The D Programming Language (was: Still more new operators)

Doug Gwyn gwyn at brl-smoke.ARPA
Fri Mar 4 23:14:09 AEST 1988


In article <1988Mar3.182645.703 at utzoo.uucp> henry at utzoo.uucp (Henry Spencer) writes:
>I once had the opportunity to ask Bill Wulf what he thought of bit-oriented
>machines; his answer was "I wish they weren't so damned slow".  I'm afraid
>I haven't seen anything since that invalidates that assessment.  There is
>something to be said for providing bit addressability, but one must realize
>that actually exploiting it will be slow and that there will still be a
>large payoff for trying to work on byte or word boundaries whenever possible.

Bit-addressable architectures need not be slow; you could apply the same line
of reasoning to "prove" that byte-addressability makes a machine too slow,
but of course they aren't necessarily slow.  The main trick to is handle most
operations at a large alignment and revert to bit accesses only when called
for, in which case they will certainly be faster than the corresponding code
on an equivalent non bit-addressable architecture.



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