user: 下面的汇编指令对应的C源代码是什么:

```asm
<strtol>:
  endbr64
  push   %r13
  push   %r12
  mov    %rsi,%r12
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  sub    $0x8,%rsp
  cmp    $0x1,%edx
  je     L128
  mov    %edx,%r9d
  cmp    $0x24,%edx
  jbe    L312
L128:
  mov    $0xa,%r9d
L312:
  movzbl 0x0(%rbp),%eax
  mov    %rbp,%rdi
  lea    -0x1(%rax),%edx
  cmp    $0x1f,%dl
  ja     L21
  cs nopw 0x0(%rax,%rax,1)
L136:
  movzbl 0x1(%rdi),%eax
  add    $0x1,%rdi
  lea    -0x1(%rax),%edx
  cmp    $0x1f,%dl
  jbe    L136
L21:
  test   %al,%al
  je     L169
  cmp    $0x2d,%al
  je     L291
  xor    %r10d,%r10d
  cmp    $0x2b,%al
  sete   %al
  movzbl %al,%eax
  add    %rax,%rdi
  movzbl 0x1(%rdi),%eax
  cmp    $0x10,%r9d
  je     L43
L51:
  cmp    $0x78,%al
  je     L72
  movzbl (%rdi),%esi
  test   %r9d,%r9d
  jne    L219
L14:
  cmp    $0x30,%sil
  je     L363
  mov    $0x7,%edx
  mov    $0xccccccc,%eax
  mov    $0xa,%r11d
  mov    $0xa,%r9d
L218:
  test   %sil,%sil
  je     L224
L398:
  mov    %rdi,%rbx
  xor    %r13d,%r13d
  xor    %r8d,%r8d
  jmp    L87
  nopl   0x0(%rax)
L239:
  je     L116
L324:
  imul   %r11d,%r8d
  movzbl 0x1(%rbx),%esi
  add    $0x1,%rbx
  add    %ecx,%r8d
  test   %sil,%sil
  je     L107
L87:
  lea    -0x30(%rsi),%ecx
  cmp    $0x9,%cl
  jbe    L349
  lea    -0x41(%rsi),%ecx
  cmp    $0x19,%cl
  ja     L377
  lea    -0x37(%rsi),%ecx
L349:
  movzbl %cl,%ecx
  cmp    %r9d,%ecx
  jge    L107
  cmp    %r8d,%eax
  jae    L239
  mov    $0x1,%r13d
L117:
  movzbl 0x1(%rbx),%esi
  add    $0x1,%rbx
  test   %sil,%sil
  jne    L87
L107:
  cmp    %rbx,%rdi
  je     L181
  test   %r12,%r12
  je     L298
  mov    %rbx,(%r12)
L298:
  lea    0x7fffffff(%r10),%eax
  test   %r13d,%r13d
  jne    L31
  mov    %r8d,%eax
  neg    %eax
  test   %r10d,%r10d
  cmove  %r8d,%eax
L31:
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  xchg   %ax,%ax
L291:
  add    $0x1,%rdi
  mov    $0x1,%r10d
  movzbl 0x1(%rdi),%eax
  cmp    $0x10,%r9d
  jne    L51
L43:
  movzbl (%rdi),%esi
  cmp    $0x30,%sil
  je     L204
L206:
  cmp    $0x78,%al
  je     L72
  mov    $0xf,%edx
  mov    $0x7ffffff,%eax
  mov    $0x10,%r11d
  jmp    L218
  nopw   0x0(%rax,%rax,1)
L377:
  lea    -0x61(%rsi),%ecx
  cmp    $0x19,%cl
  ja     L107
  lea    -0x57(%rsi),%ecx
  jmp    L349
  nopl   0x0(%rax)
L116:
  cmp    %ecx,%edx
  jae    L324
  mov    $0x1,%r13d
  jmp    L117
  nopl   0x0(%rax,%rax,1)
L169:
  test   %r12,%r12
  je     L214
L177:
  mov    %rbp,(%r12)
  add    $0x8,%rsp
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L204:
  cmp    $0x58,%al
  jne    L206
  nopw   0x0(%rax,%rax,1)
L72:
  add    $0x2,%rdi
  movzbl (%rdi),%esi
  test   %r9d,%r9d
  je     L14
L219:
  mov    $0x7fffffff,%eax
