Skip to content

Commit

Permalink
De-templetize Position::is_draw()
Browse files Browse the repository at this point in the history
Now that we always check for repetition we don't
need a template anymore.

No functional change.
  • Loading branch information
mcostalba committed Apr 10, 2013
1 parent 75221fc commit fe72c93
Show file tree
Hide file tree
Showing 3 changed files with 14 additions and 22 deletions.
28 changes: 10 additions & 18 deletions src/position.cpp
Expand Up @@ -1376,7 +1376,6 @@ 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 Position::is_draw() const {

// Draw by material?
Expand All @@ -1389,33 +1388,26 @@ bool Position::is_draw() const {
return true;

// Draw by repetition?
if (!SkipRepetition)
{
int i = 4, e = std::min(st->rule50, st->pliesFromNull);
int i = 4, e = std::min(st->rule50, st->pliesFromNull);

if (i <= e)
{
StateInfo* stp = st->previous->previous;
if (i <= e)
{
StateInfo* stp = st->previous->previous;

do {
stp = stp->previous->previous;
do {
stp = stp->previous->previous;

if (stp->key == st->key)
return true;
if (stp->key == st->key)
return true;

i += 2;
i += 2;

} while (i <= e);
}
} while (i <= e);
}

return false;
}

// Explicit template instantiations
template bool Position::is_draw<false>() const;
template bool Position::is_draw<true>() const;


/// Position::flip() flips position with the white and black sides reversed. This
/// is only useful for debugging especially for finding evaluation symmetry bugs.
Expand Down
2 changes: 1 addition & 1 deletion src/position.h
Expand Up @@ -179,7 +179,7 @@ class Position {
Thread* this_thread() const;
int64_t nodes_searched() const;
void set_nodes_searched(int64_t n);
template<bool SkipRepetition> bool is_draw() const;
bool is_draw() const;

// Position consistency check, for debugging
bool pos_is_ok(int* failedStep = NULL) const;
Expand Down
6 changes: 3 additions & 3 deletions src/search.cpp
Expand Up @@ -533,7 +533,7 @@ namespace {
if (!RootNode)
{
// Step 2. Check for aborted search and immediate draw
if (Signals.stop || pos.is_draw<false>() || ss->ply > MAX_PLY)
if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY)
return DrawValue[pos.side_to_move()];

// Step 3. Mate distance pruning. Even if we mate at the next move our score
Expand Down Expand Up @@ -1129,7 +1129,7 @@ namespace {
ss->ply = (ss-1)->ply + 1;

// Check for an instant draw or maximum ply reached
if (pos.is_draw<false>() || ss->ply > MAX_PLY)
if (pos.is_draw() || ss->ply > MAX_PLY)
return DrawValue[pos.side_to_move()];

// Decide whether or not to include checks, this fixes also the type of
Expand Down Expand Up @@ -1579,7 +1579,7 @@ void RootMove::extract_pv_from_tt(Position& pos) {
&& pos.is_pseudo_legal(m = tte->move()) // Local copy, TT could change
&& pos.pl_move_is_legal(m, pos.pinned_pieces())
&& ply < MAX_PLY
&& (!pos.is_draw<false>() || ply < 2));
&& (!pos.is_draw() || ply < 2));

pv.push_back(MOVE_NONE); // Must be zero-terminating

Expand Down

0 comments on commit fe72c93

Please sign in to comment.