castle(pos.side_to_move());
@@ -1666,6 +1668,7 @@ void Thread::idle_loop() {
           Threads.mutex.lock();
 
           assert(searching);
+          assert(activeSplitPoint);
           SplitPoint* sp = activeSplitPoint;
 
           Threads.mutex.unlock();