  xor    %edx,%edx
  mov    %r9d,%r11d
  div    %r9d
  jmp    L218
  nopw   0x0(%rax,%rax,1)
L214:
  add    $0x8,%rsp
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L224:
  mov    %rdi,%rbx
  nopl   0x0(%rax,%rax,1)
L181:
  test   %r12,%r12
  je     L214
  mov    %rbx,%rax
  sub    %rbp,%rax
  cmp    $0x1,%rax
  jle    L177
  movsbl -0x1(%rbx),%edi
  xor    %eax,%eax
  call   <__tolower@plt>
  cmp    $0x78,%eax
  jne    L177
  cmpb   $0x30,-0x2(%rbx)
  jne    L177
  sub    $0x1,%rbx
  xor    %eax,%eax
  mov    %rbx,(%r12)
  jmp    L31
  nopw   0x0(%rax,%rax,1)
L363:
  movzbl 0x1(%rdi),%eax
  and    $0xffffffdf,%eax
  cmp    $0x58,%al
  jne    L197
  movzbl 0x2(%rdi),%esi
  mov    $0xf,%edx
  add    $0x2,%rdi
  mov    $0x7ffffff,%eax
  mov    $0x10,%r11d
  mov    $0x10,%r9d
  jmp    L218
L197:
  mov    $0x7,%edx
  mov    $0xfffffff,%eax
  mov    $0x30,%esi
  mov    $0x8,%r9d
  mov    $0x8,%r11d
  jmp    L398
```

assistant: ```c
int strtol(nptr, endptr, base) const char *nptr;
char **endptr;
int base;
{
  int negative;
  register unsigned int cutoff;
  register unsigned int cutlim;
  register unsigned int i;
  register const char *s;
  register unsigned char c;
  const char *save, *end;
  int overflow;
  if (base < 0 || base == 1 || base > 36)
    base = 10;
  save = s = nptr;
  while (((unsigned char)*s) <= 32 && *s)
    ++s;
  if (*s == '\0')
    goto noconv;
  if (*s == '-') {
    negative = 1;
    ++s;
  } else if (*s == '+') {
    negative = 0;
    ++s;
  } else
    negative = 0;
  if ((base == 16 && s[0] == '0' && (s[1] == 'X')) || (s[1] == 'x'))
    s += 2;
  if (base == 0) {
    if (*s == '0') {
      if (s[1] == 'X' || s[1] == 'x') {
        s += 2;
        base = 16;
      } else
        base = 8;
    } else
      base = 10;
  }
  save = s;
  end = 0;
  cutoff = 0x7FFFFFFF / (unsigned int)base;
  cutlim = 0x7FFFFFFF % (unsigned int)base;
  overflow = 0;
  i = 0;
  for (c = *s; c != '\0'; c = *++s) {
    if (s == end)
      break;
    if (c >= '0' && c <= '9')
      c -= '0';
    else if (c >= 'A' && c <= 'Z')
      c = c - 'A' + 10;
    else if (c >= 'a' && c <= 'z')
      c = c - 'a' + 10;
    else
      break;
    if (c >= base)
      break;
    if (i > cutoff || (i == cutoff && c > cutlim))
      overflow = 1;
    else {
      i *= (unsigned int)base;
      i += c;
    }
  }
  if (s == save)
    goto noconv;
  if (endptr)
    *endptr = (char *)s;
  if (overflow)
    return negative ? (int)0x80000000 : (int)0x7FFFFFFF;
  return (negative ? -i : i);
noconv:
  if (endptr) {
    if (save - nptr >= 2 && __tolower(save[-1]) == 'x' && save[-2] == '0')
      *endptr = (char *)&save[-1];
    else
      *endptr = (char *)nptr;
  }
  return 0L;
}
```