user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<prefix2mask>:
  endbr64
  cmp    $0x20,%edi
  ja     L9
  mov    %edi,%edi
  lea    D253(%rip),%rdx
  movslq (%rdx,%rdi,4),%rax
  add    %rdx,%rax
  notrack jmp *%rax
  lea    D25(%rip),%rax
  ret
  lea    D29(%rip),%rax
  ret
  lea    D139(%rip),%rax
  ret
  lea    D203(%rip),%rax
  ret
  lea    D276(%rip),%rax
  ret
  lea    D179(%rip),%rax
  ret
  lea    D65(%rip),%rax
  ret
  lea    D169(%rip),%rax
  ret
  lea    D213(%rip),%rax
  ret
  lea    D5(%rip),%rax
  ret
  lea    D262(%rip),%rax
  ret
  lea    D150(%rip),%rax
  ret
  lea    D236(%rip),%rax
  ret
  lea    D1(%rip),%rax
  ret
  lea    D268(%rip),%rax
  ret
  lea    D254(%rip),%rax
  ret
  lea    D214(%rip),%rax
  ret
  lea    D125(%rip),%rax
  ret
  lea    D0(%rip),%rax
  ret
  lea    D86(%rip),%rax
  ret
  lea    D285(%rip),%rax
  ret
  lea    D80(%rip),%rax
  ret
  lea    D114(%rip),%rax
  ret
  lea    D58(%rip),%rax
  ret
  lea    D208(%rip),%rax
  ret
  lea    D21(%rip),%rax
  ret
  lea    D38(%rip),%rax
  ret
  lea    D240(%rip),%rax
  ret
  lea    D64(%rip),%rax
  ret
  lea    D3(%rip),%rax
  ret
  lea    D156(%rip),%rax
  ret
  lea    D344(%rip),%rax
  ret
L9:
  lea    D172(%rip),%rax
  ret
  lea    D197(%rip),%rax
  ret
```

tool_calls: name: extract_symbolic_data
arguments: data_label: D25
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D29
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D139
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D203
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D276
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D179
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D65
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D169
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D213
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D5
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D262
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D150
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D236
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D1
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D268
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D254
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D214
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D125
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D0
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D86
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D285
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D80
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D114
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D58
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D208
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D21
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D38
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D240
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D64
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D3
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D156
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D344
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D172
type_guessed: string
name: extract_symbolic_data
arguments: data_label: D197
type_guessed: string

tool: D25: 128.0.0.0

tool: D29: 192.0.0.0

tool: D139: 224.0.0.0

tool: D203: 240.0.0.0

tool: D276: 248.0.0.0

tool: D179: 252.0.0.0

tool: D65: 254.0.0.0

tool: D169: 255.0.0.0

tool: D213: 255.128.0.0

tool: D5: 255.192.0.0

tool: D262: 255.224.0.0

tool: D150: 255.240.0.0

tool: D236: 255.248.0.0

tool: D1: 255.252.0.0

tool: D268: 255.254.0.0

tool: D254: 255.255.0.0

tool: D214: 255.255.128.0

tool: D125: 255.255.192.0

tool: D0: 255.255.224.0

tool: D86: 255.255.240.0

tool: D285: 255.255.248.0

tool: D80: 255.255.252.0

tool: D114: 255.255.254.0

tool: D58: 255.255.255.0

tool: D208: 255.255.255.128

tool: D21: 255.255.255.192

tool: D38: 255.255.255.224

tool: D240: 255.255.255.240

tool: D64: 255.255.255.248

tool: D3: 255.255.255.252

tool: D156: 255.255.255.254

tool: D344: 255.255.255.255

tool: 

tool: D197: 0.0.0.0

assistant: ```c
char *prefix2mask(int idx) {
  char *mask;
  switch (idx) {
  case 0:
    mask = "0.0.0.0";
    break;
  case 1:
    mask = "128.0.0.0";
    break;
  case 2:
    mask = "192.0.0.0";
    break;
  case 3:
    mask = "224.0.0.0";
    break;
  case 4:
    mask = "240.0.0.0";
    break;
  case 5:
    mask = "248.0.0.0";
    break;
  case 6:
    mask = "252.0.0.0";
    break;
  case 7:
    mask = "254.0.0.0";
    break;
  case 8:
    mask = "255.0.0.0";
    break;
  case 9:
    mask = "255.128.0.0";
    break;
  case 10:
    mask = "255.192.0.0";
    break;
  case 11:
    mask = "255.224.0.0";
    break;
  case 12:
    mask = "255.240.0.0";
    break;
  case 13:
    mask = "255.248.0.0";
    break;
  case 14:
    mask = "255.252.0.0";
    break;
  case 15:
    mask = "255.254.0.0";
    break;
  case 16:
    mask = "255.255.0.0";
    break;
  case 17:
    mask = "255.255.128.0";
    break;
  case 18:
    mask = "255.255.192.0";
    break;
  case 19:
    mask = "255.255.224.0";
    break;
  case 20:
    mask = "255.255.240.0";
    break;
  case 21:
    mask = "255.255.248.0";
    break;
  case 22:
    mask = "255.255.252.0";
    break;
  case 23:
    mask = "255.255.254.0";
    break;
  case 24:
    mask = "255.255.255.0";
    break;
  case 25:
    mask = "255.255.255.128";
    break;
  case 26:
    mask = "255.255.255.192";
    break;
  case 27:
    mask = "255.255.255.224";
    break;
  case 28:
    mask = "255.255.255.240";
    break;
  case 29:
    mask = "255.255.255.248";
    break;
  case 30:
    mask = "255.255.255.252";
    break;
  case 31:
    mask = "255.255.255.254";
    break;
  case 32:
    mask = "255.255.255.255";
    break;
  default:
    mask = "";
  }
  return mask;
}
```