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#include <time.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include "osfreq.c"
static long myround(double u)
{
long result = u;
while (result + 0.5 < u) result += 1;
while (result - 0.5 > u) result -= 1;
return result;
}
static long long microseconds(void)
{
struct timeval t;
gettimeofday(&t,(struct timezone *) 0);
return t.tv_sec * (long long) 1000000 + t.tv_usec;
}
static int tbshift = 0;
static long long timebase(void)
{
unsigned long high;
unsigned long low;
unsigned long newhigh;
unsigned long long result;
asm volatile(
"7:mftbu %0;mftb %1;mftbu %2;cmpw %0,%2;bne 7b"
: "=r" (high), "=r" (low), "=r" (newhigh)
);
result = high;
result <<= 32;
result |= low;
return result >> tbshift;
}
static double cpufrequency = 0;
static long tbcycles = 0;
static double guesstbcycles(void)
{
long long tb0; long long us0;
long long tb1; long long us1;
tb0 = timebase();
us0 = microseconds();
do {
tb1 = timebase();
us1 = microseconds();
} while (us1 - us0 < 10000 || tb1 - tb0 < 1000);
if (tb1 <= tb0) return 0;
tb1 -= tb0;
us1 -= us0;
return (cpufrequency * 0.000001 * (double) us1) / (double) tb1;
}
static void init(void)
{
int loop;
double guess1;
double guess2;
cpufrequency = osfreq();
if (!cpufrequency) return;
for (tbshift = 0;tbshift < 10;++tbshift) {
for (loop = 0;loop < 100;++loop) {
guess1 = guesstbcycles();
guess2 = guesstbcycles();
tbcycles = myround(guess1);
if (guess1 - tbcycles > 0.1) continue;
if (tbcycles - guess1 > 0.1) continue;
if (guess2 - tbcycles > 0.1) continue;
if (tbcycles - guess2 > 0.1) continue;
return;
}
}
tbcycles = 0;
}
long long cpucycles_powerpccpuinfo(void)
{
if (!tbcycles) init();
return timebase() * tbcycles;
}
long long cpucycles_powerpccpuinfo_persecond(void)
{
if (!tbcycles) init();
return cpufrequency;
}
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