See implementation (#64)

* Prepared simple test for agin and half moves

* Moved repetition map to the board

* Fixed default board in engine class

* Added board creation

* Working GetDefault call

* fixed repetitions init

* Created test file

* Added 50 moves tests

* Added next draw tests

* Fixed 3fold

* Reworked search thread mechanics

* Fixed Thread Manager destruction

* Enforced depth limit on search

* Added SEE tests

* Added delta-prunning with SEE

* Improved delta prunning. TODO: fix bugs with ZHasher

* Added zhasher test sketch

* Added zhasher test

* Removed positional evaluation from draw meterial constelations

* Added test breaking ZHasher

* gitignore fix

* Fixed hasher bugh

* Applied clang format

* Fixed include

* Update SearchTests.cc

* Update GameTimeManager.cpp

---------

Co-authored-by: Łukasz Kryczka <60490378+kryczkal@users.noreply.github.com>

Author: Jlisowskyy

.gitignore

@@ -29,3 +29,4 @@ lib/
 c-chess*
 
 uci*
+.vs/

CMakeLists.txt

@@ -9,6 +9,22 @@ set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 # We C++ 20 is required by the main exec
 
+################################################################################
+#                             Tunable parameters                               #
+################################################################################
+
+# Uncomment to stop enforcing inline on INLINE macro
+#add_compile_definitions(PREVENT_FORCE_INLINE=1)
+
+# Uncomment to add gathering TT statistics
+add_compile_definitions(TEST_TT=1)
+
+# Uncomment to add displaying debug info about aspiration window
+add_compile_definitions(TEST_ASP_WIN=1)
+
+# Uncomment to allow usage of aspiration windows inside the search
+#add_compile_definitions(USE_ASP_WIN=1)
+
 ################################################################################
 #                     Inspecting platform capabilities                         #
 ################################################################################
@@ -122,6 +138,7 @@ set(CHECKMATE_CHARIOT_SOURCES
         include/TestsAndDebugging/TestSetup.h
         include/TestsAndDebugging/StateReconstructor.h
         include/TestsAndDebugging/DebugTools.h
+        src/DebugTools.cpp
 )
 
 # Create a library with the core functionality
@@ -142,6 +159,8 @@ add_executable(Checkmate-Chariot-Tests
         tests/Logger.cc
         tests/UCITranslator.cc
         tests/BoardEvaluator.cc
+        tests/ChessMechanics.cc
+        tests/SearchTests.cc
 )
 target_link_libraries(
         Checkmate-Chariot-Tests PRIVATE Checkmate-Core GTest::gtest_main)
@@ -174,9 +193,9 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
 
     if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-        target_compile_options(Checkmate-Core PUBLIC -fconstexpr-ops-limit=133554432;-g;-fopenmp)
+        target_compile_options(Checkmate-Core PUBLIC -fconstexpr-ops-limit=133554432;-g;-fopenmp;-O0)
     elseif (CMAKE_BUILD_TYPE STREQUAL "Release")
-        target_compile_options(Checkmate-Core PUBLIC -O3;-march=native;-fopenmp;-fconstexpr-ops-limit=1335544322 ;-funroll-loops;-fno-peel-loops;-fno-tracer)
+        target_compile_options(Checkmate-Core PUBLIC -O3;-march=native;-fopenmp;-fconstexpr-ops-limit=1335544322 ;-funroll-loops;-fno-peel-loops;-fno-tracer;)
     elseif(CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
         target_compile_options(Checkmate-Core PUBLIC -g;-fconstexpr-ops-limit=133554432;-fopenmp;-O2;-march=native;-fopenmp)
     else()
@@ -201,15 +220,6 @@ else()
     message(FATAL_ERROR "Unknown compiler")
 endif()
 
-# Uncomment to add gathering TT statistics
-add_compile_definitions(TEST_TT=1)
-
-# Uncomment to add displaying debug info about aspiration window
-add_compile_definitions(TEST_ASP_WIN=1)
-
-# Uncomment to allow usage of aspiration windows inside the search
-#add_compile_definitions(USE_ASP_WIN=1)
-
 ################################################################################
 #                                  Post build                                  #
 ################################################################################

README.md

@@ -30,7 +30,7 @@ Clone the repository to the desired directory:
 
 Use a command below to build the project:
 ```shell
-   cmake CMakeLists.txt -DCMAKE_BUILD_TYPE=RELEASE 
+   cmake CMakeLists.txt -DCMAKE_BUILD_TYPE=Release ; make -j {Number of cores on your platform} 
 ```
 ## Features
 

