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From: Boyd Roberts <boyd@strakt.com>
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To: 9fans@cse.psu.edu
Subject: Re: [9fans] how to avoid a memset() optimization
References: <9f877f9ea3f57d8602e66baf3ce1988a@plan9.bell-labs.com>
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Date: Fri, 15 Nov 2002 13:03:25 +0100
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Dennis Ritchie wrote:

>... The (early) BSD/VAX assembly
>optimizer did have something like this, however, in that it
>avoided certain instructions that wouldn't work in the I/O
>space.
>
>
>
And on the VAX this would probably be a large list.  The 8th
Edition compiler/assembler would output extract field instructions
for some 16 bit operations which broke on UNIBUS device
registers (the tu11 tape driver iirc).