user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<strtol>:
  endbr64
  push   %r15
  mov    %rdi,%r15
  push   %r14
  push   %r13
  mov    %edx,%r13d
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x28,%rsp
  mov    %rdi,0x18(%rsp)
  mov    %rsi,0x10(%rsp)
  nopw   0x0(%rax,%rax,1)
L107:
  mov    %r15,%rbx
  movsbl (%r15),%r14d
  add    $0x1,%r15
  mov    %r14d,%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L107
  cmp    $0x2d,%r14d
  je     L48
  movl   $0x0,0xc(%rsp)
  cmp    $0x2b,%r14d
  je     L112
L44:
  test   $0xffffffef,%r13d
  jne    L255
  cmp    $0x30,%r14d
  je     L120
  test   %r13d,%r13d
  jne    L255
  mov    0xc(%rsp),%esi
  movq   $0xa,(%rsp)
  mov    $0xa,%r13d
  test   %esi,%esi
  jne    L36
  nopw   0x0(%rax,%rax,1)
L76:
  mov    D38(%rip),%rax
  mov    (%rax),%rax
  jmp    L280
L157:
  test   %r13d,%r13d
  je     L8
  nopl   (%rax)
L255:
  movslq %r13d,%rax
  mov    %rax,(%rsp)
L232:
  mov    0xc(%rsp),%esi
  test   %esi,%esi
  je     L76
L36:
  mov    D26(%rip),%rax
  mov    (%rax),%rax
  neg    %rax
L280:
  xor    %edx,%edx
  xor    %ebx,%ebx
  xor    %r12d,%r12d
  divq   (%rsp)
  mov    %edx,0x8(%rsp)
  mov    %rax,%rbp
  jmp    L69
  nopl   0x0(%rax,%rax,1)
L23:
  cmp    %ecx,%r13d
  jle    L194
L75:
  test   %ebx,%ebx
  js     L286
  cmp    %rbp,%r12
  ja     L286
  jne    L300
  mov    $0xffffffff,%ebx
  cmp    0x8(%rsp),%ecx
  jle    L300
L118:
  movsbl (%r15),%r14d
  add    $0x1,%r15
L69:
  mov    %r14d,%edi
  call   <isdigit@plt>
  lea    -0x30(%r14),%ecx
  test   %rax,%rax
  jne    L23
  mov    %r14d,%edi
  call   <isalpha@plt>
  test   %rax,%rax
  je     L194
  mov    %r14d,%edi
  call   <isupper@plt>
  mov    %r14d,%ecx
  cmp    $0x1,%rax
  sbb    %eax,%eax
  and    $0x20,%eax
  add    $0x37,%eax
  sub    %eax,%ecx
  cmp    %ecx,%r13d
  jg     L75
L194:
  cmp    $0xffffffff,%ebx
  je     L136
  mov    0xc(%rsp),%edx
  mov    %r12,%rax
  neg    %rax
  test   %edx,%edx
  cmovne %rax,%r12
  cmpq   $0x0,0x10(%rsp)
  je     L254
  test   %ebx,%ebx
  jne    L260
L192:
  mov    0x10(%rsp),%rax
  mov    0x18(%rsp),%rsi
  mov    %rsi,(%rax)
L254:
  add    $0x28,%rsp
  mov    %r12,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L286:
  mov    $0xffffffff,%ebx
  jmp    L118
  nopw   0x0(%rax,%rax,1)
L300:
  imul   (%rsp),%r12
  movslq %ecx,%rcx
  mov    $0x1,%ebx
  add    %rcx,%r12
  jmp    L118
  nopl   (%rax)
L112:
  movsbl (%r15),%r14d
  lea    0x2(%rbx),%r15
  jmp    L44
  nopl   (%rax)
L136:
  mov    0xc(%rsp),%ecx
  test   %ecx,%ecx
  jne    L184
  mov    D38(%rip),%rax
  mov    (%rax),%r12
L283:
  mov    D27(%rip),%rax
  cmpq   $0x0,0x10(%rsp)
  mov    (%rax),%edx
  mov    D53(%rip),%rax
  mov    %edx,(%rax)
  je     L254
L260:
  lea    -0x1(%r15),%rax
  mov    %rax,0x18(%rsp)
  jmp    L192
  nopw   0x0(%rax,%rax,1)
L48:
  movsbl (%r15),%r14d
  movl   $0x1,0xc(%rsp)
  lea    0x2(%rbx),%r15
  jmp    L44
  nopl   (%rax)
L184:
  mov    D26(%rip),%rax
  mov    (%rax),%r12
  jmp    L283
  nopl   0x0(%rax)
L120:
  movzbl (%r15),%eax
  and    $0xffffffdf,%eax
  cmp    $0x58,%al
  jne    L157
  movsbl 0x1(%r15),%r14d
  mov    $0x10,%r13d
  add    $0x2,%r15
  movq   $0x10,(%rsp)
  jmp    L232
L8:
  movq   $0x8,(%rsp)
  mov    $0x8,%r13d
  jmp    L232
```

assistant: ```c
long strtol(const char *nptr, char **endptr, int base) {
  const char *s = nptr;
  unsigned long acc;
  int c;
  unsigned long cutoff;
  int neg = 0, any, cutlim;
  do {
    c = *s++;
  } while (isspace(c));
  if (c == '-') {
    neg = 1;
    c = *s++;
  } else if (c == '+')
    c = *s++;
  if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) {
    c = s[1];
    s += 2;
    base = 16;
  }
  if (base == 0)
    base = c == '0' ? 8 : 10;
  cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
  cutlim = cutoff % (unsigned long)base;
  cutoff /= (unsigned long)base;
  for (acc = 0, any = 0;; c = *s++) {
    if (isdigit(c))
      c -= '0';
    else if (isalpha(c))
      c -= isupper(c) ? 'A' - 10 : 'a' - 10;
    else
      break;
    if (c >= base)
      break;
    if ((any < 0) || (acc > cutoff) || ((acc == cutoff) && (c > cutlim)))
      any = -1;
    else {
      any = 1;
      acc *= base;
      acc += c;
    }
  }
  if (any < 0) {
    acc = neg ? LONG_MIN : LONG_MAX;
    errno = ERANGE;
  } else if (neg)
    acc = -acc;
  if (endptr != 0)
    *endptr = any ? (char *)(s - 1) : (char *)nptr;
  return (acc);
}
```