Unify type alias declarations

[stockfish] / src / syzygy / tbprobe.cpp

diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp
index 41e867c00a30249a9de2f5a063b68b205eb16cb0..b594ac3714e5cf3e853289ebd09f0be03f1bd22b 100644 (file)
--- a/src/syzygy/tbprobe.cpp
+++ b/src/syzygy/tbprobe.cpp
@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -24,9 +24,10 @@
 #include <fstream>
 #include <iostream>
 #include <list>
+#include <mutex>
 #include <sstream>
+#include <string_view>
 #include <type_traits>
-#include <mutex>
 
 #include "../bitboard.h"
 #include "../movegen.h"
@@ -59,6 +60,7 @@ namespace Stockfish {
 namespace {
 
 constexpr int TBPIECES = 7; // Max number of supported pieces
+constexpr int MAX_DTZ = 1 << 18; // Max DTZ supported, large enough to deal with the syzygy TB limit.
 
 enum { BigEndian, LittleEndian };
 enum TBType { WDL, DTZ }; // Used as template parameter
@@ -69,7 +71,7 @@ enum TBFlag { STM = 1, Mapped = 2, WinPlies = 4, LossPlies = 8, Wide = 16, Singl
 inline WDLScore operator-(WDLScore d) { return WDLScore(-int(d)); }
 inline Square operator^(Square s, int i) { return Square(int(s) ^ i); }
 
-const std::string PieceToChar = " PNBRQK  pnbrqk";
+constexpr std::string_view PieceToChar = " PNBRQK  pnbrqk";
 
 int MapPawns[SQUARE_NB];
 int MapB1H1H7[SQUARE_NB];
@@ -140,7 +142,7 @@ struct SparseEntry {
 
 static_assert(sizeof(SparseEntry) == 6, "SparseEntry must be 6 bytes");
 
-typedef uint16_t Sym; // Huffman symbol
+using Sym = uint16_t; // Huffman symbol
 
 struct LR {
     enum Side { Left, Right };
@@ -198,13 +200,10 @@ public:
         }
     }
 
-    // Memory map the file and check it. File should be already open and will be
-    // closed after mapping.
+    // Memory map the file and check it.
     uint8_t* map(void** baseAddress, uint64_t* mapping, TBType type) {
-
-        assert(is_open());
-
-        close(); // Need to re-open to get native file descriptor
+        if (is_open())
+            close(); // Need to re-open to get native file descriptor
 
 #ifndef _WIN32
         struct stat statbuf;
@@ -328,7 +327,7 @@ struct PairsData {
 // first access, when the corresponding file is memory mapped.
 template<TBType Type>
 struct TBTable {
-    typedef typename std::conditional<Type == WDL, WDLScore, int>::type Ret;
+    using Ret = typename std::conditional<Type == WDL, WDLScore, int>::type;
 
     static constexpr int Sides = Type == WDL ? 2 : 1;
 
@@ -1290,7 +1289,7 @@ void Tablebases::init(const std::string& paths) {
     for (auto s : diagonal)
         MapA1D1D4[s] = code++;
 
-    // MapKK[] encodes all the 461 possible legal positions of two kings where
+    // MapKK[] encodes all the 462 possible legal positions of two kings where
     // the first is in the a1-d1-d4 triangle. If the first king is on the a1-d4
     // diagonal, the other one shall not to be above the a1-h8 diagonal.
     std::vector<std::pair<int, Square>> bothOnDiagonal;
@@ -1513,7 +1512,7 @@ int Tablebases::probe_dtz(Position& pos, ProbeState* result) {
 // A return value false indicates that not all probes were successful.
 bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
 
-    ProbeState result;
+    ProbeState result = OK;
     StateInfo st;
 
     // Obtain 50-move counter for the root position
@@ -1522,7 +1521,7 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
     // Check whether a position was repeated since the last zeroing move.
     bool rep = pos.has_repeated();
 
-    int dtz, bound = Options["Syzygy50MoveRule"] ? 900 : 1;
+    int dtz, bound = Options["Syzygy50MoveRule"] ? (MAX_DTZ - 100) : 1;
 
     // Probe and rank each move
     for (auto& m : rootMoves)
@@ -1565,8 +1564,8 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
 
         // Better moves are ranked higher. Certain wins are ranked equally.
         // Losing moves are ranked equally unless a 50-move draw is in sight.
-        int r =  dtz > 0 ? (dtz + cnt50 <= 99 && !rep ? 1000 : 1000 - (dtz + cnt50))
-               : dtz < 0 ? (-dtz * 2 + cnt50 < 100 ? -1000 : -1000 + (-dtz + cnt50))
+        int r =  dtz > 0 ? (dtz + cnt50 <= 99 && !rep ? MAX_DTZ : MAX_DTZ - (dtz + cnt50))
+               : dtz < 0 ? (-dtz * 2 + cnt50 < 100 ? -MAX_DTZ : -MAX_DTZ + (-dtz + cnt50))
                : 0;
         m.tbRank = r;
 
@@ -1574,9 +1573,9 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
         // 1 cp to cursed wins and let it grow to 49 cp as the positions gets
         // closer to a real win.
         m.tbScore =  r >= bound ? VALUE_MATE - MAX_PLY - 1
-                   : r >  0     ? Value((std::max( 3, r - 800) * int(PawnValueEg)) / 200)
+                   : r >  0     ? Value((std::max( 3, r - (MAX_DTZ - 200)) * int(PawnValueEg)) / 200)
                    : r == 0     ? VALUE_DRAW
-                   : r > -bound ? Value((std::min(-3, r + 800) * int(PawnValueEg)) / 200)
+                   : r > -bound ? Value((std::min(-3, r + (MAX_DTZ - 200)) * int(PawnValueEg)) / 200)
                    :             -VALUE_MATE + MAX_PLY + 1;
     }
 
@@ -1590,9 +1589,9 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoves& rootMoves) {
 // A return value false indicates that not all probes were successful.
 bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoves& rootMoves) {
 
-    static const int WDL_to_rank[] = { -1000, -899, 0, 899, 1000 };
+    static const int WDL_to_rank[] = { -MAX_DTZ, -MAX_DTZ + 101, 0, MAX_DTZ - 101, MAX_DTZ };
 
-    ProbeState result;
+    ProbeState result = OK;
     StateInfo st;
     WDLScore wdl;