From fe3352665b2dfc6c339136856c782057a5c5476e Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sat, 9 Feb 2013 08:17:03 +0100 Subject: [PATCH] Retire TTCluster and simplify TT Also some renaming while there. No functional change. --- src/search.cpp | 8 +++---- src/tt.cpp | 36 ++++++---------------------- src/tt.h | 65 +++++++++++++++++++++----------------------------- 3 files changed, 38 insertions(+), 71 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index cabd1cca..091c00fe 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -594,8 +594,8 @@ namespace { else if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = eval = tte->static_value()) == VALUE_NONE - ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE) + if ( (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE + ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) eval = ss->staticEval = evaluate(pos, ss->evalMargin); // Can ttValue be used as a better position evaluation? @@ -1164,8 +1164,8 @@ split_point_start: // At split points actual search starts from here if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = bestValue = tte->static_value()) == VALUE_NONE - ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE) + if ( (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE + ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); } else diff --git a/src/tt.cpp b/src/tt.cpp index a7042f9e..2445f794 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -25,33 +25,21 @@ TranspositionTable TT; // Our global transposition table -TranspositionTable::TranspositionTable() { - - size = generation = 0; - entries = NULL; -} - -TranspositionTable::~TranspositionTable() { - - delete [] entries; -} - /// TranspositionTable::set_size() sets the size of the transposition table, -/// measured in megabytes. Transposition table consists of a power of 2 number of -/// TTCluster and each cluster consists of ClusterSize number of TTEntries. Each -/// non-empty entry contains information of exactly one position. +/// measured in megabytes. Transposition table consists of a power of 2 number +/// of clusters and each cluster consists of ClusterSize number of TTEntry. void TranspositionTable::set_size(size_t mbSize) { - size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTCluster)); + size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize])); if (newSize == size) return; size = newSize; delete [] entries; - entries = new (std::nothrow) TTCluster[size]; + entries = new (std::nothrow) TTEntry[size * ClusterSize]; if (!entries) { @@ -70,7 +58,7 @@ void TranspositionTable::set_size(size_t mbSize) { void TranspositionTable::clear() { - memset(entries, 0, size * sizeof(TTCluster)); + memset(entries, 0, size * sizeof(TTEntry[ClusterSize])); } @@ -90,7 +78,7 @@ void TranspositionTable::store(const Key key, Value v, Bound t, Depth d, Move m, tte = replace = first_entry(key); - for (int i = 0; i < ClusterSize; i++, tte++) + for (unsigned i = 0; i < ClusterSize; i++, tte++) { if (!tte->key() || tte->key() == key32) // Empty or overwrite old { @@ -123,19 +111,9 @@ TTEntry* TranspositionTable::probe(const Key key) const { TTEntry* tte = first_entry(key); uint32_t key32 = key >> 32; - for (int i = 0; i < ClusterSize; i++, tte++) + for (unsigned i = 0; i < ClusterSize; i++, tte++) if (tte->key() == key32) return tte; return NULL; } - - -/// 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++; -} diff --git a/src/tt.h b/src/tt.h index 705bac91..3484f0eb 100644 --- a/src/tt.h +++ b/src/tt.h @@ -44,7 +44,7 @@ class TTEntry { public: - void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value statV, Value statM) { + void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value ev, Value em) { key32 = (uint32_t)k; move16 = (uint16_t)m; @@ -52,63 +52,52 @@ public: generation8 = (uint8_t)g; value16 = (int16_t)v; depth16 = (int16_t)d; - staticValue = (int16_t)statV; - staticMargin = (int16_t)statM; + evalValue = (int16_t)ev; + evalMargin = (int16_t)em; } void set_generation(int g) { generation8 = (uint8_t)g; } - uint32_t key() const { return key32; } - Depth depth() const { return (Depth)depth16; } - Move move() const { return (Move)move16; } - Value value() const { return (Value)value16; } - Bound type() const { return (Bound)bound; } - int generation() const { return (int)generation8; } - Value static_value() const { return (Value)staticValue; } - Value static_value_margin() const { return (Value)staticMargin; } + uint32_t key() const { return key32; } + Depth depth() const { return (Depth)depth16; } + Move move() const { return (Move)move16; } + Value value() const { return (Value)value16; } + Bound type() const { return (Bound)bound; } + int generation() const { return (int)generation8; } + Value eval_value() const { return (Value)evalValue; } + Value eval_margin() const { return (Value)evalMargin; } private: uint32_t key32; uint16_t move16; uint8_t bound, generation8; - int16_t value16, depth16, staticValue, staticMargin; + int16_t value16, depth16, evalValue, evalMargin; }; -/// This is the number of TTEntry slots for each cluster -const int ClusterSize = 4; - - -/// TTCluster consists of ClusterSize number of TTEntries. Size of TTCluster -/// must not be bigger than a cache line size. In case it is less, it should -/// be padded to guarantee always aligned accesses. - -struct TTCluster { - TTEntry data[ClusterSize]; -}; - - -/// The transposition table class. This is basically just a huge array containing -/// TTCluster objects, and a few methods for writing and reading entries. +/// A TranspositionTable consists of a power of 2 number of clusters and each +/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry +/// contains information of exactly one position. Size of a cluster shall not be +/// bigger than a cache line size. In case it is less, it should be padded to +/// guarantee always aligned accesses. class TranspositionTable { - TranspositionTable(const TranspositionTable&); - TranspositionTable& operator=(const TranspositionTable&); + static const unsigned ClusterSize = 4; // A cluster is 64 Bytes public: - TranspositionTable(); - ~TranspositionTable(); + ~TranspositionTable() { delete [] entries; } + void new_search() { generation++; } + + TTEntry* probe(const Key key) const; + TTEntry* first_entry(const Key key) const; + void refresh(const TTEntry* tte) const; void set_size(size_t mbSize); void clear(); void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV, Value kingD); - TTEntry* probe(const Key key) const; - void new_search(); - TTEntry* first_entry(const Key posKey) const; - void refresh(const TTEntry* tte) const; private: size_t size; - TTCluster* entries; + TTEntry* entries; uint8_t generation; // Size must be not bigger then TTEntry::generation8 }; @@ -119,9 +108,9 @@ extern TranspositionTable TT; /// a cluster given a position. The lowest order bits of the key are used to /// get the index of the cluster. -inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { +inline TTEntry* TranspositionTable::first_entry(const Key key) const { - return entries[((uint32_t)posKey) & (size - 1)].data; + return entries + ((uint32_t)key & (size - 1)) * ClusterSize; } -- 2.39.2