X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=bc26606721413eb90ecae8923c7d4238960892d2;hp=55aad112af3c252d6006265132e8cb657d70d5f6;hb=1322ab97c737fe761bd6ae8786f852851b8f019f;hpb=06a5b602dc32e5dcbb00f32968f1c18004ec93a2 diff --git a/src/tt.cpp b/src/tt.cpp index 55aad112..bc266067 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2009 Marco Costalba + Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, 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 @@ -23,9 +23,7 @@ //// #include -#include #include -#include #include "movegen.h" #include "tt.h" @@ -39,7 +37,7 @@ TranspositionTable TT; TranspositionTable::TranspositionTable() { - size = writes = 0; + size = 0; entries = 0; generation = 0; } @@ -53,11 +51,9 @@ TranspositionTable::~TranspositionTable() { /// TranspositionTable::set_size sets the size of the transposition table, /// measured in megabytes. -void TranspositionTable::set_size(unsigned mbSize) { +void TranspositionTable::set_size(size_t mbSize) { - assert(mbSize >= 4 && mbSize <= 4096); - - unsigned newSize = 1024; + size_t newSize = 1024; // We store a cluster of ClusterSize number of TTEntry for each position // and newSize is the maximum number of storable positions. @@ -75,7 +71,6 @@ void TranspositionTable::set_size(unsigned mbSize) { << " MB for transposition table." << std::endl; Application::exit_with_failure(); } - clear(); } } @@ -91,16 +86,6 @@ void TranspositionTable::clear() { } -/// TranspositionTable::first_entry returns a pointer to the first -/// entry of a cluster given a position. The low 32 bits of the key -/// are used to get the index in the table. - -inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { - - return entries[uint32_t(posKey) & (size - 1)].data; -} - - /// TranspositionTable::store writes a new entry containing a position, /// a value, a value type, a search depth, and a best move to the /// transposition table. Transposition table is organized in clusters of @@ -111,8 +96,9 @@ inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { /// is bigger than the depth of t2. A TTEntry of type VALUE_TYPE_EVAL /// never replaces another entry for the same position. -void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, Move m) { +void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, Move m, Value statV, Value kingD) { + int c1, c2, c3; TTEntry *tte, *replace; uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key @@ -121,28 +107,25 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, { if (!tte->key() || tte->key() == posKey32) // empty or overwrite old { - // Do not overwrite when new type is VALUE_TYPE_EV_LO - if (tte->key() && t == VALUE_TYPE_EV_LO) - return; - + // Preserve any exsisting ttMove if (m == MOVE_NONE) m = tte->move(); - *tte = TTEntry(posKey32, v, t, d, m, generation); + tte->save(posKey32, v, t, d, m, generation, statV, kingD); return; } - else if (i == 0) // replace would be a no-op in this common case + + if (i == 0) // replace would be a no-op in this common case continue; - int c1 = (replace->generation() == generation ? 2 : 0); - int c2 = (tte->generation() == generation ? -2 : 0); - int c3 = (tte->depth() < replace->depth() ? 1 : 0); + c1 = (replace->generation() == generation ? 2 : 0); + c2 = (tte->generation() == generation ? -2 : 0); + c3 = (tte->depth() < replace->depth() ? 1 : 0); if (c1 + c2 + c3 > 0) replace = tte; } - *replace = TTEntry(posKey32, v, t, d, m, generation); - writes++; + replace->save(posKey32, v, t, d, m, generation, statV, kingD); } @@ -163,36 +146,13 @@ TTEntry* TranspositionTable::retrieve(const Key posKey) const { } -/// TranspositionTable::prefetch looks up the current position in the -/// transposition table and load it in L1/L2 cache. This is a non -/// blocking function and do not stalls the CPU waiting for data -/// to be loaded from RAM, that can be very slow. When we will -/// subsequently call retrieve() the TT data will be already -/// quickly accessible in L1/L2 CPU cache. - -void TranspositionTable::prefetch(const Key posKey) const { - -#if defined(__INTEL_COMPILER) || defined(__ICL) - // This hack prevents prefetches to be optimized away by the - // Intel compiler. Both MSVC and gcc seems not affected. - __asm__ (""); -#endif - - char const* addr = (char*)first_entry(posKey); - _mm_prefetch(addr, _MM_HINT_T2); - _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead -} - - /// TranspositionTable::new_search() is called at the beginning of every new /// search. It increments the "generation" variable, which is used to /// distinguish transposition table entries from previous searches from /// entries from the current search. void TranspositionTable::new_search() { - generation++; - writes = 0; } @@ -204,34 +164,36 @@ void TranspositionTable::new_search() { void TranspositionTable::insert_pv(const Position& pos, Move pv[]) { StateInfo st; - Position p(pos); + Position p(pos, pos.thread()); for (int i = 0; pv[i] != MOVE_NONE; i++) { - store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i]); + TTEntry *tte = retrieve(p.get_key()); + if (!tte || tte->move() != pv[i]) + store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i], VALUE_NONE, VALUE_NONE); p.do_move(pv[i], st); } } -/// TranspositionTable::extract_pv() extends a PV by adding moves from the -/// transposition table at the end. This should ensure that the PV is almost -/// always at least two plies long, which is important, because otherwise we -/// will often get single-move PVs when the search stops while failing high, -/// and a single-move PV means that we don't have a ponder move. +/// TranspositionTable::extract_pv() builds a PV by adding moves from the +/// transposition table. We consider also failing high nodes and not only +/// VALUE_TYPE_EXACT nodes. This allow to always have a ponder move even +/// when we fail high at root and also a long PV to print that is important +/// for position analysis. -void TranspositionTable::extract_pv(const Position& pos, Move pv[], const int PLY_MAX) { +void TranspositionTable::extract_pv(const Position& pos, Move bestMove, Move pv[], const int PLY_MAX) { const TTEntry* tte; StateInfo st; - Position p(pos); + Position p(pos, pos.thread()); int ply = 0; - // Update position to the end of current PV - while (pv[ply] != MOVE_NONE) - p.do_move(pv[ply++], st); + assert(bestMove != MOVE_NONE); + + pv[ply] = bestMove; + p.do_move(pv[ply++], st); - // Try to add moves from TT while possible while ( (tte = retrieve(p.get_key())) != NULL && tte->move() != MOVE_NONE && move_is_legal(p, tte->move()) @@ -243,14 +205,3 @@ void TranspositionTable::extract_pv(const Position& pos, Move pv[], const int PL } pv[ply] = MOVE_NONE; } - - -/// TranspositionTable::full() returns the permill of all transposition table -/// entries which have received at least one write during the current search. -/// It is used to display the "info hashfull ..." information in UCI. - -int TranspositionTable::full() const { - - double N = double(size) * ClusterSize; - return int(1000 * (1 - exp(writes * log(1.0 - 1.0/N)))); -}