user: Translate the below assembly code into C programming language:

```asm
<Tcl_Backslash>:
  endbr64
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x10,%rsp
  mov    %rdi,%r12
  mov    %rsi,%rbp
  mov    %fs:0x28,%rax
  mov    %rax,0x8(%rsp)
  xor    %eax,%eax
  movzbl 0x1(%rdi),%ebx
  cmp    $0x78,%bl
  jg     L141
  cmp    $0x60,%bl
  jle    L14
  lea    -0x61(%rbx),%eax
  cmp    $0x17,%al
  ja     L141
  movzbl %al,%eax
  lea    D1(%rip),%rdx
  movslq (%rdx,%rax,4),%rax
  add    %rdx,%rax
  notrack jmp *%rax
L14:
  test   %bl,%bl
  je     L94
  cmp    $0xa,%bl
  jne    L141
  lea    0x1(%rdi),%rax
L214:
  add    $0x1,%rax
  movzbl (%rax),%edx
  cmp    $0x20,%dl
  je     L214
  cmp    $0x9,%dl
  je     L214
  sub    %r12d,%eax
  mov    $0x20,%ebx
  jmp    L5
  mov    $0x2,%eax
  mov    $0x8,%ebx
  jmp    L5
  mov    $0x2,%eax
  mov    $0xc,%ebx
  jmp    L5
  mov    $0x2,%eax
  mov    $0xa,%ebx
  jmp    L5
  mov    $0x2,%eax
  mov    $0xd,%ebx
  jmp    L5
  mov    $0x2,%eax
  mov    $0x9,%ebx
  jmp    L5
  mov    $0x2,%eax
  mov    $0xb,%ebx
  jmp    L5
  movzbl 0x2(%rdi),%edi
  call   <isxdigit@plt>
  mov    %eax,%edx
  mov    $0x2,%eax
  test   %edx,%edx
  je     L5
  mov    %rsp,%rsi
  lea    0x2(%r12),%rdi
  mov    $0x10,%edx
  mov    $0x0,%eax
  call   <strtoul@plt>
  mov    %eax,%ebx
  mov    (%rsp),%eax
  sub    %r12d,%eax
  jmp    L5
L141:
  movzbl %bl,%edx
  sub    $0x30,%edx
  mov    $0x2,%eax
  cmp    $0x9,%edx
  ja     L5
  sub    $0x30,%ebx
  movzbl 0x2(%r12),%edx
  movzbl %dl,%eax
  sub    $0x30,%eax
  cmp    $0x9,%eax
  jbe    L178
  mov    $0x2,%eax
  jmp    L5
L178:
  lea    -0x30(%rdx,%rbx,8),%ebx
  movzbl 0x3(%r12),%edx
  movzbl %dl,%eax
  sub    $0x30,%eax
  cmp    $0x9,%eax
  jbe    L151
  mov    $0x3,%eax
  jmp    L5
L151:
  lea    -0x30(%rdx,%rbx,8),%ebx
  mov    $0x4,%eax
  jmp    L5
L94:
  mov    $0x1,%eax
  mov    $0x5c,%ebx
L5:
  test   %rbp,%rbp
  je     L2
  mov    %eax,0x0(%rbp)
L2:
  mov    0x8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L108
  mov    %ebx,%eax
  add    $0x10,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  ret
  mov    $0x2,%eax
  mov    $0x7,%ebx
  jmp    L5
L108:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
char Tcl_Backslash(src, readPtr) const char *src;
int *readPtr;
{
  const char *p = src + 1;
  char result;
  int count;
  count = 2;
  switch (*p) {
  case 'a':
    result = 0x7;
    break;
  case 'b':
    result = 0x8;
    break;
  case 'f':
    result = 0xc;
    break;
  case 'n':
    result = 0xa;
    break;
  case 'r':
    result = 0xd;
    break;
  case 't':
    result = 0x9;
    break;
  case 'v':
    result = 0xb;
    break;
  case 'x':
    if (isxdigit(((unsigned char)(p[1])))) {
      char *end;
      result = (char)strtoul(p + 1, &end, 16);
      count = end - src;
    } else {
      count = 2;
      result = 'x';
    }
    break;
  case '\n':
    do {
      p++;
    } while ((*p == ' ') || (*p == '\t'));
    result = ' ';
    count = p - src;
    break;
  case 0:
    result = '\\';
    count = 1;
    break;
  default:
    if (isdigit(((unsigned char)(*p)))) {
      result = (char)(*p - '0');
      p++;
      if (!isdigit(((unsigned char)(*p)))) {
        break;
      }
      count = 3;
      result = (char)((result << 3) + (*p - '0'));
      p++;
      if (!isdigit(((unsigned char)(*p)))) {
        break;
      }
      count = 4;
      result = (char)((result << 3) + (*p - '0'));
      break;
    }
    result = *p;
    count = 2;
    break;
  }
  if (readPtr != 0) {
    *readPtr = count;
  }
  return result;
}
```