user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<is_valid_email_address>:
  endbr64
  test   %rdi,%rdi
  je     L374
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x8,%rsp
  movzbl (%rdi),%eax
  test   %al,%al
  je     L343
  mov    %rdi,%rdx
  xor    %ebp,%ebp
  movabs $0xfbffffffffffffde,%rdi
  jmp    L137
  cs nopw 0x0(%rax,%rax,1)
L204:
  movzbl 0x1(%rdx),%eax
  add    $0x1,%rdx
  test   %al,%al
  je     L347
L137:
  lea    -0x21(%rax),%ecx
  cmp    $0x5d,%cl
  lea    -0x22(%rax),%ecx
  seta   %sil
  cmp    $0x3a,%cl
  ja     L298
  mov    %rdi,%r8
  sar    %cl,%r8
  mov    %r8,%rcx
  and    $0x1,%ecx
  xor    $0x1,%ecx
  or     %ecx,%esi
L298:
  test   %sil,%sil
  jne    L343
  cmp    $0x40,%al
  jne    L204
  test   %rbp,%rbp
  jne    L343
  mov    %rdx,%rbp
  movzbl 0x1(%rdx),%eax
  add    $0x1,%rdx
  test   %al,%al
  jne    L137
L347:
  cmp    %rbx,%rbp
  je     L343
  test   %rbp,%rbp
  je     L343
  movzbl 0x1(%rbp),%edi
  test   %dil,%dil
  je     L343
  lea    0x1(%rbp),%r12
  nopw   0x0(%rax,%rax,1)
L99:
  call   <isalnum@plt>
  test   %rax,%rax
  movzbl (%r12),%eax
  jne    L123
  lea    -0x2d(%rax),%edx
  cmp    $0x1,%dl
  jbe    L123
  cmp    $0x5f,%al
  jne    L343
L123:
  cmp    $0x2e,%al
  je     L17
  movzbl 0x1(%r12),%edi
  add    $0x1,%r12
  test   %dil,%dil
  jne    L99
  movabs $0xa000a80000000000,%r13
  mov    %rbx,%r12
  cmp    %rbx,%rbp
  ja     L377
  jmp    L20
  nopl   (%rax)
L138:
  cmp    %r12,%rbx
  je     L343
  movzbl 0x1(%r12),%eax
  cmp    $0x40,%al
  je     L343
  cmp    $0x2e,%al
  je     L343
L276:
  add    $0x1,%r12
  cmp    %r12,%rbp
  je     L20
L377:
  movzbl (%r12),%edi
  cmp    $0x2e,%dil
  je     L138
  call   <isalnum@plt>
  test   %rax,%rax
  jne    L276
  movzbl (%r12),%eax
  mov    %eax,%edx
  and    $0xfffffffd,%edx
  cmp    $0x21,%dl
  je     L276
  cmp    $0x3f,%al
  ja     L346
  cmp    $0x2a,%al
  jbe    L343
  bt     %rax,%r13
  jb     L276
  nopw   0x0(%rax,%rax,1)
L343:
  xor    %eax,%eax
L232:
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
  nopl   (%rax)
L374:
  xor    %eax,%eax
  ret
  nopl   0x0(%rax,%rax,1)
L17:
  cmpb   $0x40,-0x1(%r12)
  je     L343
  movzbl 0x1(%r12),%edi
  cmp    $0x2e,%dil
  je     L343
  test   %dil,%dil
  je     L343
  add    $0x1,%r12
  jmp    L99
L346:
  cmp    $0x5f,%al
  ja     L184
  cmp    $0x5d,%al
  jbe    L343
  jmp    L276
L184:
  cmp    $0x7e,%al
  je     L276
  jmp    L343
L20:
  mov    $0x1,%eax
  jmp    L232
```

assistant: ```c
int is_valid_email_address(const unsigned char *email_address) {
  if (!email_address || !*email_address)
    return 0;
  const unsigned char *p;
  const unsigned char *at_ptr = 0;
  for (p = email_address; *p; ++p) {
    if (*p <= ' ' || *p >= 127 || *p == '\\' || *p == '\'' || *p == '\"')
      return 0;
    if (*p == '@') {
      if (at_ptr)
        return 0;
      at_ptr = p;
    }
  }
  if (!at_ptr)
    return 0;
  if (at_ptr == email_address || !at_ptr[1])
    return 0;
  for (p = at_ptr + 1; *p; ++p) {
    if (!isalnum(*p) && *p != '-' && *p != '_' && *p != '.')
      return 0;
    if (*p == '.' && (p[-1] == '@' || !p[1] || p[1] == '.'))
      return 0;
  }
  for (p = email_address; p < at_ptr; ++p) {
    if (*p == '.') {
      if (p == email_address || p[1] == '@' || p[1] == '.')
        return 0;
    } else if (isalnum(*p)) {
    } else if (*p == '!' || *p == '#' || *p == '+' || *p == '-' || *p == '/' || *p == '=' || *p == '?' || *p == '^' || *p == '_' || *p == '~') {
    } else {
      return 0;
    }
  }
  return 1;
}
```