Merge Joona's new aspiration window search

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 8414e32901b769bd9ec1a93989478923063ab12d..21aa4f92069dbcbbf7997b73364b641444fc9ed2 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -60,11 +60,10 @@ namespace {
 
   struct IterationInfoType {
 
-    IterationInfoType(Value v = Value(0), Value sv = Value(0), bool fh = false, bool fl = false)
-    : value(v), speculatedValue(sv), failHigh(fh), failLow(fl) {}
+    IterationInfoType(Value v = Value(0), Value sv = Value(0))
+    : value(v), speculatedValue(sv) {}
 
     Value value, speculatedValue;
-    bool failHigh, failLow;
   };
 
 
@@ -712,13 +711,14 @@ namespace {
 
         // Search to the current depth
         Value value = root_search(p, ss, rml, alpha, beta);
-        if (AbortSearch)
-            break; // Value cannot be trusted. Break out immediately!
 
         // Write PV to transposition table, in case the relevant entries have
         // been overwritten during the search.
         TT.insert_pv(p, ss[0].pv);
 
+        if (AbortSearch)
+            break; // Value cannot be trusted. Break out immediately!
+
         //Save info about search result
         Value speculatedValue;
         bool fHigh = false;
@@ -735,6 +735,7 @@ namespace {
         }
         else if (value <= alpha)
         {
+            assert(value == alpha);
             assert(delta < 0);
 
             fLow = true;
@@ -744,7 +745,7 @@ namespace {
             speculatedValue = value;
 
         speculatedValue = Min(Max(speculatedValue, -VALUE_INFINITE), VALUE_INFINITE);
-        IterationInfo[Iteration] = IterationInfoType(value, speculatedValue, fHigh, fLow);
+        IterationInfo[Iteration] = IterationInfoType(value, speculatedValue);
 
         // Erase the easy move if it differs from the new best move
         if (ss[0].pv[0] != EasyMove)
@@ -857,7 +858,6 @@ namespace {
 
   Value root_search(Position &pos, SearchStack ss[], RootMoveList &rml, Value alpha, Value beta) {
 
-    //FIXME: Implement bestValue
     Value oldAlpha = alpha;
     Value value;
     Bitboard dcCandidates = pos.discovered_check_candidates(pos.side_to_move());
@@ -867,8 +867,11 @@ namespace {
     {
         if (alpha >= beta)
         {
+            // We failed high, invalidate and skip next moves, leave node-counters
+            // and beta-counters as they are and quickly return, we will try to do
+            // a research at the next iteration with a bigger aspiration window.
             rml.set_move_score(i, -VALUE_INFINITE);
-            continue; // Leave node-counters and beta-counters as they are
+            continue;
         }
         int64_t nodes;
         Move move;
@@ -951,7 +954,7 @@ namespace {
             rml.set_move_score(i, -VALUE_INFINITE);
         else
         {
-            // New best move!
+            // PV move or new best move!
 
             // Update PV
             rml.set_move_score(i, value);
@@ -2507,7 +2510,7 @@ namespace {
         return;
 
     bool overTime =     t > AbsoluteMaxSearchTime
-                     || (RootMoveNumber == 1 && t > MaxSearchTime + ExtraSearchTime && !FailLow) //FIXME: BUG??
+                     || (RootMoveNumber == 1 && t > MaxSearchTime + ExtraSearchTime && !FailLow) //FIXME: We are not checking any problem flags, BUG?
                      || (  !FailHigh && !FailLow && !fail_high_ply_1() && !Problem
                          && t > 6*(MaxSearchTime + ExtraSearchTime));