user: 请从给定的汇编指令推导出C源代码：

```asm
<fib>:
  endbr64
  mov    %edi,%r10d
  test   %edi,%edi
  je     L238
  cmp    $0x1,%edi
  je     L238
  push   %r15
  lea    -0x2(%rdi),%eax
  xor    %r10d,%r10d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %eax,0x4(%rsp)
  mov    %r10d,0x10(%rsp)
L230:
  mov    0x4(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L473
  cmp    $0x1,%eax
  je     L434
  lea    -0x1(%rdi),%eax
  xor    %r8d,%r8d
  mov    %eax,0x8(%rsp)
  mov    %r8d,0x14(%rsp)
L394:
  mov    0x8(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L479
  cmp    $0x1,%eax
  je     L4
  lea    -0x1(%rdi),%eax
  xor    %ecx,%ecx
  mov    %eax,0xc(%rsp)
  mov    %ecx,0x18(%rsp)
L51:
  mov    0xc(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L236
  cmp    $0x1,%eax
  je     L508
  xor    %ecx,%ecx
  lea    -0x1(%rdi),%r8d
  mov    %ecx,0x1c(%rsp)
  mov    %r8d,%ecx
L301:
  mov    %ecx,%eax
  add    $0x1,%eax
  je     L73
  cmp    $0x1,%eax
  je     L408
  xor    %esi,%esi
  mov    %ecx,0x20(%rsp)
  lea    -0x1(%rcx),%r9d
  mov    %esi,(%rsp)
  mov    %r9d,%r15d
L24:
  mov    %r15d,%eax
  add    $0x1,%eax
  je     L300
  cmp    $0x1,%eax
  je     L457
  lea    -0x1(%r15),%r12d
  xor    %ecx,%ecx
  mov    %r15d,%esi
L27:
  mov    %r12d,%eax
  add    $0x1,%eax
  je     L361
  cmp    $0x1,%eax
  je     L287
  xor    %ebx,%ebx
  lea    -0x1(%r12),%ebp
  mov    %r12d,%edx
  mov    %ebx,%r12d
L137:
  mov    %ebp,%eax
  add    $0x1,%eax
  je     L358
  cmp    $0x1,%eax
  je     L57
  mov    %ebp,%eax
  lea    -0x1(%rbp),%ebx
  xor    %r14d,%r14d
  mov    %ecx,%ebp
  mov    %eax,%ecx
L197:
  mov    %ebx,%r13d
  add    $0x1,%r13d
  je     L338
  cmp    $0x1,%r13d
  je     L415
  mov    %ebx,0x24(%rsp)
  xor    %r15d,%r15d
  mov    %esi,%ebx
L412:
  lea    -0x1(%r13),%edi
  mov    %ecx,0x2c(%rsp)
  mov    %edx,0x28(%rsp)
  call   <fib>
  mov    0x28(%rsp),%edx
  mov    0x2c(%rsp),%ecx
  add    %eax,%r15d
  sub    $0x2,%r13d
  je     L44
  cmp    $0x1,%r13d
  jne    L412
  mov    %ebx,%esi
  mov    0x24(%rsp),%ebx
  add    $0x1,%r15d
L216:
  add    %r15d,%r14d
  test   %ebx,%ebx
  je     L512
  cmp    $0x1,%ebx
  jne    L338
L415:
  mov    %ecx,%eax
  add    $0x1,%r14d
  mov    %ebp,%ecx
  mov    %eax,%ebp
  add    %r14d,%r12d
  test   %ebp,%ebp
  je     L111
L354:
  cmp    $0x1,%ebp
  jne    L358
L57:
  mov    %r12d,%ebx
  mov    %edx,%r12d
  add    $0x1,%ebx
L320:
  add    %ebx,%ecx
  test   %r12d,%r12d
  jne    L279
  mov    %esi,%r15d
  mov    %ecx,%r14d
  add    %r14d,(%rsp)
  mov    (%rsp),%esi
  test   %r15d,%r15d
  jne    L3
L339:
  mov    0x20(%rsp),%ecx
  add    %esi,0x1c(%rsp)
  test   %ecx,%ecx
  je     L160
L177:
  cmp    $0x1,%ecx
  je     L408
L73:
  sub    $0x2,%ecx
  jmp    L301
L358:
  sub    $0x2,%ebp
  jmp    L137
L279:
  cmp    $0x1,%r12d
  jne    L361
L287:
  mov    %ecx,%r14d
  mov    %esi,%r15d
  add    $0x1,%r14d
  add    %r14d,(%rsp)
  mov    (%rsp),%esi
  test   %r15d,%r15d
  je     L339
L3:
  cmp    $0x1,%r15d
  je     L270
L300:
  sub    $0x2,%r15d
  jmp    L24
L361:
  sub    $0x2,%r12d
  jmp    L27
L512:
  mov    %ecx,%eax
  mov    %ebp,%ecx
  add    %r14d,%r12d
  mov    %eax,%ebp
  test   %ebp,%ebp
  jne    L354
L111:
  mov    %r12d,%ebx
  mov    %edx,%r12d
  jmp    L320
  nopl   (%rax)
L44:
  mov    %ebx,%esi
  mov    0x24(%rsp),%ebx
  jmp    L216
L457:
  mov    (%rsp),%esi
L270:
  mov    0x20(%rsp),%ecx
  add    $0x1,%esi
  add    %esi,0x1c(%rsp)
  test   %ecx,%ecx
  jne    L177
L160:
  mov    0x1c(%rsp),%ecx
  add    %ecx,0x18(%rsp)
  mov    0xc(%rsp),%ecx
  test   %ecx,%ecx
  jne    L29
L427:
  mov    0x8(%rsp),%edx
  mov    0x18(%rsp),%ecx
  add    %ecx,0x14(%rsp)
  test   %edx,%edx
  jne    L424
L245:
  mov    0x14(%rsp),%r8d
  jmp    L453
L338:
  sub    $0x2,%ebx
  jmp    L197
L408:
  mov    0x1c(%rsp),%ecx
  add    $0x1,%ecx
  add    %ecx,0x18(%rsp)
  mov    0xc(%rsp),%ecx
  test   %ecx,%ecx
  je     L427
L29:
  cmpl   $0x1,0xc(%rsp)
  je     L508
L236:
  subl   $0x2,0xc(%rsp)
  jmp    L51
L508:
  mov    0x18(%rsp),%ecx
  mov    0x8(%rsp),%edx
  add    $0x1,%ecx
  add    %ecx,0x14(%rsp)
  test   %edx,%edx
  je     L245
L424:
  cmpl   $0x1,0x8(%rsp)
  je     L4
L479:
  subl   $0x2,0x8(%rsp)
  jmp    L394
L4:
  mov    0x14(%rsp),%r8d
  add    $0x1,%r8d
L453:
  mov    0x4(%rsp),%eax
  add    %r8d,0x10(%rsp)
  test   %eax,%eax
  je     L507
  cmpl   $0x1,0x4(%rsp)
  jne    L473
L434:
  mov    0x10(%rsp),%r10d
  add    $0x1,%r10d
L246:
  add    $0x38,%rsp
  mov    %r10d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L473:
  subl   $0x2,0x4(%rsp)
  jmp    L230
L238:
  mov    %r10d,%eax
  ret
L507:
  mov    0x10(%rsp),%r10d
  jmp    L246
```

assistant: ```c
int fib(int n) {
  if (n == 0)
    return 0;
  else if (n == 1)
    return 1;
  else
    return fib(n - 1) + fib(n - 2);
}
```