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#![no_std]
#![feature(asm)]

#[no_mangle]
#[inline(never)]
#[cfg(target_arch = "x86_64")]
pub fn ticks() -> u64 {
    let mask = 0x00000000FFFFFFFFu64;
    let high: u64;
    let low: u64;
    unsafe {
        asm!("lfence;rdtsc"
            : "={rdx}"(high), "={rax}"(low)
            :
            : "rdx", "rax"
            : "volatile"
        );
    }
    (mask&high) | (mask&low) 
}


#[no_mangle]
#[inline(never)]
#[cfg(target_arch = "x86")]
pub fn ticks() -> u64 {
    let high: u32;
    let low: u32;
    unsafe {
        asm!("lfence;rdtsc"
            : "={edx}"(high), "={eax}"(low)
            :
            : "edx", "eax"
            : "volatile"
        );
    }
    let high_val = (high as u64) << 32;
    let low_val = low as u64;
    high_val|low_val
}