On Fri, 2008-02-01 at 08:14 +0100, Yann Orlarey wrote: > The minimal combination to activate FTZ mode seems to be : > > "-O3 -march=native -mfpmath=sse -ffast-math" > > when you are on a sse capable cpu. Here it works, you don't have > denormals any more :-).
Ardour takes manual control of FTZ and DAZ flags, and also offers DC offsets (adding a very very tiny value to every sample) as ways to control denormals. Our experience (or our users' experience) has been that FTZ is better than DAZ, but that neither reduces denormal effects as much as a DC offset. It is still possible to see denormal-induced performance slowdowns even when FTZ is in effect, although the magnitude is reduced. code can be found in libs/pbd/fpu.cc (its hairy code, inline asm for x86 and x86_64, linux & OS X) --p _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
