Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
TranspositionTable TT; // Our global transposition table
-/// TTEntry::save saves a TTEntry
-void TTEntry::save(Key k, Value v, Bound b, Depth d, Move m, Value ev) {
+/// TTEntry::save populates the TTEntry with a new node's data, possibly
+/// overwriting an old position. Update is not atomic and can be racy.
- assert(d / ONE_PLY * ONE_PLY == d);
+void TTEntry::save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev) {
// Preserve any existing move for the same position
if (m || (k >> 48) != key16)
// Overwrite less valuable entries
if ( (k >> 48) != key16
- || d / ONE_PLY > depth8 - 4
+ || d - DEPTH_OFFSET > depth8 - 4
|| b == BOUND_EXACT)
{
+ assert(d >= DEPTH_OFFSET);
+
key16 = (uint16_t)(k >> 48);
value16 = (int16_t)v;
eval16 = (int16_t)ev;
- genBound8 = (uint8_t)(TT.generation8 | b);
- depth8 = (int8_t)(d / ONE_PLY);
+ genBound8 = (uint8_t)(TT.generation8 | uint8_t(pv) << 2 | b);
+ depth8 = (uint8_t)(d - DEPTH_OFFSET);
}
}
Threads.main()->wait_for_search_finished();
- clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
-
free(mem);
- mem = malloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1);
+ clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
+ table = static_cast<Cluster*>(aligned_ttmem_alloc(clusterCount * sizeof(Cluster), mem));
if (!mem)
{
std::cerr << "Failed to allocate " << mbSize
exit(EXIT_FAILURE);
}
- table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
clear();
}
std::vector<std::thread> threads;
- for (size_t idx = 0; idx < Options["Threads"]; idx++)
+ for (size_t idx = 0; idx < Options["Threads"]; ++idx)
{
threads.emplace_back([this, idx]() {
for (int i = 0; i < ClusterSize; ++i)
if (!tte[i].key16 || tte[i].key16 == key16)
{
- tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
+ tte[i].genBound8 = uint8_t(generation8 | (tte[i].genBound8 & 0x7)); // Refresh
return found = (bool)tte[i].key16, &tte[i];
}
TTEntry* replace = tte;
for (int i = 1; i < ClusterSize; ++i)
// Due to our packed storage format for generation and its cyclic
- // nature we add 259 (256 is the modulus plus 3 to keep the lowest
- // two bound bits from affecting the result) to calculate the entry
+ // nature we add 263 (256 is the modulus plus 7 to keep the unrelated
+ // lowest three bits from affecting the result) to calculate the entry
// age correctly even after generation8 overflows into the next cycle.
- if ( replace->depth8 - ((259 + generation8 - replace->genBound8) & 0xFC) * 2
- > tte[i].depth8 - ((259 + generation8 - tte[i].genBound8) & 0xFC) * 2)
+ if ( replace->depth8 - ((263 + generation8 - replace->genBound8) & 0xF8)
+ > tte[i].depth8 - ((263 + generation8 - tte[i].genBound8) & 0xF8))
replace = &tte[i];
return found = false, replace;
int TranspositionTable::hashfull() const {
int cnt = 0;
- for (int i = 0; i < 1000 / ClusterSize; i++)
- {
- const TTEntry* tte = &table[i].entry[0];
- for (int j = 0; j < ClusterSize; j++)
- if ((tte[j].genBound8 & 0xFC) == generation8)
- cnt++;
- }
- return cnt;
+ for (int i = 0; i < 1000; ++i)
+ for (int j = 0; j < ClusterSize; ++j)
+ cnt += (table[i].entry[j].genBound8 & 0xF8) == generation8;
+
+ return cnt / ClusterSize;
}