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SubjectRe: Winmodem support, some performance tradeoff estimates
Alan Cox wrote:

> Way off. Firstly Im dubious about the 8Mhz, secondly the R4K's tend to
> have DSP instructions (ones that are useful). Pentiums dont have an
> add/multiply with no stall instruction once per clock.

The fastest MAC on Intel Pentiums I've seen is the floating point MAC
code
(single) by Phil Karn, and it achieves one MAC every 3 cycles. And the
code is pretty ugly (which isn't Phil's fault).

When I've tried to use MMX in one of my own projects, I ended up having
fast multiplication but about 20 instructions before and afterwards
to setup/clean up registers.

Tom

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