little_2_big_gcc.cpp

little_2_big_gcc.cpp

#include <memory>
#include <chrono>
#include <iostream>
#include <immintrin.h>
#include <byteswap.h>

const int N = 1024 * 64;
long long int src_data[N];
long long int avx512_data[N];
long long int avx2_data[N];
long long int bswap_result[N];
const long long int MASK = 0x0001020304050607;
const __mmask16 bit16mask[17] = {0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff};

using namespace std;

void avx512_little_2_big(const long long int *src, long long int *dst, int n);
void avx2_little_2_big(const long long int *src, long long int *dst, int n);
void bswap_little_2_big(const long long int *src, long long int *dst, int n);

int main()
{

	for (int i = 0; i < N; i++)
	{
		src_data[i] = 0x0123456789abcdef;
	}

	// 预热
	for (int i = 0; i < 10000; i++)
	{
		avx512_little_2_big(src_data, avx512_data, N);
	}

	auto start = chrono::steady_clock::now();
	int loop = 10000;
	while (loop--)
	{
		avx512_little_2_big(src_data, avx512_data, N);
	}
	auto end = chrono::steady_clock::now();
	cout << "avx512 time: " << chrono::duration_cast<chrono::microseconds>(end - start).count() / 10 << " us" << endl;

	cout << "avx512 result:" << endl;
	for (int i = 0; i < N; i++)
	{
		//cout << hex << src_data[i] <<"  " << hex << avx512_data[i] <<endl;
	}

	// 预热
	for (int i = 0; i < 100; i++)
	{
		avx2_little_2_big(src_data, avx2_data, N);
	}

	start = chrono::steady_clock::now();
	loop = 10000;
	while (loop--)
	{
		avx2_little_2_big(src_data, avx2_data, N);
	}
	end = chrono::steady_clock::now();
	cout << "avx2 time: " << chrono::duration_cast<chrono::microseconds>(end - start).count() / 10 << " us" << endl;

	// 预热
	for (int i = 0; i < 100; i++)
	{
		bswap_little_2_big(src_data, avx2_data, N);
	}

	start = chrono::steady_clock::now();
	loop = 10000;
	while (loop--)
	{
		bswap_little_2_big(src_data, bswap_result, N);
	}
	end = chrono::steady_clock::now();
	cout << "bswap time: " << chrono::duration_cast<chrono::microseconds>(end - start).count() / 10 << " us" << endl;

	cout << "bswap result:" << endl;
	for (int i = 0; i < N; i++)
	{
		//cout << hex << src_data[i] <<"  " << hex << bswap_result[i] <<endl;
	}

	int pass = 1;
	for (int i = 0; i < N; i++)
	{
		if (bswap_result[i] != avx512_data[i] || bswap_result[i] != avx2_data[i])
		{
			cout << hex << bswap_result[i] << " " << hex << avx512_data[i] << hex << avx2_data[i];
			pass = 0;
			break;
		}
	}

	cout << "test result :" << pass << endl;
	return 0;
}

void avx512_little_2_big(const long long int *src, long long int *dst, int n)
{
	int loop_count = n / 8;
	int remainder = n % 8;

	__m512i mask = _mm512_set1_epi64(MASK);

	for (int i = 0; i < loop_count; i++)
	{
		int index = i * 8;
		__m512i input_data = _mm512_loadu_si512(&src[index]);
		__m512i output_data = _mm512_shuffle_epi8(input_data, mask);
		_mm512_storeu_si512(&avx512_data[index], output_data);
	}

	if (remainder != 0)
	{
		int index = loop_count * 8;
		__m512i padding = _mm512_set1_epi64(0);
		__m512i input_data = _mm512_mask_loadu_epi64(padding, bit16mask[remainder], &src[index]);
		__m512i output_data = _mm512_shuffle_epi8(input_data, mask);
		_mm512_mask_storeu_epi64(&avx512_data[index], bit16mask[remainder], output_data);
	}
	return;
}

void avx2_little_2_big(const long long int *src, long long int *dst, int n)
{
	int loop_count = n / 4;
	int remainder = n % 4;

	__m256i mask = _mm256_set1_epi64x(MASK);

	for (int i = 0; i < loop_count; i++)
	{
		int index = i * 4;
		__m256i input_data = _mm256_loadu_si256((__m256i *)&src[index]);
		__m256i output_data = _mm256_shuffle_epi8(input_data, mask);
		_mm256_storeu_si256((__m256i *)&avx2_data[index], output_data);
	}

	if (remainder != 0)
	{
		int index = loop_count * 4;
		for (int i = index; i < index + remainder; i++)
		{
			avx2_data[i] = bswap_64(src[i]);
		}
	}
	return;
}

void bswap_little_2_big(const long long int *src, long long int *dst, int n)
{
	for (int i = 0; i < n; i++)
	{
		dst[i] = bswap_64(src[i]);
	}
	return;
}