Pentium and Repentium

Kevin Ryde user42 at
Sat Mar 20 22:14:56 CET 2004

Torbjorn Granlund <tg at> writes:
> I'd expect we could get things to run well on this processor with
> some software pipelining.  Our current code relies on out-of-order
> execution, but Prescott's out-of-order capability seems
> insufficient for its over 30 steps deep pipeline.

There's some spare registers in most funcs, but not a lot.

> mpn_lshift      1.87            2.12

The aim there is 1.5 c/l, being 3 mmx insns for each 2 limbs.  I don't
know why it doesn't run at that pace now, in fact.  Probably

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