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

```asm
<fibonacci>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %edi,0x1c(%rsp)
  movl   $0x0,0xc(%rsp)
  cmp    $0x1,%edi
  jle    L152
  mov    %edi,0x4(%rsp)
L149:
  mov    0x4(%rsp),%eax
  movl   $0x0,0x10(%rsp)
  lea    -0x1(%rax),%edi
  mov    %edi,0x8(%rsp)
  cmp    $0x2,%eax
  je     L56
L50:
  mov    0x8(%rsp),%eax
  movl   $0x0,0x14(%rsp)
  lea    -0x1(%rax),%r11d
  cmp    $0x2,%eax
  je     L55
L134:
  movl   $0x0,0x18(%rsp)
  lea    -0x1(%r11),%eax
  cmp    $0x2,%r11d
  je     L36
  mov    %r11d,0x20(%rsp)
  mov    %eax,%r11d
L153:
  lea    -0x1(%r11),%ebp
  xor    %r15d,%r15d
  mov    $0x1,%eax
  cmp    $0x2,%r11d
  je     L163
  mov    %r11d,%r14d
L106:
  lea    -0x1(%rbp),%r12d
  xor    %edx,%edx
  mov    $0x1,%eax
  cmp    $0x2,%ebp
  je     L6
L107:
  cmp    $0x2,%r12d
  je     L160
  lea    -0x3(%r12),%r13d
  lea    -0x6(%r12),%esi
  xor    %ecx,%ecx
  mov    %r13d,%eax
  lea    -0x4(%r12),%r8d
  and    $0xfffffffe,%eax
  sub    %eax,%esi
L233:
  lea    0x2(%r8),%ebx
  xor    %r9d,%r9d
  cmp    $0xffffffff,%r8d
  je     L110
L40:
  lea    -0x1(%rbx),%r11d
  xor    %r10d,%r10d
  mov    $0x1,%eax
  cmp    $0x2,%ebx
  je     L25
L184:
  lea    -0x1(%r11),%edi
  mov    %r8d,0x3c(%rsp)
  mov    %esi,0x38(%rsp)
  mov    %r10d,0x34(%rsp)
  mov    %r9d,0x30(%rsp)
  mov    %ecx,0x2c(%rsp)
  mov    %edx,0x28(%rsp)
  mov    %r11d,0x24(%rsp)
  call   <fibonacci>
  mov    0x24(%rsp),%r11d
  mov    0x34(%rsp),%r10d
  mov    0x28(%rsp),%edx
  mov    0x2c(%rsp),%ecx
  sub    $0x2,%r11d
  add    %eax,%r10d
  mov    0x30(%rsp),%r9d
  mov    0x38(%rsp),%esi
  cmp    $0x1,%r11d
  mov    0x3c(%rsp),%r8d
  jg     L184
  lea    -0x3(%rbx),%eax
  and    $0x1,%eax
L25:
  sub    $0x2,%ebx
  cmp    $0x1,%eax
  sete   %al
  movzbl %al,%eax
  add    %r10d,%eax
  add    %eax,%r9d
  cmp    $0x1,%ebx
  jg     L40
  mov    %r8d,%ebx
  and    $0x1,%ebx
L110:
  xor    %eax,%eax
  cmp    $0x1,%ebx
  sete   %al
  sub    $0x2,%r8d
  add    %r9d,%eax
  add    %eax,%ecx
  cmp    %r8d,%esi
  jne    L233
  and    $0x1,%r13d
L141:
  xor    %eax,%eax
  sub    $0x2,%r12d
  cmp    $0x1,%r13d
  sete   %al
  add    %ecx,%eax
  add    %eax,%edx
  cmp    $0x1,%r12d
  jg     L107
  lea    -0x3(%rbp),%eax
  and    $0x1,%eax
L6:
  sub    $0x2,%ebp
  cmp    $0x1,%eax
  sete   %al
  movzbl %al,%eax
  add    %edx,%eax
  add    %eax,%r15d
  cmp    $0x1,%ebp
  jg     L106
  lea    -0x3(%r14),%eax
  mov    %r14d,%r11d
  and    $0x1,%eax
L163:
  sub    $0x2,%r11d
  cmp    $0x1,%eax
  sete   %al
  movzbl %al,%eax
  add    %r15d,%eax
  add    %eax,0x18(%rsp)
  cmp    $0x1,%r11d
  jg     L153
  mov    0x20(%rsp),%r11d
  lea    -0x3(%r11),%eax
  and    $0x1,%eax
L61:
  sub    $0x2,%r11d
  cmp    $0x1,%eax
  sete   %al
  movzbl %al,%eax
  add    0x18(%rsp),%eax
  add    %eax,0x14(%rsp)
  cmp    $0x1,%r11d
  jg     L134
  mov    0x8(%rsp),%eax
  sub    $0x3,%eax
  and    $0x1,%eax
L37:
  subl   $0x2,0x8(%rsp)
  cmp    $0x1,%eax
  mov    0x8(%rsp),%edi
  sete   %al
  movzbl %al,%eax
  add    0x14(%rsp),%eax
  add    %eax,0x10(%rsp)
  cmp    $0x1,%edi
  jg     L50
  mov    0x4(%rsp),%eax
  sub    $0x3,%eax
  and    $0x1,%eax
L235:
  subl   $0x2,0x4(%rsp)
  cmp    $0x1,%eax
  mov    0x4(%rsp),%edi
  sete   %al
  movzbl %al,%eax
  add    0x10(%rsp),%eax
  add    %eax,0xc(%rsp)
  cmp    $0x1,%edi
  jg     L149
  andl   $0x1,0x1c(%rsp)
L152:
  mov    0x1c(%rsp),%eax
  cmp    $0x1,%eax
  je     L3
L209:
  mov    0xc(%rsp),%eax
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L160:
  xor    %ecx,%ecx
  mov    $0x1,%r13d
  jmp    L141
L36:
  mov    $0x1,%eax
  jmp    L61
L55:
  mov    $0x1,%eax
  jmp    L37
L56:
  mov    $0x1,%eax
  jmp    L235
L3:
  addl   $0x1,0xc(%rsp)
  jmp    L209
```

assistant: ```c
int fibonacci(int ceil) {
  if (1 < ceil)
    return fibonacci(ceil - 1) + fibonacci(ceil - 2);
  else if (1 == ceil)
    return 1;
  else if (0 == ceil)
    return 0;
}
```