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Clean up comments in code

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- Capitalize comments
- Reformat multi-lines comments to equalize the widths of the lines
- Try to keep the width of comments around 85 characters
- Remove periods at the end of single-line comments

closes https://github.com/official-stockfish/Stockfish/pull/5469

No functional change
This commit is contained in:
Stéphane Nicolet
2024-07-11 07:29:33 +02:00
committed by Joost VandeVondele
parent 98a7bb4436
commit 7e72b37e4c
12 changed files with 356 additions and 311 deletions
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src/nnue/nnue_feature_transformer.h
+23 -17
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@@ -354,13 +354,18 @@ class FeatureTransformer {
for (IndexType j = 0; j < NumOutputChunks; ++j)
{
// What we want to do is multiply inputs in a pairwise manner (after clipping), and then shift right by 9.
// Instead, we shift left by 7, and use mulhi, stripping the bottom 16 bits, effectively shifting right by 16,
// resulting in a net shift of 9 bits. We use mulhi because it maintains the sign of the multiplication (unlike mullo),
// allowing us to make use of packus to clip 2 of the inputs, resulting in a save of 2 "vec_max_16" calls.
// A special case is when we use NEON, where we shift left by 6 instead, because the instruction "vqdmulhq_s16"
// also doubles the return value after the multiplication, adding an extra shift to the left by 1, so we
// compensate by shifting less before the multiplication.
// What we want to do is multiply inputs in a pairwise manner
// (after clipping), and then shift right by 9. Instead, we
// shift left by 7, and use mulhi, stripping the bottom 16 bits,
// effectively shifting right by 16, resulting in a net shift
// of 9 bits. We use mulhi because it maintains the sign of
// the multiplication (unlike mullo), allowing us to make use
// of packus to clip 2 of the inputs, resulting in a save of 2
// "vec_max_16" calls. A special case is when we use NEON,
// where we shift left by 6 instead, because the instruction
// "vqdmulhq_s16" also doubles the return value after the
// multiplication, adding an extra shift to the left by 1, so
// we compensate by shifting less before the multiplication.
#if defined(USE_SSE2)
constexpr int shift = 7;
@@ -426,10 +431,10 @@ class FeatureTransformer {
}
// NOTE: The parameter states_to_update is an array of position states.
// All states must be sequential, that is states_to_update[i] must either be reachable
// by repeatedly applying ->previous from states_to_update[i+1].
// computed_st must be reachable by repeatedly applying ->previous on
// states_to_update[0].
// All states must be sequential, that is states_to_update[i] must
// either be reachable by repeatedly applying ->previous from
// states_to_update[i+1], and computed_st must be reachable by
// repeatedly applying ->previous on states_to_update[0].
template<Color Perspective, size_t N>
void update_accumulator_incremental(const Position& pos,
StateInfo* computed_st,
@@ -446,7 +451,7 @@ class FeatureTransformer {
#ifdef VECTOR
// Gcc-10.2 unnecessarily spills AVX2 registers if this array
// is defined in the VECTOR code below, once in each branch
// is defined in the VECTOR code below, once in each branch.
vec_t acc[NumRegs];
psqt_vec_t psqt[NumPsqtRegs];
#endif
@@ -474,7 +479,8 @@ class FeatureTransformer {
StateInfo* st = computed_st;
// Now update the accumulators listed in states_to_update[], where the last element is a sentinel.
// Now update the accumulators listed in states_to_update[],
// where the last element is a sentinel.
#ifdef VECTOR
if (N == 1 && (removed[0].size() == 1 || removed[0].size() == 2) && added[0].size() == 1)
@@ -794,7 +800,7 @@ class FeatureTransformer {
}
// The accumulator of the refresh entry has been updated.
// Now copy its content to the actual accumulator we were refreshing
// Now copy its content to the actual accumulator we were refreshing.
std::memcpy(accumulator.accumulation[Perspective], entry.accumulation,
sizeof(BiasType) * HalfDimensions);
@@ -827,7 +833,7 @@ class FeatureTransformer {
if ((oldest_st->*accPtr).computed[Perspective])
{
// Only update current position accumulator to minimize work.
// Only update current position accumulator to minimize work
StateInfo* states_to_update[1] = {pos.state()};
update_accumulator_incremental<Perspective, 1>(pos, oldest_st, states_to_update);
}
@@ -846,8 +852,8 @@ class FeatureTransformer {
if (next == nullptr)
return;
// Now update the accumulators listed in states_to_update[], where the last element is a sentinel.
// Currently we update 2 accumulators.
// Now update the accumulators listed in states_to_update[], where
// the last element is a sentinel. Currently we update two accumulators:
// 1. for the current position
// 2. the next accumulator after the computed one
// The heuristic may change in the future.