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Merged
merged 9 commits into from
Sep 7, 2023
Merged

Changes quicksort and quickselect to use template based sorting networks #61

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bf9b413
Changed quicksort and quickselect to use template based sorting networks
sterrettm2 Aug 14, 2023
c869e20
Templatizes qsort_ more to reduce code duplication
sterrettm2 Aug 17, 2023
8d1eb31
Renamed zmm_t and ymm_t to be more generic; other smaller changes
sterrettm2 Aug 21, 2023
b050ce5
Removes xss namespace and changes to scalar pivot selection
sterrettm2 Aug 21, 2023
6967e21
Cleaned up pivot selection logic and changed to storing store/load ma…
sterrettm2 Aug 22, 2023
d9a8723
Fixed minor error
sterrettm2 Aug 23, 2023
09fce7a
Changed pivot code back to previous logic for performance reasons
sterrettm2 Aug 29, 2023
70733ff
Changed to using new unroll macro
sterrettm2 Sep 7, 2023
cea0a72
Small cleanup to pivot selection code
sterrettm2 Sep 7, 2023
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213 changes: 5 additions & 208 deletions src/avx512-16bit-common.h
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
#define AVX512_16BIT_COMMON

#include "avx512-common-qsort.h"
#include "xss-network-qsort.hpp"

/*
* Constants used in sorting 32 elements in a ZMM registers. Based on Bitonic
Expand All @@ -33,8 +34,8 @@ static const uint16_t network[6][32]
* Assumes zmm is random and performs a full sorting network defined in
* https://en.wikipedia.org/wiki/Bitonic_sorter#/media/File:BitonicSort.svg
*/
template <typename vtype, typename zmm_t = typename vtype::zmm_t>
X86_SIMD_SORT_INLINE zmm_t sort_zmm_16bit(zmm_t zmm)
template <typename vtype, typename reg_t = typename vtype::reg_t>
X86_SIMD_SORT_INLINE reg_t sort_zmm_16bit(reg_t zmm)
{
// Level 1
zmm = cmp_merge<vtype>(
Expand Down Expand Up @@ -93,8 +94,8 @@ X86_SIMD_SORT_INLINE zmm_t sort_zmm_16bit(zmm_t zmm)
}

// Assumes zmm is bitonic and performs a recursive half cleaner
template <typename vtype, typename zmm_t = typename vtype::zmm_t>
X86_SIMD_SORT_INLINE zmm_t bitonic_merge_zmm_16bit(zmm_t zmm)
template <typename vtype, typename reg_t = typename vtype::reg_t>
X86_SIMD_SORT_INLINE reg_t bitonic_merge_zmm_16bit(reg_t zmm)
{
// 1) half_cleaner[32]: compare 1-17, 2-18, 3-19 etc ..
zmm = cmp_merge<vtype>(
Expand All @@ -118,208 +119,4 @@ X86_SIMD_SORT_INLINE zmm_t bitonic_merge_zmm_16bit(zmm_t zmm)
return zmm;
}

// Assumes zmm1 and zmm2 are sorted and performs a recursive half cleaner
template <typename vtype, typename zmm_t = typename vtype::zmm_t>
X86_SIMD_SORT_INLINE void bitonic_merge_two_zmm_16bit(zmm_t &zmm1, zmm_t &zmm2)
{
// 1) First step of a merging network: coex of zmm1 and zmm2 reversed
zmm2 = vtype::permutexvar(vtype::get_network(4), zmm2);
zmm_t zmm3 = vtype::min(zmm1, zmm2);
zmm_t zmm4 = vtype::max(zmm1, zmm2);
// 2) Recursive half cleaner for each
zmm1 = bitonic_merge_zmm_16bit<vtype>(zmm3);
zmm2 = bitonic_merge_zmm_16bit<vtype>(zmm4);
}

