brk's zero-fill behavior on VAXen

[Garry Wiegand]

In a recent article hope at gatech.UUCP (Theodore Hope) wrote:
>In article <7208 at elsie.UUCP> ado at elsie.UUCP (Arthur David Olson) writes:
>>Can system performance be improved by avoiding zero filling of the new
>>memory?
>
>It can be assumed that on many architectures (such as the Vax) the process
>of zero-filling a block of memory can be done in one or a few instructions.

"One or a few" is not a meaningful criterion. The Vax's MOVC5 instruction
is indeed a single instruction - but it runs at just about the same speed
as an equivalent sequence of CLRL (reg)+ instructions.

garry wiegand   (garry%cadif-oak at cu-arpa.cs.cornell.edu)