>
> Karl-Filip Faxen <[EMAIL PROTECTED]> writes:
>
> > There is a hidden cost to trapping Int overflow ...
> > operations on Ints become unsafe i.e. may raise exceptions
> > This is a problem both for a global
> > instruction scheduler (e.g. a trace scheduler) and for other
> > optimizations based on speculative execution.
>
> Just as a note, the computer architecture folks have designed support
> for speculative execution in the presence of exception-causing
> instructions. The idea, as embodied, for example, in the
> Hewlett-Packard Playdoh architecture ...
Yes, but there is no wide spread comercial architecture supporting any
such scheme. On the other hand, from the preliminary information released
by Intel and HP, it seems that IA-64 (the new Intel/HP architecture to
be implemented in the continuously slipping Merced) will incorporate
something similar. It doesn't help cheap eagerness, though.
Karl-Filip
