Function rxcr

freebsd/amd64/include/cpufunc.h:463–470

}

static __inline u_long
rxcr(u_int reg)
{
	u_int low, high;

	__asm __volatile("xgetbv" : "=a" (low), "=d" (high) : "c" (reg));
	return (low | ((uint64_t)high << 32));
}

static __inline void
load_xcr(u_int reg, u_long val)