Révision 185 Pi/C/OpenMP/Pi_OpenMP.c

Pi_OpenMP.c (revision 185)
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#include <stdlib.h>
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#include <omp.h>
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#include <limits.h>
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#include <sys/time.h>
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// Marsaglia RNG very simple implementation


  		





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#define znew  ((z=36969*(z&65535)+(z>>16))<<16)


  		





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#define ITERATIONS 1000000000


  		





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#define PROCESS 4


  		





  
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#define PARALLELRATE 1024


  		





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#ifdef LONG


  		





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#define LENGTH long long


  		





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   return(total);


  		





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}


  		





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LENGTH splitter(LENGTH iterations,unsigned int process,


  		





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		unsigned int seed_w,unsigned int seed_z)


  		





  
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LENGTH splitter(LENGTH iterations,unsigned int seed_w,unsigned int seed_z,unsigned int ParallelRate)


  		





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{


  		





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  // Trashy static allocation...


  		





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  LENGTH inside[4096],insides=0;


  		





  
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  LENGTH *inside,insides=0;


  		





  
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  struct timeval tv1,tv2;


  		





  
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  LENGTH IterationsEach=((iterations%ParallelRate)==0)?iterations/ParallelRate:iterations/ParallelRate+1;


  		





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  inside=(LENGTH*)malloc(sizeof(LENGTH)*ParallelRate);


  		





  
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  gettimeofday(&tv1, NULL);


  		





  
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#pragma omp parallel for


  		





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  for (int i=0 ; i<process; i++) {


  		





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    inside[i]=MainLoopGlobal(iterations/process,seed_w+process,seed_z+process);


  		





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    printf("\tFound %lld for process %i\n",(long long)inside[i],i);


  		





  
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  for (int i=0 ; i<ParallelRate; i++) {


  		





  
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    inside[i]=MainLoopGlobal(IterationsEach,seed_w+i,seed_z+i);


  		





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  }


  		





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  printf("\n");


  		





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  for (int i=0 ; i<process; i++) {


  		





  
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  for (int i=0 ; i<ParallelRate; i++) {


  		





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    insides+=inside[i];


  		





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  }


  		





  
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  gettimeofday(&tv2, NULL);


  		





  
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  for (int i=0 ; i<ParallelRate; i++) {


  		





  
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    printf("\tFound %lld for ParallelRate %i\n",(long long)inside[i],i);


  		





  
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  }


  		





  
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  printf("\n");


  		





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


  		





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


  		





  
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  double itops=(double)(ParallelRate*IterationsEach)/elapsed;


  		





  
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  printf("ParallelRate %i\nElapsed Time %.2f\nItops %.0f\n",ParallelRate,elapsed,itops);


  		





  
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  free(inside);


  		





  
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  return(insides);


  		





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} 


  		





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


  		





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  unsigned int seed_w=10,seed_z=10,process=PROCESS;


  		





  
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  unsigned int seed_w=110271,seed_z=101008,ParallelRate=PARALLELRATE;


  		





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  LENGTH iterations=ITERATIONS,insides=0;


  		





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  if (argc > 1) {


  		





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    iterations=(LENGTH)atoll(argv[1]);


  		





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    process=atoi(argv[2]);


  		





  
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    ParallelRate=atoi(argv[2]);


  		





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  }


  		





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  else {


  		





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    printf("\n\tPi : Estimate Pi with Monte Carlo exploration\n\n");


  		





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    printf("\t\t#1 : number of iterations (default 1 billion)\n");


  		





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    printf("\t\t#2 : number of process (default 4)\n\n");


  		





  
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    printf("\t\t#2 : number of ParallelRate (default 1024)\n\n");


  		





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  }


  		





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  printf ("\n\tInformation about architecture:\n\n");


  		





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  printf ("\tMax long = %ld\n", LONG_MAX);


  		





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  printf ("\tMax long long = %lld\n\n", LLONG_MAX);


  		





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  insides=splitter(iterations,process,seed_w,seed_z);


  		





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  float pi=4.*(float)insides/(float)iterations;


  		





  
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  insides=splitter(iterations,seed_w,seed_z,ParallelRate);


  		





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  printf("\tPi=%f with error %f and %lld iterations\n\n",pi,


  		





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         fabs(pi-4*atan(1))/pi,(long long)iterations);


  		





  
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  LENGTH total=((iterations%ParallelRate)==0)?iterations:(iterations/ParallelRate+1)*ParallelRate;


  		





  
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  printf("Inside/Total %ld %ld\nPi estimation %f\n\n",(long int)insides,(long int)total,(4.*(float)insides/total));


  		





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}


  		












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