On Thu, Oct 27, 2011 at 9:45 PM, Christian Robottom Reis <k...@linaro.org> wrote: > On Wed, Oct 26, 2011 at 03:54:52PM -0500, Tom Gall wrote: >> Hardware used includes the imx53 QuickStart board by freescale and an >> intel core 2 duo in my Lenovo T400. >> >> The results can be found here including both the raw numbers and pretty >> graphs. >> >> https://wiki.linaro.org/TomGall/LibJpeg8 > > Again, wow, thanks for such a thorough analysis. I think this is indeed > very good material for discusing with Ubuntu. Do we have a session > scheduled with them to talk about this? > > I have a question: any idea why the gap between 8c and turbo8 is so much > more impressive on x86(_64) than on ARM?
Out of curiosity, how much is "much more impressive"? Which case in particular has caught your attention? > Could there be low-hanging fruit left in the NEON codepaths? Yes, currently missing ARM NEON optimizations for chroma upsampling/downsampling and grayscale color conversions definitely affect the tjbench results for subsampled formats and grayscale. Also huffman decoder optimizations (which are C code, not SIMD) in libjpeg-turbo seem to be providing only some barely measurable improvement on ARM, while huffman speedup is clearly more impressive on x86. This gives libjpeg-turbo more points over IJG jpeg on x86 as a result. -- Best regards, Siarhei Siamashka _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
