/*
 * Copyright 2014, Paweł Dziepak, pdziepak@quarnos.org.
 * Distributed under the terms of the MIT License.
 */


#include <stdint.h>


static uint64_t cv_factor;
static uint64_t cv_factor_nsec;


extern "C" void
__x86_setup_system_time(uint64_t cv, uint64_t cv_nsec)
{
    cv_factor = cv;
    cv_factor_nsec = cv_nsec;
}


static inline uint64_t
rdtsc()
{
    uint64_t lo, hi;
    __asm__("rdtsc" : "=a" (lo), "=d" (hi));
    return lo | (hi << 32);
}


extern "C" [[gnu::optimize("omit-frame-pointer")]] int64_t
system_time()
{
    __uint128_t time = static_cast<__uint128_t>(rdtsc()) * cv_factor;
    return time >> 64;
}


extern "C" [[gnu::optimize("omit-frame-pointer")]] int64_t
system_time_nsecs()
{
    __uint128_t t = static_cast<__uint128_t>(rdtsc()) * cv_factor_nsec;
    return t >> 32;
}