Tests/searchTests.csv

@@ -1,10 +1,10 @@
-3r2k1/B7/4q3/1R4P1/1P3r2/8/2P2P1p/R4K2 w - - 0 49, 10
-rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1, 10
-r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1, 10
-8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 1, 10
-r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1, 10
-r2q1rk1/pP1p2pp/Q4n2/bbp1p3/Np6/1B3NBn/pPPP1PPP/R3K2R b KQ - 0 1, 10
-rnbq1k1r/pp1Pbppp/2p5/8/2B5/8/PPP1NnPP/RNBQK2R w KQ - 1 8, 10
-r4rk1/1pp1qppp/p1np1n2/2b1p1B1/2B1P1b1/P1NP1N2/1PP1QPPP/R4RK1 w - - 0 10, 10
-3rr1k1/1pq2pp1/p2nb2p/2pp4/6PR/2PBPN2/PPQ2PP1/K2R4 b - - 0 20, 10
-7k/r2q1ppp/1p1p4/p1bPrPPb/P1PNPR1P/1PQ5/2B5/R5K1 w - - 23 16, 10
+3r2k1/B7/4q3/1R4P1/1P3r2/8/2P2P1p/R4K2 w - - 0 49, 9
+rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1, 9
+r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1, 9
+8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 1, 9
+r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1, 9
+r2q1rk1/pP1p2pp/Q4n2/bbp1p3/Np6/1B3NBn/pPPP1PPP/R3K2R b KQ - 0 1, 9
+rnbq1k1r/pp1Pbppp/2p5/8/2B5/8/PPP1NnPP/RNBQK2R w KQ - 1 8, 9
+r4rk1/1pp1qppp/p1np1n2/2b1p1B1/2B1P1b1/P1NP1N2/1PP1QPPP/R4RK1 w - - 0 10, 9
+3rr1k1/1pq2pp1/p2nb2p/2pp4/6PR/2PBPN2/PPQ2PP1/K2R4 b - - 0 20, 9
+7k/r2q1ppp/1p1p4/p1bPrPPb/P1PNPR1P/1PQ5/2B5/R5K1 w - - 23 16, 9

include/Board.h

@@ -8,8 +8,10 @@
 #include <array>
 #include <bitset>
 #include <cinttypes>
+#include <unordered_map>
 
 #include "BitOperations.h"
+#include "CompilationConstants.h"
 
 /*
  * Given enum defines values and order of both colors. All indexing schemes used across the projects follows given
@@ -100,6 +102,16 @@ enum CastlingPossibilities : size_t
 
 struct Board
 {
+    // ------------------------------
+    // Class creation
+    // ------------------------------
+
+    Board()  = default;
+    ~Board() = default;
+
+    Board(const Board &)            = default;
+    Board &operator=(const Board &) = default;
+
     // ------------------------------
     // class interaction
     // ------------------------------
@@ -115,6 +127,8 @@ struct Board
 
     constexpr uint64_t GetFigBoard(int col, size_t figDesc) const { return BitBoards[col * BitBoardsPerCol + figDesc]; }
 
+    [[nodiscard]] bool IsEndGame() const { return LastPhase < END_GAME_PHASE; }
+
     // ------------------------------
     // Class fields
     // ------------------------------
@@ -155,12 +169,28 @@ struct Board
         MinMsbPossible << 61 | MinMsbPossible << 62, MinMsbPossible << 58 | MinMsbPossible << 59 | MinMsbPossible << 57
     };
 
-    std::bitset<CastlingCount + 1> Castlings{0}; // additional sentinel field
-    uint64_t ElPassantField                = MaxMsbPossible >> InvalidElPassantField;
-    int MovingColor                        = WHITE;
-    int HalfMoves                          = {};
-    uint64_t BitBoards[BitBoardsCount + 1] = {}; // additional sentinel board
-    uint16_t Age{};                              // stores total half moves since the beginning of the game
+    // --------------------------------
+    // Main processing components
+    // --------------------------------
+
+    std::bitset<CastlingCount + 1> Castlings           = {0}; // additional sentinel field
+    uint64_t ElPassantField                            = MaxMsbPossible >> InvalidElPassantField;
+    int MovingColor                                    = WHITE;
+    std::array<uint64_t, BitBoardsCount + 1> BitBoards = {}; // additional sentinel board
+
+    // --------------------------------------
+    // Draw and state monitoring fields
+    // --------------------------------------
+
+    int HalfMoves                                 = {};
+    uint16_t Age                                  = {}; // stores total half moves since the beginning of the game
+    std::unordered_map<uint64_t, int> Repetitions = {}; // Stores hashes of previous encountered positions
+
+    // ------------------------------
+    // Optimisation components
+    // ------------------------------
+
+    int LastPhase = {}; // Field used to save previously calculated phase during evaluation
 };
 
