Centre Blaise Pascal » Bench4GPU

/* Simple Sum function in C */

/* compilation with : gcc -O3 -o MySteps_1 MySteps_1.c -lm */

#include <math.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/time.h>

#define PI 3.141592653589793

#define MYFLOAT float

void MySum(MYFLOAT *res, MYFLOAT *a, MYFLOAT *b, int size)

{

  for (uint i=0; i<size;i++) 

    {

      res[i] = a[i] + b[i];

    }

}

MYFLOAT MyNorm(MYFLOAT *a,MYFLOAT *b,int size)

{

  MYFLOAT norm=0.;

  for (int i=0;i<size;i++)

    {

      norm+=pow(a[i]-b[i],2);

    }

  return(sqrt(norm));

}

void MyPrint(MYFLOAT *a,int size)

{

  printf("[");

  for (int i=0;i<size;i++)

    {

      printf(" %.8e ",a[i]);

    }

  printf("]\n");

}

int main(int argc,char *argv[])

{

  float *a,*b,*res,*resacc;

  int size=1024;

  struct timeval tv1,tv2;

  if (argc > 1) {

    size=(int)atoll(argv[1]);

  }

  else {

    printf("\n\tMySteps : Estimate SillySum\n\n\t\t#1 : size (default 1024)\n\n");

  }

  printf("%i\n",size);

  a=(float*)malloc(size*sizeof(MYFLOAT));

  b=(float*)malloc(size*sizeof(MYFLOAT));

  res=(float*)malloc(size*sizeof(MYFLOAT));

  srand(110271);

  for (int i=0;i<size;i++)

    {

      a[i]=(MYFLOAT)rand()/(MYFLOAT)RAND_MAX;

      b[i]=(MYFLOAT)rand()/(MYFLOAT)RAND_MAX;

      res[i]=0.;

    }

  gettimeofday(&tv1, NULL);

  MySum(res,a,b,size);

  gettimeofday(&tv2, NULL);

  MYFLOAT elapsed=(MYFLOAT)((tv2.tv_sec-tv1.tv_sec) * 1000000L +

                            (tv2.tv_usec-tv1.tv_usec))/1000000;

#ifdef VERBOSE

  MyPrint(res,size);

#endif

  printf("Elapsed Time: %.3f\n",elapsed);

  printf("NaiveRate: %.lld\n",(unsigned long)((float)size/elapsed));

  free(a);

  free(b);

  free(res);

}