user: What is the c source code of the assembly code below?

```asm
<calc_fib>:
  endbr64
  mov    %edi,%eax
  test   %edi,%edi
  je     L384
  cmp    $0x1,%edi
  je     L384
  push   %r15
  lea    -0x2(%rax),%edi
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  movl   $0x0,0x4(%rsp)
  mov    %edi,0xc(%rsp)
  cmp    $0x2,%eax
  je     L224
L328:
  sub    $0x1,%eax
  mov    %eax,0x10(%rsp)
  cmp    $0x1,%edi
  je     L105
  xor    %r10d,%r10d
  mov    %r10d,(%rsp)
L491:
  mov    0xc(%rsp),%eax
  lea    -0x2(%rax),%edi
  mov    %edi,0x8(%rsp)
  cmp    $0x2,%eax
  je     L467
  sub    $0x1,%eax
  mov    %eax,0xc(%rsp)
  cmp    $0x1,%edi
  je     L392
  xor    %esi,%esi
L337:
  mov    0x8(%rsp),%eax
  lea    -0x2(%rax),%r10d
  cmp    $0x2,%eax
  je     L401
  sub    $0x1,%eax
  mov    %eax,0x8(%rsp)
  cmp    $0x1,%r10d
  je     L259
  mov    %esi,0x14(%rsp)
  xor    %r8d,%r8d
  mov    %r8d,%r15d
L125:
  lea    -0x2(%r10),%r11d
  cmp    $0x2,%r10d
  je     L289
  sub    $0x1,%r10d
  cmp    $0x1,%r11d
  je     L326
  mov    %r10d,0x1c(%rsp)
  xor    %r9d,%r9d
  mov    %r15d,0x18(%rsp)
  mov    %r9d,%r14d
  mov    %r11d,%r15d
L297:
  lea    -0x2(%r15),%edx
  cmp    $0x2,%r15d
  je     L441
  sub    $0x1,%r15d
  cmp    $0x1,%edx
  je     L306
  xor    %r13d,%r13d
  mov    %r14d,%esi
  mov    %r15d,%r8d
  mov    %r13d,%ecx
L458:
  lea    -0x2(%rdx),%r12d
  cmp    $0x2,%edx
  je     L92
  sub    $0x1,%edx
  cmp    $0x1,%r12d
  je     L43
  xor    %ebx,%ebx
L154:
  lea    -0x2(%r12),%r13d
  cmp    $0x2,%r12d
  je     L368
L227:
  sub    $0x1,%r12d
  cmp    $0x1,%r13d
  je     L364
  xor    %ebp,%ebp
L253:
  lea    -0x2(%r13),%r15d
  cmp    $0x2,%r13d
  je     L325
L218:
  sub    $0x1,%r13d
  cmp    $0x1,%r15d
  je     L116
  mov    %r12d,0x20(%rsp)
  xor    %r14d,%r14d
  mov    %ebp,%r12d
  mov    %ecx,%ebp
  mov    %ebx,0x24(%rsp)
  mov    %esi,%ebx
  mov    %r13d,0x28(%rsp)
  mov    %r8d,%r13d
L287:
  lea    -0x2(%r15),%edi
  mov    %edx,0x2c(%rsp)
  call   <calc_fib>
  mov    0x2c(%rsp),%edx
  add    %eax,%r14d
  sub    $0x1,%r15d
  je     L73
  cmp    $0x1,%r15d
  jne    L287
  mov    %ebx,%esi
  mov    %ebp,%ecx
  mov    %r13d,%r8d
  mov    %r12d,%ebp
  mov    0x24(%rsp),%ebx
  mov    0x20(%rsp),%r12d
  add    $0x1,%r14d
  mov    0x28(%rsp),%r13d
L516:
  add    %r14d,%ebp
  test   %r13d,%r13d
  jne    L252
L277:
  add    %ebp,%ebx
  test   %r12d,%r12d
  jne    L535
  add    %ebx,%ecx
  test   %edx,%edx
  jne    L371
L302:
  mov    %esi,%r14d
  mov    %ecx,%r13d
  mov    %r8d,%r15d
L385:
  add    %r13d,%r14d
  test   %r15d,%r15d
  jne    L290
  mov    0x18(%rsp),%r15d
  mov    0x1c(%rsp),%r10d