 #endif // BOARD_H

include/CompilationConstants.h

@@ -24,14 +24,26 @@ static constexpr int16_t SPECIAL_DRAW_SCORE = 0;
 
 static constexpr int RESERVED_SCORE_VALUES           = 64;
 static constexpr int TIME_STOP_RESERVED_VALUE        = std::numeric_limits<int16_t>::max() - 1;
-static constexpr int NO_EVAL                         = std::numeric_limits<int16_t>::max() - 2;
+static constexpr int NO_EVAL_RESERVED_VALUE          = std::numeric_limits<int16_t>::max() - 2;
+static constexpr int EVAL_DRAW_RESERVED_VALUE        = std::numeric_limits<int16_t>::max() - 3;
 static constexpr int NEGATIVE_INFINITY               = std::numeric_limits<int16_t>::min() + RESERVED_SCORE_VALUES + 1;
 static constexpr int POSITIVE_INFINITY               = std::numeric_limits<int16_t>::max() - RESERVED_SCORE_VALUES;
 static constexpr int BEST_MATE_VALUE                 = NEGATIVE_INFINITY + MAX_SEARCH_DEPTH;
 static constexpr int BEST_MATE_VALUE_ABS             = -(BEST_MATE_VALUE);
 static constexpr uint16_t QUIESENCE_AGE_DIFF_REPLACE = 16;
 static constexpr uint16_t DEFAULT_AGE_DIFF_REPLACE   = 10;
 
+// average pawn value + some part of average pawn
+static constexpr int DELTA_PRUNNING_SAFETY_MARGIN = 115 + 115 / 6;
+// average queen value - average pawn value
+static constexpr int DELTA_PRUNNING_PROMO = 1000 - 115;
+
+// value below which SEE capture is considered bad
+static constexpr int SEE_GOOD_MOVE_BOUNDARY = 115 / 2;
+
+// value of phase below game is considering to be an end-game
+static constexpr int END_GAME_PHASE = 64;
+
 /* Depth from which Internal Iterative Deepening (IID) is used */
 static constexpr int IID_MIN_DEPTH = 6;
 
@@ -63,6 +75,11 @@ static constexpr int MAX_ASP_WINDOW_RETRIES       = 4;
 
 #endif
 
+#else
+
+// No forced inline allowed
+#define INLINE
+
 #endif // PREVENT_FORCE_INLINE
 
 // ------------------------------

include/Engine.h

@@ -28,7 +28,7 @@ class Engine
     // --------------------------------------
 
     public:
-    Engine() = default;
+    Engine();
 
     /* Load with initial state */
     Engine(const Board &bd) : _board(bd), _startingBoard(bd) {}
@@ -72,7 +72,11 @@ class Engine
     /* Simply returns the moving color */
     [[nodiscard]] int GetMovingColor() const { return _board.MovingColor; }
 
-    [[nodiscard]] uint16_t GetAge() const { return _board.Age; }
+    [[nodiscard]] uint16_t GetAge() const
+    {
+        TraceIfFalse(_board.Age >= 1, "Board contains age smaller than 1!");
+        return _board.Age;
+    }
 
     /* Returns FEN encoded actual board state */
     [[nodiscard]] std::string GetFenTranslation() const;
@@ -128,10 +132,10 @@ class Engine
     // private fields
     // ------------------------------
 
-    Board _board         = FenTranslator::GetDefault();
-    Board _startingBoard = FenTranslator::GetDefault();
+    const Board _defaultBoard;
+    Board _board;
+    Board _startingBoard;
     OpeningBook _book{};
-    std::unordered_map<uint64_t, int> _repetitionMap{};
     std::string _bookPath = _defaultBookPath;
 
     bool _isStartPosPlayed                            = true;

include/EngineUtils.h

@@ -74,7 +74,22 @@ std::string ConvertToStrPos(uint64_t boardMap);
 extern const char IndexToFigCharMap[Board::BitBoardsCount];
 
