user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<fn_cl_33_33_36_36_38_46_48_59_61_61_64_91_95_95_97_122_126_126_160_55295_63744_64975_65008_65519_65533_65533_65536_131069_131072_196605_196608_262141_262144_327677_327680_393213_393216_458749_458752_524285_524288_589821_589824_655357_655360_720893_720896_786429_786432_851965_851968_917501_917504_983037>:
  endbr64
  sub    $0x18,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x8(%rsp)
  xor    %eax,%eax
  lea    0x4(%rsp),%rsi
  movl   $0x0,0x4(%rsp)
  call   <next_utf8@plt>
  cmp    $0x21,%eax
  je     L415
  cmp    $0x2fffd,%eax
  ja     L386
  cmp    $0x1ffff,%eax
  ja     L415
  cmp    $0x7e,%eax
  ja     L162
  cmp    $0x3f,%eax
  ja     L194
  lea    -0x24(%rax),%edx
  cmp    $0x19,%edx
  ja     L334
  movabs $0x2fff7fd000000000,%rdx
  bt     %rax,%rdx
  jae    L334
  nopl   0x0(%rax,%rax,1)
L415:
  mov    0x4(%rsp),%r8d
L280:
  mov    0x8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L28
  mov    %r8d,%eax
  add    $0x18,%rsp
  ret
  nopl   0x0(%rax)
L386:
  cmp    $0x9fffd,%eax
  ja     L14
  cmp    $0x8ffff,%eax
  ja     L415
  cmp    $0x6fffd,%eax
  ja     L347
  cmp    $0x5ffff,%eax
  ja     L415
  cmp    $0x4fffd,%eax
  ja     L181
  cmp    $0x3ffff,%eax
  ja     L415
  sub    $0x30000,%eax
  cmp    $0xfffd,%eax
  jbe    L415
  cs nopw 0x0(%rax,%rax,1)
L334:
  mov    $0xffffffff,%r8d
  jmp    L280
  nopl   0x0(%rax,%rax,1)
L14:
  cmp    $0xcfffd,%eax
  ja     L222
  cmp    $0xbffff,%eax
  ja     L415
  cmp    $0xafffd,%eax
  jbe    L246
  sub    $0xb0000,%eax
  cmp    $0xfffd,%eax
  jbe    L415
  jmp    L334
  nopl   0x0(%rax,%rax,1)
L246:
  cmp    $0x9ffff,%eax
  ja     L415
  mov    $0xffffffff,%r8d
  jmp    L280
  cs nopw 0x0(%rax,%rax,1)
L222:
  cmp    $0xdfffd,%eax
  jbe    L30
  sub    $0xe0000,%eax
  cmp    $0xfffd,%eax
  jbe    L415
  jmp    L334
  nopl   0x0(%rax)
L30:
  cmp    $0xcffff,%eax
  ja     L415
  mov    $0xffffffff,%r8d
  jmp    L280
  cs nopw 0x0(%rax,%rax,1)
L162:
  cmp    $0xffef,%eax
  ja     L109
  cmp    $0xfdef,%eax
  ja     L415
  cmp    $0xd7ff,%eax
  jbe    L155
  sub    $0xf900,%eax
  cmp    $0x4cf,%eax
  jbe    L415
  jmp    L334
  xchg   %ax,%ax
L155:
  cmp    $0x9f,%eax
  ja     L415
  mov    $0xffffffff,%r8d
  jmp    L280
  cs nopw 0x0(%rax,%rax,1)
L109:
  cmp    $0xfffd,%eax
  je     L415
  sub    $0x10000,%eax
  mov    $0xffffffff,%r8d
  cmp    $0xfffd,%eax
  ja     L280
  jmp    L415
  cs nopw 0x0(%rax,%rax,1)
L194:
  movabs $0x47fffffe8fffffff,%rdx
  sub    $0x40,%eax
  bt     %rax,%rdx
  jb     L415
  jmp    L334
  nopl   0x0(%rax)
L181:
  sub    $0x50000,%eax
  cmp    $0xfffd,%eax
  jbe    L415
  jmp    L334
  nopl   (%rax)
L347:
  cmp    $0x7fffd,%eax
  jbe    L387
  sub    $0x80000,%eax
  cmp    $0xfffd,%eax
  jbe    L415
  jmp    L334
  nopl   0x0(%rax)
L387:
  cmp    $0x6ffff,%eax
  ja     L415
  mov    $0xffffffff,%r8d
  jmp    L280
L28:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int fn_cl_33_33_36_36_38_46_48_59_61_61_64_91_95_95_97_122_126_126_160_55295_63744_64975_65008_65519_65533_65533_65536_131069_131072_196605_196608_262141_262144_327677_327680_393213_393216_458749_458752_524285_524288_589821_589824_655357_655360_720893_720896_786429_786432_851965_851968_917501_917504_983037(const char *text) {
  int pos = 0;
  unsigned int c = next_utf8(text, &pos);
  if (c >= 33 && c <= 33)
    return pos;
  if (c >= 36 && c <= 36)
    return pos;
  if (c >= 38 && c <= 46)
    return pos;
  if (c >= 48 && c <= 59)
    return pos;
  if (c >= 61 && c <= 61)
    return pos;
  if (c >= 64 && c <= 91)
    return pos;
  if (c >= 95 && c <= 95)
    return pos;
  if (c >= 97 && c <= 122)
    return pos;
  if (c >= 126 && c <= 126)
    return pos;
  if (c >= 160 && c <= 55295)
    return pos;
  if (c >= 63744 && c <= 64975)
    return pos;
  if (c >= 65008 && c <= 65519)
    return pos;
  if (c >= 65533 && c <= 65533)
    return pos;
  if (c >= 65536 && c <= 131069)
    return pos;
  if (c >= 131072 && c <= 196605)
    return pos;
  if (c >= 196608 && c <= 262141)
    return pos;
  if (c >= 262144 && c <= 327677)
    return pos;
  if (c >= 327680 && c <= 393213)
    return pos;
  if (c >= 393216 && c <= 458749)
    return pos;
  if (c >= 458752 && c <= 524285)
    return pos;
  if (c >= 524288 && c <= 589821)
    return pos;
  if (c >= 589824 && c <= 655357)
    return pos;
  if (c >= 655360 && c <= 720893)
    return pos;
  if (c >= 720896 && c <= 786429)
    return pos;
  if (c >= 786432 && c <= 851965)
    return pos;
  if (c >= 851968 && c <= 917501)
    return pos;
  if (c >= 917504 && c <= 983037)
    return pos;
  return -1;
}
```