Negative clock cycle measurements with back-to-back rdtsc?

Question

I am writing a C code for measuring the number of clock cycles needed to acquire a semaphore. I am using rdtsc, and before doing the measurement on the semaphore, I call rdt

Answer 1

I tested your code on my machine and I figured that during RDTSC fuction only uint32_t is reasonable.

I do the following in my code to correct it:

if(before_t