 /* Does the same thing as above but in reverse */
-extern const std::unordered_map<char, size_t> FigCharToIndexMap;
+/* This object must be inline due to problem with extern initialisation on startup  */
+/* When FenTranslator referred empty not initialised map on its static field init */
+inline static const std::unordered_map<char, size_t> FigCharToIndexMap{
+    {'P',   wPawnsIndex},
+    {'N', wKnightsIndex},
+    {'B', wBishopsIndex},
+    {'R',   wRooksIndex},
+    {'Q',  wQueensIndex},
+    {'K',    wKingIndex},
+    {'p',   bPawnsIndex},
+    {'n', bKnightsIndex},
+    {'b', bBishopsIndex},
+    {'r',   bRooksIndex},
+    {'q',  bQueensIndex},
+    {'k',    bKingIndex}
+};
 
 /*
  * Function checks whether given score is a mate,

include/Evaluation/BoardEvaluator.h

@@ -122,11 +122,19 @@ class BoardEvaluator
         const auto [isSuccess, counts] = _countFigures(bd);
         const int32_t phase            = _calcPhase(counts);
 
+        // save phase for later usage
+        bd.LastPhase = phase;
+
         if constexpr (mode == EvalMode::PrintMode)
             BoardEvaluatorPrinter::setPhase<mode>(phase);
 
         const int32_t materialEval =
             isSuccess ? _materialTable[_getMaterialBoardIndex(counts)] : _slowMaterialCalculation<mode>(counts, phase);
+
+        // Avoid positional evaluation on material constellations that are enforced draws
+        if (materialEval == EVAL_DRAW_RESERVED_VALUE)
+            return DRAW_SCORE;
+
         const int32_t positionEval = _evaluateFields<mode>(bd, phase);
 
         // only to print bonuses
@@ -165,6 +173,16 @@ class BoardEvaluator
         return {whiteMaterial, blackMaterial};
     }
 
+    /* Function calculates phase of the given board and saves the results inside LastPhase field */
+    static void PopulateLastPhase(Board &bd)
+    {
+        const auto [isSuccess, counts] = _countFigures(bd);
+        const int32_t phase            = _calcPhase(counts);
+
+        // save phase for later usage
+        bd.LastPhase = phase;
+    }
+
     // ------------------------------
     // Private class methods
     // ------------------------------
@@ -436,6 +454,21 @@ class BoardEvaluator
         -10000 // king
     };
 
+    static constexpr int16_t ColorlessBasicFigureValues[]{
+        100,   // Pawn
+        325,   // Knight
+        325,   // Bishop
+        500,   // RookS
+        975,   // Queen
+        10000, // king
+        100,   // Pawn
+        325,   // Knight
+        325,   // Bishop
+        500,   // Rook
+        975,   // Queen
+        10000  // king
+    };
+
     // values that are used to calculate material value of given board at the end-game stage
     static constexpr int16_t EndGameFigureValues[]{
         130,  // Pawn
@@ -564,6 +597,8 @@ class BoardEvaluator
 
     static constexpr size_t BlackFigStartIndex = 5;
 
+    // Table stores hashed material values for material constellations limited by hash function mentioned above
+    // In case of draw material stored value is equal to EVAL_DRAW_RESERVED_VALUE
     static MaterialArrayT _materialTable;
 };
 

include/Interface/FenTranslator.h

@@ -17,12 +17,19 @@ struct FenTranslator
     // Class interaction
     // ------------------------------
 
-    static const Board &GetDefault();
+    static INLINE Board GetDefault()
+    {
+        Board rv;
+        Translate(StartingPosition, rv);
+        return rv;
+    }
 
     static bool Translate(const std::string &fenPos, Board &bd)
         // Function simply translates position from FEN notation into inner representation.
         ;
 
+    static Board GetTranslated(const std::string &fenPos);
+
     static std::string Translate(const Board &board);
 
     // ------------------------------
@@ -97,21 +104,6 @@ struct FenTranslator
 
     public:
     static constexpr auto StartingPosition = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
-
-    static constexpr Board StartBoard = {
-        .Castlings      = {0b11111},
-        .ElPassantField = Board::InvalidElPassantBitBoard,
-        .MovingColor    = WHITE,
-        .BitBoards =
-            {
-                           65280LLU, 66LLU,
-                           36LLU, 129LLU,
-                           8LLU, 16LLU,
-                           71776119061217280LLU, 4755801206503243776LLU,
-                           2594073385365405696LLU, 9295429630892703744LLU,
-                           576460752303423488LLU, 1152921504606846976LLU,
-                           }
-    };
 };
 
 #endif // FENTRANSLATOR_H