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#include <mach/mach_time.h>
#include <stdint.h>
#include <stdlib.h>
double intervalInCycles( uint64_t startTime, uint64_t endTime )
{
uint64_t rawTime = endTime - startTime;
static double conversion = 0.0;
if( 0.0 == conversion )
{
mach_timebase_info_data_t info;
kern_return_t err = mach_timebase_info( &info );
if( 0 != err )
return 0;
uint64_t freq = 0;
size_t freqSize = sizeof( freq );
int err2 = sysctlbyname( "hw.cpufrequency", &freq, &freqSize, NULL, 0L );
if( 0 != err2 )
return 0;
conversion = (double) freq * (1e-9 * (double) info.numer / (double) info.denom);
}
return (double) rawTime * conversion;
}
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