user: 请从给定的汇编指令推导出C源代码：

```asm
<ucase_flip>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x48,%rsp
  mov    %rdi,-0x58(%rbp)
  mov    %esi,-0x5c(%rbp)
  mov    %rdx,-0x68(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  cmpl   $0x0,-0x5c(%rbp)
  jne    L24
  mov    -0x58(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,D37(%rip)
L24:
  mov    -0x68(%rbp),%rax
  mov    (%rax),%rax
  mov    %rax,-0x50(%rbp)
  jmp    L75
L58:
  mov    -0x5c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x58(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  cmp    $0x40,%al
  jle    L43
  mov    -0x5c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x58(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  cmp    $0x5a,%al
  jg     L43
  mov    %rsp,%rax
  mov    %rax,%rbx
  mov    D37(%rip),%eax
  add    $0x1,%eax
  movslq %eax,%rdx
  sub    $0x1,%rdx
  mov    %rdx,-0x48(%rbp)
  movslq %eax,%rdx
  mov    %rdx,%r12
  mov    $0x0,%r13d
  movslq %eax,%rdx
  mov    %rdx,%r14
  mov    $0x0,%r15d
  cltq
  mov    $0x10,%edx
  sub    $0x1,%rdx
  add    %rdx,%rax
  mov    $0x10,%esi
  mov    $0x0,%edx
  div    %rsi
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L7:
  cmp    %rdx,%rsp
  je     L97
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L7
L97:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L41
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L41:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x58(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcpy@plt>
  mov    -0x5c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x58(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  add    $0x20,%eax
  mov    %eax,%ecx
  mov    -0x40(%rbp),%rdx
  mov    -0x5c(%rbp),%eax
  cltq
  mov    %cl,(%rdx,%rax,1)
  mov    D37(%rip),%eax
  cmp    %eax,-0x5c(%rbp)
  je     L103
  mov    -0x5c(%rbp),%eax
  lea    0x1(%rax),%ecx
  mov    -0x68(%rbp),%rdx
  mov    -0x58(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <ucase_flip>
  mov    -0x5c(%rbp),%eax
  lea    0x1(%rax),%ecx
  mov    -0x68(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <ucase_flip>
  jmp    L47
L103:
  mov    -0x68(%rbp),%rax
  lea    0x8(%rax),%rdx
  mov    -0x58(%rbp),%rax
  mov    -0x50(%rbp),%rcx
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   *%rcx
  mov    -0x68(%rbp),%rax
  lea    0x8(%rax),%rdx
  mov    -0x40(%rbp),%rax
  mov    -0x50(%rbp),%rcx
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   *%rcx
L47:
  mov    %rbx,%rsp
  jmp    L119
L43:
  addl   $0x1,-0x5c(%rbp)
L75:
  mov    D37(%rip),%eax
  cmp    %eax,-0x5c(%rbp)
  jl     L58
  mov    -0x68(%rbp),%rax
  lea    0x8(%rax),%rdx
  mov    -0x58(%rbp),%rax
  mov    -0x50(%rbp),%rcx
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   *%rcx
L119:
  mov    -0x38(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L84
  call   <__stack_chk_fail@plt>
L84:
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

assistant: ```c
void ucase_flip(char *pass, int cnt, void **nxt_f) {
  static int lpass = 0;
  if (cnt == 0)
    lpass = strlen(pass);
  void (*func)(char *pass, int cnt, void **nxt_f) = *nxt_f;
  for (; cnt < lpass; cnt++) {
    if (pass[cnt] >= 0x41 && pass[cnt] <= 0x5A) {
      char holder[lpass + 1];
      strcpy(holder, pass);
      holder[cnt] = pass[cnt] + 0x20;
      if (cnt != lpass) {
        ucase_flip(pass, cnt + 1, nxt_f);
        ucase_flip(holder, cnt + 1, nxt_f);
      } else {
        func(pass, 0, nxt_f + 1);
        func(holder, 0, nxt_f + 1);
      }
      return;
    }
  }
  func(pass, 0, nxt_f + 1);
}
```