HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-19 08:36:33 +08:00
Code Issues Packages Projects Releases Wiki Activity

Extend full 3 fold detection to PvNodes

Browse Source 
And restore old behaviour of not returning from a RootNode
without updating RootMoves[].

Also renamed is_draw() template parameters to reflect a
'positive' logic (Check instead of Skip) that is easier
to follow.

New bench: 5312693
This commit is contained in:
Marco Costalba
2012-10-26 11:08:06 +02:00
parent 71f37ac1aa
commit c594b989c0
3 changed files with 14 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
src/position.cpp
View File

@@ -1467,39 +1467,31 @@ Value Position::compute_non_pawn_material(Color c) const {
/// Position::is_draw() tests whether the position is drawn by material,
/// repetition, or the 50 moves rule. It does not detect stalemates, this
/// must be done by the search.
template<bool SkipRepetition, bool SkipThreeFoldCheck>
template<bool CheckRepetition, bool CheckThreeFold>
bool Position::is_draw() const {
// Draw by material?
if ( !pieces(PAWN)
&& (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
return true;
// Draw by the 50 moves rule?
if (st->rule50 > 99 && (!in_check() || MoveList<LEGAL>(*this).size()))
return true;
// Draw by repetition?
if (!SkipRepetition)
if (CheckRepetition)
{
int i = 4, e = std::min(st->rule50, st->pliesFromNull), rep_count=0;
int i = 4, e = std::min(st->rule50, st->pliesFromNull);
if (i <= e)
{
StateInfo* stp = st->previous->previous;
do {
for (int cnt = 0; i <= e; i += 2)
{
stp = stp->previous->previous;
if (stp->key == st->key)
{
if(SkipThreeFoldCheck) return true;
else if(++rep_count>=2) return true;
}
i +=2;
} while (i <= e);
if (stp->key == st->key && (!CheckThreeFold || ++cnt >= 2))
return true;
}
}
}
@@ -1507,8 +1499,8 @@ bool Position::is_draw() const {
}
// Explicit template instantiations
template bool Position::is_draw<false,true>() const;
template bool Position::is_draw<true,true>() const;
template bool Position::is_draw<true, true>() const;
template bool Position::is_draw<true, false>() const;
template bool Position::is_draw<false,false>() const;