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vondelezamar
vondele
authored and
zamar
committed
Always have counterMoves associated
Simplifies away all associated checks, leading to a ~0.5% speedup. The code now explicitly checks if moves are OK, rather than using nullptr checks. Verified for no regression: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 32218 W: 5762 L: 5660 D: 20796 No functional change Closes #1021
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3 files changed

+26
-29
lines changed

3 files changed

+26
-29
lines changed

‎src/movepick.cpp‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -149,9 +149,9 @@ void MovePicker::score<QUIETS>() {
149149
Color c = pos.side_to_move();
150150

151151
for (auto& m : *this)
152-
m.value = (cmh ? (*cmh)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
153-
+ (fmh ? (*fmh)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
154-
+ (fmh2 ? (*fmh2)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
152+
m.value = (*cmh)[pos.moved_piece(m)][to_sq(m)]
153+
+ (*fmh)[pos.moved_piece(m)][to_sq(m)]
154+
+ (*fmh2)[pos.moved_piece(m)][to_sq(m)]
155155
+ history.get(c, m);
156156
}
157157

‎src/position.cpp‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -377,7 +377,7 @@ void Position::set_state(StateInfo* si) const {
377377

378378

379379
/// Position::set() is an overload to initialize the position object with
380-
/// the given endgame code string like "KBPKN". It is manily an helper to
380+
/// the given endgame code string like "KBPKN". It is mainly a helper to
381381
/// get the material key out of an endgame code. Position is not playable,
382382
/// indeed is even not guaranteed to be legal.
383383

‎src/search.cpp‎

Lines changed: 22 additions & 25 deletions
Original file line numberDiff line numberDiff line change
@@ -324,6 +324,8 @@ void Thread::search() {
324324
MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
325325

326326
std::memset(ss-4, 0, 7 * sizeof(Stack));
327+
for(int i = -4; i < 0; i++)
328+
(ss+i)->counterMoves = &this->counterMoveHistory[NO_PIECE][0]; // use as sentinel.
327329

328330
bestValue = delta = alpha = -VALUE_INFINITE;
329331
beta = VALUE_INFINITE;
@@ -593,7 +595,7 @@ namespace {
593595
assert(0 <= ss->ply && ss->ply < MAX_PLY);
594596

595597
ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
596-
ss->counterMoves = nullptr;
598+
ss->counterMoves = &thisThread->counterMoveHistory[NO_PIECE][0];
597599
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
598600
Square prevSq = to_sq((ss-1)->currentMove);
599601

@@ -729,14 +731,15 @@ namespace {
729731
&& (ss->staticEval >= beta - 35 * (depth / ONE_PLY - 6) || depth >= 13 * ONE_PLY)
730732
&& pos.non_pawn_material(pos.side_to_move()))
731733
{
732-
ss->currentMove = MOVE_NULL;
733-
ss->counterMoves = nullptr;
734734

735735
assert(eval - beta >= 0);
736736

737737
// Null move dynamic reduction based on depth and value
738738
Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
739739

740+
ss->currentMove = MOVE_NULL;
741+
ss->counterMoves = &thisThread->counterMoveHistory[NO_PIECE][0];
742+
740743
pos.do_null_move(st);
741744
Value nullValue = depth-R < ONE_PLY ? -qsearch<NonPV, false>(pos, ss+1, -beta, -beta+1)
742745
: - search<NonPV>(pos, ss+1, -beta, -beta+1, depth-R, !cutNode, true);
@@ -771,8 +774,7 @@ namespace {
771774
Depth rdepth = depth - 4 * ONE_PLY;
772775

773776
assert(rdepth >= ONE_PLY);
774-
assert((ss-1)->currentMove != MOVE_NONE);
775-
assert((ss-1)->currentMove != MOVE_NULL);
777+
assert(is_ok((ss-1)->currentMove));
776778

