user: 下面的汇编指令对应的C源代码是什么：

```asm
<digest_md5_getsubopt>:
  endbr64
  push   %r15
  push   %r14
  mov    %rdi,%r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    (%rdi),%rdi
  mov    %rdx,0x8(%rsp)
  movzbl (%rdi),%eax
  test   %al,%al
  je     L153
  mov    %rsi,%r13
  mov    %rdi,%rbx
  xor    %edx,%edx
  cmp    $0x2c,%al
  je     L139
  nopl   0x0(%rax)
L113:
  mov    %edx,%esi
  xor    $0x1,%esi
  cmp    $0x22,%al
  cmove  %esi,%edx
  movzbl 0x1(%rbx),%eax
  add    $0x1,%rbx
  test   %al,%al
  je     L114
  cmp    $0x2c,%al
  jne    L113
  test   $0x1,%dl
  jne    L113
L114:
  mov    %ebx,%edx
  sub    %edi,%edx
L139:
  mov    $0x3d,%esi
  call   <memchr@plt>
  mov    0x0(%r13),%rsi
  mov    (%r14),%rdi
  mov    %rax,%r12
  test   %rax,%rax
  cmove  %rbx,%r12
  test   %rsi,%rsi
  je     L229
  xor    %ebp,%ebp
  nopl   (%rax)
L192:
  mov    %r12d,%edx
  mov    %ebp,%r15d
  sub    %edi,%edx
  call   <memcmp@plt>
  mov    (%r14),%rdi
  test   %rax,%rax
  jne    L42
  mov    0x0(%r13,%rbp,8),%rdx
  mov    %r12,%rax
  sub    %rdi,%rax
  cmpb   $0x0,(%rdx,%rax,1)
  je     L247
L42:
  add    $0x1,%rbp
  mov    0x0(%r13,%rbp,8),%rsi
  test   %rsi,%rsi
  jne    L192
L229:
  mov    0x8(%rsp),%rax
  mov    %rdi,(%rax)
  cmpb   $0x0,(%rbx)
  je     L70
  movb   $0x0,(%rbx)
  add    $0x1,%rbx
L70:
  mov    %rbx,(%r14)
  movzbl (%rbx),%eax
  cmp    $0x20,%al
  ja     L153
  movabs $0xfffffffeffffd9ff,%rsi
  bt     %rax,%rsi
  jb     L153
  lea    0x1(%rbx),%rax
  cs nopw 0x0(%rax,%rax,1)
L253:
  mov    %rax,(%r14)
  movzbl (%rax),%edx
  cmp    $0x20,%dl
  ja     L153
  add    $0x1,%rax
  bt     %rdx,%rsi
  jae    L253
  nopl   (%rax)
L153:
  mov    $0xffffffff,%r15d
L180:
  add    $0x18,%rsp
  mov    %r15d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L247:
  cmp    %rbx,%r12
  je     L111
  mov    0x8(%rsp),%rax
  add    $0x1,%r12
  movabs $0x400002400,%rdx
  mov    %r12,(%rax)
  nop
L115:
  movzbl (%r12),%eax
  cmp    $0x20,%al
  je     L206
  cmp    $0x9,%al
  je     L206
  cmp    $0x22,%al
  ja     L72
  bt     %rax,%rdx
  jb     L206
L72:
  cmpb   $0x0,(%rbx)
  mov    %rbx,%rax
  jne    L93
L100:
  movabs $0x400002400,%rsi
  mov    %rax,(%r14)
  lea    -0x1(%rbx),%rax
L134:
  movzbl (%rax),%edx
  cmp    $0x20,%dl
  je     L174
  cmp    $0x9,%dl
  je     L174
  cmp    $0x22,%dl
  ja     L10
  bt     %rdx,%rsi
  jb     L174
L10:
  mov    (%r14),%rax
  movzbl (%rax),%edx
  cmp    $0x20,%dl
  ja     L180
  movabs $0xfffffffeffffd9ff,%rsi
  bt     %rdx,%rsi
  jb     L180
  add    $0x1,%rax
  nop
L288:
  mov    %rax,(%r14)
  movzbl (%rax),%edx
  cmp    $0x20,%dl
  ja     L180
  add    $0x1,%rax
  bt     %rdx,%rsi
  jae    L288
  jmp    L180
  xchg   %ax,%ax
L174:
  sub    $0x1,%rax
  movb   $0x0,0x1(%rax)
  jmp    L134
  nopw   0x0(%rax,%rax,1)
L206:
  mov    0x8(%rsp),%rax
  add    $0x1,%r12
  mov    %r12,(%rax)
  jmp    L115
L93:
  movb   $0x0,(%rbx)
  lea    0x1(%rbx),%rax
  jmp    L100
L111:
  mov    0x8(%rsp),%rax
  movq   $0x0,(%rax)
  jmp    L72
```

assistant: ```c
int digest_md5_getsubopt(char **optionp, const char *const *tokens, char **valuep) {
  char *endp, *vstart;
  int cnt;
  int inside_quote = 0;
  if (**optionp == '\0')
    return -1;
  endp = *optionp;
  while (*endp != '\0' && (inside_quote || (!inside_quote && *endp != ','))) {
    if (*endp == '"')
      inside_quote = !inside_quote;
    endp++;
  }
  vstart = memchr(*optionp, '=', endp - *optionp);
  if (vstart == NULL)
    vstart = endp;
  for (cnt = 0; tokens[cnt] != NULL; ++cnt)
    if (memcmp(*optionp, tokens[cnt], vstart - *optionp) == 0 && tokens[cnt][vstart - *optionp] == '\0') {
      *valuep = vstart != endp ? vstart + 1 : NULL;
      while (*valuep && (**valuep == ' ' || **valuep == '\t' || **valuep == '\r' || **valuep == '\n' || **valuep == '"'))
        (*valuep)++;
      if (*endp != '\0') {
        *endp = '\0';
        *optionp = endp + 1;
      } else
        *optionp = endp;
      endp--;
      while (*endp == ' ' || *endp == '\t' || *endp == '\r' || *endp == '\n' || *endp == '"')
        *endp-- = '\0';
      while (**optionp == ' ' || **optionp == '\t' || **optionp == '\r' || **optionp == '\n')
        (*optionp)++;
      return cnt;
    }
  *valuep = *optionp;
  if (*endp != '\0')
    *endp++ = '\0';
  *optionp = endp;
  while (**optionp == ' ' || **optionp == '\t' || **optionp == '\r' || **optionp == '\n')
    (*optionp)++;
  return -1;
}
```