On Thu, 27 Aug 2015 10:59:52 +0100, Pekka Paalanen <[email protected]> wrote:
It would be *really* nice if we could somehow use a benchmark mode where we could run an operation with every possible implementation and compare them. I wonder, can we already do that with PIXMAN_DISABLE?
That would certainly help detect some issues, where we get worse performance at supposedly more advanced implementation levels. Obviously it wouldn't make any sense to bother with certain combinations, such as PIXMAN_DISABLE=arm-neon when testing on an x86. One thing it wouldn't be able to detect, though, would be where the fetch/ combine/writeback iterators are faster than fast paths for the *same* implementation level - such as with the ARMv6 nearest-scaled patches I was revisiting recently. In that specific case, it turned out that my original solution of bespoke C wrappers for the fetchers turned out to be even faster - but we don't have any way at present of detecting if there are other cases where we would be better off deleting the fast paths and letting the iterators do the work instead. Ben _______________________________________________ Pixman mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/pixman
