OK.. but try the 0.44 build on my site - the one from Raspian is quite old :)
M On Sun, Jan 20, 2013 at 09:28:30PM +0100, katja wrote: > Miller, the vanilla Pd which can be installed from Raspbian with > apt-get or Synaptic does have the subnormals problem, as can be > checked with a test patch attached with my first post. When an input > signal to [lop~] is shut off, CPU load increases substantially. Output > values go down in the order of 1e-44, subnormal range. I was working > on reverb algo's showing the same problem, and compiled with option > -ffastmath / --fast-math to see if that would turn on RunFast mode, > but it didn't. > > I'm not familiar with ARM and it's coprocessors, but from Intel I do > know that gcc doesn't implement certain specified optimization options > (notably SSE versions) unless you also mention a processor type that > can handle it . A similar case could be with Rpi's vfpv2; it can do > RunFast mode but gcc doesn't implement it, until you find a way to > specify vfpv2 (vfpv1 can't do RunFast). Miller, if you succeeded in > getting automatic flush-to-zero on the Pi, it may be related to other > flags which you've set. Arch flags which I've set so far are > -march=armv6 and -mfpu=vfp. Option -mfpu=vfpv2 is not allowed. I would > be happy to do further testing with compiler options, if you know > some. The big-or-small checks are rather expensive for RPi, that's > what I've found. > > Katja > > > On Sun, Jan 20, 2013 at 8:24 PM, Miller Puckette <m...@ucsd.edu> wrote: > > Hi all... > > > > I think it's possible to get flush-to-zero behavior on the Pi (ARMv6) by > > calling gcc with --fast-math. At any rate what I found was that, if I > > compiled without --fast-math, when numbers got small (e.g., when a > > reverberator decays down past 10^-38 or so), the patch would suddenly jump > > in CPI usage as if it were trappnig to the kernel (as it does for i386). > > But when I added --fast-math the problem went away. > > > > On i386 and x86_64, I believe that one can't get flush-to-zero (at least in > > the "normal" non-SSE floating point instructions) so there's no choice but > > to use a macro such as PD_BADFLOAT to protect against that. So in m_pd.h > > the > > PD_BADFLOAT macro is only "turned on" for Intel. > > > > However I've been mistaken many times about all this in the past and won't > > be surprised if I'm mistaken again. > > > > cheers > > Miller > > > > On Sun, Jan 20, 2013 at 11:12:28AM -0500, Hans-Christoph Steiner wrote: > >> > >> I think this is what you want, from 'man gcc'. Its interesting to note > >> that > >> the NEON mode, which provides SIMD, also does not do denormals: > >> > >> -mfpu=name > >> -mfpe=number > >> -mfp=number > >> This specifies what floating point hardware (or hardware emulation) is > >> available on the target. Permissible names are: fpa, fpe2, fpe3, > >> maverick, > >> vfp, vfpv3, vfpv3-fp16, vfpv3-d16, vfpv3-d16-fp16, vfpv3xd, > >> vfpv3xd-fp16, > >> neon, neon-fp16, vfpv4, vfpv4-d16, fpv4-sp-d16 and neon-vfpv4. -mfp > >> and > >> -mfpe are synonyms for -mfpu=fpenumber, for compatibility with older > >> versions of GCC. > >> > >> If -msoft-float is specified this specifies the format of floating > >> point > >> values. > >> > >> If the selected floating-point hardware includes the NEON extension > >> (e.g. > >> -mfpu=neon), note that floating-point operations will not be used by > >> GCC's > >> auto-vectorization pass unless -funsafe-math-optimizations is also > >> specified. This is because NEON hardware does not fully implement the > >> IEEE > >> 754 standard for floating-point arithmetic (in particular denormal > >> values > >> are treated as zero), so the use of NEON instructions may lead to a > >> loss of > >> precision. > >> > >> > >> .hc > >> > >> On 01/20/2013 06:54 AM, katja wrote: > >> > I was assuming, or maybe just hoping? that Raspberry Pi (and ARM > >> > devices in general) would not suffer from Denormal's disease like > >> > Intel processors do. But guess what: Pi's float coprocessor is IEEE > >> > 754 compliant and does all denormals by default (can check with > >> > attached denorm-test.pd). Bummer! As if one would use an ARM device to > >> > calculate the size of a Majorana particle, rather than doing simple > >> > dsp. Do we really need to enable PD-BIGORSMALL() checks for this poor > >> > little processor? There seems to be something called 'RunFast mode' > >> > for Pi's float processor vfpv2, but I see no way how to enable this > >> > via gcc. Option -ffast-math is allowed but doesn't do the trick. Can't > >> > find an option to set vfpv2 specifically, in gcc docs. > >> > > >> > Katja > >> > > >> > > >> > > >> > _______________________________________________ > >> > Pd-list@iem.at mailing list > >> > UNSUBSCRIBE and account-management -> > >> > http://lists.puredata.info/listinfo/pd-list > >> > > >> > >> _______________________________________________ > >> Pd-list@iem.at mailing list > >> UNSUBSCRIBE and account-management -> > >> http://lists.puredata.info/listinfo/pd-list > > > > _______________________________________________ > > Pd-list@iem.at mailing list > > UNSUBSCRIBE and account-management -> > > http://lists.puredata.info/listinfo/pd-list _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list