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// Copyright (c) 2021-2024, Intel Corporation
// SPDX-License-Identifier: BSD-3-Clause
#include <benchmark/benchmark.h>
#include <bitset>
#include <cstdint>
#include <stdio.h>
#include "../common.h"
#include "03_popcnt_ispc.h"
static Docs docs("Check popcnt implmentation of stdlib functions:\n"
"[int32, int64] x [uniform, varying] x [all, even] versions.\n"
"Observations:\n"
" - popcnt is very lightweight, so 8 popcnt are chained.\n"
" - chaining doesn't cause optimizing out popcnt, 8 seems to be good enough"
" - varying versions have overhead on insert/extract\n"
" - for even versions mask is statically known and compiler is able to optimize out inactive lanes\n"
"Expectation:\n"
" - No regressions\n");
WARM_UP_RUN();
// Minimum size is maximum target width, i.e. 64.
// Larger buffer is better, but preferably to stay within L1.
#define ARGS Arg(8192)
// #define ARGS RangeMultiplier(2)->Range(64, 64<<15)->Complexity(benchmark::oN)
template <typename T> static void init(T *src, T *dst, int count) {
for (int i = 0; i < count; i++) {
src[i] = static_cast<T>(i);
dst[i] = 0;
}
}
template <typename T> static void check_all(T *src, T *dst, int count) {
for (int i = 0; i < count; i++) {
// for single popcnt() here's the formula, but we chain 8 popcnt()
// int count = std::bitset< std::numeric_limits<T>::digits >(src[i]).count();
int count = (i == 0) ? 0 : 1;
if (dst[i] != count) {
printf("Error i=%d\n", i);
return;
}
}
}
template <typename T> static void check_even(T *src, T *dst, int count) {
for (int i = 0; i < count; i += 2) {
// for single popcnt() here's the formula, but we chain 8 popcnt()
// int count = std::bitset< std::numeric_limits<T>::digits >(src[i]).count();
int count = (i == 0) ? 0 : 1;
if (dst[i] != count) {
printf("Error i=%d\n", i);
return;
}
}
}
#define POPCNT(T_C, T_ISPC, V, ALL) \
static void popcnt_stdlib_##V##_##T_ISPC##_##ALL(benchmark::State &state) { \
int count = static_cast<int>(state.range(0)); \
T_C *src = static_cast<T_C *>(aligned_alloc_helper(sizeof(T_C) * count)); \
T_C *dst = static_cast<T_C *>(aligned_alloc_helper(sizeof(T_C) * count)); \
init(src, dst, count); \
\
for (auto _ : state) { \
ispc::popcnt_##V##_##T_ISPC##_##ALL(src, dst, count); \
} \
\
check_##ALL(src, dst, count); \
aligned_free_helper(src); \
aligned_free_helper(dst); \
state.SetComplexityN(state.range(0)); \
} \
BENCHMARK(popcnt_stdlib_##V##_##T_ISPC##_##ALL)->ARGS;
POPCNT(int, int32, uniform, all)
POPCNT(int, int32, varying, all)
POPCNT(int, int32, uniform, even)
POPCNT(int, int32, varying, even)
POPCNT(int64_t, int64, uniform, all)
POPCNT(int64_t, int64, varying, all)
POPCNT(int64_t, int64, uniform, even)
POPCNT(int64_t, int64, varying, even)
BENCHMARK_MAIN();
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