Is gettimeofday() guaranteed to be of microsecond resolution?

11867927879484732
11867927879692217
it took this long to call printf: 207485

#include <stdio.h>
#include <stdint.h>

inline uint64_t rdtsc() {
    uint32_t lo, hi;
    __asm__ __volatile__ (
      "xorl %%eax, %%eax
"
      "cpuid
"
      "rdtsc
"
      : "=a" (lo), "=d" (hi)
      :
      : "%ebx", "%ecx");
    return (uint64_t)hi << 32 | lo;
}

main()
{
    unsigned long long x;
    unsigned long long y;
    x = rdtsc();
    printf("%lld
",x);
    y = rdtsc();
    printf("%lld
",y);
    printf("it took this long to call printf: %lld
",y-x);
}

Related code-snippets:

• How can I get the value of in a loop?
• What is error log per Virtual Host?
• What's the API for GTK messagebox?
• How do I get root permission for my file inside vi?
• What does wiggling the mouse do?
• How can I retrieve a windows filename?
• Sharepoint: executing stsadm from a timer job + SHAREPOINTSystem rights + SHAREPOINTSystem rights.
• Windows Equivalent of 'nice'.
• Can I use Xming X Window Server over a VPN?
• How do you create your own moniker (URL Protocol) on Windows systems?
• How can I kill Linux processes older than a certain age?
• How can I fix the Java Time Zone?
• Date arithmetic in Unix shell scripts.
• What's a quicker way to find duplicates conditioned by time?
• How do I encode XML files to XFS,?