Subject: Re: bcopy, bzero, copypage, and zeropage
To: Guenther Grau <>
From: Jason Thorpe <>
List: tech-kern
Date: 12/14/1996 08:37:28
On Fri, 13 Dec 1996 04:12:02 +0100 
 Guenther Grau <> wrote:

 > Hmm, if you really want to microoptimize, I guess you'll have to write
 > a version for each cpu we support and use the usual tricks to test for
 > the cpu just once, preferably during boot and after that just use the
 > functions without having to test for the cpu over and over again.

A much better approach is to gave a single function that does the
comparisons only if configured for multiple CPU variants.  If only
configured for one, the comparisons aren't there (they're #ifdef'd).

This eliminates unnecessary code size and overhead from indirect
function calls in the critical path.

Jason R. Thorpe                             
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