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Only evaluate the PSQT part of the small net for large evals.
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Thanks to Viren6 for suggesting to set complexity to 0.

STC https://tests.stockfishchess.org/tests/view/65d7d6709b2da0226a5a203f
LLR: 2.92 (-2.94,2.94) <0.00,2.00>
Total: 328384 W: 85316 L: 84554 D: 158514
Ptnml(0-2): 1414, 39076, 82486, 39766, 1450

LTC https://tests.stockfishchess.org/tests/view/65dce6d290f639b028a54d2e
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 165162 W: 41918 L: 41330 D: 81914
Ptnml(0-2): 102, 18332, 45124, 18922, 101

closes #5083

bench: 1504003
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@mstembera @vondele
mstembera authored and vondele committed Mar 3, 2024
1 parent 0a3eb1d commit 7831131
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Showing 6 changed files with 189 additions and 144 deletions.
5 changes: 3 additions & 2 deletions src/evaluate.cpp
View file
Expand Up @@ -194,11 +194,12 @@ Value Eval::evaluate(const Position& pos, int optimism) {

int simpleEval = simple_eval(pos, pos.side_to_move());
bool smallNet = std::abs(simpleEval) > 1050;
bool psqtOnly = std::abs(simpleEval) > 2500;

int nnueComplexity;

Value nnue = smallNet ? NNUE::evaluate<NNUE::Small>(pos, true, &nnueComplexity)
: NNUE::evaluate<NNUE::Big>(pos, true, &nnueComplexity);
Value nnue = smallNet ? NNUE::evaluate<NNUE::Small>(pos, true, &nnueComplexity, psqtOnly)
: NNUE::evaluate<NNUE::Big>(pos, true, &nnueComplexity, false);

// Blend optimism and eval with nnue complexity and material imbalance
optimism += optimism * (nnueComplexity + std::abs(simpleEval - nnue)) / 512;
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47 changes: 27 additions & 20 deletions src/nnue/evaluate_nnue.cpp
View file
Expand Up @@ -179,16 +179,16 @@ write_parameters(std::ostream& stream, NetSize netSize, const std::string& netDe

void hint_common_parent_position(const Position& pos) {

int simpleEval = simple_eval(pos, pos.side_to_move());
if (std::abs(simpleEval) > 1050)
featureTransformerSmall->hint_common_access(pos);
int simpleEvalAbs = std::abs(simple_eval(pos, pos.side_to_move()));
if (simpleEvalAbs > 1050)
featureTransformerSmall->hint_common_access(pos, simpleEvalAbs > 2500);
else
featureTransformerBig->hint_common_access(pos);
featureTransformerBig->hint_common_access(pos, false);
}

// Evaluation function. Perform differential calculation.
template<NetSize Net_Size>
Value evaluate(const Position& pos, bool adjusted, int* complexity) {
Value evaluate(const Position& pos, bool adjusted, int* complexity, bool psqtOnly) {

// We manually align the arrays on the stack because with gcc < 9.3
// overaligning stack variables with alignas() doesn't work correctly.
Expand All @@ -213,15 +213,19 @@ Value evaluate(const Position& pos, bool adjusted, int* complexity) {

ASSERT_ALIGNED(transformedFeatures, alignment);

const int bucket = (pos.count<ALL_PIECES>() - 1) / 4;
const auto psqt = Net_Size == Small
? featureTransformerSmall->transform(pos, transformedFeatures, bucket)
: featureTransformerBig->transform(pos, transformedFeatures, bucket);
const auto positional = Net_Size == Small ? networkSmall[bucket]->propagate(transformedFeatures)
: networkBig[bucket]->propagate(transformedFeatures);
const int bucket = (pos.count<ALL_PIECES>() - 1) / 4;
const auto psqt =
Net_Size == Small
? featureTransformerSmall->transform(pos, transformedFeatures, bucket, psqtOnly)
: featureTransformerBig->transform(pos, transformedFeatures, bucket, psqtOnly);

const auto positional =
!psqtOnly ? (Net_Size == Small ? networkSmall[bucket]->propagate(transformedFeatures)
: networkBig[bucket]->propagate(transformedFeatures))
: 0;

if (complexity)
*complexity = std::abs(psqt - positional) / OutputScale;
*complexity = !psqtOnly ? std::abs(psqt - positional) / OutputScale : 0;

