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void *malloc ();
struct timeval {
long tv_sec;
long tv_usec;
};
struct timezone {
int tz_minuteswest;
int tz_dsttime;
};
struct itimerval {
struct timeval it_interval;
struct timeval it_value;
};
typedef int sigset_t;
typedef unsigned int speed_t;
typedef unsigned long tcflag_t;
typedef unsigned char cc_t;
typedef int pid_t;
typedef unsigned short mode_t;
typedef short nlink_t;
typedef long clock_t;
typedef long time_t;
typedef int size_t;
typedef int ptrdiff_t;
typedef unsigned short wchar_t;
struct tm {
int tm_sec;
int tm_min;
int tm_hour;
int tm_mday;
int tm_mon;
int tm_year;
int tm_wday;
int tm_yday;
int tm_isdst;
char *tm_zone;
long tm_gmtoff;
};
extern struct tm *gmtime(), *localtime();
extern char *asctime(), *ctime();
extern void tzset(), tzsetwall();
extern int dysize();
extern time_t timelocal(), timegm();
struct rusage {
struct timeval ru_utime;
struct timeval ru_stime;
long ru_maxrss;
long ru_ixrss;
long ru_idrss;
long ru_isrss;
long ru_minflt;
long ru_majflt;
long ru_nswap;
long ru_inblock;
long ru_oublock;
long ru_msgsnd;
long ru_msgrcv;
long ru_nsignals;
long ru_nvcsw;
long ru_nivcsw;
};
struct rlimit {
int rlim_cur;
int rlim_max;
};
unsigned long
cputime ()
{
struct rusage rus;
getrusage (0, &rus);
return (((rus.ru_utime.tv_sec + rus.ru_stime.tv_sec) * 1000000) +
rus.ru_utime.tv_usec + rus.ru_stime.tv_usec) / 1000;
}
int
do_assoc_test (mem, start, cc)
register char *mem;
register int start;
register int cc;
{
register int j;
register int ind = start;
register int x;
for (j = 0x100000; --j >= 0; )
{
int x = ((volatile char *) mem)[ind];
ind -= cc;
if (ind < 0)
ind = start;
}
return x;
}
int
determine_assoc (size)
{
register char *mem = malloc (size * (1 << 5 ));
int cc = size;
int lbsets;
int times[5 + 1];
for (lbsets = 0; lbsets <= 5; lbsets++)
{
int t = cputime ();
do_assoc_test (mem, (cc << lbsets) - cc, cc);
t = cputime () - t;
times[lbsets] = t;
printf ("sets = %2u: %u ms\n", 1 << lbsets, t);
}
free (mem);
{
int max = 1000 * times[1] / times[0];
int maxindex = 0;
int min = 1000 * times[1] / times[0];
int minindex = 0;
for (lbsets = 1; lbsets < 4; lbsets++)
{
int x = 1000 * times[lbsets + 1] / times[lbsets];
if (x > max)
{
max = x;
maxindex = lbsets;
}
if (x < min)
{
min = x;
minindex = lbsets;
}
}
if (min * 100 > max * 75)
return 0;
return 1 << maxindex;
}
}
do_size_test(mem, size, reps)
register int *mem;
register int size;
register int reps;
{
register int j, i, x;
mem += size;
for (j = reps; --j >= 0;)
for (i = -size; i < 0; i++)
x = ((volatile int *) mem)[i];
}
int
determine_size()
{
register int *mem = malloc (1 << 20 );
int lbsize;
int times[20 ];
for (lbsize = 12; lbsize < 20; lbsize++)
{
int t = cputime ();
do_size_test (mem, (1 << lbsize) / sizeof (int) - 64,
0x1000000 >> lbsize);
t = cputime () - t;
times[lbsize] = t;
printf ("size = %2u: %u ms\n", 1 << lbsize, t);
}
free (mem);
{
int max = 1000 * times[12 + 1] / times[12 ];
int maxindex = 0;
int min = 1000 * times[12 + 1] / times[12 ];
int minindex = 0;
for (lbsize = 12; lbsize < 20 - 1; lbsize++)
{
int x = 1000 * times[lbsize + 1] / times[lbsize];
if (x > max)
{
max = x;
maxindex = lbsize;
}
if (x < min)
{
min = x;
minindex = lbsize;
}
}
if (min * 100 > max * 75)
return 0;
return 1 << maxindex;
}
}
int
main()
{
int size, assoc;
size = determine_size();
if (size)
printf ("I guess this cache is %d bytes.\n", size);
else
printf ("I can't determine the size from this run.\n");
if (size == 0)
size = 65536;
assoc = determine_assoc(size);
if (assoc > 1)
printf ("I guess this cache is %d-way set associative.\n", assoc);
else if (assoc == 1)
printf ("I guess this cache is direct mapped.\n");
else
printf ("I can't determine the associativity from this run.\n");
return 0;
}
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