Merge pull request LeelaChessZero#8 from LeelaChessZero/master

Merge Master

Author: Naphthalin

src/chess/board.cc

@@ -969,7 +969,7 @@ MoveList ChessBoard::GenerateLegalMoves() const {
   return result;
 }
 
-void ChessBoard::SetFromFen(const std::string& fen, int* no_capture_ply,
+void ChessBoard::SetFromFen(const std::string& fen, int* rule50_ply,
                             int* moves) {
   Clear();
   int row = 7;
@@ -980,10 +980,10 @@ void ChessBoard::SetFromFen(const std::string& fen, int* no_capture_ply,
   string who_to_move;
   string castlings;
   string en_passant;
-  int no_capture_halfmoves;
+  int rule50_halfmoves;
   int total_moves;
   fen_str >> board >> who_to_move >> castlings >> en_passant >>
-      no_capture_halfmoves >> total_moves;
+      rule50_halfmoves >> total_moves;
 
   if (!fen_str) throw Exception("Bad fen string: " + fen);
 
@@ -1096,7 +1096,7 @@ void ChessBoard::SetFromFen(const std::string& fen, int* no_capture_ply,
   if (who_to_move == "b" || who_to_move == "B") {
     Mirror();
   }
-  if (no_capture_ply) *no_capture_ply = no_capture_halfmoves;
+  if (rule50_ply) *rule50_ply = rule50_halfmoves;
   if (moves) *moves = total_moves;
 }
 

src/chess/board.h

@@ -67,10 +67,10 @@ class ChessBoard {
   static const BitBoard kPawnMask;
 
   // Sets position from FEN string.
-  // If @no_capture_ply and @moves are not nullptr, they are filled with number
+  // If @rule50_ply and @moves are not nullptr, they are filled with number
   // of moves without capture and number of full moves since the beginning of
   // the game.
-  void SetFromFen(const std::string& fen, int* no_capture_ply = nullptr,
+  void SetFromFen(const std::string& fen, int* rule50_ply = nullptr,
                   int* moves = nullptr);
   // Nullifies the whole structure.
   void Clear();

src/chess/position.cc

@@ -32,17 +32,17 @@
 namespace lczero {
 
 Position::Position(const Position& parent, Move m)
-    : no_capture_ply_(parent.no_capture_ply_ + 1),
+    : rule50_ply_(parent.rule50_ply_ + 1),
       ply_count_(parent.ply_count_ + 1) {
   them_board_ = parent.us_board_;
-  const bool capture = them_board_.ApplyMove(m);
+  const bool is_zeroing = them_board_.ApplyMove(m);
   us_board_ = them_board_;
   us_board_.Mirror();
-  if (capture) no_capture_ply_ = 0;
+  if (is_zeroing) rule50_ply_ = 0;
 }
 
-Position::Position(const ChessBoard& board, int no_capture_ply, int game_ply)
-    : no_capture_ply_(no_capture_ply), repetitions_(0), ply_count_(game_ply) {
+Position::Position(const ChessBoard& board, int rule50_ply, int game_ply)
+    : rule50_ply_(rule50_ply), repetitions_(0), ply_count_(game_ply) {
   us_board_ = board;
   them_board_ = board;
   them_board_.Mirror();
@@ -67,17 +67,17 @@ GameResult PositionHistory::ComputeGameResult() const {
   }
 
   if (!board.HasMatingMaterial()) return GameResult::DRAW;
-  if (Last().GetNoCaptureNoPawnPly() >= 100) return GameResult::DRAW;
+  if (Last().GetRule50Ply() >= 100) return GameResult::DRAW;
   if (Last().GetGamePly() >= 450) return GameResult::DRAW;
   if (Last().GetRepetitions() >= 2) return GameResult::DRAW;
 
   return GameResult::UNDECIDED;
 }
 
-void PositionHistory::Reset(const ChessBoard& board, int no_capture_ply,
+void PositionHistory::Reset(const ChessBoard& board, int rule50_ply,
                             int game_ply) {
   positions_.clear();
-  positions_.emplace_back(board, no_capture_ply, game_ply);
+  positions_.emplace_back(board, rule50_ply, game_ply);
 }
 
 void PositionHistory::Append(Move m) {
@@ -91,14 +91,14 @@ void PositionHistory::Append(Move m) {
 int PositionHistory::ComputeLastMoveRepetitions() const {
   const auto& last = positions_.back();
   // TODO(crem) implement hash/cache based solution.
-  if (last.GetNoCaptureNoPawnPly() < 4) return 0;
+  if (last.GetRule50Ply() < 4) return 0;
 
