Consolidate Square Flipping

Add a flip_rank() and flip_file() so that all of the square flipping can be consolidated.

STC
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 57234 W: 11064 L: 10969 D: 35201
Ptnml(0-2): 822, 6562, 13801, 6563, 869
http://tests.stockfishchess.org/tests/view/5e5d2f2aafe6254521f2ffaa

closes https://github.com/official-stockfish/Stockfish/pull/2568

No functional change.

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 5fdd307e4427c49556dc4bb49cbf1afc92ba8771..16c072beb2c9a6e8250cec1ad26d2b0ed8aabc62 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -74,9 +74,9 @@ namespace {
     assert(pos.count<PAWN>(strongSide) == 1);
 
     if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)
     assert(pos.count<PAWN>(strongSide) == 1);
 
     if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)

-        sq = Square(int(sq) ^ 7); // Mirror SQ_H1 -> SQ_A1
+        sq = flip_file(sq);

 
 

-    return strongSide == WHITE ? sq : ~sq;
+    return strongSide == WHITE ? sq : flip_rank(sq);

   }
 
 } // namespace
   }
 
 } // namespace

diff --git a/src/psqt.cpp b/src/psqt.cpp
index 8bad7ed427c5c2dd2f2de48ab9a5bf64b58d8b29..f6f5933cb250ab394e2030cdc6fb35954bc3ac45 100644 (file)
--- a/src/psqt.cpp
+++ b/src/psqt.cpp
@@ -114,7 +114,7 @@ void init() {
           File f = map_to_queenside(file_of(s));
           psq[ pc][ s] = score + (type_of(pc) == PAWN ? PBonus[rank_of(s)][file_of(s)]
                                                       : Bonus[pc][rank_of(s)][f]);
           File f = map_to_queenside(file_of(s));
           psq[ pc][ s] = score + (type_of(pc) == PAWN ? PBonus[rank_of(s)][file_of(s)]
                                                       : Bonus[pc][rank_of(s)][f]);

-          psq[~pc][~s] = -psq[pc][s];
+          psq[~pc][flip_rank(s)] = -psq[pc][s];

       }
   }
 }
       }
   }
 }

diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp
index 721a0ef5ba62fc950af0877fc961f0f24a229bf1..6f36945587f8e6f2e4f81a95e99e107337ccb7a9 100644 (file)
--- a/src/syzygy/tbprobe.cpp
+++ b/src/syzygy/tbprobe.cpp
@@ -66,7 +66,6 @@ enum TBType { KEY, WDL, DTZ }; // Used as template parameter
 enum TBFlag { STM = 1, Mapped = 2, WinPlies = 4, LossPlies = 8, Wide = 16, SingleValue = 128 };
 
 inline WDLScore operator-(WDLScore d) { return WDLScore(-int(d)); }
 enum TBFlag { STM = 1, Mapped = 2, WinPlies = 4, LossPlies = 8, Wide = 16, SingleValue = 128 };
 
 inline WDLScore operator-(WDLScore d) { return WDLScore(-int(d)); }

-inline Square operator^=(Square& s, int i) { return s = Square(int(s) ^ i); }

 inline Square operator^(Square s, int i) { return Square(int(s) ^ i); }
 
 const std::string PieceToChar = " PNBRQK  pnbrqk";
 inline Square operator^(Square s, int i) { return Square(int(s) ^ i); }
 
 const std::string PieceToChar = " PNBRQK  pnbrqk";


@@ -743,7 +742,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
     // the triangle A1-D1-D4.
     if (file_of(squares[0]) > FILE_D)
         for (int i = 0; i < size; ++i)
     // the triangle A1-D1-D4.
     if (file_of(squares[0]) > FILE_D)
         for (int i = 0; i < size; ++i)

-            squares[i] ^= 7; // Horizontal flip: SQ_H1 -> SQ_A1
+            squares[i] = flip_file(squares[i]);

 
     // Encode leading pawns starting with the one with minimum MapPawns[] and
     // proceeding in ascending order.
 
     // Encode leading pawns starting with the one with minimum MapPawns[] and
     // proceeding in ascending order.


@@ -762,7 +761,7 @@ Ret do_probe_table(const Position& pos, T* entry, WDLScore wdl, ProbeState* resu
     // piece is below RANK_5.
     if (rank_of(squares[0]) > RANK_4)
         for (int i = 0; i < size; ++i)
     // piece is below RANK_5.
     if (rank_of(squares[0]) > RANK_4)
         for (int i = 0; i < size; ++i)

-            squares[i] ^= SQ_A8; // Vertical flip: SQ_A8 -> SQ_A1
+            squares[i] = flip_rank(squares[i]);

 
     // Look for the first piece of the leading group not on the A1-D4 diagonal
     // and ensure it is mapped below the diagonal.
 
     // Look for the first piece of the leading group not on the A1-D4 diagonal
     // and ensure it is mapped below the diagonal.


@@ -1344,7 +1343,7 @@ void Tablebases::init(const std::string& paths) {
                 if (leadPawnsCnt == 1)
                 {
                     MapPawns[sq] = availableSquares--;
                 if (leadPawnsCnt == 1)
                 {
                     MapPawns[sq] = availableSquares--;

-                    MapPawns[sq ^ 7] = availableSquares--; // Horizontal flip
+                    MapPawns[flip_file(sq)] = availableSquares--;

                 }
                 LeadPawnIdx[leadPawnsCnt][sq] = idx;
                 idx += Binomial[leadPawnsCnt - 1][MapPawns[sq]];
                 }
                 LeadPawnIdx[leadPawnsCnt][sq] = idx;
                 idx += Binomial[leadPawnsCnt - 1][MapPawns[sq]];

diff --git a/src/types.h b/src/types.h
index 58d05d2c6d8486ee8ba760d6760fe8040837470d..d4937fd65cd6b7c1425156a8ea853ad068aa0472 100644 (file)
--- a/src/types.h
+++ b/src/types.h
@@ -358,8 +358,12 @@ constexpr Color operator~(Color c) {
   return Color(c ^ BLACK); // Toggle color
 }
 
   return Color(c ^ BLACK); // Toggle color
 }
 

-constexpr Square operator~(Square s) {
-  return Square(s ^ SQ_A8); // Vertical flip SQ_A1 -> SQ_A8
+constexpr Square flip_rank(Square s) {
+  return Square(s ^ SQ_A8);
+}
+
+constexpr Square flip_file(Square s) {
+  return Square(s ^ SQ_H1);

 }
 
 constexpr Piece operator~(Piece pc) {
 }
 
 constexpr Piece operator~(Piece pc) {