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

```asm
<fib>:
  endbr64
  test   %edi,%edi
  je     L490
  mov    %edi,%eax
  cmp    $0x1,%edi
  je     L130
  push   %r15
  sub    $0x2,%eax
  xor    %r10d,%r10d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x58,%rsp
  mov    %eax,0x18(%rsp)
  mov    %r10,0x20(%rsp)
L63:
  mov    0x18(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L263
  cmp    $0x1,%eax
  je     L168
  lea    -0x1(%rdi),%eax
  xor    %r8d,%r8d
  mov    %eax,0x14(%rsp)
  mov    %r8,0x28(%rsp)
L472:
  mov    0x14(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L157
  cmp    $0x1,%eax
  je     L277
  lea    -0x1(%rdi),%eax
  xor    %ecx,%ecx
  mov    %eax,0x1c(%rsp)
  mov    %rcx,0x30(%rsp)
L501:
  mov    0x1c(%rsp),%edi
  mov    %edi,%eax
  add    $0x1,%eax
  je     L481
  cmp    $0x1,%eax
  je     L26
  xor    %ecx,%ecx
  lea    -0x1(%rdi),%r8d
  mov    %rcx,0x38(%rsp)
  mov    %r8d,%ecx
L425:
  mov    %ecx,%eax
  add    $0x1,%eax
  je     L288
  cmp    $0x1,%eax
  je     L456
  xor    %esi,%esi
  mov    %ecx,0x40(%rsp)
  lea    -0x1(%rcx),%r9d
  mov    %rsi,0x8(%rsp)
  mov    %r9d,%r15d
L30:
  mov    %r15d,%eax
  add    $0x1,%eax
  je     L178
  cmp    $0x1,%eax
  je     L370
  lea    -0x1(%r15),%r12d
  xor    %ecx,%ecx
  mov    %r15d,%esi
L118:
  mov    %r12d,%eax
  add    $0x1,%eax
  je     L401
  cmp    $0x1,%eax
  je     L195
  xor    %ebx,%ebx
  lea    -0x1(%r12),%ebp
  mov    %r12d,%edx
  mov    %rbx,%r12
L529:
  mov    %ebp,%eax
  add    $0x1,%eax
  je     L223
  cmp    $0x1,%eax
  je     L92
  mov    %ebp,%eax
  lea    -0x1(%rbp),%ebx
  xor    %r14d,%r14d
  mov    %rcx,%rbp
  mov    %eax,%ecx
L78:
  mov    %ebx,%r13d
  add    $0x1,%r13d
  je     L132
  cmp    $0x1,%r13d
  je     L380
  mov    %ebx,0x44(%rsp)
  xor    %r15d,%r15d
  mov    %esi,%ebx
L183:
  lea    -0x1(%r13),%edi
  mov    %ecx,0x4c(%rsp)
  mov    %edx,0x48(%rsp)
  call   <fib>
  mov    0x48(%rsp),%edx
  mov    0x4c(%rsp),%ecx
  add    %rax,%r15
  sub    $0x2,%r13d
  je     L291
  cmp    $0x1,%r13d
  jne    L183
  mov    %ebx,%esi
  mov    0x44(%rsp),%ebx
  add    $0x1,%r15
L121:
  add    %r15,%r14
  test   %ebx,%ebx
  je     L469
  cmp    $0x1,%ebx
  jne    L132
L380:
  mov    %ecx,%eax
  add    $0x1,%r14
  mov    %rbp,%rcx
  mov    %eax,%ebp
  add    %r14,%r12
  test   %ebp,%ebp
  je     L98
L265:
  cmp    $0x1,%ebp
  jne    L223
L92:
  mov    %r12,%rbx
  mov    %edx,%r12d
  add    $0x1,%rbx
L102:
  add    %rbx,%rcx
  test   %r12d,%r12d
  jne    L499
  mov    %esi,%r15d
  mov    %rcx,%r14
  add    %r14,0x8(%rsp)
  mov    0x8(%rsp),%rsi
  test   %r15d,%r15d
  jne    L274
L137:
  mov    0x40(%rsp),%ecx
  add    %rsi,0x38(%rsp)
  test   %ecx,%ecx
  je     L141
L285:
  cmp    $0x1,%ecx
  je     L456
L288:
  sub    $0x2,%ecx
  jmp    L425
L223:
  sub    $0x2,%ebp
  jmp    L529
L499:
  cmp    $0x1,%r12d
  jne    L401
L195:
  mov    %rcx,%r14
  mov    %esi,%r15d
  add    $0x1,%r14
  add    %r14,0x8(%rsp)
  mov    0x8(%rsp),%rsi
  test   %r15d,%r15d
  je     L137
L274:
  cmp    $0x1,%r15d
  je     L370
L178:
  sub    $0x2,%r15d
  jmp    L30
L401:
  sub    $0x2,%r12d
  jmp    L118
L469:
  mov    %ecx,%eax
  mov    %rbp,%rcx
  add    %r14,%r12
  mov    %eax,%ebp
  test   %ebp,%ebp
  jne    L265
L98:
  mov    %r12,%rbx
  mov    %edx,%r12d
  jmp    L102
  nopl   0x0(%rax)
L291:
  mov    %ebx,%esi
  mov    0x44(%rsp),%ebx
  jmp    L121
L370:
  mov    0x8(%rsp),%rsi
  mov    0x40(%rsp),%ecx
  add    $0x1,%rsi
  add    %rsi,0x38(%rsp)
  test   %ecx,%ecx
  jne    L285
L141:
  mov    0x38(%rsp),%rcx
  add    %rcx,0x30(%rsp)
  mov    0x1c(%rsp),%ecx
  test   %ecx,%ecx
  jne    L82
L484:
  mov    0x14(%rsp),%edx
  mov    0x30(%rsp),%rcx
  add    %rcx,0x28(%rsp)
  test   %edx,%edx
  jne    L19
L477:
  mov    0x28(%rsp),%r8
  jmp    L126
  nopl   0x0(%rax,%rax,1)
L132:
  sub    $0x2,%ebx
  jmp    L78
L456:
  mov    0x38(%rsp),%rcx
  add    $0x1,%rcx
  add    %rcx,0x30(%rsp)
  mov    0x1c(%rsp),%ecx
  test   %ecx,%ecx
  je     L484
L82:
  cmpl   $0x1,0x1c(%rsp)
  je     L26
L481:
  subl   $0x2,0x1c(%rsp)
  jmp    L501
L26:
  mov    0x30(%rsp),%rcx
  mov    0x14(%rsp),%edx
  add    $0x1,%rcx
  add    %rcx,0x28(%rsp)
  test   %edx,%edx
  je     L477
L19:
  cmpl   $0x1,0x14(%rsp)
  je     L277
L157:
  subl   $0x2,0x14(%rsp)
  jmp    L472
L277:
  mov    0x28(%rsp),%r8
  add    $0x1,%r8
L126:
  mov    0x18(%rsp),%eax
  add    %r8,0x20(%rsp)
  test   %eax,%eax
  je     L376
  cmpl   $0x1,0x18(%rsp)
  jne    L263
L168:
  mov    0x20(%rsp),%r10
  add    $0x1,%r10
L347:
  add    $0x58,%rsp
  mov    %r10,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L263:
  subl   $0x2,0x18(%rsp)
  jmp    L63
L490:
  xor    %r10d,%r10d
L93:
  mov    %r10,%rax
  ret
L130:
  mov    $0x1,%r10d
  jmp    L93
L376:
  mov    0x20(%rsp),%r10
  jmp    L347
```

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