// Give more value to positional evaluation when adjusted flag is set
if (adjusted)
Expand All @@ -231,8 +235,8 @@ Value evaluate(const Position& pos, bool adjusted, int* complexity) {
return static_cast<Value>((psqt + positional) / OutputScale);
}

template Value evaluate<Big>(const Position& pos, bool adjusted, int* complexity);
template Value evaluate<Small>(const Position& pos, bool adjusted, int* complexity);
template Value evaluate<Big>(const Position& pos, bool adjusted, int* complexity, bool psqtOnly);
template Value evaluate<Small>(const Position& pos, bool adjusted, int* complexity, bool psqtOnly);

struct NnueEvalTrace {
static_assert(LayerStacks == PSQTBuckets);
Expand Down Expand Up @@ -265,8 +269,9 @@ static NnueEvalTrace trace_evaluate(const Position& pos) {
t.correctBucket = (pos.count<ALL_PIECES>() - 1) / 4;
for (IndexType bucket = 0; bucket < LayerStacks; ++bucket)
{
const auto materialist = featureTransformerBig->transform(pos, transformedFeatures, bucket);
const auto positional = networkBig[bucket]->propagate(transformedFeatures);
const auto materialist =
featureTransformerBig->transform(pos, transformedFeatures, bucket, false);
const auto positional = networkBig[bucket]->propagate(transformedFeatures);

t.psqt[bucket] = static_cast<Value>(materialist / OutputScale);
t.positional[bucket] = static_cast<Value>(positional / OutputScale);
Expand Down Expand Up @@ -370,16 +375,18 @@ std::string trace(Position& pos) {
auto st = pos.state();

pos.remove_piece(sq);
st->accumulatorBig.computed[WHITE] = false;
st->accumulatorBig.computed[BLACK] = false;
st->accumulatorBig.computed[WHITE] = st->accumulatorBig.computed[BLACK] =
st->accumulatorBig.computedPSQT[WHITE] = st->accumulatorBig.computedPSQT[BLACK] =
false;

Value eval = evaluate<NNUE::Big>(pos);
eval = pos.side_to_move() == WHITE ? eval : -eval;
v = base - eval;

pos.put_piece(pc, sq);
st->accumulatorBig.computed[WHITE] = false;
st->accumulatorBig.computed[BLACK] = false;
st->accumulatorBig.computed[WHITE] = st->accumulatorBig.computed[BLACK] =
st->accumulatorBig.computedPSQT[WHITE] = st->accumulatorBig.computedPSQT[BLACK] =
false;
}

writeSquare(f, r, pc, v);
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5 changes: 4 additions & 1 deletion src/nnue/evaluate_nnue.h
View file
Expand Up @@ -76,7 +76,10 @@ using LargePagePtr = std::unique_ptr<T, LargePageDeleter<T>>;

std::string trace(Position& pos);
template<NetSize Net_Size>
Value evaluate(const Position& pos, bool adjusted = false, int* complexity = nullptr);
Value evaluate(const Position& pos,
bool adjusted = false,
int* complexity = nullptr,
bool psqtOnly = false);
void hint_common_parent_position(const Position& pos);

std::optional<std::string> load_eval(std::istream& stream, NetSize netSize);
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1 change: 1 addition & 0 deletions src/nnue/nnue_accumulator.h
View file
Expand Up @@ -34,6 +34,7 @@ struct alignas(CacheLineSize) Accumulator {
std::int16_t accumulation[2][Size];
std::int32_t psqtAccumulation[2][PSQTBuckets];
bool computed[2];
bool computedPSQT[2];
};

} // namespace Stockfish::Eval::NNUE
Expand Down

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