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TranspositionTable: add first_entry() helper

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An inline function to retrieve the first TT entry
given a position.

Plus usual whitespace noise.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2008-09-06 12:30:07 +02:00
parent 61f41a057d
commit c2c0ba875f
4 changed files with 46 additions and 42 deletions
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56
src/tt.cpp
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@@ -6,12 +6,12 @@
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Glaurung is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
@@ -105,7 +105,7 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d,
Move m, ValueType type) {
TTEntry *tte, *replace;
tte = replace = entries + int(pos.get_key() & (size - 1)) * 4;
tte = replace = first_entry(pos);
for (int i = 0; i < 4; i++)
{
if (!(tte+i)->key()) // still empty
@@ -118,12 +118,12 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d,
{
if (m == MOVE_NONE)
m = (tte+i)->move();
*(tte+i) = TTEntry(pos.get_key(), v, type, d, m, generation);
return;
}
if ( i == 0 // already is (replace == tte+i), common case
|| replace->generation() < (tte+i)->generation())
|| replace->generation() < (tte+i)->generation())
continue;
if ( replace->generation() > (tte+i)->generation()
@@ -143,28 +143,33 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d,
bool TranspositionTable::retrieve(const Position &pos, Value *value,
Depth *d, Move *move,
ValueType *type) const {
TTEntry *tte;
bool found = false;
TTEntry *tte = first_entry(pos);
tte = entries + int(pos.get_key() & (size - 1)) * 4;
for (int i = 0; i < 4 && !found ; i++)
if ((tte+i)->key() == pos.get_key())
for (int i = 0; i < 4; i++)
{
tte += i;
if (tte->key() == pos.get_key())
{
tte = tte + i;
found = true;
*value = tte->value();
*type = tte->type();
*d = tte->depth();
*move = tte->move();
return true;
}
if (!found) {
*move = MOVE_NONE;
return false;
}
*value = tte->value();
*type = tte->type();
*d = tte->depth();
*move = tte->move();
return true;
*move = MOVE_NONE;
return false;
}
/// 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 {
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
/// distinguish transposition table entries from previous searches from
@@ -177,7 +182,7 @@ void TranspositionTable::new_search() {
}
/// TranspositionTable::insert_pv() is called at the end of a 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.
@@ -212,12 +217,9 @@ TTEntry::TTEntry() {
}
TTEntry::TTEntry(Key k, Value v, ValueType t, Depth d, Move m,
int generation) {
key_ = k;
data = (m & 0x7FFFF) | (t << 20) | (generation << 23);
value_ = v;
depth_ = int16_t(d);
}
int generation) :
key_ (k), data((m & 0x7FFFF) | (t << 20) | (generation << 23)),
value_(v), depth_(int16_t(d)) {}
/// Functions for extracting data from TTEntry objects.