Skip to content

Commit

Permalink
Merge pull request #209 from ashbob999/fix-hybrid-sort
Browse files Browse the repository at this point in the history 
Fix: hybrid bench sort issues
  • Loading branch information
@ashvardanian
ashvardanian authored Feb 14, 2025
2 parents 554f50d + 9880f26 commit 94941bc
Showing 1 changed file with 80 additions and 16 deletions.
96 changes: 80 additions & 16 deletions scripts/bench_sort.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -66,44 +66,108 @@ void populate_from_file(std::string path, strings_t &strings,
while (strings.size() < limit && std::getline(f, s, ' ')) strings.push_back(s);
}

constexpr size_t offset_in_word = 0;
constexpr size_t offset_in_word = 4;

static idx_t hybrid_sort_cpp(strings_t const &strings, sz_u64_t *order) {

// What if we take up-to 4 first characters and the index
for (size_t i = 0; i != strings.size(); ++i)
std::memcpy((char *)&order[i] + offset_in_word, strings[order[i]].c_str(),
std::min<std::size_t>(strings[order[i]].size(), 4ul));
for (size_t i = 0; i != strings.size(); ++i) {
size_t index = order[i];

for (size_t j = 0; j < std::min<std::size_t>(strings[(sz_size_t)index].size(), 4ul); ++j) {
std::memcpy((char *)&order[i] + offset_in_word + 3 - j, strings[(sz_size_t)index].c_str() + j, 1ul);
}
}

std::sort(order, order + strings.size(), [&](sz_u64_t i, sz_u64_t j) {
char *i_bytes = (char *)&i;
char *j_bytes = (char *)&j;
return *(uint32_t *)(i_bytes + offset_in_word) < *(uint32_t *)(j_bytes + offset_in_word);
});

for (size_t i = 0; i != strings.size(); ++i) std::memset((char *)&order[i] + offset_in_word, 0, 4ul);
const auto extract_bytes = [](sz_u64_t v) -> uint32_t {
char *bytes = (char *)&v;
return *(uint32_t *)(bytes + offset_in_word);
};

if (strings.size() >= 2) {
size_t prev_index = 0;
uint64_t prev_bytes = extract_bytes(order[0]);

for (size_t i = 1; i < strings.size(); ++i) {
uint32_t bytes = extract_bytes(order[i]);
if (bytes != prev_bytes) {
std::sort(order + prev_index, order + i, [&](sz_u64_t i, sz_u64_t j) {
// Assumes: offset_in_word==4
sz_size_t i_index = i & 0xFFFF'FFFF;
sz_size_t j_index = j & 0xFFFF'FFFF;
return strings[i_index] < strings[j_index];
});
prev_index = i;
prev_bytes = bytes;
}
}

std::sort(order + prev_index, order + strings.size(), [&](sz_u64_t i, sz_u64_t j) {
sz_size_t i_index = i & 0xFFFF'FFFF;
sz_size_t j_index = j & 0xFFFF'FFFF;
return strings[i_index] < strings[j_index];
});
}

std::sort(order, order + strings.size(), [&](sz_u64_t i, sz_u64_t j) { return strings[i] < strings[j]; });
for (size_t i = 0; i != strings.size(); ++i) std::memset((char *)&order[i] + offset_in_word, 0, 4ul);

return strings.size();
}

static idx_t hybrid_stable_sort_cpp(strings_t const &strings, sz_u64_t *order) {

// What if we take up-to 4 first characters and the index
for (size_t i = 0; i != strings.size(); ++i)
std::memcpy((char *)&order[i] + offset_in_word, strings[order[i]].c_str(),
std::min<std::size_t>(strings[order[i]].size(), 4ull));
for (size_t i = 0; i != strings.size(); ++i) {
size_t index = order[i];

for (size_t j = 0; j < std::min<std::size_t>(strings[(sz_size_t)index].size(), 4ul); ++j) {
std::memcpy((char *)&order[i] + offset_in_word + 3 - j, strings[(sz_size_t)index].c_str() + j, 1ul);
}
}

std::stable_sort(order, order + strings.size(), [&](sz_u64_t i, sz_u64_t j) {
char *i_bytes = (char *)&i;
char *j_bytes = (char *)&j;
return *(uint32_t *)(i_bytes + offset_in_word) < *(uint32_t *)(j_bytes + offset_in_word);
});

for (size_t i = 0; i != strings.size(); ++i) std::memset((char *)&order[i] + offset_in_word, 0, 4ul);
const auto extract_bytes = [](sz_u64_t v) -> uint32_t {
char *bytes = (char *)&v;
return *(uint32_t *)(bytes + offset_in_word);
};

if (strings.size() >= 2) {
size_t prev_index = 0;
uint64_t prev_bytes = extract_bytes(order[0]);

for (size_t i = 1; i < strings.size(); ++i) {
uint32_t bytes = extract_bytes(order[i]);
if (bytes != prev_bytes) {
std::stable_sort(order + prev_index, order + i, [&](sz_u64_t i, sz_u64_t j) {
// Assumes: offset_in_word==4
sz_size_t i_index = i & 0xFFFF'FFFF;
sz_size_t j_index = j & 0xFFFF'FFFF;
return strings[i_index] < strings[j_index];
});
prev_index = i;
prev_bytes = bytes;
}
}

std::stable_sort(order + prev_index, order + strings.size(), [&](sz_u64_t i, sz_u64_t j) {
sz_size_t i_index = i & 0xFFFF'FFFF;
sz_size_t j_index = j & 0xFFFF'FFFF;
return strings[i_index] < strings[j_index];
});
}

std::stable_sort(order, order + strings.size(), [&](sz_u64_t i, sz_u64_t j) { return strings[i] < strings[j]; });
for (size_t i = 0; i != strings.size(); ++i) std::memset((char *)&order[i] + offset_in_word, 0, 4ul);

return strings.size();
}
Expand Down Expand Up @@ -196,7 +260,7 @@ int main(int argc, char const **argv) {
});
expect_sorted(strings, permute_new);

#if __linux__ && defined(_GNU_SOURCE)
#if __linux__ && defined(_GNU_SOURCE) && !defined(__BIONIC__)
bench_permute("qsort_r", strings, permute_new, [](strings_t const &strings, permute_t &permute) {
sz_sequence_t array;
array.order = permute.data();
Expand Down Expand Up @@ -232,12 +296,12 @@ int main(int argc, char const **argv) {
});
expect_sorted(strings, permute_base);

bench_permute(
"hybrid_stable_sort_cpp", strings, permute_base,
[](strings_t const &strings, permute_t &permute) { hybrid_stable_sort_cpp(strings, permute.data()); });
bench_permute("hybrid_stable_sort_cpp", strings, permute_new, [](strings_t const &strings, permute_t &permute) {
hybrid_stable_sort_cpp(strings, permute.data());
});
expect_sorted(strings, permute_new);
expect_same(permute_base, permute_new);
}

return 0;
}
}

0 comments on commit 94941bc

Please sign in to comment.