矩阵乘的不同算法
这里涉及五种：普通矩阵乘、循环展开、循环分块、手工向量化（标量尾循环、矢量尾循环（只写了尾巴为16的情况））。
#include
for(k=block*32;k<N;k+=16){
yymm0=_mm256_loadu_ps(s+16*k);
yymm1=_mm256_loadu_ps(&a[i][k]);
yymm2=_mm256_loadu_ps(&a[i][k+8]);
yymm5=_mm256_loadu_ps(&d[j][k]); //j对于d来说相当于d[i]
yymm6=_mm256_loadu_ps(&d[j][k+8]);
yymm15=_mm256_mul_ps(yymm1,yymm5);
yymm26=_mm256_mul_ps(yymm2,yymm6);
yymm12=_mm256_add_ps(yymm15,yymm26);
yymm31=_mm256_hadd_ps(yymm12,yymm0);
yymm3311=_mm256_hadd_ps(yymm31,yymm0);
_mm256_storeu_ps(s,yymm3311);
c[i][j]+=s[0]+s[4];
//printf("%5f ",c[i][j]);
}
c[i][j]+=e[i][j];
//printf("%5f ",c[i][j]);
}
}
}
//重置数组
void reset(float c[N][N]){
int i, j;
for(i = 0; i < N; i++){
for(j = 0; j < N; j++){
c[i][j] = 0;
}
}
}
int main(){
int i, j;
float t = 1.0;
float a[N][N] = {0};
float b[N][N] = {0};
float c[N][N] = {0};
float d[N][N] = {0};
//a， b数组赋值
for(i = 0; i < N; i++){
for(j = 0; j < N; j++){
a[i][j] = t;
b[i][j] = t;
}
t = t + 1.0;
}
//矩阵乘循环
struct timeval starttime,endtime;
gettimeofday(&starttime,0);
matrix_multiply(a, b, c);
gettimeofday(&endtime,0);
int timeuse = 1000000*(endtime.tv_sec - starttime.tv_sec) + endtime.tv_usec - starttime.tv_usec;
printf("matrix_multiply time = %d us\n", timeuse);
reset(c);
//四层循环展开
struct timeval starttim,endtim;
gettimeofday(&starttim,0);
matrix_unroll4(a, b, c);
gettimeofday(&endtim,0);
int timeus = 1000000*(endtim.tv_sec - starttim.tv_sec) + endtim.tv_usec - starttim.tv_usec;
printf("matrix_unroll4 time = %d us\n", timeus);
reset(c);
//循环分块
struct timeval startti,endti;
gettimeofday(&startti,0);
matrix_block(a, b, c);
gettimeofday(&endti,0);
int timeu = 1000000*(endti.tv_sec - startti.tv_sec) + endti.tv_usec - startti.tv_usec;
printf("matrix_block time = %d us\n", timeu);
reset(c);
for(i=0;i<N;i++){
for(j=0;j<N;j++){
d[i][j]=b[j][i];
}
}//b矩阵的转置
//标量尾循环
struct timeval startt,endt;
gettimeofday(&startt,0);
matrix_scalar(a, d, c);
gettimeofday(&endt,0);
int time = 1000000*(endt.tv_sec - startt.tv_sec) + endt.tv_usec - startt.tv_usec;
printf("matrix_s_tail time = %d us\n", time);
reset(c);
//向量尾循环
struct timeval start,end;
gettimeofday(&start,0);
matrix_vector(a, d, c);
gettimeofday(&end,0);
int tim = 1000000*(end.tv_sec - start.tv_sec) + end.tv_usec - start.tv_usec;
printf("matrix_v_tail time = %d us\n", tim);
reset(c);
}
运行结果：
Add:
#include