user: Please show me the C implementation that matches the assembly code listed below:

```asm
<int64tostrtime>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x40,%rsp
  mov    %edi,-0x34(%rbp)
  mov    %rsi,-0x40(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  mov    -0x34(%rbp),%eax
  mov    %eax,-0x28(%rbp)
  lea    -0x20(%rbp),%rdx
  lea    -0x28(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <gmtime_r@plt>
  mov    -0x20(%rbp),%eax
  add    $0x76c,%eax
  mov    %eax,-0x24(%rbp)
  addq   $0x3,-0x40(%rbp)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    -0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    -0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    -0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  add    $0x30,%eax
  mov    %eax,%edx
  mov    -0x40(%rbp),%rax
  mov    %dl,(%rax)
  addq   $0x4,-0x40(%rbp)
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  movb   $0x2d,(%rax)
  mov    -0x1c(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  movb   $0x2d,(%rax)
  mov    -0x18(%rbp),%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  movb   $0x54,(%rax)
  mov    -0x14(%rbp),%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  movb   $0x3a,(%rax)
  mov    -0x10(%rbp),%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  movb   $0x3a,(%rax)
  mov    -0xc(%rbp),%eax
  movslq %eax,%rdx
  imul   $0xffffffff88888889,%rdx,%rdx
  shr    $0x20,%rdx
  add    %eax,%edx
  sar    $0x5,%edx
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  sub    %ecx,%edx
  mov    %edx,-0x24(%rbp)
  mov    -0x24(%rbp),%edx
  imul   $0x3c,%edx,%edx
  sub    %edx,%eax
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%eax
  movslq %eax,%rdx
  imul   $0x66666667,%rdx,%rdx
  shr    $0x20,%rdx
  sar    $0x2,%edx
  sar    $0x1f,%eax
  mov    %eax,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x24(%rbp),%edx
  movslq %edx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%ecx
  mov    %ecx,%eax
  shl    $0x2,%eax
  add    %ecx,%eax
  add    %eax,%eax
  mov    %edx,%ecx
  sub    %eax,%ecx
  mov    %ecx,%eax
  lea    0x30(%rax),%ecx
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  mov    %ecx,%edx
  mov    %dl,(%rax)
  mov    -0x40(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x40(%rbp)
  movb   $0x5a,(%rax)
  mov    -0x40(%rbp),%rax
  movb   $0x0,(%rax)
  nop
  mov    -0x8(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L9
  call   <__stack_chk_fail@plt>
L9:
  leave
  ret
```

assistant: ```c
void int64tostrtime(uint64_t v, char *sp) {
  time_t vtime;
  struct tm tm;
  int i;
  vtime = v;
  gmtime_r(&vtime, &tm);
  i = tm.tm_year + 1900;
  sp += 3;
  *sp-- = i % 10 + '0';
  i /= 10;
  *sp-- = i % 10 + '0';
  i /= 10;
  *sp-- = i % 10 + '0';
  i /= 10;
  *sp = i % 10 + '0';
  sp += 4;
  *sp++ = '-';
  i = tm.tm_mon + 1;
  *sp++ = i / 10 + '0';
  *sp++ = i % 10 + '0';
  *sp++ = '-';
  i = tm.tm_mday;
  *sp++ = i / 10 + '0';
  *sp++ = i % 10 + '0';
  *sp++ = 'T';
  i = tm.tm_hour;
  *sp++ = i / 10 + '0';
  *sp++ = i % 10 + '0';
  *sp++ = ':';
  i = tm.tm_min;
  *sp++ = i / 10 + '0';
  *sp++ = i % 10 + '0';
  *sp++ = ':';
  i = tm.tm_sec % 60;
  *sp++ = i / 10 + '0';
  *sp++ = i % 10 + '0';
  *sp++ = 'Z';
  *sp = 0;
}
```