user: 下面的汇编指令对应的C源代码是什么：

```asm
<fib>:
  endbr64
  mov    %edi,%r11d
  test   %edi,%edi
  je     L198
  cmp    $0x1,%edi
  je     L198
  push   %r15
  xor    %r11d,%r11d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %edi,(%rsp)
  mov    %r11d,0x4(%rsp)
L44:
  mov    (%rsp),%eax
  xor    %r9d,%r9d
  mov    %r9d,0x8(%rsp)
  sub    $0x1,%eax
  mov    %eax,0x24(%rsp)
L57:
  mov    0x24(%rsp),%eax
  cmp    $0x1,%eax
  je     L276
  sub    $0x1,%eax
  xor    %esi,%esi
  mov    %eax,0x28(%rsp)
  mov    %esi,0xc(%rsp)
L125:
  mov    0x28(%rsp),%eax
  cmp    $0x1,%eax
  je     L188
  xor    %esi,%esi
  lea    -0x1(%rax),%r9d
  mov    %esi,0x10(%rsp)
  mov    %r9d,%esi
L37:
  cmp    $0x1,%esi
  je     L29
  xor    %r8d,%r8d
  mov    %esi,0x2c(%rsp)
  lea    -0x1(%rsi),%r10d
  mov    %r8d,0x14(%rsp)
  mov    %r10d,%r15d
L239:
  cmp    $0x1,%r15d
  je     L76
  lea    -0x1(%r15),%r12d
  mov    %r15d,%ecx
  xor    %r8d,%r8d
  mov    %r12d,%r15d
L51:
  cmp    $0x1,%r15d
  je     L12
  xor    %r13d,%r13d
  lea    -0x1(%r15),%ebx
  mov    %r15d,%edx
  mov    %r13d,%r15d
L48:
  cmp    $0x1,%ebx
  je     L206
  mov    %r15d,%eax
  lea    -0x1(%rbx),%r13d
  mov    %ebx,%r15d
  xor    %r12d,%r12d
  mov    %ecx,%ebx
  mov    %eax,%ecx
L236:
  cmp    $0x1,%r13d
  je     L8
  mov    %r13d,0x18(%rsp)
  lea    -0x1(%r13),%ebp
  xor    %r14d,%r14d
  mov    %r8d,%r13d
  mov    %r12d,0x1c(%rsp)
  mov    %edx,%r12d
L182:
  cmp    $0x1,%ebp
  je     L32
  lea    -0x1(%rbp),%edi
  mov    %ecx,0x20(%rsp)
  call   <fib>
  mov    0x20(%rsp),%ecx
  add    %eax,%r14d
  sub    $0x2,%ebp
  jne    L182
  mov    %r12d,%edx
  mov    %r13d,%r8d
  mov    0x1c(%rsp),%r12d
  mov    0x18(%rsp),%r13d
L191:
  add    %r14d,%r12d
  sub    $0x2,%r13d
  jne    L236
  mov    %ecx,%eax
  mov    %ebx,%ecx
  mov    %r15d,%ebx
  mov    %eax,%r15d
L287:
  add    %r12d,%r15d
  sub    $0x2,%ebx
  jne    L48
  mov    %r15d,%r13d
  mov    %edx,%r15d
L118:
  add    %r13d,%r8d
  sub    $0x2,%r15d
  jne    L51
  mov    %ecx,%r15d
L207:
  add    %r8d,0x14(%rsp)
  sub    $0x2,%r15d
  jne    L239
  mov    0x2c(%rsp),%esi
  mov    0x14(%rsp),%r8d
L134:
  add    %r8d,0x10(%rsp)
  sub    $0x2,%esi
  jne    L37
  mov    0x10(%rsp),%esi
L226:
  add    %esi,0xc(%rsp)
  subl   $0x2,0x28(%rsp)
  jne    L125
  mov    0xc(%rsp),%esi
L212:
  add    %esi,0x8(%rsp)
  subl   $0x2,0x24(%rsp)
  jne    L57
  mov    0x8(%rsp),%r9d
  add    %r9d,0x4(%rsp)
  subl   $0x2,(%rsp)
  jne    L17
L107:
  mov    0x4(%rsp),%r11d
  jmp    L171
  nopl   0x0(%rax)
L32:
  mov    %r12d,%edx
  mov    %r13d,%r8d
  mov    0x1c(%rsp),%r12d
  mov    0x18(%rsp),%r13d
  add    $0x1,%r14d
  jmp    L191
  nopl   0x0(%rax)
L8:
  mov    %ecx,%eax
  add    $0x1,%r12d
  mov    %ebx,%ecx
  mov    %r15d,%ebx
  mov    %eax,%r15d
  jmp    L287
L12:
  mov    %ecx,%r15d
  add    $0x1,%r8d
  jmp    L207
L206:
  mov    %r15d,%r13d
  mov    %edx,%r15d
  add    $0x1,%r13d
  jmp    L118
L76:
  mov    0x14(%rsp),%r8d
  mov    0x2c(%rsp),%esi
  add    $0x1,%r8d
  jmp    L134
L29:
  mov    0x10(%rsp),%esi
  add    $0x1,%esi
  jmp    L226
L188:
  mov    0xc(%rsp),%esi
  add    $0x1,%esi
  jmp    L212
L276:
  mov    0x8(%rsp),%r9d
  add    $0x1,%r9d
  add    %r9d,0x4(%rsp)
  subl   $0x2,(%rsp)
  je     L107
L17:
  cmpl   $0x1,(%rsp)
  jne    L44
  mov    0x4(%rsp),%r11d
  add    $0x1,%r11d
L171:
  add    $0x38,%rsp
  mov    %r11d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L198:
  mov    %r11d,%eax
  ret
```

assistant: ```c
unsigned fib(unsigned f) {
  if (f == 0)
    return 0;
  if (f == 1)
    return 1;
  return fib(f - 1) + fib(f - 2);
}
```