3.5.3: remove instant tbmoves at root (#281)

vshcherbyna · web-flow · commit 60db05e6f118 · 2023-07-03T17:32:34.000+01:00
http://chess.grantnet.us/test/32640/ ELO | -1.20 +- 1.31 (95%) SPRT | 10.0+0.10s Threads=1 Hash=8MB LLR | -2.97 (-2.94, 2.94) [-3.00, 1.00] GAMES | N: 138784 W: 35302 L: 35780 D: 67702
diff --git a/src/search.cpp b/src/search.cpp
@@ -798,92 +798,6 @@ bool Search::ProbeHash(TEntry & hentry)
     return TTable::instance().retrieve(hash, hentry);
 }
 
-#if defined (SYZYGY_SUPPORT)
-Move Search::tableBaseRootSearch()
-{
-    if (!TB_LARGEST || countBits(m_position.BitsAll()) > TB_LARGEST)
-        return 0;
-
-    auto result =
-        tb_probe_root(m_position.BitsAll(WHITE), m_position.BitsAll(BLACK),
-            m_position.Bits(KW) | m_position.Bits(KB),
-            m_position.Bits(QW) | m_position.Bits(QB),
-            m_position.Bits(RW) | m_position.Bits(RB),
-            m_position.Bits(BW) | m_position.Bits(BB),
-            m_position.Bits(NW) | m_position.Bits(NB),
-            m_position.Bits(PW) | m_position.Bits(PB),
-            m_position.Fifty(),
-            m_position.CanCastle(m_position.Side(), KINGSIDE) || m_position.CanCastle(m_position.Side(), QUEENSIDE),
-            0,
-            m_position.Side() == WHITE, nullptr);
-
-    //
-    //  Validate result of a probe, if uncertain, return 0 and fallback to igel's main search at root
-    //
-
-    if (result == TB_RESULT_FAILED || result == TB_RESULT_CHECKMATE || result == TB_RESULT_STALEMATE)
-        return 0;
-
-    //
-    // Different board representation
-    //
-
-    auto to = abs(int(TB_GET_TO(result)) - 63);
-    auto from = abs(int(TB_GET_FROM(result)) - 63);
-    auto promoted = TB_GET_PROMOTES(result);
-    auto ep = TB_GET_EP(result);
-
-    Move tableBaseMove;
-
-    assert(!ep);
-
-    PIECE piece = m_position[from];
-    PIECE capture = m_position[to];
-
-    if (!promoted && !ep)
-        tableBaseMove = Move(from, to, piece, capture);
-    else {
-        switch (promoted)
-        {
-        case TB_PROMOTES_QUEEN:
-            tableBaseMove = Move(from, to, m_position[from], capture, QW | m_position.Side());
-            break;
-        case TB_PROMOTES_ROOK:
-            tableBaseMove = Move(from, to, m_position[from], capture, RW | m_position.Side());
-            break;
-        case TB_PROMOTES_BISHOP:
-            tableBaseMove = Move(from, to, m_position[from], capture, BW | m_position.Side());
-            break;
-        case TB_PROMOTES_KNIGHT:
-            tableBaseMove = Move(from, to, m_position[from], capture, NW | m_position.Side());
-            break;
-        default:
-            assert(false);
-            break;
-        }
-    }
-
-    //
-    //  Sanity check, make sure move generated by tablebase probe is a valid one
-    //
-
-    MoveList moves;
-    if (m_position.InCheck())
-        GenMovesInCheck(m_position, moves);
-    else
-        GenAllMoves(m_position, moves);
-
-    auto mvSize = moves.Size();
-    for (size_t i = 0; i < mvSize; ++i) {
-        if (moves[i].m_mv == tableBaseMove)
-            return tableBaseMove;
-    }
-
-    assert(false);
-    return 0;
-}
-#endif
-
 void Search::startWorkerThreads(Time time)
 {
     for (unsigned int i = 0; i < m_thc; ++i) {
@@ -1006,39 +920,6 @@ uint64_t Search::startSearch(Time time, int depth, bool ponderSearch, bool bench
         std::cout << std::endl;
     };
 
-    if (m_principalSearcher) {
-
-        //
-        //  Check if game is over
-        //
-
-        std::string result, comment;
-        int legalMoves = 0;
-        Move onlyMove {};
-        if (isGameOver(m_position, result, comment, onlyMove, legalMoves)) {
-            waitUntilCompletion();
-            std::cout << result << " " << comment << std::endl << std::endl;
-            printBestMove(this, m_position, onlyMove, m_ponder);
-            return 0;
-        }
-
-#if defined (SYZYGY_SUPPORT)
-        //
-        //  Probe tablebases/tt at root
-        //
-
-        auto bestTb = tableBaseRootSearch();
-
-        if (bestTb) {
-            waitUntilCompletion();
-            printBestMove(this, m_position, bestTb, m_ponder);
-            return 1;
-        }
-#endif
-
-        m_best = onlyMove; // set best move to first legal move in case we are low on time
-    }
-
     //
     //  Perform search for a best move
     //
diff --git a/src/search.h b/src/search.h
@@ -88,9 +88,6 @@ class Search
     void stopWorkerThreads();
     void lazySmpSearcher();
     void indicateWorkersStop();
-#if defined (SYZYGY_SUPPORT)
-    Move tableBaseRootSearch();
-#endif
     EVAL abSearch(EVAL alpha, EVAL beta, int depth, int ply, bool isNull, bool rootNode, bool cutNode, Move skipMove = 0);
     EVAL qSearch(EVAL alpha, EVAL beta, int ply, int depth, bool isNull = false);
     inline int extensionRequired(bool inCheck, bool onPV, int cmhistory, int fmhistory);
diff --git a/src/uci.cpp b/src/uci.cpp
@@ -31,7 +31,7 @@
 #include <iostream>
 #include <sstream>
 
-const std::string VERSION = "3.5.2";
+const std::string VERSION = "3.5.3";
 const std::string ARCHITECTURE = " 64 "
 
 #if _BTYPE==0
@@ -129,7 +129,7 @@ int Uci::handleCommands()
 void Uci::onUci()
 {
     std::cout << "id name Igel " << VERSION << ARCHITECTURE << std::endl;
-    std::cout << "id author V. Medvedev, V. Shcherbyna" << std::endl;
+    std::cout << "id author V. Shcherbyna (Igel author 2018-2023), V. Medvedev (GreKo author 2002-2018)" << std::endl;
 
     std::cout << "option name Hash type spin"   <<
         " default " << DEFAULT_HASH_SIZE        <<
