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#pragma once
#include "defaults.h"
#include "platform.h"
#if defined(_win_)
#include <intrin.h>
#pragma intrinsic(__rdtsc)
#endif // _win_
#if defined(_darwin_) && !defined(_x86_)
#include <mach/mach_time.h>
#endif
/// util/system/datetime.h contains only system time providers
/// for handy datetime utilities include util/datetime/base.h
/// Current time in microseconds since epoch
ui64 MicroSeconds() noexcept;
/// Current time in milliseconds since epoch
inline ui64 MilliSeconds() {
return MicroSeconds() / ui64(1000);
}
/// Current time in milliseconds since epoch (deprecated, use MilliSeconds instead)
inline ui64 millisec() {
return MilliSeconds();
}
/// Current time in seconds since epoch
ui32 Seconds() noexcept;
/// Current thread time in microseconds
ui64 ThreadCPUUserTime() noexcept;
ui64 ThreadCPUSystemTime() noexcept;
ui64 ThreadCPUTime() noexcept;
void NanoSleep(ui64 ns) noexcept;
#if defined(_x86_)
namespace NPrivate {
bool HaveRdtscpImpl();
}
#endif
// GetCycleCount guarantees to return synchronous values on different cores
// and provide constant rate only on modern Intel and AMD processors
// NOTE: rdtscp is used to prevent out of order execution
// rdtsc can be reordered, while rdtscp cannot be reordered
// with preceding instructions
// PERFORMANCE: rdtsc - 15 cycles per call , rdtscp - 19 cycles per call
// WARNING: following instruction can be executed out-of-order
Y_FORCE_INLINE ui64 GetCycleCount() noexcept {
#if defined(_MSC_VER)
// Generates the rdtscp instruction, which returns the processor time stamp.
// The processor time stamp records the number of clock cycles since the last reset.
static const bool haveRdtscp = ::NPrivate::HaveRdtscpImpl();
if (haveRdtscp) {
unsigned int aux;
return __rdtscp(&aux);
} else {
return __rdtsc();
}
#elif defined(_x86_64_)
static const bool haveRdtscp = ::NPrivate::HaveRdtscpImpl();
unsigned hi, lo;
if (haveRdtscp) {
__asm__ __volatile__("rdtscp"
: "=a"(lo), "=d"(hi)::"%rcx");
} else {
__asm__ __volatile__("rdtsc"
: "=a"(lo), "=d"(hi));
}
return ((unsigned long long)lo) | (((unsigned long long)hi) << 32);
#elif defined(_i386_)
static const bool haveRdtscp = ::NPrivate::HaveRdtscpImpl();
ui64 x;
if (haveRdtscp) {
__asm__ volatile("rdtscp\n\t"
: "=A"(x)::"%ecx");
} else {
__asm__ volatile("rdtsc\n\t"
: "=A"(x));
}
return x;
#elif defined(_darwin_)
return mach_absolute_time();
#elif defined(__clang__) && !defined(_arm_)
return __builtin_readcyclecounter();
#elif defined(_arm32_)
return MicroSeconds();
#elif defined(_arm64_)
ui64 x;
__asm__ __volatile__("isb; mrs %0, cntvct_el0"
: "=r"(x));
return x;
#else
#error "unsupported arch"
#endif
}
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