Re: Break 2.4 VM in five easy steps

Maciej Zenczykowski
2001-06-11T12:05:08Z

On Fri, 8 Jun 2001, Pavel Machek wrote:

> That modulo is likely slower than dereference.
>
> > + if (count % 256 == 0) {

You are forgetting that this case should be converted to and 255 or a
plain byte reference by any optimizing compiler - and gcc surely is,
on x86 this code can be reduced to around 2 cycles (Pentium: mov, or, jnz,
with preceding code intertwined to cancel stalls and jnz being likely in
the code buffer)...

Maciek