Michael Niedermayer schrieb: > On Wed, Oct 21, 2009 at 12:33:21PM +0200, Thilo Borgmann wrote: >> Michael Niedermayer schrieb: >>> On Tue, Oct 20, 2009 at 03:00:40PM +0200, thilo.borgmann wrote: >>>> Author: thilo.borgmann >>>> Date: Tue Oct 20 15:00:40 2009 >>>> New Revision: 5419 >>>> >>>> Log: >>>> Splits reading of block data and decoding of block data. >>>> Introduces ALSBlockData struct. >>> You are missing the "why" part, that should be explained in the commit >>> message >> Yes, sorry. >> >>> also this needs a benchmark as there are many additional dereferences >>> added >> It is a necessary evil to support MCC. If it would be faster the "old" >> way for non-MCC files, would this reason to have both, a split read & >> decode function pair and an all-in-one function? > > I think a benchmark is usefull to judge if we should spend time thinking > about alternatives to the many dereferences or not >
The combined (old) function: 848450 dezicycles in combined, 1 runs, 0 skips 436625 dezicycles in combined, 2 runs, 0 skips 422562 dezicycles in combined, 4 runs, 0 skips 251822 dezicycles in combined, 8 runs, 0 skips 275631 dezicycles in combined, 16 runs, 0 skips 244726 dezicycles in combined, 32 runs, 0 skips 206217 dezicycles in combined, 64 runs, 0 skips 179422 dezicycles in combined, 119 runs, 9 skips 179422 dezicycles in combined, 119 runs, 137 skips The separate (new) functions: 984100 dezicycles in separate, 1 runs, 0 skips 499555 dezicycles in separate, 2 runs, 0 skips 534420 dezicycles in separate, 4 runs, 0 skips 369905 dezicycles in separate, 8 runs, 0 skips 340817 dezicycles in separate, 16 runs, 0 skips 280026 dezicycles in separate, 32 runs, 0 skips 263883 dezicycles in separate, 64 runs, 0 skips 231872 dezicycles in separate, 119 runs, 9 skips 231872 dezicycles in separate, 119 runs, 137 skips This is a 30% difference which makes me think to try these alternatives. What comes into my mind would be to use local copies, thus dereferencing the field of *bd just twice. One at the top and one at the bottom of the function. Anything else? -Thilo _______________________________________________ FFmpeg-soc mailing list FFmpeg-soc@mplayerhq.hu https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-soc
