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Article #22563Re: hmmm, BitBlt, New Instructions For RISC
From: Henry Spencer
Date: Fri, 23 Feb 1990 18:17
Date: Fri, 23 Feb 1990 18:17
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In article <7452@pdn.paradyne.com> alan@oz.paradyne.com (Alan Lovejoy) writes: >>>... It only takes roughly 50 cycles (on an 88k) to setup for a blit... >>I'd be interested to know exactly what you include under "setup". Pike's >>numbers showed a much greater disparity the other way, counting *all* >>the overhead. > >Consulting my source code reveals the following: > >Given two pointers to two bitmaps (source and destination) which are structs >describing... Where do you get those two pointers? For character blitting you'll need font lookup and possibly some other bits of overhead, depending on exactly how the stuff is being invoked by higher levels. The relevant measurement of overhead for character blitting is "end to end", including absolutely everything. However, done well, that's probably not going to add a whole lot more. That *is* an impressively fast setup you've got there. -- "The N in NFS stands for Not, | Henry Spencer at U of Toronto Zoology or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry henry@zoo.toronto.edu
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Newsgroups: comp.arch Path: arc1-ca.pugleaf.net!utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: hmmm, BitBlt, New Instructions For RISC Message-ID: <1990Feb23.181713.14334@utzoo.uucp> Organization: U of Toronto Zoology References: <7398@pdn.paradyne.com> <1990Feb18.084034.7015@utzoo.uucp> <7404@pdn.paradyne.com> <1990Feb19.174926.7899@utzoo.uucp> <7452@pdn.paradyne.com> Date: Fri, 23 Feb 90 18:17:13 GMT