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 <[email protected]> > An: "Christof Ressi" <[email protected]> > Cc: pd-list <[email protected]>, "Miller Puckette" <[email protected]> > 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 <[email protected]> > 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" <[email protected]> > >> An: [email protected], "Miller Puckette" <[email protected]> > >> 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_______________________________________________ > >> [email protected] mailing list > >> UNSUBSCRIBE and account-management -> > >> https://lists.puredata.info/listinfo/pd-list > >> > > _______________________________________________ > > [email protected] mailing list > > UNSUBSCRIBE and account-management -> > > https://lists.puredata.info/listinfo/pd-list > > > _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
