user: 请从给定的汇编指令推导出C源代码:

```asm
<fib>:
  endbr64
  test   %edi,%edi
  jle    L72
  mov    %edi,%r11d
  cmp    $0x1,%edi
  je     L184
  push   %r15
  xor    %r11d,%r11d
  lea    -0x2(%rdi),%esi
  push   %r14
  mov    %esi,%r9d
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %r11d,(%rsp)
L289:
  lea    0x1(%r9),%eax
  xor    %r11d,%r11d
  mov    %r9d,0x28(%rsp)
  mov    %eax,0x20(%rsp)
  mov    %r11d,0x4(%rsp)
L257:
  mov    0x20(%rsp),%eax
  cmp    $0x1,%eax
  je     L104
  sub    $0x1,%eax
  xor    %esi,%esi
  mov    %eax,0x24(%rsp)
  mov    %esi,0x8(%rsp)
L164:
  mov    0x24(%rsp),%eax
  cmp    $0x1,%eax
  je     L175
  xor    %esi,%esi
  lea    -0x1(%rax),%r9d
  mov    %esi,0xc(%rsp)
  mov    %r9d,%esi
L245:
  cmp    $0x1,%esi
  je     L277
  xor    %r8d,%r8d
  mov    %esi,0x2c(%rsp)
  lea    -0x1(%rsi),%r10d
  mov    %r8d,0x10(%rsp)
  mov    %r10d,%r15d
L221:
  cmp    $0x1,%r15d
  je     L158
  lea    -0x1(%r15),%r12d
  mov    %r15d,%esi
  xor    %ecx,%ecx
  mov    %r12d,%r15d
L264:
  cmp    $0x1,%r15d
  je     L260
  xor    %r13d,%r13d
  lea    -0x1(%r15),%ebx
  mov    %r15d,%edx
  mov    %r13d,%r15d
L285:
  cmp    $0x1,%ebx
  je     L178
  mov    %ebx,%eax
  lea    -0x1(%rbx),%r13d
  xor    %r12d,%r12d
  mov    %edx,%ebx
  mov    %r15d,%edx
  mov    %ecx,%r15d
  mov    %eax,%ecx
L1:
  cmp    $0x1,%r13d
  je     L181
  mov    %r13d,0x14(%rsp)
  lea    -0x1(%r13),%ebp
  xor    %r14d,%r14d
  mov    %r12d,%r13d
  mov    %edx,%r12d
L195:
  cmp    $0x1,%ebp
  je     L174
  lea    -0x1(%rbp),%edi
  mov    %ecx,0x1c(%rsp)
  mov    %esi,0x18(%rsp)
  call   <fib>
  mov    0x18(%rsp),%esi
  mov    0x1c(%rsp),%ecx
  add    %eax,%r14d
  sub    $0x2,%ebp
  jne    L195
  mov    %r12d,%edx
  mov    %r13d,%r12d
  mov    0x14(%rsp),%r13d
L157:
  add    %r14d,%r12d
  sub    $0x2,%r13d
  jne    L1
  mov    %ecx,%eax
  mov    %r15d,%ecx
  mov    %edx,%r15d
  mov    %ebx,%edx
  mov    %eax,%ebx
L96:
  add    %r12d,%r15d
  sub    $0x2,%ebx
  jne    L285
  mov    %r15d,%r13d
  mov    %edx,%r15d
L160:
  add    %r13d,%ecx
  sub    $0x2,%r15d
  jne    L264
  mov    %esi,%r15d
L63:
  add    %ecx,0x10(%rsp)
  sub    $0x2,%r15d
  jne    L221
  mov    0x2c(%rsp),%esi
  mov    0x10(%rsp),%r8d
L256:
  add    %r8d,0xc(%rsp)
  sub    $0x2,%esi
  jne    L245
  mov    0xc(%rsp),%esi
L278:
  add    %esi,0x8(%rsp)
  subl   $0x2,0x24(%rsp)
  jne    L164
  mov    0x8(%rsp),%esi
L112:
  add    %esi,0x4(%rsp)
  subl   $0x2,0x20(%rsp)
  jne    L257
  mov    0x28(%rsp),%r9d
  mov    0x4(%rsp),%r11d
  add    %r11d,(%rsp)
  mov    %r9d,%eax
  test   %r9d,%r9d
  jg     L105
L269:
  mov    (%rsp),%r11d
  jmp    L284
  cs nopw 0x0(%rax,%rax,1)
L174:
  mov    %r12d,%edx
  add    $0x1,%r14d
  mov    %r13d,%r12d
  mov    0x14(%rsp),%r13d
  jmp    L157
  nopl   0x0(%rax)
L181:
  mov    %ecx,%eax
  add    $0x1,%r12d
  mov    %r15d,%ecx
  mov    %edx,%r15d
  mov    %ebx,%edx
  mov    %eax,%ebx
  jmp    L96
L260:
  mov    %esi,%r15d
  add    $0x1,%ecx
  jmp    L63
L178:
  mov    %r15d,%r13d
  mov    %edx,%r15d
  add    $0x1,%r13d
  jmp    L160
L158:
  mov    0x10(%rsp),%r8d
  mov    0x2c(%rsp),%esi
  add    $0x1,%r8d
  jmp    L256
L277:
  mov    0xc(%rsp),%esi
  add    $0x1,%esi
  jmp    L278
L175:
  mov    0x8(%rsp),%esi
  add    $0x1,%esi
  jmp    L112
L104:
  mov    0x4(%rsp),%r11d
  mov    0x28(%rsp),%r9d
  add    $0x1,%r11d
  mov    %r9d,%eax
  add    %r11d,(%rsp)
  test   %r9d,%r9d
  jle    L269
L105:
  sub    $0x2,%r9d
  cmp    $0x1,%eax
  jne    L289
  mov    (%rsp),%r11d
  add    $0x1,%r11d
L284:
  add    $0x38,%rsp
  mov    %r11d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L72:
  xor    %r11d,%r11d
L184:
  mov    %r11d,%eax
  ret
```

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