rdtscp.h

#ifndef RDTSCP_H_
#define RDTSCP_H_

#include <stdint.h>

static inline uint64_t rdtscp(void) {
	uint32_t cycles_low, cycles_high;
	__asm volatile(
		"RDTSCP\n\t"
		"mov %%edx, %0\n\t"
		"mov %%eax, %1\n\t"
		: "=r" (cycles_high), "=r" (cycles_low)
		:
		: "eax", "edx", "ecx"
		);
	return ((uint64_t)cycles_high << 32 | cycles_low);
}

static inline uint64_t logtwo(const uint64_t x) {
	uint64_t y;
	__asm volatile( "\tbsr %1, %0\n"
			: "=r"(y)
			: "r" (x)
	    );
	return y;
}
#endif