user: 下面的汇编指令对应的C源代码是什么:

```asm
<cgi_parse_string>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %rdi,-0x48(%rbp)
  movq   $0x0,-0x18(%rbp)
  movl   $0x1,-0x34(%rbp)
  cmpq   $0x0,-0x48(%rbp)
  jne    L96
  mov    $0x0,%eax
  jmp    L24
L96:
  mov    -0x48(%rbp),%rax
  mov    %rax,-0x28(%rbp)
  jmp    L107
L158:
  addl   $0x1,-0x34(%rbp)
  addq   $0x1,-0x28(%rbp)
L107:
  mov    -0x28(%rbp),%rax
  mov    $0x26,%esi
  mov    %rax,%rdi
  call   <strchr@plt>
  mov    %rax,-0x28(%rbp)
  cmpq   $0x0,-0x28(%rbp)
  jne    L158
  mov    -0x34(%rbp),%eax
  add    %eax,%eax
  add    $0x1,%eax
  mov    $0x8,%esi
  mov    %eax,%edi
  call   <calloc@plt>
  mov    %rax,-0x18(%rbp)
  mov    -0x48(%rbp),%rax
  mov    %rax,-0x28(%rbp)
  movl   $0x0,-0x30(%rbp)
L66:
  movl   $0x0,-0x2c(%rbp)
  mov    -0x28(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x26,%al
  jne    L95
  addq   $0x1,-0x28(%rbp)
L95:
  mov    -0x28(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  jmp    L18
L39:
  addl   $0x1,-0x2c(%rbp)
  addq   $0x1,-0x20(%rbp)
L18:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x3d,%al
  je     L98
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  je     L98
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x26,%al
  jne    L39
L98:
  mov    -0x30(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x18(%rbp),%rax
  lea    (%rdx,%rax,1),%rbx
  mov    -0x2c(%rbp),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,%esi
  mov    %rax,%rdi
  call   <hex_to_asc@plt>
  mov    %rax,(%rbx)
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x26,%al
  jne    L35
  mov    -0x2c(%rbp),%eax
  cltq
  add    %rax,-0x28(%rbp)
  addl   $0x1,-0x30(%rbp)
  jmp    L90
L35:
  mov    -0x2c(%rbp),%eax
  cltq
  add    $0x1,%rax
  add    %rax,-0x28(%rbp)
  mov    -0x28(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  addl   $0x1,-0x30(%rbp)
  movl   $0x0,-0x2c(%rbp)
  jmp    L38
L147:
  addl   $0x1,-0x2c(%rbp)
  addq   $0x1,-0x20(%rbp)
L38:
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x26,%al
  je     L22
  mov    -0x20(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L147
L22:
  mov    -0x30(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x18(%rbp),%rax
  lea    (%rdx,%rax,1),%rbx
  mov    -0x2c(%rbp),%edx
  mov    -0x28(%rbp),%rax
  mov    %edx,%esi
  mov    %rax,%rdi
  call   <hex_to_asc@plt>
  mov    %rax,(%rbx)
  cmpl   $0x0,-0x2c(%rbp)
  jle    L13
  addq   $0x1,-0x28(%rbp)
L13:
  addl   $0x1,-0x30(%rbp)
L90:
  mov    -0x28(%rbp),%rax
  mov    $0x26,%esi
  mov    %rax,%rdi
  call   <strchr@plt>
  mov    %rax,-0x28(%rbp)
  cmpq   $0x0,-0x28(%rbp)
  jne    L66
  mov    -0x18(%rbp),%rax
L24:
  mov    -0x8(%rbp),%rbx
  leave
  ret
```

assistant: ```c
char **cgi_parse_string(const char *str) {
  char **kv = NULL;
  const char *p, *end;
  int num = 1, i;
  int len;
  if (!str)
    return (NULL);
  p = str;
  while ((p = strchr(p, '&')) != NULL) {
    num++;
    p++;
  }
  kv = (char **)calloc((num * 2 + 1), sizeof(char **));
  p = str;
  i = 0;
  do {
    len = 0;
    if (*p == '&') {
      p++;
    }
    end = p;
    while ((*end != '=') && (*end != '\0') && (*end != '&')) {
      len++;
      end++;
    }
    kv[i] = hex_to_asc(p, len);
    if (*end == '&') {
      p += len;
      i++;
      continue;
    }
    p += len + 1;
    end = p;
    i++;
    len = 0;
    while ((*end != '&') && (*end != '\0')) {
      len++;
      end++;
    }
    kv[i] = hex_to_asc(p, len);
    if (len > 0)
      p++;
    i++;
  } while ((p = strchr(p, '&')) != NULL);
  return (kv);
}
```