user: 下面的汇编指令对应的C源代码是什么：

```asm
<serpent_convert_from_string>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %edi,%r12d
  mov    %rsi,%rdi
  mov    %rsi,0x8(%rsp)
  mov    %rdx,0x10(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x38(%rsp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    %eax,%edx
  lea    0x6(%r12),%eax
  mov    %r12d,%ecx
  add    $0x3,%ecx
  cmovns %ecx,%eax
  sar    $0x2,%eax
  mov    %eax,%r13d
  cmp    %eax,%edx
  jl     L97
L83:
  test   %r12d,%r12d
  js     L22
  lea    0x0(,%r13,4),%eax
  cmp    %r12d,%eax
  jl     L100
  sub    $0x3,%eax
  cmp    %r12d,%eax
  jg     L228
  test   %r13d,%r13d
  jle    L91
  mov    0x8(%rsp),%rdi
  mov    %rdi,%rcx
  lea    -0x1(%r13),%eax
  lea    0x1(%rdi,%rax,1),%rsi
  jmp    L156
L97:
  mov    0x8(%rsp),%rdi
  call   <strlen@plt>
  mov    %eax,%r13d
  jmp    L83
L11:
  add    $0x1,%rcx
  cmp    %rsi,%rcx
  je     L203
L156:
  movzbl (%rcx),%eax
  mov    %eax,%edx
  and    $0xffffffdf,%edx
  sub    $0x41,%edx
  cmp    $0x5,%dl
  jbe    L11
  sub    $0x30,%eax
  cmp    $0x9,%al
  jbe    L11
  mov    $0xffffffff,%ecx
L183:
  mov    0x38(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L119
  mov    %ecx,%eax
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L132:
  lea    0x2e(%rsp),%rbp
  mov    %r13d,%edx
  mov    0x8(%rsp),%rsi
  mov    %rbp,%rdi
  call   <strncpy@plt>
  movslq %r13d,%r13
  movb   $0x0,0x2e(%rsp,%r13,1)
  lea    0x20(%rsp),%rdx
  lea    D7(%rip),%rsi
  mov    %rbp,%rdi
  call   <sscanf@plt>
  movslq %ebx,%rax
  mov    0x20(%rsp),%rdx
  mov    0x10(%rsp),%rsi
  mov    %rdx,(%rsi,%rax,8)
  lea    0x1(%rbx),%ebx
  jmp    L92
L22:
  mov    $0xffffffff,%ecx
  jmp    L183
L100:
  mov    $0xffffffff,%ecx
  jmp    L183
L228:
  mov    $0xffffffff,%ecx
  jmp    L183
L42:
  mov    %ebx,%ecx
  jmp    L183
L203:
  mov    $0x0,%ebx
  cmp    $0x7,%r13d
  jle    L132
L106:
  movslq %r13d,%rax
  mov    0x8(%rsp),%rbx
  lea    -0x8(%rbx,%rax,1),%rbp
  mov    0x10(%rsp),%rdi
  mov    %rdi,%rbx
  lea    -0x8(%r13),%eax
  shr    $0x3,%eax
  mov    %eax,0x1c(%rsp)
  mov    %eax,%eax
  lea    0x8(%rdi,%rax,8),%r15
  lea    D7(%rip),%r14
L63:
  lea    0x20(%rsp),%rdx
  mov    %r14,%rsi
  mov    %rbp,%rdi
  call   <sscanf@plt>
  mov    0x20(%rsp),%rax
  mov    %rax,(%rbx)
  sub    $0x8,%rbp
  add    $0x8,%rbx
  cmp    %r15,%rbx
  jne    L63
  mov    0x1c(%rsp),%edi
  mov    %edi,%eax
  neg    %eax
  lea    -0x8(%r13,%rax,8),%r13d
  add    $0x1,%edi
  mov    %edi,%ebx
  test   %r13d,%r13d
  jg     L132
L92:
  lea    0x3e(%r12),%edx
  add    $0x1f,%r12d
  cmovns %r12d,%edx
  sar    $0x5,%edx
  mov    %edx,%ecx
  cmp    %edx,%ebx
  jge    L42
  movslq %ebx,%rsi
  mov    0x10(%rsp),%rdi
  lea    (%rdi,%rsi,8),%rax
  sub    $0x1,%edx
  sub    %ebx,%edx
  add    %rsi,%rdx
  lea    0x8(%rdi,%rdx,8),%rdx
L110:
  movq   $0x0,(%rax)
  add    $0x8,%rax
  cmp    %rdx,%rax
  jne    L110
  jmp    L183
L91:
  mov    $0x0,%ebx
  cmp    $0x7,%r13d
  jg     L106
  jmp    L92
L119:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: extract_symbolic_data
arguments: label: D7
datatype: string

tool: D7: %08lX

assistant: ```c
int serpent_convert_from_string(int len, char *str, unsigned long *val) {
  int is, iv;
  int slen = (((strlen(str)) < ((len + 3) / 4)) ? (strlen(str)) : ((len + 3) / 4));
  if (len < 0)
    return -1;
  if (len > slen * 4 || len < slen * 4 - 3)
    return -1;
  for (is = 0; is < slen; is++)
    if (((str[is] < '0') || (str[is] > '9')) && ((str[is] < 'A') || (str[is] > 'F')) && ((str[is] < 'a') || (str[is] > 'f')))
      return -1;
  for (is = slen, iv = 0; is >= 8; is -= 8, iv++) {
    unsigned long t;
    sscanf(&str[is - 8], "%08lX", &t);
    val[iv] = t;
  }
  if (is > 0) {
    char tmp[10];
    unsigned long t;
    strncpy(tmp, str, is);
    tmp[is] = 0;
    sscanf(tmp, "%08lX", &t);
    val[iv++] = t;
  }
  for (; iv < (len + 31) / 32; iv++)
    val[iv] = 0;
  return iv;
}
```