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

```asm
<fib>:
  endbr64
  test   %edi,%edi
  je     L294
  cmp    $0x1,%edi
  je     L85
  push   %r15
  xor    %r11d,%r11d
  mov    %edi,%r9d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x58,%rsp
  mov    %r11,(%rsp)
L199:
  lea    -0x1(%r9),%eax
  xor    %r11d,%r11d
  mov    %r9d,0x48(%rsp)
  mov    %eax,0x40(%rsp)
  mov    %r11,0x8(%rsp)
L284:
  mov    0x40(%rsp),%eax
  cmp    $0x1,%eax
  je     L114
  sub    $0x1,%eax
  xor    %esi,%esi
  mov    %eax,0x44(%rsp)
  mov    %rsi,0x10(%rsp)
L259:
  mov    0x44(%rsp),%eax
  cmp    $0x1,%eax
  je     L221
  xor    %esi,%esi
  lea    -0x1(%rax),%r9d
  mov    %rsi,0x18(%rsp)
  mov    %r9d,%esi
L231:
  cmp    $0x1,%esi
  je     L60
  xor    %r8d,%r8d
  mov    %esi,0x4c(%rsp)
  lea    -0x1(%rsi),%r10d
  mov    %r8,0x20(%rsp)
  mov    %r10d,%r15d
L95:
  cmp    $0x1,%r15d
  je     L146
  lea    -0x1(%r15),%r12d
  mov    %r15d,%ecx
  xor    %r8d,%r8d
  mov    %r12d,%r15d
L265:
  cmp    $0x1,%r15d
  je     L205
  xor    %r13d,%r13d
  lea    -0x1(%r15),%ebx
  mov    %r15d,%edx
  mov    %r13,%r15
L148:
  cmp    $0x1,%ebx
  je     L166
  mov    %r15,%rax
  lea    -0x1(%rbx),%r13d
  mov    %ebx,%r15d
  xor    %r12d,%r12d
  mov    %ecx,%ebx
  mov    %rax,%rcx
L82:
  cmp    $0x1,%r13d
  je     L29
  mov    %r13d,0x2c(%rsp)
  lea    -0x1(%r13),%ebp
  xor    %r14d,%r14d
  mov    %r8,%r13
  mov    %r12,0x30(%rsp)
  mov    %edx,%r12d
L289:
  cmp    $0x1,%ebp
  je     L161
  lea    -0x1(%rbp),%edi
  mov    %rcx,0x38(%rsp)
  call   <fib>
  mov    0x38(%rsp),%rcx
  add    %rax,%r14
  sub    $0x2,%ebp
  jne    L289
  mov    %r12d,%edx
  mov    %r13,%r8
  mov    0x30(%rsp),%r12
  mov    0x2c(%rsp),%r13d
L169:
  add    %r14,%r12
  sub    $0x2,%r13d
  jne    L82
  mov    %rcx,%rax
  mov    %ebx,%ecx
  mov    %r15d,%ebx
  mov    %rax,%r15
L263:
  add    %r12,%r15
  sub    $0x2,%ebx
  jne    L148
  mov    %r15,%r13
  mov    %edx,%r15d
L201:
  add    %r13,%r8
  sub    $0x2,%r15d
  jne    L265
  mov    %ecx,%r15d
L17:
  add    %r8,0x20(%rsp)
  sub    $0x2,%r15d
  jne    L95
  mov    0x4c(%rsp),%esi
  mov    0x20(%rsp),%r8
L92:
  add    %r8,0x18(%rsp)
  sub    $0x2,%esi
  jne    L231
  mov    0x18(%rsp),%rsi
L282:
  add    %rsi,0x10(%rsp)
  subl   $0x2,0x44(%rsp)
  jne    L259
  mov    0x10(%rsp),%rsi
L41:
  add    %rsi,0x8(%rsp)
  subl   $0x2,0x40(%rsp)
  jne    L284
  mov    0x48(%rsp),%r9d
  mov    0x8(%rsp),%r11
  add    %r11,(%rsp)
  sub    $0x2,%r9d
  jne    L113
L143:
  mov    (%rsp),%r11
  jmp    L217
  nopl   0x0(%rax,%rax,1)
L161:
  mov    %r12d,%edx
  mov    %r13,%r8
  mov    0x30(%rsp),%r12
  mov    0x2c(%rsp),%r13d
  add    $0x1,%r14
  jmp    L169
  nopl   0x0(%rax)
L29:
  mov    %rcx,%rax
  add    $0x1,%r12
  mov    %ebx,%ecx
  mov    %r15d,%ebx
  mov    %rax,%r15
  jmp    L263
L205:
  mov    %ecx,%r15d
  add    $0x1,%r8
  jmp    L17
L166:
  mov    %r15,%r13
  mov    %edx,%r15d
  add    $0x1,%r13
  jmp    L201
L146:
  mov    0x20(%rsp),%r8
  mov    0x4c(%rsp),%esi
  add    $0x1,%r8
  jmp    L92
L60:
  mov    0x18(%rsp),%rsi
  add    $0x1,%rsi
  jmp    L282
L221:
  mov    0x10(%rsp),%rsi
  add    $0x1,%rsi
  jmp    L41
L114:
  mov    0x8(%rsp),%r11
  mov    0x48(%rsp),%r9d
  add    $0x1,%r11
  add    %r11,(%rsp)
  sub    $0x2,%r9d
  je     L143
L113:
  cmp    $0x1,%r9d
  jne    L199
  mov    (%rsp),%r11
  add    $0x1,%r11
L217:
  add    $0x58,%rsp
  mov    %r11,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L294:
  xor    %r11d,%r11d
L274:
  mov    %r11,%rax
  ret
L85:
  mov    $0x1,%r11d
  jmp    L274
```

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