X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=d18b512cd429f8a161c583de962e1a68ef4964b3;hp=f598e3bf1318d4a57e7368d5e9b18a284f86e56b;hb=c13b53a5144163a81d214fb72733b3400b2da002;hpb=a86057649364547066f65d088809ae490856587b diff --git a/src/tt.cpp b/src/tt.cpp index f598e3bf..d18b512c 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -17,29 +17,18 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include #include #include #include "tt.h" -// The main transposition table -TranspositionTable TT; - -//// -//// Functions -//// +TranspositionTable TT; // Our global transposition table TranspositionTable::TranspositionTable() { - size = 0; - entries = 0; - generation = 0; + size = generation = 0; + entries = NULL; } TranspositionTable::~TranspositionTable() { @@ -48,7 +37,7 @@ TranspositionTable::~TranspositionTable() { } -/// TranspositionTable::set_size sets the size of the transposition table, +/// TranspositionTable::set_size() sets the size of the transposition table, /// measured in megabytes. void TranspositionTable::set_size(size_t mbSize) { @@ -78,10 +67,9 @@ void TranspositionTable::set_size(size_t mbSize) { } -/// TranspositionTable::clear overwrites the entire transposition table +/// TranspositionTable::clear() overwrites the entire transposition table /// with zeroes. It is called whenever the table is resized, or when the /// user asks the program to clear the table (from the UCI interface). -/// Perhaps we should also clear it when the "ucinewgame" command is received? void TranspositionTable::clear() { @@ -89,23 +77,22 @@ void TranspositionTable::clear() { } -/// TranspositionTable::store writes a new entry containing position key and -/// valuable information of current position. -/// The Lowest order bits of position key are used to decide on which cluster -/// the position will be placed. +/// TranspositionTable::store() writes a new entry containing position key and +/// valuable information of current position. The lowest order bits of position +/// key are used to decide on which cluster the position will be placed. /// When a new entry is written and there are no empty entries available in cluster, -/// it replaces the least valuable of entries. -/// A TTEntry t1 is considered to be more valuable than a TTEntry t2 if t1 is from the -/// current search and t2 is from a previous search, or if the depth of t1 -/// is bigger than the depth of t2. +/// it replaces the least valuable of entries. A TTEntry t1 is considered to be +/// more valuable than a TTEntry t2 if t1 is from the current search and t2 is from +/// a previous search, or if the depth of t1 is bigger than the depth of t2. 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 + uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key inside the cluster tte = replace = first_entry(posKey); + for (int i = 0; i < ClusterSize; i++, tte++) { if (!tte->key() || tte->key() == posKey32) // Empty or overwrite old @@ -118,10 +105,7 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, return; } - // Replacing first entry is default and already set before entering for-loop - if (i == 0) - continue; - + // Implement replace strategy c1 = (replace->generation() == generation ? 2 : 0); c2 = (tte->generation() == generation ? -2 : 0); c3 = (tte->depth() < replace->depth() ? 1 : 0); @@ -133,9 +117,9 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, } -/// TranspositionTable::retrieve looks up the current position in the -/// transposition table. Returns a pointer to the TTEntry or NULL -/// if position is not found. +/// TranspositionTable::retrieve() looks up the current position in the +/// transposition table. Returns a pointer to the TTEntry or NULL if +/// position is not found. TTEntry* TranspositionTable::retrieve(const Key posKey) const {