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Code style in tt.cpp

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2011-04-15 18:14:12 +02:00
parent a860576493
commit c13b53a514
2 changed files with 73 additions and 92 deletions

View file

@ -17,29 +17,18 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
////
//// Includes
////
#include <cassert>
#include <cstring>
#include <iostream>
#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 {

113
src/tt.h
View file

@ -25,40 +25,8 @@
#include "move.h"
#include "types.h"
/// A simple fixed size hash table used to store pawns and material
/// configurations. It is basically just an array of Entry objects.
/// Without cluster concept or overwrite policy.
template<class Entry, int HashSize>
class SimpleHash {
SimpleHash(const SimpleHash&);
SimpleHash& operator=(const SimpleHash&);
public:
SimpleHash() {
entries = new (std::nothrow) Entry[HashSize];
if (!entries)
{
std::cerr << "Failed to allocate " << HashSize * sizeof(Entry)
<< " bytes for material hash table." << std::endl;
exit(EXIT_FAILURE);
}
memset(entries, 0, HashSize * sizeof(Entry));
}
virtual ~SimpleHash() { delete [] entries; }
Entry* find(Key key) const { return entries + ((uint32_t)key & (HashSize - 1)); }
void prefetch(Key key) const { ::prefetch((char*)find(key)); }
protected:
Entry* entries;
};
/// The TTEntry class is the class of transposition table entries
/// The TTEntry is the class of transposition table entries
///
/// A TTEntry needs 128 bits to be stored
///
@ -93,41 +61,37 @@ public:
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); }
ValueType type() const { return ValueType(valueType); }
int generation() const { return generation8; }
Value static_value() const { return Value(staticValue); }
Value static_value_margin() const { return Value(staticMargin); }
Depth depth() const { return (Depth)depth16; }
Move move() const { return (Move)move16; }
Value value() const { return (Value)value16; }
ValueType type() const { return (ValueType)valueType; }
int generation() const { return (int)generation8; }
Value static_value() const { return (Value)staticValue; }
Value static_value_margin() const { return (Value)staticMargin; }
private:
uint32_t key32;
uint16_t move16;
uint8_t valueType;
uint8_t generation8;
int16_t value16;
int16_t depth16;
int16_t staticValue;
int16_t staticMargin;
uint8_t valueType, generation8;
int16_t value16, depth16, staticValue, staticMargin;
};
/// 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.
/// 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 new entries
/// and reading new ones.
/// The transposition table class. This is basically just a huge array containing
/// TTCluster objects, and a few methods for writing and reading entries.
class TranspositionTable {
@ -148,15 +112,15 @@ public:
private:
size_t size;
TTCluster* entries;
uint8_t generation; // To properly compare, size must be smaller then TT stored value
uint8_t generation; // Size must be not bigger then TTEntry::generation8
};
extern TranspositionTable TT;
/// TranspositionTable::first_entry returns a pointer to the first
/// entry of a cluster given a position. The lowest order bits of the key
/// are used to get the index of the cluster.
/// TranspositionTable::first_entry() returns a pointer to the first entry of
/// 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 {
@ -164,12 +128,45 @@ inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
}
/// TranspositionTable::refresh updates the 'generation' value of the TTEntry
/// to avoid aging. Normally called after a TT hit, before to return.
/// TranspositionTable::refresh() updates the 'generation' value of the TTEntry
/// to avoid aging. Normally called after a TT hit.
inline void TranspositionTable::refresh(const TTEntry* tte) const {
const_cast<TTEntry*>(tte)->set_generation(generation);
}
/// A simple fixed size hash table used to store pawns and material
/// configurations. It is basically just an array of Entry objects.
/// Without cluster concept or overwrite policy.
template<class Entry, int HashSize>
class SimpleHash {
SimpleHash(const SimpleHash&);
SimpleHash& operator=(const SimpleHash&);
public:
SimpleHash() {
entries = new (std::nothrow) Entry[HashSize];
if (!entries)
{
std::cerr << "Failed to allocate " << HashSize * sizeof(Entry)
<< " bytes for material hash table." << std::endl;
exit(EXIT_FAILURE);
}
memset(entries, 0, HashSize * sizeof(Entry));
}
virtual ~SimpleHash() { delete [] entries; }
Entry* find(Key key) const { return entries + ((uint32_t)key & (HashSize - 1)); }
void prefetch(Key key) const { ::prefetch((char*)find(key)); }
protected:
Entry* entries;
};
#endif // !defined(TT_H_INCLUDED)