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Code style cleanup in transposition table code

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Assorted fixes but no functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2009-04-27 13:21:49 +01:00
parent 2550c6383b
commit 2f2e48fad2
3 changed files with 73 additions and 100 deletions
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124
src/tt.cpp
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@@ -33,20 +33,13 @@
//// Functions
////
/// Constructor
TranspositionTable::TranspositionTable() {
TranspositionTable::TranspositionTable(unsigned mbSize) {
size = 0;
generation = 0;
writes = 0;
size = writes = 0;
entries = 0;
set_size(mbSize);
generation = 0;
}
/// Destructor
TranspositionTable::~TranspositionTable() {
delete [] entries;
@@ -64,27 +57,27 @@ void TranspositionTable::set_size(unsigned mbSize) {
// We store a cluster of 4 TTEntry for each position and newSize is
// the maximum number of storable positions
for ( ; newSize * 4 * (sizeof(TTEntry)) <= (mbSize << 20); newSize *= 2);
newSize /= 2;
while ((2 * newSize) * 4 * (sizeof(TTEntry)) <= (mbSize << 20))
newSize *= 2;
if (newSize != size)
{
size = newSize;
delete [] entries;
entries = new TTEntry[size * 4];
if (!entries)
{
std::cerr << "Failed to allocate " << mbSize
<< " MB for transposition table."
<< std::endl;
exit(EXIT_FAILURE);
}
clear();
size = newSize;
delete [] entries;
entries = new TTEntry[size * 4];
if (!entries)
{
std::cerr << "Failed to allocate " << mbSize
<< " MB for transposition table." << std::endl;
exit(EXIT_FAILURE);
}
clear();
}
}
/// TranspositionTable::clear overwrites the entire transposition table
/// with zeroes. It is called whenever the table is resized, or when the
/// 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 recieved?
@@ -96,45 +89,44 @@ void TranspositionTable::clear() {
/// 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. The transposition table is organized in clusters
/// of four TTEntry objects, and when a new entry is written, it replaces
/// the least valuable of the four entries in a cluster. A TTEntry t1 is
/// transposition table. Transposition table is organized in clusters of
/// four TTEntry objects, and when a new entry is written, it replaces
/// the least valuable of the four entries in a cluster. 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. A TTEntry of type VALUE_TYPE_EVAL
/// never replaces another entry for the same position.
void TranspositionTable::store(const Position &pos, Value v, Depth d,
Move m, ValueType type) {
void TranspositionTable::store(const Position& p, Value v, ValueType t, Depth d, Move m) {
TTEntry *tte, *replace;
tte = replace = first_entry(pos);
tte = replace = first_entry(p);
for (int i = 0; i < 4; i++, tte++)
{
if (!tte->key() || tte->key() == pos.get_key()) // empty or overwrite old
{
// Do not overwrite position entry when VALUE_TYPE_EVAL
if ( tte->key()
&& type == VALUE_TYPE_EVAL)
return;
if (!tte->key() || tte->key() == p.get_key()) // empty or overwrite old
{
// Do not overwrite when new type is VALUE_TYPE_EVAL
if (tte->key() && t == VALUE_TYPE_EVAL)
return;
if (m == MOVE_NONE)
m = tte->move();
if (m == MOVE_NONE)
m = tte->move();
*tte = TTEntry(pos.get_key(), v, type, d, m, generation);
return;
}
else if (i == 0) // replace would be a no-op in this common case
continue;
*tte = TTEntry(p.get_key(), v, t, d, m, generation);
return;
}
else 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);
int c1 = (replace->generation() == generation ? 2 : 0);
int c2 = (tte->generation() == generation ? -2 : 0);
int c3 = (tte->depth() < replace->depth() ? 1 : 0);
if (c1 + c2 + c3 > 0)
replace = tte;
if (c1 + c2 + c3 > 0)
replace = tte;
}
*replace = TTEntry(pos.get_key(), v, type, d, m, generation);
*replace = TTEntry(p.get_key(), v, t, d, m, generation);
writes++;
}
@@ -143,15 +135,14 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d,
/// transposition table. Returns a pointer to the TTEntry or NULL
/// if position is not found.
TTEntry* TranspositionTable::retrieve(const Position &pos) const {
TTEntry* TranspositionTable::retrieve(const Position& pos) const {
TTEntry *tte = first_entry(pos);
for (int i = 0; i < 4; i++, tte++)
{
if (tte->key() == pos.get_key())
return tte;
}
return NULL;
}
@@ -159,13 +150,13 @@ TTEntry* TranspositionTable::retrieve(const Position &pos) const {
/// TranspositionTable::first_entry returns a pointer to the first
/// entry of a cluster given a position.
inline TTEntry* TranspositionTable::first_entry(const Position &pos) const {
inline TTEntry* TranspositionTable::first_entry(const Position& pos) const {
return entries + (int(pos.get_key() & (size - 1)) << 2);
}
/// TranspositionTable::new_search() is called at the beginning of every new
/// search. It increments the "generation" variable, which is used to
/// search. It increments the "generation" variable, which is used to
/// distinguish transposition table entries from previous searches from
/// entries from the current search.
@@ -177,19 +168,19 @@ void TranspositionTable::new_search() {
/// TranspositionTable::insert_pv() is called at the end of a search
/// iteration, and inserts the PV back into the PV. This makes sure the
/// old PV moves are searched first, even if the old TT entries have been
/// overwritten.
/// iteration, and inserts the PV back into the PV. This makes sure
/// the old PV moves are searched first, even if the old TT entries
/// have been overwritten.
void TranspositionTable::insert_pv(const Position &pos, Move pv[]) {
void TranspositionTable::insert_pv(const Position& pos, Move pv[]) {
StateInfo st;
Position p(pos);
for (int i = 0; pv[i] != MOVE_NONE; i++)
{
store(p, VALUE_NONE, Depth(-127*OnePly), pv[i], VALUE_TYPE_NONE);
p.do_move(pv[i], st);
store(p, VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i]);
p.do_move(pv[i], st);
}
}
@@ -198,19 +189,8 @@ void TranspositionTable::insert_pv(const Position &pos, Move pv[]) {
/// 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() {
int TranspositionTable::full() const {
double N = double(size) * 4.0;
return int(1000 * (1 - exp(writes * log(1.0 - 1.0/N))));
}
/// Constructors
TTEntry::TTEntry() {
}
TTEntry::TTEntry(Key k, Value v, ValueType t, Depth d, Move m,
int generation) :
key_ (k), data((m & 0x1FFFF) | (t << 20) | (generation << 23)),
value_(int16_t(v)), depth_(int16_t(d)) {}