// Assumes [zmm0, zmm1] and [zmm2, zmm3] are sorted and performs a recursive
// half cleaner
template <typename vtype, typename zmm_t = typename vtype::zmm_t>
X86_SIMD_SORT_INLINE void bitonic_merge_four_zmm_16bit(zmm_t *zmm)
{
zmm_t zmm2r = vtype::permutexvar(vtype::get_network(4), zmm[2]);
zmm_t zmm3r = vtype::permutexvar(vtype::get_network(4), zmm[3]);
zmm_t zmm_t1 = vtype::min(zmm[0], zmm3r);
zmm_t zmm_t2 = vtype::min(zmm[1], zmm2r);
zmm_t zmm_t3 = vtype::permutexvar(vtype::get_network(4),
vtype::max(zmm[1], zmm2r));
zmm_t zmm_t4 = vtype::permutexvar(vtype::get_network(4),
vtype::max(zmm[0], zmm3r));
zmm_t zmm0 = vtype::min(zmm_t1, zmm_t2);
zmm_t zmm1 = vtype::max(zmm_t1, zmm_t2);
zmm_t zmm2 = vtype::min(zmm_t3, zmm_t4);
zmm_t zmm3 = vtype::max(zmm_t3, zmm_t4);
zmm[0] = bitonic_merge_zmm_16bit<vtype>(zmm0);
zmm[1] = bitonic_merge_zmm_16bit<vtype>(zmm1);
zmm[2] = bitonic_merge_zmm_16bit<vtype>(zmm2);
zmm[3] = bitonic_merge_zmm_16bit<vtype>(zmm3);
}

template <typename vtype, typename type_t>
X86_SIMD_SORT_INLINE void sort_32_16bit(type_t *arr, int32_t N)
{
typename vtype::opmask_t load_mask = ((0x1ull << N) - 0x1ull) & 0xFFFFFFFF;
typename vtype::zmm_t zmm
= vtype::mask_loadu(vtype::zmm_max(), load_mask, arr);
vtype::mask_storeu(arr, load_mask, sort_zmm_16bit<vtype>(zmm));
}

template <typename vtype, typename type_t>
X86_SIMD_SORT_INLINE void sort_64_16bit(type_t *arr, int32_t N)
{
if (N <= 32) {
sort_32_16bit<vtype>(arr, N);
return;
}
using zmm_t = typename vtype::zmm_t;
typename vtype::opmask_t load_mask
= ((0x1ull << (N - 32)) - 0x1ull) & 0xFFFFFFFF;
zmm_t zmm1 = vtype::loadu(arr);
zmm_t zmm2 = vtype::mask_loadu(vtype::zmm_max(), load_mask, arr + 32);
zmm1 = sort_zmm_16bit<vtype>(zmm1);
zmm2 = sort_zmm_16bit<vtype>(zmm2);
bitonic_merge_two_zmm_16bit<vtype>(zmm1, zmm2);
vtype::storeu(arr, zmm1);
vtype::mask_storeu(arr + 32, load_mask, zmm2);
}

template <typename vtype, typename type_t>
X86_SIMD_SORT_INLINE void sort_128_16bit(type_t *arr, int32_t N)
{
if (N <= 64) {
sort_64_16bit<vtype>(arr, N);
return;
}
using zmm_t = typename vtype::zmm_t;
using opmask_t = typename vtype::opmask_t;
zmm_t zmm[4];
zmm[0] = vtype::loadu(arr);
zmm[1] = vtype::loadu(arr + 32);
opmask_t load_mask1 = 0xFFFFFFFF, load_mask2 = 0xFFFFFFFF;
if (N != 128) {
uint64_t combined_mask = (0x1ull << (N - 64)) - 0x1ull;
load_mask1 = combined_mask & 0xFFFFFFFF;
load_mask2 = (combined_mask >> 32) & 0xFFFFFFFF;
}
zmm[2] = vtype::mask_loadu(vtype::zmm_max(), load_mask1, arr + 64);
zmm[3] = vtype::mask_loadu(vtype::zmm_max(), load_mask2, arr + 96);
zmm[0] = sort_zmm_16bit<vtype>(zmm[0]);
zmm[1] = sort_zmm_16bit<vtype>(zmm[1]);
zmm[2] = sort_zmm_16bit<vtype>(zmm[2]);
zmm[3] = sort_zmm_16bit<vtype>(zmm[3]);
bitonic_merge_two_zmm_16bit<vtype>(zmm[0], zmm[1]);
bitonic_merge_two_zmm_16bit<vtype>(zmm[2], zmm[3]);
bitonic_merge_four_zmm_16bit<vtype>(zmm);
vtype::storeu(arr, zmm[0]);
vtype::storeu(arr + 32, zmm[1]);
vtype::mask_storeu(arr + 64, load_mask1, zmm[2]);
vtype::mask_storeu(arr + 96, load_mask2, zmm[3]);
}

