On Mon, 27 Oct 2003, Jeff Clites wrote:
> On Oct 26, 2003, at 10:39 AM, Melvin Smith wrote:
>
> > I think a compromise would be to do define a interpreter global PMCNull
> > and point (or init) all Px registers to it.
> ...
> > The downside is fast initialization of register blocks. memsetting
> > with NULL (0)
> > will not be possible, but I'd have to actually go check and see if that
> > is really all that common.
>
> If we determine that it makes a difference, we can store away a
> register block filled with our PMCNull, and memcpy (or memmove) from
> that to initialize a block. Should be nearly as fast.
Yup. Going all-NULL bought us a win when we were moving the registers
around on top of frames, since new frames were always NULL--joys of zeroed
allocations from the OS, about the fastest way to get all-zeroed memory.
(Often faster than explicitly zeroing the page out, courtesy of MMU
hardware) We don't do that any more so it's not nearly as much of an
issue.
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