   for (int idx = positions_.size() - 3; idx >= 0; idx -= 2) {
     const auto& pos = positions_[idx];
     if (pos.GetBoard() == last.GetBoard()) {
       return 1 + pos.GetRepetitions();
     }
-    if (pos.GetNoCaptureNoPawnPly() < 2) return 0;
+    if (pos.GetRule50Ply() < 2) return 0;
   }
   return 0;
 }
@@ -107,7 +107,7 @@ bool PositionHistory::DidRepeatSinceLastZeroingMove() const {
   for (auto iter = positions_.rbegin(), end = positions_.rend(); iter != end;
        ++iter) {
     if (iter->GetRepetitions() > 0) return true;
-    if (iter->GetNoCaptureNoPawnPly() == 0) return false;
+    if (iter->GetRule50Ply() == 0) return false;
   }
   return false;
 }
@@ -119,7 +119,7 @@ uint64_t PositionHistory::HashLast(int positions) const {
     if (!positions--) break;
     hash = HashCat(hash, iter->Hash());
   }
-  return HashCat(hash, Last().GetNoCaptureNoPawnPly());
+  return HashCat(hash, Last().GetRule50Ply());
 }
 
 }  // namespace lczero

src/chess/position.h

@@ -38,7 +38,7 @@ class Position {
   // From parent position and move.
   Position(const Position& parent, Move m);
   // From particular position.
-  Position(const ChessBoard& board, int no_capture_ply, int game_ply);
+  Position(const ChessBoard& board, int rule50_ply, int game_ply);
 
   uint64_t Hash() const;
   bool IsBlackToMove() const { return us_board_.flipped(); }
@@ -54,7 +54,7 @@ class Position {
   void SetRepetitions(int repetitions) { repetitions_ = repetitions; }
 
   // Number of ply with no captures and pawn moves.
-  int GetNoCaptureNoPawnPly() const { return no_capture_ply_; }
+  int GetRule50Ply() const { return rule50_ply_; }
 
   // Gets board from the point of view of player to move.
   const ChessBoard& GetBoard() const { return us_board_; }
@@ -70,7 +70,7 @@ class Position {
   ChessBoard them_board_;
 
   // How many half-moves without capture or pawn move was there.
-  int no_capture_ply_ = 0;
+  int rule50_ply_ = 0;
   // How many repetitions this position had before. For new positions it's 0.
   int repetitions_;
   // number of half-moves since beginning of the game.
@@ -102,7 +102,7 @@ class PositionHistory {
   int GetLength() const { return positions_.size(); }
 
   // Resets the position to a given state.
-  void Reset(const ChessBoard& board, int no_capture_ply, int game_ply);
+  void Reset(const ChessBoard& board, int rule50_ply, int game_ply);
 
   // Appends a position to history.
   void Append(Move m);

src/mcts/node.cc

@@ -380,18 +380,21 @@ V5TrainingData Node::GetV5TrainingData(
   // Other params.
   if (input_format ==
       pblczero::NetworkFormat::INPUT_112_WITH_CANONICALIZATION) {
-    result.side_to_move = position.GetBoard().en_passant().as_int() >> 56;
+    result.side_to_move_or_enpassant =
+        position.GetBoard().en_passant().as_int() >> 56;
     if ((transform & FlipTransform) != 0) {
-      result.side_to_move = ReverseBitsInBytes(result.side_to_move);
+      result.side_to_move_or_enpassant =
+          ReverseBitsInBytes(result.side_to_move_or_enpassant);
     }
     // Send transform in deprecated move count so rescorer can reverse it to
     // calculate the actual move list from the input data.
-    result.deprecated_move_count = transform;
+    result.invariance_info =
+        transform | (position.IsBlackToMove() ? (1u << 7) : 0u);
   } else {
-    result.side_to_move = position.IsBlackToMove() ? 1 : 0;
-    result.deprecated_move_count = 0;
+    result.side_to_move_or_enpassant = position.IsBlackToMove() ? 1 : 0;
+    result.invariance_info = 0;
   }
-  result.rule50_count = position.GetNoCaptureNoPawnPly();
+  result.rule50_count = position.GetRule50Ply();
 
   // Game result.
   if (game_result == GameResult::WHITE_WON) {
@@ -468,7 +471,9 @@ bool NodeTree::ResetToPosition(const std::string& starting_fen,
   int no_capture_ply;
   int full_moves;
   starting_board.SetFromFen(starting_fen, &no_capture_ply, &full_moves);
-  if (gamebegin_node_ && history_.Starting().GetBoard() != starting_board) {
+  if (gamebegin_node_ &&
+      (history_.Starting().GetBoard() != starting_board ||
+       history_.Starting().GetNoCaptureNoPawnPly() != no_capture_ply)) {
     // Completely different position.
     DeallocateTree();
   }

src/mcts/search.cc

@@ -1138,7 +1138,7 @@ void SearchWorker::ExtendNode(Node* node) {
       return;
     }
 
-    if (history_.Last().GetNoCaptureNoPawnPly() >= 100) {
+    if (history_.Last().GetRule50Ply() >= 100) {
       node->MakeTerminal(GameResult::DRAW);
       return;
     }
@@ -1150,7 +1150,7 @@ void SearchWorker::ExtendNode(Node* node) {
 
