On 5 September 2011 04:21, Michael Hope <michael.h...@linaro.org> wrote: > On Fri, Sep 2, 2011 at 4:08 PM, Michael Hope <michael.h...@linaro.org> wrote: >> Hi Dave. I've been hacking away and have checked in a couple of >> benchmarking and plotting scripts to lp:cortex-strings. The current >> results are at: >> http://people.linaro.org/~michaelh/incoming/strings-performance/ >> >> All are done on an A9. The results are very incomplete due to how >> long things take to run. I'll leave ursa3 doing these over the >> weekend which should flesh this out for the other routines. > > Right, that's done. The new graphs are up at: > http://people.linaro.org/~michaelh/incoming/strings-performance/ > > The original data is at: > http://people.linaro.org/~michaelh/incoming/strings-performance/epic.txt > > Here's the relative performance for all routines with eight byte > aligned data and 128 byte blocks: > http://people.linaro.org/~michaelh/incoming/strings-performance/top-000128.png > > memchr, memcpy, strcpy, and strlen all look good at this block size.
Good. > Here's the speed versus block size for eight byte aligned data: > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-memchr-08.png Nice; odd dip between 8 and 16 chars - I don't switch to the smarter stuff until 16 bytes. > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-memset-08.png Hmm yes the short ones could be a bit faster - I always tended to use log X scales :-) The really small ones I wouldn't worry too much about, the interesting stuff is 32-512 where I'd have expected it to have got it's act in gear. > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-strchr-08.png > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-strchr-08.png The version of strchr that's in there is the simple-as-possible strchr; it's byte at a time - I also have a version that uses similar code to memchr that goes fast at large sizes but is slower for small matches: See: https://wiki.linaro.org/WorkingGroups/ToolChain/Benchmarks/InitialStrchr?action=AttachFile&do=get&target=panda-01-strchr-git44154ec-strchr-abs.png I'd made the call that performance at smaller strings was probably more important. > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-strcmp-08.png Huh? I haven't written a strcmp - that looks like newlibs? > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-strcpy-08.png Ditto. > http://people.linaro.org/~michaelh/incoming/strings-performance/sizes-strlen-08.png That's very nice - although quite bizarre; even the lower end of the steps are suitably fast so not really anything to worry about; but it would be great to understand where the 1500 cycle difference is going at the large end. Dave _______________________________________________ linaro-toolchain mailing list linaro-toolchain@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-toolchain