777779
MovePicker mp(pos, ttMove, rbeta - ss->staticEval);
778780

@@ -781,6 +783,7 @@ namespace {
781783
{
782784
ss->currentMove = move;
783785
ss->counterMoves = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)];
786+
784787
pos.do_move(move, st);
785788
value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode, false);
786789
pos.undo_move(move);
@@ -806,6 +809,9 @@ namespace {
806809
const CounterMoveStats* cmh = (ss-1)->counterMoves;
807810
const CounterMoveStats* fmh = (ss-2)->counterMoves;
808811
const CounterMoveStats* fmh2 = (ss-4)->counterMoves;
812+
const bool cm_ok = is_ok((ss-1)->currentMove);
813+
const bool fm_ok = is_ok((ss-2)->currentMove);
814+
const bool fm2_ok = is_ok((ss-4)->currentMove);
809815

810816
MovePicker mp(pos, ttMove, depth, ss);
811817
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
@@ -905,9 +911,9 @@ namespace {
905911

906912
// Countermoves based pruning
907913
if ( lmrDepth < 3
908-
&& (!cmh || (*cmh )[moved_piece][to_sq(move)] < VALUE_ZERO)
909-
&& (!fmh || (*fmh )[moved_piece][to_sq(move)] < VALUE_ZERO)
910-
&& (!fmh2 || (*fmh2)[moved_piece][to_sq(move)] < VALUE_ZERO || (cmh && fmh)))
914+
&& (((*cmh )[moved_piece][to_sq(move)] < VALUE_ZERO) || !cm_ok)
915+
&& (((*fmh )[moved_piece][to_sq(move)] < VALUE_ZERO) || !fm_ok)
916+
&& (((*fmh2)[moved_piece][to_sq(move)] < VALUE_ZERO) || !fm2_ok || (cm_ok && fm_ok)))
911917
continue;
912918

913919
// Futility pruning: parent node
@@ -967,9 +973,9 @@ namespace {
967973
&& !pos.see_ge(make_move(to_sq(move), from_sq(move)), VALUE_ZERO))
968974
r -= 2 * ONE_PLY;
969975

970-
ss->history = (cmh ? (*cmh )[moved_piece][to_sq(move)] : VALUE_ZERO)
971-
+ (fmh ? (*fmh )[moved_piece][to_sq(move)] : VALUE_ZERO)
972-
+ (fmh2 ? (*fmh2)[moved_piece][to_sq(move)] : VALUE_ZERO)
976+
ss->history = (*cmh )[moved_piece][to_sq(move)]
977+
+ (*fmh )[moved_piece][to_sq(move)]
978+
+ (*fmh2)[moved_piece][to_sq(move)]
973979
+ thisThread->history.get(~pos.side_to_move(), move)
974980
- 4000; // Correction factor
975981

@@ -1112,7 +1118,7 @@ namespace {
11121118
// Bonus for prior countermove that caused the fail low
11131119
else if ( depth >= 3 * ONE_PLY
11141120
&& !pos.captured_piece()
1115-
&& is_ok((ss-1)->currentMove))
1121+
&& cm_ok)
11161122
update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth));
11171123

11181124
tte->save(posKey, value_to_tt(bestValue, ss->ply),
@@ -1372,18 +1378,9 @@ namespace {
13721378

13731379
void update_cm_stats(Stack* ss, Piece pc, Square s, Value bonus) {
13741380

1375-
CounterMoveStats* cmh = (ss-1)->counterMoves;
1376-
CounterMoveStats* fmh1 = (ss-2)->counterMoves;
1377-
CounterMoveStats* fmh2 = (ss-4)->counterMoves;
1378-
1379-
if (cmh)
1380-
cmh->update(pc, s, bonus);
1381-
1382-
if (fmh1)
1383-
fmh1->update(pc, s, bonus);
1384-
1385-
if (fmh2)
1386-
fmh2->update(pc, s, bonus);
1381+
for (int i : {1, 2, 4})
1382+
if (is_ok((ss-i)->currentMove))
1383+
(ss-i)->counterMoves->update(pc, s, bonus);
13871384
}
13881385

13891386

@@ -1403,7 +1400,7 @@ namespace {
14031400
thisThread->history.update(c, move, bonus);
14041401
update_cm_stats(ss, pos.moved_piece(move), to_sq(move), bonus);
14051402

1406-
if ((ss-1)->counterMoves)
1403+
if (is_ok((ss-1)->currentMove))
14071404
{
14081405
Square prevSq = to_sq((ss-1)->currentMove);
14091406
thisThread->counterMoves.update(pos.piece_on(prevSq), prevSq, move);

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