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

```asm
<fib>:
  endbr64
  push   %r15
  mov    $0x1,%eax
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  movl   $0x0,0x4(%rsp)
  cmp    $0x1,%edi
  jle    L12
  lea    -0x2(%rdi),%r11d
  mov    %r11d,%r10d
L183:
  movl   $0x0,0x8(%rsp)
  lea    -0x2(%r10),%r11d
  cmp    $0x1,%r10d
  jbe    L297
  mov    %r10d,0xc(%rsp)
L172:
  movl   $0x0,(%rsp)
  lea    -0x2(%r11),%ecx
  cmp    $0x1,%r11d
  jbe    L220
L277:
  lea    -0x2(%rcx),%esi
  xor    %r10d,%r10d
  cmp    $0x1,%ecx
  jbe    L214
L82:
  lea    -0x2(%rsi),%r12d
  xor    %r15d,%r15d
  cmp    $0x1,%esi
  jbe    L171
L207:
  lea    -0x2(%r12),%ebp
  xor    %r13d,%r13d
  cmp    $0x1,%r12d
  jbe    L226
L57:
  lea    -0x4(%rbp),%r8d
  xor    %edx,%edx
  cmp    $0x1,%ebp
  jbe    L212
  nop
L133:
  mov    %r8d,%ebx
  xor    %r14d,%r14d
  cmp    $0xfffffffe,%r8d
  jae    L59
L88:
  lea    -0x2(%rbx),%edi
  xor    %r9d,%r9d
  cmp    $0x1,%ebx
  jle    L320
  nopl   0x0(%rax,%rax,1)
L326:
  mov    %r8d,0x2c(%rsp)
  mov    %r11d,0x28(%rsp)
  mov    %esi,0x24(%rsp)
  mov    %ecx,0x20(%rsp)
  mov    %r10d,0x1c(%rsp)
  mov    %r9d,0x18(%rsp)
  mov    %edx,0x14(%rsp)
  mov    %edi,0x10(%rsp)
  call   <fib>
  mov    0x10(%rsp),%edi
  mov    0x18(%rsp),%r9d
  mov    0x14(%rsp),%edx
  mov    0x1c(%rsp),%r10d
  sub    $0x1,%edi
  add    %eax,%r9d
  mov    0x20(%rsp),%ecx
  mov    0x24(%rsp),%esi
  cmp    $0xffffffff,%edi
  mov    0x28(%rsp),%r11d
  mov    0x2c(%rsp),%r8d
  jne    L326
  sub    $0x1,%ebx
  lea    0x1(%r9,%r14,1),%r14d
  xor    %r9d,%r9d
  lea    -0x2(%rbx),%edi
  cmp    $0x1,%ebx
  jg     L326
L320:
  lea    0x1(%r14),%eax
  sub    $0x1,%ebx
  jae    L121
  add    $0x2,%r14d
  sub    $0x1,%r8d
  add    %r14d,%edx
  cmp    $0xfffffffd,%r8d
  jne    L133
  lea    0x1(%rdx,%r13,1),%r13d
  sub    $0x1,%ebp
L260:
  lea    -0x4(%rbp),%r8d
  xor    %edx,%edx
  cmp    $0x1,%ebp
  ja     L133
L212:
  lea    0x1(%r13),%eax
  test   %ebp,%ebp
  jne    L149
  sub    $0x1,%r12d
  lea    0x2(%r13,%r15,1),%r15d
  xor    %r13d,%r13d
  lea    -0x2(%r12),%ebp
  cmp    $0x1,%r12d
  ja     L57
L226:
  lea    0x1(%r15),%eax
  test   %r12d,%r12d
  jne    L11
  sub    $0x1,%esi
  lea    0x2(%r15,%r10,1),%r10d
  xor    %r15d,%r15d
  lea    -0x2(%rsi),%r12d
  cmp    $0x1,%esi
  ja     L207
L171:
  lea    0x1(%r10),%eax
  test   %esi,%esi
  jne    L272
  mov    (%rsp),%eax
  sub    $0x1,%ecx
  lea    -0x2(%rcx),%esi
  lea    0x2(%r10,%rax,1),%eax
  xor    %r10d,%r10d
  mov    %eax,(%rsp)
  cmp    $0x1,%ecx
  ja     L82
L214:
  mov    (%rsp),%eax
  add    $0x1,%eax
  test   %ecx,%ecx
  jne    L184
  mov    0x8(%rsp),%eax
  mov    (%rsp),%edi
  sub    $0x1,%r11d
  lea    0x2(%rax,%rdi,1),%eax
L321:
  mov    %eax,0x8(%rsp)
  jmp    L172
  nop
L59:
  mov    $0x1,%r14d
  sub    $0x1,%r8d
  add    %r14d,%edx
  cmp    $0xfffffffd,%r8d
  jne    L133
  lea    0x1(%rdx,%r13,1),%r13d
  sub    $0x1,%ebp
  jmp    L260
L220:
  mov    0x8(%rsp),%eax
  add    $0x1,%eax
  test   %r11d,%r11d
  jne    L293
  mov    0xc(%rsp),%r10d
  mov    0x4(%rsp),%eax
  mov    0x8(%rsp),%edi
  sub    $0x1,%r10d
  lea    0x2(%rax,%rdi,1),%eax
L31:
  mov    %eax,0x4(%rsp)
  jmp    L183
L297:
  mov    0x4(%rsp),%eax
  add    $0x1,%eax
  test   %r10d,%r10d
  jne    L213
  mov    0x4(%rsp),%eax
  add    $0x2,%eax
L12:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L149:
  mov    %eax,%r13d
  xor    %ebp,%ebp
  jmp    L57
L213:
  xor    %r10d,%r10d
  jmp    L31
L293:
  xor    %r11d,%r11d
  jmp    L321
L184:
  mov    %eax,(%rsp)
  xor    %ecx,%ecx
  jmp    L277
L272:
  mov    %eax,%r10d
  xor    %esi,%esi
  jmp    L82
L11:
  mov    %eax,%r15d
  xor    %r12d,%r12d
  jmp    L207
L121:
  mov    %eax,%r14d
  jmp    L88
```

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