mode1.cpp

// mode1

#include <immintrin.h>  // portable to all x86 compilers
#include <stdio.h>
#include <time.h>

#define DATA float

const int SIZE = 128;
// size  128 / 256 / 512 

DATA __attribute__((aligned(16))) A[SIZE] ;
DATA __attribute__((aligned(16))) B[SIZE] ;


double seconds() {
  struct timespec now;
  clock_gettime(CLOCK_MONOTONIC, &now);
  return now.tv_sec + now.tv_nsec / 1000000000.0;
}

void initialize_array(DATA a[], int size) {
	for (int i = 0 ;  i < size ; i++) a[i] = rand()%2;
}

int vec(DATA *s1, DATA *s2,int size) {
    int i;
    DATA prod = 0;
 
    for(i=0; i<size; i++) prod += s1[i] * s2[i];
    
    return prod;
}

int vec_sse(DATA *m1, DATA *m2,int size) {
    DATA prod = 0;
    int i;

    __m128 X, Y, Z;

    Z[0] = Z[1] = Z[2] = Z[3] = 0;

    for(i=0; i<size; i+=4) {
        X = _mm_load_ps(&m1[i]);
        Y = _mm_load_ps(&m2[i]);
        X = _mm_mul_ps(X, Y);
        Z = _mm_add_ps(X, Z);
    }

    for(i=0; i<4; i++) prod += Z[i];
    
    return prod;
}

int main() {
	DATA r;
	double before,after;

	initialize_array(A,SIZE);
	initialize_array(B,SIZE);

	before = seconds();
	r = vec(A,B,SIZE);
	after = seconds();
	printf("Result:%f Time:%f\n",r,after-before);

	before = seconds();
	r = vec_sse(A,B,SIZE);
	after = seconds();
	printf("Result:%f Time:%f\n",r,after-before);

    return 0;
}