🚀 go-pugleaf

In article <GRUNWALD.89Mar27224353@flute.cs.uiuc.edu> grunwald@flute.cs.uiuc.edu writes:
>In article <46500057@uxe.cso.uiuc.edu> mcdonald@uxe.cso.uiuc.edu writes:
>	....
>
>   Resolved: Layered software functionality is sluggish, and therefore
>   undesirable.
>
>I'd state it as `layered software sacrifices speed for portability, and
>therefore keep CPU architecture employed.'

Actually, layered software doesn't *have* to be sluggish. However, it takes
quite a bit of work to build an efficient layered product. You have
to design an initial version, use it for a while, measure it, redesign
it (possibly moving features between levels), use it for a while,
measure it, etc etc etc.

Measuring should also include making instruction traces across all levels,
especially for the 'most-common-case'. This will often lead you to 
functionality that is cheaper to provide at a different level.

Also, using caching at each level can also give you a layered product
a performance that is only slightly worse than that of a non-layered one.

This method should give you good performance and a maintainable product.
Unfortunately, it will be years in designing..........
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