From kde-kimageshop Sun Nov 04 12:12:54 2012 From: Boudewijn Rempt Date: Sun, 04 Nov 2012 12:12:54 +0000 To: kde-kimageshop Subject: Re: A small analysis of vector composition results on different architectures Message-Id: X-MARC-Message: https://marc.info/?l=kde-kimageshop&m=135203118403159 MIME-Version: 1 Content-Type: multipart/mixed; boundary="--8323584-969550849-1352031175=:3089" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323584-969550849-1352031175=:3089 Content-Type: TEXT/PLAIN; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT On Sun, 4 Nov 2012, Dmitry Kazakov wrote: > Hi! > > First, thanks everyone who helped me with running the composition benchmark on their machines! Now I have some > important information about what we should do next with these optimizations! > > In the first attached document you can find a table, comparing the results on various architectures. > > Here are conclusions I came to: > > 1) On some architectures, e.g. non-Intel, the usage of Vc may degrade the performance, so Krita should have some > automatic benchmarking capabilities (in settings dialog, for example), which would select the best available > implementation of the composite op. Such benchmark might be executed on the first run of Krita and its result > might be written to a Krita config file. > > 2) Some old processors (Nehalem, Merom) have some problems when one of the pixels (src or dst) have alpha > channel set to 255. I can't explain right now why this happens. Probably, there is some branch misprediction... > The rest of the cases on these CPUs are handled properly. > > So in general, I  think these two problems should be solved and after that the branch can be merged into master. > Very cool work! Boudewijn --8323584-969550849-1352031175=:3089 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ kimageshop mailing list kimageshop@kde.org https://mail.kde.org/mailman/listinfo/kimageshop --8323584-969550849-1352031175=:3089--