cpu_benchmark_2.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <pthread.h>
#include <immintrin.h>

char OPERATION='F';
long NUM_OPERATIONS = 10000000;

void* calculate_FLOPS(void* arg){
    // IF AVX is supported
    __m256d vector_a = _mm256_set_pd(7.0, 4.0, 6.0, 5.0);
    __m256d vector_b = _mm256_set_pd(1.0, 2.0, 3.0, 2.0);
    __m256d vector_c = _mm256_set_pd(1.0, 1.0, 1.0, 1.0);
    int i;
    for (i=0;i<NUM_OPERATIONS;i++){
	    // adding vector_a and vector_b and storing the result into vector_c 
	    vector_c = _mm256_add_pd(vector_a, vector_b); //8 operations - 4 additions and 4 assignments
	    // subtracting vector_b from vector_a and storing the result into vector_c
	    vector_c = _mm256_sub_pd(vector_a, vector_b); //8 operations - 4 subtractions and 4 assignments
	    // multiplying vector_a and vector_b and storing the result into vector_c
	    vector_c = _mm256_mul_pd(vector_a, vector_b); //8 operations - 4 multiplications and 4 assignments
    }
    pthread_exit(NULL);
}

void* calculate_IOPS(void* arg) {
    // IF AVX2 is supported
    __m256i vector_a = _mm256_set_epi32(7, 4, 6, 5, 5, 7, 8, 2);
    __m256i vector_b = _mm256_set_epi32(1, 2, 3, 2, 8, 6, 5, 3);
    __m256i vector_c = _mm256_set_epi32(1, 1, 1, 1, 8, 5, 6, 8);
    int i;
    for (i=0;i<NUM_OPERATIONS;i++){
	    // adding vector_a and vector_b and storing the result into vector_c
	    vector_c = _mm256_add_epi32(vector_a, vector_b); //16 operations - 8 additions and 8 assignments
	    // subtracting vector_b from vector_a and storing the result into vector_c
	    vector_c = _mm256_sub_epi32(vector_a, vector_b); //16 operations - 8 subtractions and 8 assignments
	    // multiplying vector_a and vector_b and storing the result into vector_c
	    vector_c = _mm256_mul_epi32(vector_a, vector_b); //16 operations - 8 multiplications and 8 assignments
    }
    pthread_exit(NULL);
}

void calculate_operations_per_sec(){
    pthread_t thread_id[8];
    int thread[8]; int i;
    
    double total_time;int count=0;
    struct timeval start_time, end_time;
    gettimeofday(&start_time, NULL );
    
    while(total_time<1){
        count++;
        if(OPERATION == 'F') {
            for (i=0;i<8;i++) {
                thread[i] = pthread_create(&(thread_id[i]),NULL,calculate_FLOPS,NULL);
            }
        } else {
            for (i=0;i<8;i++) {
                thread[i] = pthread_create(&(thread_id[i]),NULL,calculate_IOPS,NULL);
            }
        }  
        for (i=0;i<8;i++) {
            pthread_join(thread_id[i], NULL);
        }
        
        gettimeofday(&end_time, NULL);
        total_time = ((end_time.tv_sec+(end_time.tv_usec/1000000.0))-(start_time.tv_sec+(start_time.tv_usec/1000000.0)));
    }
    double ops;
    if(OPERATION == 'F') {
	ops = (8*count*24*NUM_OPERATIONS)/total_time;
    } else {
	ops = (8*count*48*NUM_OPERATIONS)/total_time;
    }
    printf("CPU, 8 threads, speed = %.2lf %s\n",ops,OPERATION == 'F'?"FLOPS/sec":"IOPS/sec");
}

int main(int argc, char *argv[]){
   int arg;
    while((arg=getopt(argc, argv, "if")) != -1) {
        switch(arg) {
            case 'i':
            OPERATION='I'; // for IOPS calculation
            break;
            case 'f':
            OPERATION='F'; // for FLOPS calculation
            break;
            default:
            break;
        }
    }
    
    struct timeval begin,end;
    double one_second_timer=0;
    gettimeofday(&begin, NULL );
    
    while (one_second_timer<600) {
        calculate_operations_per_sec();
        gettimeofday(&end, NULL );
        one_second_timer = ((end.tv_sec+(end.tv_usec/1000000.0))-(begin.tv_sec+(begin.tv_usec/1000000.0)));
    }
    return 0;
}