How much better is the performance when using linear interpolation instead of fourth order? -~Chris
On 11/18/2012 11:42 PM, David Henningsson wrote: > On 11/18/2012 07:56 PM, Pedro Lopez-Cabanillas wrote: >> El Domingo, 18 de noviembre de 2012 12:51:58 David Henningsson escribió: >>> I'll do some experiments with it when I have some more time. >> >> My bet is floating point exceptions. > > I tried to verify this theory on my Nexus 7 device. I've tried to > compile with -ffast-math, with according to documentation should > activate flush-to-zero mode, as well as activating it explicitly with > this code: > > asm( > "vmrs r10, FPSCR \n" > "orr r10, r10, #0x01000000 \n" > "vmsr FPSCR, r10 \n" > ); > > ...but this did not give a notable performance difference. > > I also compared double vs single precision floats, and singles were > somewhat faster. > > My test scenario was this command line: > > time fluidsynth -F /tmp/result.wav -z 4096 > /usr/share/sounds/sf2/FluidR3_GM.sf2 ~/Downloads/NIGHTSIN.KAR > > Doubles: 81 seconds > Singles: 65 seconds > ...so about 20% faster. > > I also ran it with perf. Here are the top five results: > > Doubles: > 31.86% 24682 fluid_rvoice_dsp_interpolate_4th_order > 29.41% 22568 fluid_rvoice_buffers_mix > 14.81% 11418 fluid_iir_filter_apply > 9.01% 6952 fluid_revmodel_processmix > 3.31% 2568 fluid_rvoice_write > > Singles: > 34.70% 21826 fluid_rvoice_dsp_interpolate_4th_order > 24.55% 15519 fluid_rvoice_buffers_mix > 15.00% 9506 fluid_iir_filter_apply > 9.21% 5837 fluid_revmodel_processmix > 3.76% 2297 fluid_rvoice_write > > // David > > > _______________________________________________ > fluid-dev mailing list > fluid-dev@nongnu.org > https://lists.nongnu.org/mailman/listinfo/fluid-dev > _______________________________________________ fluid-dev mailing list fluid-dev@nongnu.org https://lists.nongnu.org/mailman/listinfo/fluid-dev
