Skip to content

Deyu/perf #1281

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Deyu Kong (cave-g-f) merged 1 commit into from
Jul 28, 2026
Merged

Deyu/perf #1281

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 5 additions & 5 deletions src/filter_match_proxy.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,16 +7,16 @@ template <typename LabelT>
void bitmask_filter_match<LabelT>::build_query_mask(const std::vector<LabelT>& filter_labels, LabelT unv_label)
{
// _query_bitmask_buf is already bound (by the ctor init list) to either the
// caller-supplied scratch buffer or the owned buffer. Size it to at least
// AVX2_TAIL_PADDING words so the 256-bit load in test_full_mask_val never
// reads past the end.
// caller-supplied scratch buffer or the owned buffer. Size it to
// _bitmask_size + AVX2_TAIL_PADDING words so the unconditional 256-bit load
// in test_full_mask_val's fast path never reads past the end (matches the
// node-side simple_bitmask_buf padding scheme).
//
// clear() first so the resize zero-fills every word: a reused scratch buffer
// may already be at padded_size, in which case a bare resize is a no-op that
// leaves stale high words from a previous query -- test_full_mask_val's
// unconditional 256-bit AND would then treat them as real filter bits.
const std::uint64_t padded_size =
std::max(_bitmask_filters._bitmask_size, simple_bitmask_buf::AVX2_TAIL_PADDING);
const std::uint64_t padded_size = _bitmask_filters._bitmask_size + simple_bitmask_buf::AVX2_TAIL_PADDING;
_query_bitmask_buf.clear();
_query_bitmask_buf.resize(padded_size, 0);
_bitmask_full_val._mask = _query_bitmask_buf.data();
Expand Down
4 changes: 2 additions & 2 deletions src/index.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2577,12 +2577,12 @@ void Index<T, TagT, LabelT>::aggregate_points_by_bitmask_label(
std::advance(itr, lbl);
auto& x = *itr;

// Pad to >=AVX2_TAIL_PADDING words: test_full_mask_val issues an
// Pad by AVX2_TAIL_PADDING words: test_full_mask_val issues an
// unconditional 256-bit load over this query mask, so it must be at least
// 4 words long. clear() first so resize zero-fills every word (no stale
// bits carried across label iterations).
label_bitmask.clear();
label_bitmask.resize(std::max(_bitmask_buf._bitmask_size, simple_bitmask_buf::AVX2_TAIL_PADDING), 0);
label_bitmask.resize(_bitmask_buf._bitmask_size + simple_bitmask_buf::AVX2_TAIL_PADDING, 0);

simple_bitmask_full_val bitmask_full_val;
bitmask_full_val._mask = label_bitmask.data();
Expand Down
40 changes: 19 additions & 21 deletions tests/filter_match_proxy_tests.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,16 +51,14 @@ BOOST_AUTO_TEST_SUITE(FilterMatchProxy_tests)

// ---- (2) AVX2 padding of query_bitmask_buf ----------------------------------
//
// The optimization changed the ctor from:
// query_bitmask_buf.resize(_bitmask_filters._bitmask_size, 0);
// to:
// size_t padded_size = std::max(_bitmask_size, (uint64_t)4);
// query_bitmask_buf.resize(padded_size, 0);
// This ensures a 256-bit (4x uint64) AVX2 load starting at
// query_bitmask_buf.data() never runs past the buffer end even when the
// natural bitmask_size is 1, 2, or 3 words.

BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_to_at_least_4_words_when_size_1)
// build_query_mask sizes the query buffer to:
// bitmask_size + AVX2_TAIL_PADDING
// (unified with the node-side simple_bitmask_buf padding scheme). This ensures a
// 256-bit (4x uint64) AVX2 load starting at query_bitmask_buf.data() never runs
// past the buffer end for any bitmask_size, and the trailing padding words stay
// zero so they never contribute false bits to the intersection test.

BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_1)
{
// 1 word covers up to 64 bits; use 64 bits total.
auto filters = make_bitmask_buf(/*num_points*/ 8, /*total_bits*/ 64,
Expand All @@ -71,8 +69,8 @@ BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_to_at_least_4_words_when_size_1
std::vector<std::uint32_t> filter_labels = {3};
bitmask_filter_match<std::uint32_t> m(filters, qbuf, filter_labels, /*unv*/ 0);

// Must be padded up to 4 for AVX2 safety.
BOOST_TEST(qbuf.size() == (size_t)4);
// size + 4 padding.
BOOST_TEST(qbuf.size() == (size_t)5);
}

BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_2)
Expand All @@ -85,7 +83,7 @@ BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_2)
std::vector<std::uint32_t> filter_labels = {1};
bitmask_filter_match<std::uint32_t> m(filters, qbuf, filter_labels, 0);

BOOST_TEST(qbuf.size() == (size_t)4);
BOOST_TEST(qbuf.size() == (size_t)6);
}

BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_3)
Expand All @@ -98,33 +96,33 @@ BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_3)
std::vector<std::uint32_t> filter_labels = {0};
bitmask_filter_match<std::uint32_t> m(filters, qbuf, filter_labels, 0);

BOOST_TEST(qbuf.size() == (size_t)4);
BOOST_TEST(qbuf.size() == (size_t)7);
}

BOOST_AUTO_TEST_CASE(bitmask_ctor_no_padding_when_size_ge_4)
BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_4)
{
// 256 bits -> bitmask_size == 4; no extra padding needed.
// 256 bits -> bitmask_size == 4.
auto filters = make_bitmask_buf(4, 256, 0, {});
BOOST_TEST(filters._bitmask_size == (std::uint64_t)4);

std::vector<std::uint64_t> qbuf;
std::vector<std::uint32_t> filter_labels = {0};
bitmask_filter_match<std::uint32_t> m(filters, qbuf, filter_labels, 0);

BOOST_TEST(qbuf.size() == (size_t)4);
BOOST_TEST(qbuf.size() == (size_t)8);
}

BOOST_AUTO_TEST_CASE(bitmask_ctor_keeps_size_when_larger_than_4)
BOOST_AUTO_TEST_CASE(bitmask_ctor_pads_query_buf_when_size_larger_than_4)
{
// 512 bits -> bitmask_size == 8; must not be truncated.
// 512 bits -> bitmask_size == 8; padded to 8 + 4.
auto filters = make_bitmask_buf(4, 512, 0, {});
BOOST_TEST(filters._bitmask_size == (std::uint64_t)8);

std::vector<std::uint64_t> qbuf;
std::vector<std::uint32_t> filter_labels = {0};
bitmask_filter_match<std::uint32_t> m(filters, qbuf, filter_labels, 0);

BOOST_TEST(qbuf.size() == (size_t)8);
BOOST_TEST(qbuf.size() == (size_t)12);
}

BOOST_AUTO_TEST_CASE(bitmask_ctor_size_zero_leaves_query_buf_empty)
Expand Down Expand Up @@ -389,7 +387,7 @@ BOOST_AUTO_TEST_CASE(bitmask_reused_query_buffer_is_rezeroed)
std::vector<std::uint32_t> f1 = {5};
bitmask_filter_match<std::uint32_t> m1(filters, qbuf, f1, /*unv*/ 0);
BOOST_TEST(m1.contain_filtered_label(2) == true);
BOOST_TEST(qbuf.size() == (size_t)4); // padded
BOOST_TEST(qbuf.size() == (size_t)5); // size 1 + 4 padding
}
// qbuf now retains proxy #1's bits (filter label 5 in word 0). A second
// proxy filtering a DISJOINT label must not inherit label 5.
Expand Down
Loading