/* floatspeed.c  (c) by Benno Senoner  ( sbenno@gardena.net )
   hack to benchmark, 
   the passing of buffers between floats and doubles

   compile with cc -O2 -o floatspeed floatspeed.c -lm
   run with ./floatspeed

 */


#include <stdio.h>
#include <stdlib.h>

#include <sys/time.h>
#include <unistd.h>

#define NUMLOOPS 2000000

#define MYSIZE 1024
#define MYSIZEDIV4 256

double my_gettime(void);


main()
{
  float  *inbuf32ptr;
  double *inbuf64ptr;
  float  *outbuf32ptr;
  double *outbuf64ptr;

  float  inbuf32[MYSIZE];
  double inbuf64[MYSIZE];
  float  outbuf32[MYSIZE];
  double outbuf64[MYSIZE];

  int i,u;
  double time1,time2,delta;

  for(i=0; i<MYSIZE; i++) {
    inbuf32[i]=drand48() * pow(10.0,100*( drand48()-0.5));
    inbuf64[i]=(double) inbuf32[i];
  }


  time1=my_gettime();
  for(u=0 ; u<NUMLOOPS ; u++) {
    inbuf32ptr=inbuf32;
    outbuf32ptr=outbuf32;
      for(i=0; i<MYSIZEDIV4; i++) {
        *outbuf32ptr++ = *inbuf32ptr++;
        *outbuf32ptr++ = *inbuf32ptr++;
        *outbuf32ptr++ = *inbuf32ptr++;
        *outbuf32ptr++ = *inbuf32ptr++;
      }
  }
  time2=my_gettime();
  delta=time2-time1;
  printf("\nfloat to float buffers\n");
  printf("time delta=%f\n",delta);
  printf("million operations/sec=%.3f\n",NUMLOOPS*MYSIZE/delta/1000000.0);

  time1=my_gettime();
  for(u=0 ; u<NUMLOOPS ; u++) {
    inbuf64ptr=inbuf64;
    outbuf64ptr=outbuf64;
      for(i=0; i<MYSIZEDIV4; i++) {
        *outbuf64ptr++ = *inbuf64ptr++;
        *outbuf64ptr++ = *inbuf64ptr++;
        *outbuf64ptr++ = *inbuf64ptr++;
        *outbuf64ptr++ = *inbuf64ptr++;
      }
  }
  time2=my_gettime();
  delta=time2-time1;
  printf("\ndouble to double buffers\n");
  printf("time delta=%f\n",delta);
  printf("million operations/sec=%.3f\n",NUMLOOPS*MYSIZE/delta/1000000.0);

  time1=my_gettime();
  for(u=0 ; u<NUMLOOPS ; u++) {
    inbuf32ptr=inbuf32;
    outbuf64ptr=outbuf64;
      for(i=0; i<MYSIZEDIV4; i++) {
        *outbuf64ptr++ = (double) *inbuf32ptr++;
        *outbuf64ptr++ = (double) *inbuf32ptr++;
        *outbuf64ptr++ = (double) *inbuf32ptr++;
        *outbuf64ptr++ = (double) *inbuf32ptr++;
      }
  }
  time2=my_gettime();
  delta=time2-time1;
  printf("\nfloat to double buffers\n");
  printf("time delta=%f\n",delta);
  printf("million operations/sec=%.3f\n",NUMLOOPS*MYSIZE/delta/1000000.0);


  time1=my_gettime();
  for(u=0 ; u<NUMLOOPS ; u++) {
    inbuf64ptr=inbuf64;
    outbuf32ptr=outbuf32;
      for(i=0; i<MYSIZEDIV4; i++) {
        *outbuf32ptr++ = (float) *inbuf64ptr++;
        *outbuf32ptr++ = (float) *inbuf64ptr++;
        *outbuf32ptr++ = (float) *inbuf64ptr++;
        *outbuf32ptr++ = (float) *inbuf64ptr++;
      }
  }
  time2=my_gettime();
  delta=time2-time1;
  printf("\ndouble to float buffers\n");
  printf("time delta=%f\n",delta);
  printf("million operations/sec=%.3f\n",NUMLOOPS*MYSIZE/delta/1000000.0);

}


double my_gettime(void) {

  double res;
  struct timeval mytv;

  gettimeofday(&mytv,NULL);
  res=mytv.tv_sec+mytv.tv_usec/1000000.0;
  return(res);
}