Add support for 7-man Syzygy tablebases.

diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp
index ffd731af27bd4965d506e7e7a5c1eed40fab7408..fea825bf4da4502cf6605f51c309b632401f6551 100644 (file)
--- a/src/syzygy/tbprobe.cpp
+++ b/src/syzygy/tbprobe.cpp
@@ -55,7 +55,7 @@ int Tablebases::MaxCardinality;
 
 namespace {
 
-constexpr int TBPIECES = 6; // Max number of supported pieces
+constexpr int TBPIECES = 7; // Max number of supported pieces
 
 enum { BigEndian, LittleEndian };
 enum TBType { KEY, WDL, DTZ }; // Used as template parameter
@@ -74,9 +74,9 @@ int MapB1H1H7[SQUARE_NB];
 int MapA1D1D4[SQUARE_NB];
 int MapKK[10][SQUARE_NB]; // [MapA1D1D4][SQUARE_NB]
 
-int Binomial[6][SQUARE_NB];    // [k][n] k elements from a set of n elements
-int LeadPawnIdx[5][SQUARE_NB]; // [leadPawnsCnt][SQUARE_NB]
-int LeadPawnsSize[5][4];       // [leadPawnsCnt][FILE_A..FILE_D]
+int Binomial[7][SQUARE_NB];    // [k][n] k elements from a set of n elements
+int LeadPawnIdx[6][SQUARE_NB]; // [leadPawnsCnt][SQUARE_NB]
+int LeadPawnsSize[6][4];       // [leadPawnsCnt][FILE_A..FILE_D]
 
 // Comparison function to sort leading pawns in ascending MapPawns[] order
 bool pawns_comp(Square i, Square j) { return MapPawns[i] < MapPawns[j]; }
@@ -1280,7 +1280,7 @@ void Tablebases::init(const std::string& paths) {
     Binomial[0][0] = 1;
 
     for (int n = 1; n < 64; n++) // Squares
-        for (int k = 0; k < 6 && k <= n; ++k) // Pieces
+        for (int k = 0; k < 7 && k <= n; ++k) // Pieces
             Binomial[k][n] =  (k > 0 ? Binomial[k - 1][n - 1] : 0)
                             + (k < n ? Binomial[k    ][n - 1] : 0);
 
@@ -1290,9 +1290,9 @@ void Tablebases::init(const std::string& paths) {
     // among pawns with same file, the one with lowest rank.
     int availableSquares = 47; // Available squares when lead pawn is in a2
 
-    // Init the tables for the encoding of leading pawns group: with 6-men TB we
-    // can have up to 4 leading pawns (KPPPPK).
-    for (int leadPawnsCnt = 1; leadPawnsCnt <= 4; ++leadPawnsCnt)
+    // Init the tables for the encoding of leading pawns group: with 7-men TB we
+    // can have up to 5 leading pawns (KPPPPPK).
+    for (int leadPawnsCnt = 1; leadPawnsCnt <= 5; ++leadPawnsCnt)
         for (File f = FILE_A; f <= FILE_D; ++f)
         {
             // Restart the index at every file because TB table is splitted
@@ -1336,11 +1336,22 @@ void Tablebases::init(const std::string& paths) {
             for (PieceType p3 = PAWN; p3 <= p2; ++p3) {
                 TBTables.add({KING, p1, p2, p3, KING});
 
-                for (PieceType p4 = PAWN; p4 <= p3; ++p4)
+                for (PieceType p4 = PAWN; p4 <= p3; ++p4) {
                     TBTables.add({KING, p1, p2, p3, p4, KING});
 
-                for (PieceType p4 = PAWN; p4 < KING; ++p4)
+                    for (PieceType p5 = PAWN; p5 <= p4; ++p5)
+                        TBTables.add({KING, p1, p2, p3, p4, p5, KING});
+
+                    for (PieceType p5 = PAWN; p5 < KING; ++p5)
+                        TBTables.add({KING, p1, p2, p3, p4, KING, p5});
+                }
+
+                for (PieceType p4 = PAWN; p4 < KING; ++p4) {
                     TBTables.add({KING, p1, p2, p3, KING, p4});
+
+                    for (PieceType p5 = PAWN; p5 <= p4; ++p5)
+                        TBTables.add({KING, p1, p2, p3, KING, p4, p5});
+                }
             }
 
             for (PieceType p3 = PAWN; p3 <= p1; ++p3)

diff --git a/src/ucioption.cpp b/src/ucioption.cpp
index 7b831e8059705713e8ae8839de73e9a5dbc99ce2..0ea31735fc2402e1ac6470f5904bb182494a691f 100644 (file)
--- a/src/ucioption.cpp
+++ b/src/ucioption.cpp
@@ -84,7 +84,7 @@ void init(OptionsMap& o) {
   o["SyzygyPath"]            << Option("<empty>", on_tb_path);
   o["SyzygyProbeDepth"]      << Option(1, 1, 100);
   o["Syzygy50MoveRule"]      << Option(true);
-  o["SyzygyProbeLimit"]      << Option(6, 0, 6);
+  o["SyzygyProbeLimit"]      << Option(7, 0, 7);
   o["RPCServerAddress"]      << Option("<empty>", on_rpc_server_address);
 }