我希望有人可以在这里帮忙。从simd基于mask的大型矢量加载矢量
我有一个大的字节向量,从中创建一个小字节向量(基于掩码),然后用simd处理。
当前掩码是baseOffset +子掩码(byte [256])的数组,对于存储进行了优化,因为存在> 10^8。我创建一个maxsize子向量,然后循环遍历mask数组,并将baseOffssetby 256乘以大值向量的掩码加载中的每个位偏移量,然后将这些值依次放入较小的向量中。然后通过多个VPMADDUBSW处理较小的矢量并进行累加。我可以改变这种结构。例如,走一遍使用8K位数组缓冲区,然后创建小向量。
有没有更快的方法可以创建子数组?
我把代码退出应用到测试程序,但原来是在变化的状态(移动到AVX2和拉动多出来的C#)
#include "stdafx.h"
#include<stdio.h>
#include <mmintrin.h>
#include <emmintrin.h>
#include <tmmintrin.h>
#include <smmintrin.h>
#include <immintrin.h>
//from
char N[4096] = { 9, 5, 5, 5, 9, 5, 5, 5, 5, 5 };
//W
char W[4096] = { 1, 2, -3, 5, 5, 5, 5, 5, 5, 5 };
char buffer[4096] ;
__declspec(align(2))
struct packed_destination{
char blockOffset;
__int8 bitMask[32];
};
__m128i sum = _mm_setzero_si128();
packed_destination packed_destinations[10];
void process128(__m128i u, __m128i s)
{
__m128i calc = _mm_maddubs_epi16(u, s); // pmaddubsw
__m128i loints = _mm_cvtepi16_epi32(calc);
__m128i hiints = _mm_cvtepi16_epi32(_mm_shuffle_epi32(calc, 0x4e));
sum = _mm_add_epi32(_mm_add_epi32(loints, hiints), sum);
}
void process_array(char n[], char w[], int length)
{
sum = _mm_setzero_si128();
int length128th = length >> 7;
for (int i = 0; i < length128th; i++)
{
__m128i u = _mm_load_si128((__m128i*)&n[i * 128]);
__m128i s = _mm_load_si128((__m128i*)&w[i * 128]);
process128(u, s);
}
}
void populate_buffer_from_vector(packed_destination packed_destinations[], char n[] , int dest_length)
{
int buffer_dest_index = 0;
for (int i = 0; i < dest_length; i++)
{
int blockOffset = packed_destinations[i].blockOffset <<8 ;
// go through mask and copy to buffer
for (int j = 0; j < 32; j++)
{
int joffset = blockOffset + j << 3;
int mask = packed_destinations[i].bitMask[j];
if (mask & 1 << 0)
buffer[buffer_dest_index++] = n[joffset + 1<<0 ];
if (mask & 1 << 1)
buffer[buffer_dest_index++] = n[joffset + 1<<1];
if (mask & 1 << 2)
buffer[buffer_dest_index++] = n[joffset + 1<<2];
if (mask & 1 << 3)
buffer[buffer_dest_index++] = n[joffset + 1<<3];
if (mask & 1 << 4)
buffer[buffer_dest_index++] = n[joffset + 1<<4];
if (mask & 1 << 5)
buffer[buffer_dest_index++] = n[joffset + 1<<5];
if (mask & 1 << 6)
buffer[buffer_dest_index++] = n[joffset + 1<<6];
if (mask & 1 << 7)
buffer[buffer_dest_index++] = n[joffset + 1<<7];
};
}
}
int _tmain(int argc, _TCHAR* argv[])
{
for (int i = 0; i < 32; ++i)
{
packed_destinations[0].bitMask[i] = 0x0f;
packed_destinations[1].bitMask[i] = 0x04;
}
packed_destinations[1].blockOffset = 1;
populate_buffer_from_vector(packed_destinations, N, 1);
process_array(buffer, W, 256);
int val = sum.m128i_i32[0] +
sum.m128i_i32[1] +
sum.m128i_i32[2] +
sum.m128i_i32[3];
printf("sum is %d" , val);
printf("Press Any Key to Continue\n");
getchar();
return 0;
}
通常掩模用法是5-一些工作负荷为15%,这将是25-100%。
MASKMOVDQU是接近,但那么我们将不得不根据保存前面罩重新包装/ SWL ..
如果您发布现有代码,它可能会有所帮助。 –
在 – user1496062
中放入了一些代码你的'process128'函数看起来坏了 - 它实际上并没有使用传递给它的参数? –