Merge remote-tracking branch 'upstream/master' into HEAD

[stockfish] / src / syzygy / tbprobe.cpp

diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp
index 115815e121abbe57114e9ae00527c4e8cb0c8078..887160c7cfa3081b5ff8f521dcf755e2fac31363 100644 (file)
--- a/src/syzygy/tbprobe.cpp
+++ b/src/syzygy/tbprobe.cpp
@@ -50,9 +50,11 @@
 #include <windows.h>
 #endif
 
-using namespace Tablebases;
+using namespace Stockfish::Tablebases;
 
-int Tablebases::MaxCardinality;
+int Stockfish::Tablebases::MaxCardinality;
+
+namespace Stockfish {
 
 namespace {
 
@@ -74,7 +76,7 @@ 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 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]
 
@@ -103,9 +105,6 @@ template<> inline void swap_endian<uint8_t>(uint8_t&) {}
 
 template<typename T, int LE> T number(void* addr)
 {
-    static const union { uint32_t i; char c[4]; } Le = { 0x01020304 };
-    static const bool IsLittleEndian = (Le.c[0] == 4);
-
     T v;
 
     if ((uintptr_t)addr & (alignof(T) - 1)) // Unaligned pointer (very rare)
@@ -190,7 +189,8 @@ public:
         std::stringstream ss(Paths);
         std::string path;
 
-        while (std::getline(ss, path, SepChar)) {
+        while (std::getline(ss, path, SepChar))
+        {
             fname = path + "/" + f;
             std::ifstream::open(fname);
             if (is_open())
@@ -565,7 +565,8 @@ int decompress_pairs(PairsData* d, uint64_t idx) {
     int buf64Size = 64;
     Sym sym;
 
-    while (true) {
+    while (true)
+    {
         int len = 0; // This is the symbol length - d->min_sym_len
 
         // Now get the symbol length. For any symbol s64 of length l right-padded
@@ -603,8 +604,8 @@ int decompress_pairs(PairsData* d, uint64_t idx) {
     // We binary-search for our value recursively expanding into the left and
     // right child symbols until we reach a leaf node where symlen[sym] + 1 == 1
     // that will store the value we need.
-    while (d->symlen[sym]) {
-
+    while (d->symlen[sym])
+    {
         Sym left = d->btree[sym].get<LR::Left>();
 
         // If a symbol contains 36 sub-symbols (d->symlen[sym] + 1 = 36) and
@@ -709,7 +710,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
 
         leadPawns = b = pos.pieces(color_of(pc), PAWN);
         do
-            squares[size++] = pop_lsb(&b) ^ flipSquares;
+            squares[size++] = pop_lsb(b) ^ flipSquares;
         while (b);
 
         leadPawnsCnt = size;
@@ -729,7 +730,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
     // directly map them to the correct color and square.
     b = pos.pieces() ^ leadPawns;
     do {
-        Square s = pop_lsb(&b);
+        Square s = pop_lsb(b);
         squares[size] = s ^ flipSquares;
         pieces[size++] = Piece(pos.piece_on(s) ^ flipColor);
     } while (b);
@@ -1321,7 +1322,7 @@ 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);
 
@@ -1535,6 +1536,14 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
             WDLScore wdl = -probe_wdl(pos, &result);
             dtz = dtz_before_zeroing(wdl);
         }
+        else if (pos.is_draw(1))
+        {
+            // In case a root move leads to a draw by repetition or
+            // 50-move rule, we set dtz to zero. Note: since we are
+            // only 1 ply from the root, this must be a true 3-fold
+            // repetition inside the game history.
+            dtz = 0;
+        }
         else
         {
             // Otherwise, take dtz for the new position and correct by 1 ply
@@ -1585,6 +1594,7 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) {
 
     ProbeState result;
     StateInfo st;
+    WDLScore wdl;
 
     bool rule50 = Options["Syzygy50MoveRule"];
 
@@ -1593,7 +1603,10 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) {
     {
         pos.do_move(m.pv[0], st);
 
-        WDLScore wdl = -probe_wdl(pos, &result);
+        if (pos.is_draw(1))
+            wdl = WDLDraw;
+        else
+            wdl = -probe_wdl(pos, &result);
 
         pos.undo_move(m.pv[0]);
 
@@ -1610,3 +1623,5 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) {
 
     return true;
 }
+
+} // namespace Stockfish