user: 这段汇编代码用C语言表示是什么样的?

```asm
<isa>:
  endbr64
  mov    %rdi,%rdx
  mov    %esi,%eax
  test   %rdi,%rdi
  je     L175
  movzbl 0x1(%rdi),%ecx
  test   %cl,%cl
  jne    L123
  mov    %esi,%r8d
  and    $0x1,%r8d
  je     L171
  movzbl (%rdi),%ecx
  sub    $0x2b,%ecx
  and    $0xfd,%ecx
  je     L184
L171:
  test   $0x2,%al
  je     L108
  movzbl (%rdx),%ecx
  cmp    $0x2f,%cl
  ja     L108
  movabs $0xffff7bdfffffffff,%rsi
  mov    $0x1,%r8d
  bt     %rcx,%rsi
  jae    L184
  nopl   0x0(%rax,%rax,1)
L108:
  test   $0x10,%al
  jne    L103
L220:
  and    $0x8,%eax
  mov    %eax,%r8d
  je     L184
  movzbl (%rdx),%esi
  cmp    $0x3c,%sil
  je     L346
L115:
  xor    %r8d,%r8d
  cmp    $0x3e,%sil
  sete   %r8b
  add    %r8d,%r8d
L184:
  mov    %r8d,%eax
  ret
  nopw   0x0(%rax,%rax,1)
L123:
  cmpb   $0x0,0x2(%rdi)
  jne    L220
  test   $0x10,%al
  je     L284
  movzbl (%rdi),%esi
  cmp    $0x7c,%sil
  je     L185
  cmp    $0x3c,%sil
  je     L306
  cmp    $0x3e,%cl
  jne    L284
  mov    $0x1,%r8d
  cmp    $0x3e,%sil
  je     L184
  nopw   0x0(%rax,%rax,1)
L284:
  test   $0x4,%al
  je     L220
  movzbl (%rdx),%esi
  cmp    $0x3d,%sil
  je     L231
  cmp    $0x21,%sil
  jne    L220
  cmp    $0x3d,%cl
  je     L240
  cmp    $0x7e,%cl
  je     L154
L221:
  and    $0x8,%eax
  mov    %eax,%r8d
  jne    L115
  jmp    L184
  nop
L103:
  movzbl (%rdx),%ecx
  lea    -0x28(%rcx),%esi
  lea    -0x21(%rcx),%edi
  cmp    $0x1,%sil
  setbe  %sil
  cmp    $0x1,%dil
  setbe  %dil
  or     %dil,%sil
  jne    L11
  and    $0xffffffdf,%ecx
  cmp    $0x5e,%cl
  jne    L220
L11:
  mov    $0x1,%r8d
  jmp    L184
  nopl   (%rax)
L175:
  shr    $0x4,%eax
  mov    %eax,%r8d
  and    $0x1,%r8d
  mov    %r8d,%eax
  ret
  cs nopw 0x0(%rax,%rax,1)
L306:
  mov    $0x1,%r8d
  cmp    $0x3c,%cl
  jne    L220
  jmp    L184
  nopl   0x0(%rax)
L231:
  mov    $0x1,%r8d
  cmp    $0x3d,%cl
  je     L184
  cmp    $0x7e,%cl
  jne    L221
  mov    $0x7,%r8d
  jmp    L184
  nopl   0x0(%rax,%rax,1)
L185:
  mov    $0x1,%r8d
  cmp    $0x26,%cl
  jne    L220
  jmp    L184
  nopl   0x0(%rax)
L346:
  mov    $0x4,%r8d
  jmp    L184
L240:
  mov    $0x6,%r8d
  jmp    L184
L154:
  mov    $0x8,%r8d
  jmp    L184
```

assistant: ```c
isa(cp, what) register char *cp;
register int what;
{
  if (cp == 0)
    return ((what & 16) != 0);
  if (cp[1] == 0) {
    if (what & 1 && (*cp == '+' || *cp == '-'))
      return (1);
    if (what & 2 && (*cp == '*' || *cp == '/' || *cp == '%'))
      return (1);
    if (what & 16 && (*cp == '(' || *cp == ')' || *cp == '!' || *cp == '~' || *cp == '^' || *cp == '"'))
      return (1);
  } else if (cp[2] == 0) {
    if (what & 16) {
      if (cp[0] == '|' && cp[1] == '&')
        return (1);
      if (cp[0] == '<' && cp[1] == '<')
        return (1);
      if (cp[0] == '>' && cp[1] == '>')
        return (1);
    }
    if (what & 4) {
      if (cp[0] == '=') {
        if (cp[1] == '=')
          return (1);
        if (cp[1] == '~')
          return (7);
      } else if (cp[0] == '!') {
        if (cp[1] == '=')
          return (6);
        if (cp[1] == '~')
          return (8);
      }
    }
  }
  if (what & 8) {
    if (*cp == '<')
      return (4);
    if (*cp == '>')
      return (2);
  }
  return (0);
}
```