the SSE optimizations don't seem to matter at all. skipping -ffast-math gives a slight overall CPU rise, while skipping -O3 gives me huge CPU rise (20 bob~ filters are already to much for one core). Even when skipping all of those flags, the denormals issue is still not present.
Maybe it has something to do with the compiler? > Gesendet: Mittwoch, 21. September 2016 um 22:47 Uhr > Von: katja <katjavet...@gmail.com> > An: "Christof Ressi" <christof.re...@gmx.at>, "pd-list@lists.iem.at" > <pd-list@lists.iem.at> > Betreff: Re: Re: [PD] [bob~] denormals issue? > > I'm curious to know if the flags do flush denormals on your processor. > Forgot to mention that '-O3 -ffast-math' are also set, > platform-independent. So if you have a chance to try which flag does > something... It's just curiosity. > > On Wed, Sep 21, 2016 at 10:34 PM, Christof Ressi <christof.re...@gmx.at> > wrote: > > Hi Katja, > > > >> Even if your test reveals a beneficial effect from compiler flags, > >> it is better when denormals are detected and flushed in the C code. > > > > definitely! Maybe using the PD_BIGORSMALL macro on each filter state at the > > end of the DSP routine does the trick, just like in all the other recursive > > filters in Pd. > > > > > > > >> Von: katja <katjavet...@gmail.com> > >> An: "Christof Ressi" <christof.re...@gmx.at> > >> Cc: pd-list <pd-l...@iem.at>, "Miller Puckette" <m...@ucsd.edu> > >> Betreff: Re: [PD] [bob~] denormals issue? > >> > >> Hi Christof, > >> > >> Makefile.pdlibbuilder passes flags '-march=pentium4 -msse -msse2 > >> -mfpmath=sse' for optimization to the compiler on Windows. You could > >> try compiling without (some of) these flags to see if they are > >> responsible for the different behavior. Makefile-defined optimization > >> flags can be overriden with argument CFLAGS given on command line. > >> > >> The effect of optimization flags on denormals varies per processor > >> type, unfortunately. When we had denormals on Raspberry Pi ARMv6 they > >> wouldn't go away no matter what flags, is what I remember. Even if > >> your test reveals a beneficial effect from compiler flags, it is > >> better when denormals are detected and flushed in the C code. Anyway, > >> it is still interesting to know what makes the difference. > >> > >> Katja > >> > >> On Wed, Sep 21, 2016 at 12:32 AM, Christof Ressi <christof.re...@gmx.at> > >> wrote: > >> > Hmmm... I compiled [bob~] myself with MinGW and pd-lib-builder and I > >> > noticed two things: > >> > 1) the CPU rise is gone > >> > 2) it needs only half the CPU. I put 20 [bob~] objects in a switched > >> > subpatch and measured the CPU load. The DLL which comes with the Windows > >> > binaries needs 15%, while my own DLL needs only 7%! That's quite a > >> > deal... > >> > > >> > Christof > >> > > >> > PS: I attached the DLL in case you wanna try it yourself. > >> > > >> > > >> >> Gesendet: Samstag, 17. September 2016 um 22:58 Uhr > >> >> Von: "Christof Ressi" <christof.re...@gmx.at> > >> >> An: pd-l...@iem.at, "Miller Puckette" <m...@ucsd.edu> > >> >> Betreff: [PD] [bob~] denormals issue? > >> >> > >> >> Hi Miller, > >> >> > >> >> feeding audio into [bob~] and then going to zero will increase the CPU > >> >> load by ca. 6%. Clearing the filter or adding a tiny amount of noise > >> >> brings the CPU load back to its usual level immediately, so I guess > >> >> it's a problem with denormals. > >> >> My Pd load meter won't really show the increase, but it's clearly > >> >> visibly on Process Explorer. > >> >> > >> >> See my attached patch. Tried with Pd 0.47.1, Lenovo Thinkpad L440, > >> >> Windows 7. > >> >> > >> >> Christof_______________________________________________ > >> >> Pd-list@lists.iem.at mailing list > >> >> UNSUBSCRIBE and account-management -> > >> >> https://lists.puredata.info/listinfo/pd-list > >> >> > >> > _______________________________________________ > >> > Pd-list@lists.iem.at mailing list > >> > UNSUBSCRIBE and account-management -> > >> > https://lists.puredata.info/listinfo/pd-list > >> > > >> > _______________________________________________ Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
