user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<getop>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x18,%rsp
  nopl   (%rax)
L87:
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,(%rbx)
  mov    %eax,%r12d
  mov    %eax,%ebp
  cmp    $0x9,%eax
  je     L87
  cmp    $0x20,%al
  je     L87
  movb   $0x0,0x1(%rbx)
  cmp    $0x2d,%eax
  jne    L360
  movb   $0x2d,(%rbx)
  xor    %eax,%eax
  xor    %r15d,%r15d
  mov    $0x1,%r13d
  mov    $0x1,%r14d
  call   <getch@plt>
  movsbl %al,%edi
  mov    %eax,%r12d
  mov    %eax,%ebp
  call   <isdigit@plt>
  test   %rax,%rax
  je     L345
L241:
  cmpb   $0x2d,(%rbx,%r15,1)
  jne    L317
  mov    %bpl,(%rbx,%r13,1)
L317:
  lea    0x1(%r14),%ebp
  movslq %ebp,%rbp
  nopl   0x0(%rax)
L51:
  xor    %eax,%eax
  movslq %ebp,%r14
  mov    %rbp,%r13
  call   <getch@plt>
  mov    %al,(%rbx,%rbp,1)
  movsbl %al,%edi
  mov    %eax,%r12d
  add    $0x1,%rbp
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L51
L345:
  add    %rbx,%r13
  cmp    $0x2e,%r12d
  je     L299
L214:
  mov    D2(%rip),%rax
  movb   $0x0,0x0(%r13)
  cmp    %r12d,(%rax)
  jne    L342
  cmpb   $0x2d,(%rbx)
  mov    $0x30,%r12d
  je     L152
L94:
  add    $0x18,%rsp
  mov    %r12d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nop
L152:
  cmpb   $0x1,0x1(%rbx)
  sbb    %r12d,%r12d
  and    $0xfffffffd,%r12d
  add    $0x30,%r12d
  jmp    L94
  nopl   0x0(%rax)
L342:
  mov    %r12d,%edi
  mov    $0x30,%r12d
  call   <ungetch@plt>
  cmpb   $0x2d,(%rbx)
  jne    L94
  jmp    L152
  nopl   (%rax)
L360:
  movsbl %al,%edi
  mov    %edi,0xc(%rsp)
  call   <isdigit@plt>
  mov    0xc(%rsp),%edi
  test   %rax,%rax
  jne    L279
  cmp    $0x64,%r12d
  je     L76
  jle    L74
  cmp    $0x65,%r12d
  je     L230
  cmp    $0x73,%r12d
  jne    L94
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,0x1(%rbx)
  cmp    $0x69,%al
  je     L208
  mov    $0x77,%r12d
  cmp    $0x77,%eax
  je     L94
L225:
  mov    $0x5f,%r12d
  jmp    L94
L74:
  cmp    $0x2e,%r12d
  je     L154
  cmp    $0x63,%r12d
  jne    L94
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,0x1(%rbx)
  cmp    $0x6c,%al
  jne    L225
  jmp    L94
L154:
  mov    $0x2e,%edi
  xor    %r14d,%r14d
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L68
  nopw   0x0(%rax,%rax,1)
L299:
  lea    0x1(%rbx,%r14,1),%rbp
  nopl   (%rax)
L82:
  xor    %eax,%eax
  mov    %rbp,%r13
  add    $0x1,%rbp
  call   <getch@plt>
  mov    %al,-0x1(%rbp)
  movsbl %al,%edi
  mov    %eax,%r12d
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L82
  jmp    L214
  xchg   %ax,%ax
L279:
  xor    %r13d,%r13d
  xor    %r14d,%r14d
  mov    $0xffffffffffffffff,%r15
  call   <isdigit@plt>
  test   %rax,%rax
  je     L345
  jmp    L241
L230:
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,0x1(%rbx)
  cmp    $0x78,%al
  jne    L225
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,0x2(%rbx)
  cmp    $0x70,%al
  jne    L225
  jmp    L94
L68:
  mov    $0x2e,%ebp
  mov    $0xffffffffffffffff,%r15
  xor    %r13d,%r13d
  xor    %r14d,%r14d
  jmp    L241
L208:
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,0x2(%rbx)
  cmp    $0x6e,%al
  jne    L225
  jmp    L94
  nopw   0x0(%rax,%rax,1)
L76:
  xor    %eax,%eax
  call   <getch@plt>
  mov    %al,0x1(%rbx)
  cmp    $0x70,%al
  jne    L225
  jmp    L94
```

assistant: ```c
int getop(char s[]) {
  int i, c;
  while ((s[0] = c = getch()) == ' ' || c == '\t')
    ;
  s[1] = 0;
  if (c != '-' && !isdigit(c) && c != '.') {
    if (c == 's') {
      if ((s[1] = c = getch()) == 'i') {
        if ((s[2] = c = getch()) == 'n')
          return 's';
        else
          return '_';
      } else if (c == 'w')
        return 'w';
      else
        return '_';
    } else if (c == 'd') {
      if ((s[1] = c = getch()) == 'p')
        return 'd';
      else
        return '_';
    } else if (c == 'c') {
      if ((s[1] = c = getch()) == 'l')
        return 'c';
      else
        return '_';
    } else if (c == 'e') {
      if ((s[1] = c = getch()) == 'x') {
        if ((s[2] = c = getch()) == 'p')
          return 'e';
        else
          return '_';
      } else
        return '_';
    } else
      return c;
  }
  i = 0;
  if (c == '-') {
    s[i++] = c;
    c = getch();
  }
  if (isdigit(c)) {
    if (s[i - 1] == '-')
      s[i] = c;
    while (isdigit(s[++i] = c = getch()))
      ;
  }
  if (c == '.') {
    while (isdigit(s[++i] = c = getch()))
      ;
  }
  s[i] = '\0';
  if (c != EOF)
    ungetch(c);
  if (s[0] == '-' && s[1] == '\0')
    return s[0];
  return '0';
}
```