refine vcfsearch

test f15

Rapfi/search/ab/search.cpp

@@ -1483,7 +1483,6 @@ Value vcfsearch(Board &board, SearchStack *ss, Value alpha, Value beta, Depth de
 
     // Step 1. Initialize node
     SearchThread *thisThread = board.thisThread();
-    ABSearchData *searchData = thisThread->searchDataAs<ABSearchData>();
     thisThread->numNodes.fetch_add(1, std::memory_order_relaxed);
 
     Color self = board.sideToMove(), oppo = ~self;
@@ -1505,10 +1504,6 @@ Value vcfsearch(Board &board, SearchStack *ss, Value alpha, Value beta, Depth de
     if (board.movesLeft() == 0 || board.nonPassMoveCount() >= thisThread->options().maxMoves)
         return getDrawValue(board, thisThread->options(), ss->ply);
 
-    // Check if we reached the max ply
-    if (ss->ply >= MAX_PLY)
-        return Evaluation::evaluate<Rule>(board, alpha, beta);
-
     // Check for immediate winning
     if ((value = quickWinCheck<Rule>(board, ss->ply, beta)) != VALUE_ZERO) {
         // Do not return mate that longer than maxMoves option
@@ -1518,6 +1513,10 @@ Value vcfsearch(Board &board, SearchStack *ss, Value alpha, Value beta, Depth de
         return value;
     }
 
+    // Check if we reached the max ply
+    if (ss->ply >= MAX_PLY)
+        return Evaluation::evaluate<Rule>(board, alpha, beta);
+
     // Step 3. Mate distance pruning
     alpha = std::max(mated_in(ss->ply), alpha);
     beta  = std::min(mate_in(ss->ply + 1), beta);
@@ -1681,31 +1680,27 @@ Value vcfdefend(Board &board, SearchStack *ss, Value alpha, Value beta, Depth de
 
     Color    self = board.sideToMove(), oppo = ~self;
     uint16_t oppo5 = board.p4Count(oppo, A_FIVE);  // opponent five
-    Value    value;
 
     // Update selDepth (selDepth counts from 1, ply from 0)
     if (PvNode && thisThread->selDepth <= ss->ply)
         thisThread->selDepth = ss->ply + 1;
 
     // Step 2. Check for immediate evaluation, draw and winning
-    // Return evaluation immediately if there is no vcf threat
-    if (!oppo5)
-        return Evaluation::evaluate<Rule>(board, alpha, beta);
-
     // Check if the board has been filled or we have reached the max game ply.
     if (board.movesLeft() == 0 || board.nonPassMoveCount() >= thisThread->options().maxMoves)
         return getDrawValue(board, thisThread->options(), ss->ply);
 
-    // Check if we reached the max ply
-    if (ss->ply >= MAX_PLY)
+    // Check if we reached the max ply or if there is no vcf threat
+    if (ss->ply >= MAX_PLY || !oppo5)
         return Evaluation::evaluate<Rule>(board, alpha, beta);
 
     // Step 3. Search the only defence move
     Pos move = board.stateInfo().lastPattern4(oppo, A_FIVE);
     assert(board.cell(move).pattern4[oppo] == A_FIVE);
 
-    // For renju, if black's defence move is a forbidden point, black loses in two steps.
+    Value value;
     if (Rule == Rule::RENJU && self == BLACK && board.checkForbiddenPoint(move)) {
+        // For renju, if black's defence move is a forbidden point, black loses in two steps.
         value = mated_in(ss->ply + 2);
     }
     else {