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

```asm
<merge>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %rdi,-0x28(%rbp)
  mov    %rsi,-0x30(%rbp)
  mov    %rdx,-0x38(%rbp)
  mov    %rcx,-0x40(%rbp)
  mov    %r8,-0x48(%rbp)
  mov    -0x38(%rbp),%rax
  sub    -0x28(%rbp),%rax
  mov    %eax,%edx
  mov    -0x40(%rbp),%rax
  add    %edx,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x8(%rbp)
  mov    -0x28(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  mov    -0x30(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x18(%rbp)
  mov    -0x8(%rbp),%rax
  mov    %rax,-0x10(%rbp)
  jmp    L31
L43:
  mov    -0x18(%rbp),%rdx
  mov    -0x20(%rbp),%rax
  mov    -0x48(%rbp),%rcx
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   *%rcx
  cmp    $0xffffffff,%eax
  jne    L87
  mov    -0x40(%rbp),%rax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rcx
  mov    -0x10(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x40(%rbp),%rax
  add    %rax,-0x20(%rbp)
  jmp    L67
L87:
  mov    -0x40(%rbp),%rax
  mov    %eax,%edx
  mov    -0x18(%rbp),%rcx
  mov    -0x10(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x40(%rbp),%rax
  add    %rax,-0x18(%rbp)
L67:
  mov    -0x40(%rbp),%rax
  add    %rax,-0x10(%rbp)
L31:
  mov    -0x30(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  cmp    %rax,-0x20(%rbp)
  je     L44
  mov    -0x38(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  cmp    %rax,-0x18(%rbp)
  jne    L43
  jmp    L44
L60:
  mov    -0x40(%rbp),%rax
  mov    %eax,%edx
  mov    -0x20(%rbp),%rcx
  mov    -0x10(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x40(%rbp),%rax
  add    %rax,-0x10(%rbp)
  mov    -0x40(%rbp),%rax
  add    %rax,-0x20(%rbp)
L44:
  mov    -0x30(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  cmp    %rax,-0x20(%rbp)
  jne    L60
  jmp    L80
L42:
  mov    -0x40(%rbp),%rax
  mov    %eax,%edx
  mov    -0x18(%rbp),%rcx
  mov    -0x10(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x40(%rbp),%rax
  add    %rax,-0x18(%rbp)
  mov    -0x40(%rbp),%rax
  add    %rax,-0x10(%rbp)
L80:
  mov    -0x38(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  cmp    %rax,-0x18(%rbp)
  jne    L42
  mov    -0x38(%rbp),%rax
  sub    -0x28(%rbp),%rax
  mov    %eax,%edx
  mov    -0x40(%rbp),%rax
  add    %edx,%eax
  mov    %eax,%edx
  mov    -0x8(%rbp),%rcx
  mov    -0x28(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x8(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  nop
  leave
  ret
```

assistant: ```c
void merge(void *l, void *q, void *r, size_t size, int (*comp)(void *key1, void *key2)) {
  void *tmp_arr = malloc(r - l + size);
  void *i = l;
  void *j = q + size;
  void *k = tmp_arr;
  while (i != (q + size) && j != (r + size)) {
    if (comp(i, j) == -1) {
      memcpy(k, i, size);
      i += size;
    } else {
      memcpy(k, j, size);
      j += size;
    }
    k += size;
  }
  while (i != (q + size)) {
    memcpy(k, i, size);
    k += size;
    i += size;
  }
  while (j != (r + size)) {
    memcpy(k, j, size);
    j += size;
    k += size;
  }
  memcpy(l, tmp_arr, r - l + size);
  free(tmp_arr);
}
```