Re: MCL 2.0.1

[bill@cambridge.apple.com (Bill St. Clair)]

At  9:20 AM 12/28/93 -0600, Sheldon S. Ball wrote:
>What are the differences between MCL 2.0 & MCL 2.0.1?
>Are there any which might influence performance on a
>Quadra 950 or a IIfx?

"MCL 2.0.1" is "MCL 2.0" + "mcl2.0p1.fasl" + "mcl2.0p2.fasl" +
"faster-make-instance-patch" + "mcl2.0.1p0.fasl" + a couple of patched
kernel resources. To put it another way, MCL 2.0.1 is MCL 2.0p2 plus a
handful of patches to make MCL work correctly on Macintosh models that
were released between April of 1992 and October of 1993.

The only patch I can think of that would influence performance is
"faster-make-instance-patch". It speeds up MAKE-INSTANCE.

Another possible performance change could be due to newly including or
excluding the "ptable" init. "ptable" slows down a 68030 machine (e.g.
the IIfx) because it reduces the page table size so that the MMU misses
its cache more often. There is probably a slight slow-down on a 68040
machine (e.g. the Quadra 950), but since the page tables default to 8K
on a 68040 machine, and ptable reduces them to 4K, I doubt that it will
be noticeable.

When I timed compiling a file on my IIfx, it went about 10% faster
without ptable.