     // Neither by-position or by-rule termination, but maybe it's a TB position.
     if (search_->syzygy_tb_ && board.castlings().no_legal_castle() &&
-        history_.Last().GetNoCaptureNoPawnPly() == 0 &&
+        history_.Last().GetRule50Ply() == 0 &&
         (board.ours() | board.theirs()).count() <=
             search_->syzygy_tb_->max_cardinality()) {
       ProbeState state;

src/neural/encoder.cc

@@ -181,7 +181,7 @@ InputPlanes EncodePositionForNN(
     } else {
       if (we_are_black) result[kAuxPlaneBase + 4].SetAll();
     }
-    result[kAuxPlaneBase + 5].Fill(history.Last().GetNoCaptureNoPawnPly());
+    result[kAuxPlaneBase + 5].Fill(history.Last().GetRule50Ply());
     // Plane kAuxPlaneBase + 6 used to be movecount plane, now it's all zeros.
     // Plane kAuxPlaneBase + 7 is all ones to help NN find board edges.
     result[kAuxPlaneBase + 7].SetAll();
@@ -245,7 +245,7 @@ InputPlanes EncodePositionForNN(
     if (history_idx > 0) flip = !flip;
     // If no capture no pawn is 0, the previous was start of game, capture or
     // pawn push, so no need to go back further if stopping early.
-    if (stop_early && position.GetNoCaptureNoPawnPly() == 0) break;
+    if (stop_early && position.GetRule50Ply() == 0) break;
   }
   if (transform != NoTransform) {
     // Transform all masks.

src/neural/writer.h

@@ -26,7 +26,9 @@
 */
 
 #include <zlib.h>
+
 #include <fstream>
+
 #include "utils/cppattributes.h"
 
 #pragma once
@@ -44,9 +46,14 @@ struct V5TrainingData {
   uint8_t castling_us_oo;
   uint8_t castling_them_ooo;
   uint8_t castling_them_oo;
-  uint8_t side_to_move;
+  // For input type 3 contains enpassant column as a mask.
+  uint8_t side_to_move_or_enpassant;
   uint8_t rule50_count;
-  uint8_t deprecated_move_count;  // left in to keep 8 int8 fields.
+  // For input type 3 contains a bit field indicating the transform that was
+  // used and the original side to move info.
+  // Side to move is in the top bit, transform in the lower bits.
+  // In versions prior to v5 this spot contained an unused move count field.
+  uint8_t invariance_info;
   int8_t result;
   float root_q;
   float best_q;

src/selfplay/game.cc

@@ -281,7 +281,11 @@ void SelfPlayGame::WriteTrainingData(TrainingDataWriter* writer) const {
   // different approach.
   float m_estimate = training_data_.back().best_m + training_data_.size() - 1;
   for (auto chunk : training_data_) {
-    const bool black_to_move = chunk.side_to_move;
+    bool black_to_move = chunk.side_to_move_or_enpassant;
+    if (chunk.input_format ==
+        pblczero::NetworkFormat::INPUT_112_WITH_CANONICALIZATION) {
+      black_to_move = (chunk.invariance_info & (1u << 7)) != 0;
+    }
     if (game_result_ == GameResult::WHITE_WON) {
       chunk.result = black_to_move ? -1 : 1;
     } else if (game_result_ == GameResult::BLACK_WON) {

src/syzygy/syzygy.cc

@@ -1598,7 +1598,7 @@ int SyzygyTablebase::probe_dtz(const Position& pos, ProbeState* result) {
   int min_DTZ = 0xFFFF;
   for (const Move& move : pos.GetBoard().GenerateLegalMoves()) {
     Position next_pos = Position(pos, move);
-    const bool zeroing = next_pos.GetNoCaptureNoPawnPly() == 0;
+    const bool zeroing = next_pos.GetRule50Ply() == 0;
     // For zeroing moves we want the dtz of the move _before_ doing it,
     // otherwise we will get the dtz of the next move sequence. Search the
     // position after the move to get the score sign (because even in a winning
@@ -1629,7 +1629,7 @@ bool SyzygyTablebase::root_probe(const Position& pos, bool has_repeated,
   ProbeState result;
   auto root_moves = pos.GetBoard().GenerateLegalMoves();
   // Obtain 50-move counter for the root position
-  const int cnt50 = pos.GetNoCaptureNoPawnPly();
+  const int cnt50 = pos.GetRule50Ply();
   // Check whether a position was repeated since the last zeroing move.
   const bool rep = has_repeated;
   int dtz;
@@ -1640,7 +1640,7 @@ bool SyzygyTablebase::root_probe(const Position& pos, bool has_repeated,
   for (auto& m : root_moves) {
     Position next_pos = Position(pos, m);
     // Calculate dtz for the current move counting from the root position
-    if (next_pos.GetNoCaptureNoPawnPly() == 0) {
+    if (next_pos.GetRule50Ply() == 0) {
       // In case of a zeroing move, dtz is one of -101/-1/0/1/101
       const WDLScore wdl = static_cast<WDLScore>(-probe_wdl(next_pos, &result));
       dtz = dtz_before_zeroing(wdl);