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
  jle    L147
L175:
  movl   $0x0,0xc(%rsp)
  lea    -0x2(%r11),%r10d
  cmp    $0x1,%r11d
  jbe    L97
  mov    %r11d,0x14(%rsp)
  mov    %r10d,%r11d
L111:
  movl   $0x0,0x10(%rsp)
  lea    -0x2(%r11),%r10d
  cmp    $0x1,%r11d
  jbe    L67
  mov    %r11d,0x18(%rsp)
L35:
  lea    -0x2(%r10),%ecx
  xor    %r11d,%r11d
  cmp    $0x1,%r10d
  jbe    L152
L2:
  mov    %r10d,0x1c(%rsp)
L172:
  lea    -0x2(%rcx),%r13d
  xor    %r15d,%r15d
  cmp    $0x1,%ecx
  jbe    L76
L56:
  lea    -0x2(%r13),%ebx
  xor    %r12d,%r12d
  cmp    $0x1,%r13d
  jbe    L113
L281:
  mov    %ebx,%r8d
  cmp    $0x1,%ebx
  jbe    L136
L306:
  lea    -0x2(%rbx),%edx
  lea    -0x4(%rbx),%r9d
  xor    %esi,%esi
L131:
  mov    %edx,%eax
  mov    %r9d,%ebp
  xor    %r14d,%r14d
  cmp    $0x1,%edx
  jle    L273
L71:
  lea    -0x2(%rbp),%edi
  xor    %r10d,%r10d
  cmp    $0x1,%ebp
  jle    L277
  nopw   0x0(%rax,%rax,1)
L159:
  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    L159
  sub    $0x1,%ebp
  lea    0x1(%r10,%r14,1),%r14d
  xor    %r10d,%r10d
  lea    -0x2(%rbp),%edi
  cmp    $0x1,%ebp
  jg     L159
L277:
  add    %ebp,%r14d
  sub    $0x1,%ebp
  jae    L71
  sub    %r8d,%r14d
  lea    0x3(%r14,%rdx,1),%eax
L273:
  sub    $0x1,%r8d
  add    %eax,%esi
  sub    $0x1,%edx
  sub    $0x1,%r9d
  cmp    $0x1,%r8d
  jne    L131
  sub    $0x1,%ebx
  lea    0x1(%rsi,%r12,1),%r12d
  mov    %ebx,%r8d
  cmp    $0x1,%ebx
  ja     L306
L136:
  add    %ebx,%r12d
  test   %ebx,%ebx
  jne    L265
  sub    $0x1,%r13d
  lea    0x1(%r15,%r12,1),%r15d
  xor    %r12d,%r12d
  lea    -0x2(%r13),%ebx
  cmp    $0x1,%r13d
  ja     L281
L113:
  add    %r13d,%r15d
  test   %r13d,%r13d
  jne    L289
  sub    $0x1,%ecx
  lea    0x1(%r11,%r15,1),%r11d
  xor    %r15d,%r15d
  lea    -0x2(%rcx),%r13d
  cmp    $0x1,%ecx
  ja     L56
L76:
  add    %ecx,%r11d
  test   %ecx,%ecx
  jne    L309
  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     L2
L152:
  add    %r10d,0x10(%rsp)
  test   %r10d,%r10d
  jne    L253
  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    L111
L67:
  add    %r11d,0xc(%rsp)
  test   %r11d,%r11d
  jne    L232
  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    L175
L97:
  add    %r11d,0x8(%rsp)
  test   %r11d,%r11d
  jne    L4
  mov    0x8(%rsp),%eax
  add    $0x1,%eax
L147:
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L265:
  xor    %ebx,%ebx
  jmp    L281
L4:
  xor    %r11d,%r11d
  jmp    L175
L232:
  xor    %r11d,%r11d
  jmp    L111
L253:
  xor    %r10d,%r10d
  jmp    L35
L309:
  xor    %ecx,%ecx
  jmp    L172
L289:
  xor    %r13d,%r13d
  jmp    L56
```

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