user: Demonstrate the C code that generates the assembly output below:

```asm
<fib>:
  endbr64
  push   %r15
  lea    -0x2(%rdi),%r11d
  mov    %edi,%eax
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  movl   $0x0,0x8(%rsp)
  cmp    $0x1,%edi
  jbe    L315
L80:
  movl   $0x0,0xc(%rsp)
  lea    -0x2(%r11),%r10d
  cmp    $0x1,%r11d
  jbe    L249
  mov    %r11d,0x14(%rsp)
  mov    %r10d,%r11d
L190:
  movl   $0x0,0x10(%rsp)
  lea    -0x2(%r11),%r10d
  cmp    $0x1,%r11d
  jbe    L3
  mov    %r11d,0x18(%rsp)
L299:
  lea    -0x2(%r10),%ecx
  xor    %r11d,%r11d
  cmp    $0x1,%r10d
  jbe    L81
L173:
  mov    %r10d,0x1c(%rsp)
L286:
  lea    -0x2(%rcx),%r12d
  xor    %r15d,%r15d
  cmp    $0x1,%ecx
  jbe    L23
L238:
  lea    -0x2(%r12),%ebx
  xor    %ebp,%ebp
  cmp    $0x1,%r12d
  jbe    L217
L28:
  mov    %ebx,%r8d
  cmp    $0x1,%ebx
  jbe    L117
L157:
  lea    -0x2(%rbx),%edx
  lea    -0x4(%rbx),%r9d
  xor    %esi,%esi
L261:
  mov    %edx,%eax
  mov    %r9d,%r13d
  xor    %r14d,%r14d
  cmp    $0x1,%edx
  jbe    L318
L2:
  lea    -0x2(%r13),%edi
  xor    %r10d,%r10d
  cmp    $0x1,%r13d
  jbe    L197
  nopl   0x0(%rax)
L231:
  mov    %edx,0x3c(%rsp)
  mov    %r9d,0x38(%rsp)
  mov    %ecx,0x34(%rsp)
  mov    %r11d,0x30(%rsp)
  mov    %r10d,0x2c(%rsp)
  mov    %esi,0x28(%rsp)
  mov    %r8d,0x24(%rsp)
  mov    %edi,0x20(%rsp)
  call   <fib>
  mov    0x20(%rsp),%edi
  mov    0x2c(%rsp),%r10d
  mov    0x24(%rsp),%r8d
  mov    0x28(%rsp),%esi
  sub    $0x1,%edi
  add    %eax,%r10d
  mov    0x30(%rsp),%r11d
  mov    0x34(%rsp),%ecx
  cmp    $0xffffffff,%edi
  mov    0x38(%rsp),%r9d
  mov    0x3c(%rsp),%edx
  jne    L231
  sub    $0x1,%r13d
  lea    0x1(%r10,%r14,1),%r14d
  xor    %r10d,%r10d
  lea    -0x2(%r13),%edi
  cmp    $0x1,%r13d
  ja     L231
L197:
  add    %r13d,%r14d
  test   %r13d,%r13d
  jne    L153
  sub    %r8d,%r14d
  lea    0x3(%r14,%rdx,1),%eax
L318:
  sub    $0x1,%r8d
  add    %eax,%esi
  sub    $0x1,%edx
  sub    $0x1,%r9d
  cmp    $0x1,%r8d
  jne    L261
  sub    $0x1,%ebx
  lea    0x1(%rsi,%rbp,1),%ebp
  mov    %ebx,%r8d
  cmp    $0x1,%ebx
  ja     L157
L117:
  add    %ebx,%ebp
  test   %ebx,%ebx
  jne    L96
  sub    $0x1,%r12d
  lea    0x1(%r15,%rbp,1),%r15d
  xor    %ebp,%ebp
  lea    -0x2(%r12),%ebx
  cmp    $0x1,%r12d
  ja     L28
L217:
  add    %r12d,%r15d
  test   %r12d,%r12d
  jne    L146
  sub    $0x1,%ecx
  lea    0x1(%r11,%r15,1),%r11d
  xor    %r15d,%r15d
  lea    -0x2(%rcx),%r12d
  cmp    $0x1,%ecx
  ja     L238
L23:
  add    %ecx,%r11d
  test   %ecx,%ecx
  jne    L134
  mov    0x10(%rsp),%eax
  mov    0x1c(%rsp),%r10d
  lea    0x1(%rax,%r11,1),%eax
  sub    $0x1,%r10d
  xor    %r11d,%r11d
  mov    %eax,0x10(%rsp)
  lea    -0x2(%r10),%ecx
  cmp    $0x1,%r10d
  ja     L173
L81:
  add    %r10d,0x10(%rsp)
  test   %r10d,%r10d
  jne    L151
  mov    0xc(%rsp),%eax
  mov    0x10(%rsp),%edi
  mov    0x18(%rsp),%r11d
  lea    0x1(%rax,%rdi,1),%eax
  mov    %eax,0xc(%rsp)
  sub    $0x1,%r11d
  jmp    L190
L3:
  add    %r11d,0xc(%rsp)
  test   %r11d,%r11d
  jne    L20
  mov    0x8(%rsp),%eax
  mov    0xc(%rsp),%edi
  mov    0x14(%rsp),%r11d
  lea    0x1(%rax,%rdi,1),%eax
  mov    %eax,0x8(%rsp)
  sub    $0x1,%r11d
  jmp    L80
L249:
  add    %r11d,0x8(%rsp)
  test   %r11d,%r11d
  jne    L42
  mov    0x8(%rsp),%eax
  add    $0x1,%eax
L315:
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L96:
  xor    %ebx,%ebx
  jmp    L28
L42:
  xor    %r11d,%r11d
  jmp    L80
L20:
  xor    %r11d,%r11d
  jmp    L190
L151:
  xor    %r10d,%r10d
  jmp    L299
L134:
  xor    %ecx,%ecx
  jmp    L286
L146:
  xor    %r12d,%r12d
  jmp    L238
L153:
  xor    %r13d,%r13d
  jmp    L2
```

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