user: 这段汇编代码用C语言表示是什么样的：

```asm
<http1_atol16>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %rbx
  mov    %rdi,-0x20(%rbp)
  mov    %rsi,-0x28(%rbp)
  mov    $0x0,%ebx
  movb   $0x0,-0x15(%rbp)
  movl   $0x0,-0x14(%rbp)
  jmp    L64
L144:
  addq   $0x1,-0x20(%rbp)
  addl   $0x1,-0x14(%rbp)
L64:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x20,%al
  je     L68
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x9,%al
  je     L68
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0xc,%al
  jne    L10
L68:
  cmpl   $0x1f,-0x14(%rbp)
  jle    L144
L10:
  movl   $0x0,-0x10(%rbp)
  jmp    L176
L57:
  mov    -0x20(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x20(%rbp)
  movzbl (%rax),%eax
  cmp    $0x2d,%al
  sete   %al
  movzbl %al,%eax
  xor    %al,-0x15(%rbp)
  addl   $0x1,-0x10(%rbp)
L176:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2d,%al
  je     L183
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2b,%al
  jne    L54
L183:
  cmpl   $0x1f,-0x10(%rbp)
  jle    L57
L54:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x30,%al
  jne    L98
  addq   $0x1,-0x20(%rbp)
L98:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  or     $0x20,%eax
  cmp    $0x78,%al
  jne    L13
  addq   $0x1,-0x20(%rbp)
L13:
  movl   $0x0,-0xc(%rbp)
  jmp    L73
L2:
  addq   $0x1,-0x20(%rbp)
  addl   $0x1,-0xc(%rbp)
L73:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x30,%al
  jne    L168
  cmpl   $0x1f,-0xc(%rbp)
  jle    L2
  jmp    L168
L148:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  jle    L133
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x39,%al
  jg     L133
  shl    $0x4,%rbx
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  sub    $0x30,%eax
  cltq
  or     %rax,%rbx
  jmp    L178
L133:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  or     $0x20,%eax
  cmp    $0x60,%al
  jle    L42
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  or     $0x20,%eax
  cmp    $0x66,%al
  jg     L42
  shl    $0x4,%rbx
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  or     $0x20,%eax
  movsbl %al,%eax
  sub    $0x57,%eax
  cltq
  or     %rax,%rbx
L178:
  addq   $0x1,-0x20(%rbp)
L168:
  movabs $0xf000000000000000,%rax
  and    %rbx,%rax
  test   %rax,%rax
  je     L148
L42:
  cmpb   $0x0,-0x15(%rbp)
  je     L222
  neg    %rbx
L222:
  cmpq   $0x0,-0x28(%rbp)
  je     L34
  mov    -0x28(%rbp),%rax
  mov    -0x20(%rbp),%rdx
  mov    %rdx,(%rax)
L34:
  mov    %rbx,%rax
  mov    -0x8(%rbp),%rbx
  leave
  ret
```

assistant: ```c
long long http1_atol16(const uint8_t *buf, const uint8_t **end) {
  register unsigned long long i = 0;
  uint8_t inv = 0;
  for (int limit_ = 0; (*buf == ' ' || *buf == '\t' || *buf == '\f') && limit_ < 32; ++limit_)
    ++buf;
  for (int limit_ = 0; (*buf == '-' || *buf == '+') && limit_ < 32; ++limit_)
    inv ^= (*(buf++) == '-');
  if (*buf == '0')
    ++buf;
  if ((*buf | 32) == 'x')
    ++buf;
  for (int limit_ = 0; (*buf == '0') && limit_ < 32; ++limit_)
    ++buf;
  while (!(i & (~((~(0ULL)) >> 4)))) {
    if (*buf >= '0' && *buf <= '9') {
      i <<= 4;
      i |= *buf - '0';
    } else if ((*buf | 32) >= 'a' && (*buf | 32) <= 'f') {
      i <<= 4;
      i |= (*buf | 32) - ('a' - 10);
    } else
      break;
    ++buf;
  }
  if (inv)
    i = 0ULL - i;
  if (end)
    *end = buf;
  return i;
}
```