Annotate an unlikely condition

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index be9f108a3a0e2ce90769200d89dfb97757c3f63e..c6bc8e372bcd28d4c02c8b2a6ccd1b22a3e4a6e8 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -298,7 +298,7 @@ namespace {
     int depth, prevBestMoveChanges;
     Value bestValue, alpha, beta, delta;
 
-    memset(ss-1, 0, 4 * sizeof(Stack));
+    std::memset(ss-1, 0, 4 * sizeof(Stack));
     (ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains
 
     depth = BestMoveChanges = 0;
@@ -623,7 +623,7 @@ namespace {
         Gains.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval);
     }
 
-    // Step 6. Razoring (is omitted in PV nodes)
+    // Step 6. Razoring (skipped when in check)
     if (   !PvNode
         &&  depth < 4 * ONE_PLY
         &&  eval + razor_margin(depth) < beta
@@ -639,7 +639,7 @@ namespace {
             return v;
     }
 
-    // Step 7. Static null move pruning (is omitted in PV nodes)
+    // Step 7. Static null move pruning (skipped when in check)
     // We're betting that the opponent doesn't have a move that will reduce
     // the score by more than futility_margin(depth) if we do a null move.
     if (   !PvNode
@@ -710,7 +710,7 @@ namespace {
         }
     }
 
-    // Step 9. ProbCut (is omitted in PV nodes)
+    // Step 9. ProbCut (skipped when in check)
     // If we have a very good capture (i.e. SEE > seeValues[captured_piece_type])
     // and a reduced search returns a value much above beta, we can (almost) safely
     // prune the previous move.
@@ -741,7 +741,7 @@ namespace {
             }
     }
 
-    // Step 10. Internal iterative deepening
+    // Step 10. Internal iterative deepening (skipped when in check)
     if (   depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
         && ttMove == MOVE_NONE
         && (PvNode || ss->staticEval + Value(256) >= beta))
@@ -762,7 +762,7 @@ moves_loop: // When in check and at SpNode search starts from here
     Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first,
                             Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].second };
 
-    MovePicker mp(pos, ttMove, depth, History, countermoves, ss, PvNode ? -VALUE_INFINITE : beta);
+    MovePicker mp(pos, ttMove, depth, History, countermoves, ss);
     CheckInfo ci(pos);
     value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
     singularExtensionNode =   !RootNode
@@ -1126,7 +1126,7 @@ moves_loop: // When in check and at SpNode search starts from here
     Key posKey;
     Move ttMove, move, bestMove;
     Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
-    bool givesCheck, enoughMaterial, evasionPrunable;
+    bool givesCheck, evasionPrunable;
     Depth ttDepth;
 
     // To flag BOUND_EXACT a node with eval above alpha and no available moves
@@ -1168,7 +1168,6 @@ moves_loop: // When in check and at SpNode search starts from here
     {
         ss->staticEval = ss->evalMargin = VALUE_NONE;
         bestValue = futilityBase = -VALUE_INFINITE;
-        enoughMaterial = false;
     }
     else
     {
@@ -1196,7 +1195,6 @@ moves_loop: // When in check and at SpNode search starts from here
             alpha = bestValue;
 
         futilityBase = ss->staticEval + ss->evalMargin + Value(128);
-        enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMg;
     }
 
     // Initialize a MovePicker object for the current position, and prepare
@@ -1218,7 +1216,6 @@ moves_loop: // When in check and at SpNode search starts from here
           && !InCheck
           && !givesCheck
           &&  move != ttMove
-          &&  enoughMaterial
           &&  type_of(move) != PROMOTION
           && !pos.is_passed_pawn_push(move))
       {
@@ -1457,7 +1454,7 @@ moves_loop: // When in check and at SpNode search starts from here
                        | (attacks_bb<BISHOP>(m2to, occ) & pos.pieces(color_of(pc), QUEEN, BISHOP));
 
         // Verify attackers are triggered by our move and not already existing
-        if (xray && (xray ^ (xray & pos.attacks_from<QUEEN>(m2to))))
+        if (unlikely(xray) && (xray & ~pos.attacks_from<QUEEN>(m2to)))
             return true;
     }
 
@@ -1676,7 +1673,7 @@ void Thread::idle_loop() {
           Stack stack[MAX_PLY_PLUS_2], *ss = stack+1; // To allow referencing (ss-1)
           Position pos(*sp->pos, this);
 
-          memcpy(ss-1, sp->ss-1, 4 * sizeof(Stack));
+          std::memcpy(ss-1, sp->ss-1, 4 * sizeof(Stack));
           ss->splitPoint = sp;
 
           sp->mutex.lock();