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calc.c
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calc.c
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#include <stdio.h>
#include <time.h>
<<<<<<< HEAD
#include <sys/times.h>
#include <sys/types.h>
#ifndef CLK_TCK
#define CLK_TCK 60 /* number clock ticks per second */
#endif
#define INTERVALS 10000000
#define CLOCK_RATE_GHZ 2.3e9
double get_seconds() { /* routine to read time */
struct tms rusage;
times(&rusage); /* UNIX utility: time in clock ticks */
return (double) (rusage.tms_utime)/CLK_TCK;
}
static __inline__ unsigned long long RDTSC(void) {
unsigned hi,lo;
__asm__ volatile("rdtsc" : "=a"(lo),"=d"(hi));
return ((unsigned long long) lo)| (((unsigned long long)hi) << 32);
}
=======
#define INTERVALS 100000
>>>>>>> task2
double a[INTERVALS], b[INTERVALS];
int main(int argc, char **argv)
{
double time2;
time_t time1 = clock();
double *to = b;
double *from = a;
int time_steps = 100;
<<<<<<< HEAD
double cycles0, cycles; /* timing variables */
=======
>>>>>>> task2
/* Set up initial and boundary conditions. */
from[0] = 1.0;
from[INTERVALS - 1] = 0.0;
to[0] = from[0];
to[INTERVALS - 1] = from[INTERVALS - 1];
for(long i = 1; i < INTERVALS; i++)
from[i] = 0.0;
printf("Number of intervals: %ld. Number of time steps: %d\n", INTERVALS, time_steps);
<<<<<<< HEAD
//cycles = 0; /* initialize timer */
/* Apply stencil iteratively. */
while(time_steps-- > 0)
{
// cycles0 = get_seconds(); /* start timer */
unsigned long long cycles = RDTSC();
=======
/* Apply stencil iteratively. */
while(time_steps-- > 0)
{
>>>>>>> task2
for(long i = 1; i < (INTERVALS - 1); i++)
to[i] = from[i] + 0.1*(from[i - 1] - 2*from[i] + from[i + 1]);
{
double* tmp = from;
from = to;
to = tmp;
}
<<<<<<< HEAD
cycles = (get_seconds() - cycles0);/* end timer */
cycles = RDTSC()-cycles;
double microseconds = cycles/CLOCK_RATE_GHZ*1e6;
printf("elapsed time is %6.2f ns\n", cycles);
=======
>>>>>>> task2
}
time2 = (clock() - time1) / (double) CLOCKS_PER_SEC;
printf("Elapsed time (s) = %f\n", time2);
<<<<<<< HEAD
for(long i = 2; i < 30; i += 2)
=======
for(long i = 2; i < 12; i += 2)
>>>>>>> task2
printf("Interval %ld: %f\n", i, to[i]);
return 0;
}
<<<<<<< HEAD
=======
>>>>>>> task2