QEMU cpuid shennanigans

// QEMU vulnerable to disclosing real host values for cpuid, this is bad for security and for breaking reliant code

bool is_64(void)
{
    register int eax asm("eax");
    register int esi asm("esi");
    asm(".intel_syntax noprefix\n"
    "xor eax, eax\n"
    "cpuid\n"
    "mov esi, eax\n"
    "mov eax, 0x80000000\n"
    "cpuid\n");
    return (eax == esi) ? false : true;
}