Re: Pentium memcpy patch. Unintended effect?

Chad Page (cpage@comp3244.resnet.sjsu.edu)
Fri, 7 Feb 1997 12:03:08 -0800 (PST)


On Fri, 7 Feb 1997 aidas@ixsrs4.ix.netcom.com wrote:

>
> I patched and compiled 2.1.25 with the Pentium memcpy patch. Everything
> works fine, except for Quake. Now, Quake runs a fair bit choppier.
>
> I'm not really concerned about Quake. I'm more concerned whether this is
> some kind of defect in my hardware, or simply a side effect of the design
> of Quake. The latter seems more likely.

Quake *heavily* uses the FPU, and from what Ted just said it would
sound like the pentium memcpy patch would affect Quake since the floating
point registers would be swapped every time pentium memcpy is used. This
is also similar to why Carmack won't use MMX instructions in quake :)

- Chad