user: What would the C source look like for the assembly code provided here?

```asm
<fib>:
  endbr64
  mov    %edi,%r10d
  test   %edi,%edi
  je     L462
  cmp    $0x1,%edi
  je     L462
  push   %r15
  lea    -0x2(%rdi),%eax
  xor    %r10d,%r10d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %eax,0x8(%rsp)
  mov    %r10d,0x10(%rsp)
L157:
  mov    0x8(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L17
  cmp    $0x1,%eax
  je     L378
  lea    -0x1(%rdi),%eax
  xor    %r8d,%r8d
  mov    %eax,0x4(%rsp)
  mov    %r8d,0x14(%rsp)
L12:
  mov    0x4(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L4
  cmp    $0x1,%eax
  je     L56
  lea    -0x1(%rdi),%eax
  xor    %ecx,%ecx
  mov    %eax,0xc(%rsp)
  mov    %ecx,0x18(%rsp)
L164:
  mov    0xc(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L487
  cmp    $0x1,%eax
  je     L326
  xor    %ecx,%ecx
  lea    -0x1(%rdi),%r8d
  mov    %ecx,0x1c(%rsp)
  mov    %r8d,%ecx
L510:
  mov    %ecx,%eax
  add    $0x1,%eax
  je     L7
  cmp    $0x1,%eax
  je     L57
  xor    %esi,%esi
  mov    %ecx,0x20(%rsp)
  lea    -0x1(%rcx),%r9d
  mov    %esi,(%rsp)
  mov    %r9d,%r15d
L425:
  mov    %r15d,%eax
  add    $0x1,%eax
  je     L359
  cmp    $0x1,%eax
  je     L358
  lea    -0x1(%r15),%r12d
  xor    %ecx,%ecx
  mov    %r15d,%esi
L355:
  mov    %r12d,%eax
  add    $0x1,%eax
  je     L19
  cmp    $0x1,%eax
  je     L423
  xor    %ebx,%ebx
  lea    -0x1(%r12),%ebp
  mov    %r12d,%edx
  mov    %ebx,%r12d
L161:
  mov    %ebp,%eax
  add    $0x1,%eax
  je     L96
  cmp    $0x1,%eax
  je     L246
  mov    %ebp,%eax
  lea    -0x1(%rbp),%ebx
  xor    %r14d,%r14d
  mov    %ecx,%ebp
  mov    %eax,%ecx
L163:
  mov    %ebx,%r13d
  add    $0x1,%r13d
  je     L81
  cmp    $0x1,%r13d
  je     L418
  mov    %ebx,0x24(%rsp)
  xor    %r15d,%r15d
  mov    %esi,%ebx
L334:
  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     L304
  cmp    $0x1,%r13d
  jne    L334
  mov    %ebx,%esi
  mov    0x24(%rsp),%ebx
  add    $0x1,%r15d
L0:
  add    %r15d,%r14d
  test   %ebx,%ebx
  je     L20
  cmp    $0x1,%ebx
  jne    L81
L418:
  mov    %ecx,%eax
  add    $0x1,%r14d
  mov    %ebp,%ecx
  mov    %eax,%ebp
  add    %r14d,%r12d
  test   %ebp,%ebp
  je     L428
L467:
  cmp    $0x1,%ebp
  jne    L96
L246:
  mov    %r12d,%ebx
  mov    %edx,%r12d
  add    $0x1,%ebx
L520:
  add    %ebx,%ecx
  test   %r12d,%r12d
  jne    L511
  mov    %esi,%r15d
  mov    %ecx,%r14d
  add    %r14d,(%rsp)
  mov    (%rsp),%esi
  test   %r15d,%r15d
  jne    L449
L453:
  mov    0x20(%rsp),%ecx
  add    %esi,0x1c(%rsp)
  test   %ecx,%ecx
  je     L46
L325:
  cmp    $0x1,%ecx
  je     L57
L7:
  sub    $0x2,%ecx
  jmp    L510
L96:
  sub    $0x2,%ebp
  jmp    L161
L511:
  cmp    $0x1,%r12d
  jne    L19
L423:
  mov    %ecx,%r14d
  mov    %esi,%r15d
  add    $0x1,%r14d
  add    %r14d,(%rsp)
  mov    (%rsp),%esi
  test   %r15d,%r15d
  je     L453
L449:
  cmp    $0x1,%r15d
  je     L358
L359:
  sub    $0x2,%r15d
  jmp    L425
L19:
  sub    $0x2,%r12d
  jmp    L355
L20:
  mov    %ecx,%eax
  mov    %ebp,%ecx
  add    %r14d,%r12d
  mov    %eax,%ebp
  test   %ebp,%ebp
  jne    L467
L428:
  mov    %r12d,%ebx
  mov    %edx,%r12d
  jmp    L520
  nopl   (%rax)
L304:
  mov    %ebx,%esi
  mov    0x24(%rsp),%ebx
  jmp    L0
L358:
  mov    (%rsp),%esi
  mov    0x20(%rsp),%ecx
  add    $0x1,%esi
  add    %esi,0x1c(%rsp)
  test   %ecx,%ecx
  jne    L325
L46:
  mov    0x1c(%rsp),%ecx
  add    %ecx,0x18(%rsp)
  mov    0xc(%rsp),%ecx
  test   %ecx,%ecx
  jne    L230
L443:
  mov    0x4(%rsp),%edx
  mov    0x18(%rsp),%ecx
  add    %ecx,0x14(%rsp)
  test   %edx,%edx
  jne    L450
L155:
  mov    0x14(%rsp),%r8d
  jmp    L122
L81:
  sub    $0x2,%ebx
  jmp    L163
L57:
  mov    0x1c(%rsp),%ecx
  add    $0x1,%ecx
  add    %ecx,0x18(%rsp)
  mov    0xc(%rsp),%ecx
  test   %ecx,%ecx
  je     L443
L230:
  cmpl   $0x1,0xc(%rsp)
  je     L326
L487:
  subl   $0x2,0xc(%rsp)
  jmp    L164
L326:
  mov    0x18(%rsp),%ecx
  mov    0x4(%rsp),%edx
  add    $0x1,%ecx
  add    %ecx,0x14(%rsp)
  test   %edx,%edx
  je     L155
L450:
  cmpl   $0x1,0x4(%rsp)
  je     L56
L4:
  subl   $0x2,0x4(%rsp)
  jmp    L12
L56:
  mov    0x14(%rsp),%r8d
  add    $0x1,%r8d
L122:
  mov    0x8(%rsp),%eax
  add    %r8d,0x10(%rsp)
  test   %eax,%eax
  je     L143
  cmpl   $0x1,0x8(%rsp)
  jne    L17
L378:
  mov    0x10(%rsp),%r10d
  add    $0x1,%r10d
L154:
  add    $0x38,%rsp
  mov    %r10d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L17:
  subl   $0x2,0x8(%rsp)
  jmp    L157
L462:
  mov    %r10d,%eax
  ret
L143:
  mov    0x10(%rsp),%r10d
  jmp    L154
```

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);
}
```