Make enums unsigned

Speed up by using unsigned enums.

No functional change

Author: KazApps

src/bitboard.cpp

@@ -58,12 +58,15 @@ std::string Bitboards::pretty(Bitboard b) {
 
     std::string s = "+---+---+---+---+---+---+---+---+---+\n";
 
-    for (Rank r = RANK_9; r >= RANK_0; --r)
+    for (Rank r = RANK_9;; --r)
     {
         for (File f = FILE_A; f <= FILE_I; ++f)
             s += b & make_square(f, r) ? "| X " : "|   ";
 
         s += "| " + std::to_string(r) + "\n+---+---+---+---+---+---+---+---+---+\n";
+
+        if (r == RANK_0)
+            break;
     }
     s += "  a   b   c   d   e   f   g   h   i\n";
 

src/movegen.cpp

@@ -45,7 +45,7 @@ inline Move* write_moves(Move* moveList, uint32_t mask, __m512i vector) {
 inline Move* splat_moves(Move* moveList, Square from, Bitboard to_bb) {
     alignas(64) static constexpr auto SPLAT_TABLE = [] {
         std::array<Move, 90> table{};
-        for (int8_t i = 0; i < 90; i++)
+        for (uint8_t i = 0; i < 90; i++)
             table[i] = {Move(SQUARE_ZERO, Square{i})};
         return table;
     }();

src/nnue/features/full_threats.cpp

@@ -54,10 +54,10 @@ auto ThreatOffsets = []() {
     // clang-format on
 
     // Initialize threat offsets to be all Dimension
-    for (size_t i = 0; i < PIECE_NB; ++i)
-        for (size_t j = 0; j < SQUARE_NB; ++j)
-            for (size_t k = 0; k < SQUARE_NB; ++k)
-                for (size_t l = 0; l < PIECE_NB; ++l)
+    for (uint8_t i = 0; i < PIECE_NB; ++i)
+        for (uint8_t j = 0; j < SQUARE_NB; ++j)
+            for (uint8_t k = 0; k < SQUARE_NB; ++k)
+                for (uint8_t l = 0; l < PIECE_NB; ++l)
                     ThreatOffsets[i][j][k][l] = FullThreats::Dimensions;
 
     int cumulativeOffset = 0;

src/position.cpp

@@ -60,12 +60,15 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) {
 
     os << "\n +---+---+---+---+---+---+---+---+---+\n";
 
-    for (Rank r = RANK_9; r >= RANK_0; --r)
+    for (Rank r = RANK_9;; --r)
     {
         for (File f = FILE_A; f <= FILE_I; ++f)
             os << " | " << PieceToChar[pos.piece_on(make_square(f, r))];
 
         os << " | " << int(r) << "\n +---+---+---+---+---+---+---+---+---+\n";
+
+        if (r == RANK_0)
+            break;
     }
 
     os << "   a   b   c   d   e   f   g   h   i\n"
@@ -256,7 +259,7 @@ string Position::fen() const {
     int                emptyCnt;
     std::ostringstream ss;
 
-    for (Rank r = RANK_9; r >= RANK_0; --r)
+    for (Rank r = RANK_9;; --r)
     {
         for (File f = FILE_A; f <= FILE_I; ++f)
         {
@@ -270,8 +273,9 @@ string Position::fen() const {
                 ss << PieceToChar[piece_on(make_square(f, r))];
         }
 
-        if (r > RANK_0)
-            ss << '/';
+        if (r == RANK_0)
+            break;
+        ss << '/';
     }
 
     ss << (sideToMove == WHITE ? " w " : " b ");
@@ -1304,10 +1308,13 @@ void Position::flip() {
     string            f, token;
     std::stringstream ss(fen());
 
-    for (Rank r = RANK_9; r >= RANK_0; --r)  // Piece placement
+    for (Rank r = RANK_9;; --r)  // Piece placement
     {
         std::getline(ss, token, r > RANK_0 ? '/' : ' ');
         f.insert(0, token + (f.empty() ? " " : "/"));
+
+        if (r == RANK_0)
+            break;
     }
 
     ss >> token;                        // Active color

src/timeman.h

@@ -26,7 +26,7 @@
 namespace Stockfish {
 
 class OptionsMap;
-enum Color : int8_t;
+enum Color : uint8_t;
 
 namespace Search {
 struct LimitsType;

src/types.h

@@ -127,13 +127,13 @@ using Bitboard = __uint128_t;
 constexpr int MAX_MOVES = 128;
 constexpr int MAX_PLY   = 246;
 
-enum Color : int8_t {
+enum Color : uint8_t {
     WHITE,
     BLACK,
     COLOR_NB = 2
 };
 
-enum Bound : int8_t {
+enum Bound : uint8_t {
     BOUND_NONE,
     BOUND_UPPER,
     BOUND_LOWER,
@@ -176,13 +176,13 @@ constexpr Value KnightValue  = 720;
 constexpr Value BishopValue  = 187;
 
 // clang-format off
-enum PieceType : std::int8_t {
+enum PieceType : std::uint8_t {
     NO_PIECE_TYPE, ROOK, ADVISOR, CANNON, PAWN, KNIGHT, BISHOP, KING, KNIGHT_TO, PAWN_TO,
     ALL_PIECES = 0,
     PIECE_TYPE_NB = 8
 };
 
-enum Piece : std::int8_t {
+enum Piece : std::uint8_t {
     NO_PIECE,
     W_ROOK           , W_ADVISOR, W_CANNON, W_PAWN, W_KNIGHT, W_BISHOP, W_KING,
     B_ROOK = ROOK + 8, B_ADVISOR, B_CANNON, B_PAWN, B_KNIGHT, B_BISHOP, B_KING,
@@ -214,7 +214,7 @@ constexpr Depth DEPTH_UNSEARCHED   = -2;
 constexpr Depth DEPTH_ENTRY_OFFSET = -3;
 
 // clang-format off
-enum Square : int8_t {
+enum Square : uint8_t {
     SQ_A0, SQ_B0, SQ_C0, SQ_D0, SQ_E0, SQ_F0, SQ_G0, SQ_H0, SQ_I0,
     SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1, SQ_I1,
     SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2, SQ_I2,
@@ -244,7 +244,7 @@ enum Direction : int8_t {
     NORTH_WEST = NORTH + WEST
 };
 
-enum File : int8_t {
+enum File : uint8_t {
     FILE_A,
     FILE_B,
     FILE_C,
@@ -257,7 +257,7 @@ enum File : int8_t {
     FILE_NB
 };
 
-enum Rank : int8_t {
+enum Rank : uint8_t {
     RANK_0,
     RANK_1,
     RANK_2,

src/uci.h

@@ -33,7 +33,7 @@ namespace Stockfish {
 class Position;
 class Move;
 class Score;
-enum Square : int8_t;
+enum Square : uint8_t;
 using Value = int;
 
 class UCIEngine {