Centre Blaise Pascal » Bench4GPU

/* Simple Sum function in C and OpenACC/C */

/* compilation with sequential compute : gcc -O3 -fopenacc -foffload=nvptx-none -foffload="-O3 -misa=sm_35 -lm" -o MySteps_1_openacc MySteps_1_openacc.c -lm */

/* compilation without sequential compute : gcc -DNOSERIAL -O3 -fopenacc -foffload=nvptx-none -foffload="-O3 -misa=sm_35 -lm" -o MySteps_1_openacc_NoSerial MySteps_1_openacc.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];

    }

}

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

{

  #pragma acc data copyin(a[0:size],b[0:size]),copyout(res[0:size])

  #pragma acc parallel loop

  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\tPi : 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));

  resacc=(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.;

      resacc[i]=0.;

    }

#ifndef NOSERIAL 

  gettimeofday(&tv1, NULL);

  MySum(res,a,b,size);

  gettimeofday(&tv2, NULL);

#endif

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

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

  gettimeofday(&tv1, NULL);

  MySumOpenACC(resacc,a,b,size);

  gettimeofday(&tv2, NULL);

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

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

#ifndef NOSERIAL 

  MYFLOAT MyChecker=MyNorm(res,resacc,size);

  printf("Norm: %.8e\n",MyChecker);

#endif

#ifdef VERBOSE

  MyPrint(res,size);

  MyPrint(resacc,size);

#endif

#ifndef NOSERIAL 

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

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

#endif

#ifndef NOSERIAL 

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

#endif

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

#ifndef NOSERIAL 

  printf("OpenACCRatio: %.3f\n",elapsed/elapsedAcc);

#endif

  free(a);

  free(b);

  free(res);

  free(resacc);

}