  mov    %r14d,%r9d
  add    %r9d,%r15d
  test   %r10d,%r10d
  je     L412
L330:
  cmp    $0x1,%r10d
  jne    L125
L289:
  mov    0x14(%rsp),%esi
  mov    %r15d,%r8d
  mov    0x8(%rsp),%edi
  add    $0x1,%r8d
  add    %r8d,%esi
  test   %edi,%edi
  jne    L313
L111:
  mov    0xc(%rsp),%ecx
  add    %esi,(%rsp)
  test   %ecx,%ecx
  je     L479
L361:
  cmpl   $0x1,0xc(%rsp)
  jne    L491
L467:
  mov    (%rsp),%r10d
  mov    0x4(%rsp),%eax
  mov    0x10(%rsp),%edx
  add    $0x1,%r10d
  add    %r10d,%eax
  test   %edx,%edx
  jne    L156
L167:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L364:
  add    $0x1,%ebx
  lea    -0x2(%r12),%r13d
  cmp    $0x2,%r12d
  jne    L227
L368:
  add    $0x1,%ebx
L155:
  add    %ebx,%ecx
  test   %edx,%edx
  je     L302
L371:
  cmp    $0x1,%edx
  jne    L458
L92:
  mov    %ecx,%r13d
  mov    %esi,%r14d
  mov    %r8d,%r15d
  add    $0x1,%r13d
  jmp    L385
L43:
  add    $0x1,%ecx
  jmp    L458
  nopw   0x0(%rax,%rax,1)
L73:
  mov    %ebx,%esi
  mov    %ebp,%ecx
  mov    %r13d,%r8d
  mov    %r12d,%ebp
  mov    0x24(%rsp),%ebx
  mov    0x20(%rsp),%r12d
  mov    0x28(%rsp),%r13d
  jmp    L516
L290:
  cmp    $0x1,%r15d
  jne    L297
L441:
  mov    0x18(%rsp),%r15d
  mov    %r14d,%r9d
  mov    0x1c(%rsp),%r10d
  add    $0x1,%r9d
  add    %r9d,%r15d
  test   %r10d,%r10d
  jne    L330
L412:
  mov    0x14(%rsp),%esi
  mov    0x8(%rsp),%edi
  mov    %r15d,%r8d
  add    %r8d,%esi
  test   %edi,%edi
  je     L111
L313:
  cmpl   $0x1,0x8(%rsp)
  jne    L337
L401:
  mov    0xc(%rsp),%ecx
  add    $0x1,%esi
  add    %esi,(%rsp)
  test   %ecx,%ecx
  jne    L361
L479:
  mov    (%rsp),%r10d
  mov    0x4(%rsp),%eax
  mov    0x10(%rsp),%edx
  add    %r10d,%eax
  test   %edx,%edx
  je     L167
L156:
  cmpl   $0x1,0x10(%rsp)
  je     L187
L338:
  mov    %eax,0x4(%rsp)
  mov    0x10(%rsp),%eax
  lea    -0x2(%rax),%edi
  mov    %edi,0xc(%rsp)
  cmp    $0x2,%eax
  jne    L328
L224:
  mov    0x4(%rsp),%eax
L187:
  add    $0x38,%rsp
  add    $0x1,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L116:
  add    $0x1,%ebp
  lea    -0x2(%r13),%r15d
  cmp    $0x2,%r13d
  jne    L218
  nopl   0x0(%rax)
L325:
  add    $0x1,%ebp
  jmp    L277
L306:
  add    $0x1,%r14d
  jmp    L297
L326:
  add    $0x1,%r15d
  jmp    L125
L535:
  cmp    $0x1,%r12d
  jne    L154
  add    $0x1,%ebx
  jmp    L155
L252:
  cmp    $0x1,%r13d
  jne    L253
  add    $0x1,%ebp
  jmp    L277
L259:
  add    $0x1,%esi
  jmp    L337
L392:
  addl   $0x1,(%rsp)
  jmp    L491
L105:
  mov    0x4(%rsp),%eax
  add    $0x1,%eax
  jmp    L338
L384:
  ret
```

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