template <typename vtype, typename type_t>
X86_SIMD_SORT_INLINE type_t get_pivot_16bit(type_t *arr,
const int64_t left,
const int64_t right)
{
// median of 32
int64_t size = (right - left) / 32;
type_t vec_arr[32] = {arr[left],
arr[left + size],
arr[left + 2 * size],
arr[left + 3 * size],
arr[left + 4 * size],
arr[left + 5 * size],
arr[left + 6 * size],
arr[left + 7 * size],
arr[left + 8 * size],
arr[left + 9 * size],
arr[left + 10 * size],
arr[left + 11 * size],
arr[left + 12 * size],
arr[left + 13 * size],
arr[left + 14 * size],
arr[left + 15 * size],
arr[left + 16 * size],
arr[left + 17 * size],
arr[left + 18 * size],
arr[left + 19 * size],
arr[left + 20 * size],
arr[left + 21 * size],
arr[left + 22 * size],
arr[left + 23 * size],
arr[left + 24 * size],
arr[left + 25 * size],
arr[left + 26 * size],
arr[left + 27 * size],
arr[left + 28 * size],
arr[left + 29 * size],
arr[left + 30 * size],
arr[left + 31 * size]};
typename vtype::zmm_t rand_vec = vtype::loadu(vec_arr);
typename vtype::zmm_t sort = sort_zmm_16bit<vtype>(rand_vec);
return ((type_t *)&sort)[16];
}

template <typename vtype, typename type_t>
static void
qsort_16bit_(type_t *arr, int64_t left, int64_t right, int64_t max_iters)
{
/*
* Resort to std::sort if quicksort isnt making any progress
*/
if (max_iters <= 0) {
std::sort(arr + left, arr + right + 1, comparison_func<vtype>);
return;
}
/*
* Base case: use bitonic networks to sort arrays <= 128
*/
if (right + 1 - left <= 128) {
sort_128_16bit<vtype>(arr + left, (int32_t)(right + 1 - left));
return;
}

type_t pivot = get_pivot_16bit<vtype>(arr, left, right);
type_t smallest = vtype::type_max();
type_t biggest = vtype::type_min();
int64_t pivot_index = partition_avx512<vtype>(
arr, left, right + 1, pivot, &smallest, &biggest);
if (pivot != smallest)
qsort_16bit_<vtype>(arr, left, pivot_index - 1, max_iters - 1);
if (pivot != biggest)
qsort_16bit_<vtype>(arr, pivot_index, right, max_iters - 1);
}

template <typename vtype, typename type_t>
static void qselect_16bit_(type_t *arr,
int64_t pos,
int64_t left,
int64_t right,
int64_t max_iters)
{
/*
* Resort to std::sort if quicksort isnt making any progress
*/
if (max_iters <= 0) {
std::sort(arr + left, arr + right + 1, comparison_func<vtype>);
return;
}
/*
* Base case: use bitonic networks to sort arrays <= 128
*/
if (right + 1 - left <= 128) {
sort_128_16bit<vtype>(arr + left, (int32_t)(right + 1 - left));
return;
}

type_t pivot = get_pivot_16bit<vtype>(arr, left, right);
type_t smallest = vtype::type_max();
type_t biggest = vtype::type_min();
int64_t pivot_index = partition_avx512<vtype>(
arr, left, right + 1, pivot, &smallest, &biggest);
if ((pivot != smallest) && (pos < pivot_index))
qselect_16bit_<vtype>(arr, pos, left, pivot_index - 1, max_iters - 1);
else if ((pivot != biggest) && (pos >= pivot_index))
qselect_16bit_<vtype>(arr, pos, pivot_index, right, max_iters - 1);
}

#endif // AVX512_16BIT_COMMON
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