Fix LazySMP when searching to a fixed depth.

Currently, helper threads will only search up to the
specified depth limit. Now let them search until the
main thread has finished the specified depth.

On the other hand, we don't want to pick a thread with
a higher search depth.

This may be considered cheating. ;-)

No functional change.

diff --git a/src/search.cpp b/src/search.cpp
index a50f7990f2cf20c6e8171f832d16fa2fa40ac170..6b8949569f753b38f1f9ee98960d1a8fba7bdaf9 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -350,6 +350,7 @@ void MainThread::search() {
   Thread* bestThread = this;
   if (   !this->easyMovePlayed
       &&  Options["MultiPV"] == 1
+      && !Limits.depth
       && !Skill(Options["Skill Level"]).enabled()
       &&  rootMoves[0].pv[0] != MOVE_NONE)
   {
@@ -411,7 +412,7 @@ void Thread::search() {
   multiPV = std::min(multiPV, rootMoves.size());
 
   // Iterative deepening loop until requested to stop or the target depth is reached.
-  while (++rootDepth < DEPTH_MAX && !Signals.stop && (!Limits.depth || rootDepth <= Limits.depth))
+  while (++rootDepth < DEPTH_MAX && !Signals.stop && (!Limits.depth || Threads.main()->rootDepth <= Limits.depth))
   {
       // Set up the new depths for the helper threads skipping on average every
       // 2nd ply (using a half-density matrix).
@@ -1006,7 +1007,7 @@ moves_loop: // When in check search starts from here
           Depth r = reduction<PvNode>(improving, depth, moveCount);
           Value hValue = thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)];
           Value cmhValue = cmh[pos.piece_on(to_sq(move))][to_sq(move)];
-          
+
           const CounterMoveStats* fm = (ss - 2)->counterMoves;
           const CounterMoveStats* fm2 = (ss - 4)->counterMoves;
           Value fmValue = (fm ? (*fm)[pos.piece_on(to_sq(move))][to_sq(move)] : VALUE_ZERO);