hmm, I would think that it would actually be a libc problem not a kernel problem. Since that is where the math is handled I think. I don't see how the kernel can do anything about denormals, other then providing a /proc interface for processor switches.
well, by switching DAZ on, which is a processor flag ...
also, i don't think that it's a big problem with the libc, since the main source for denormal numbers in dsp algorithms are feedback loops, that don't use the libc ...
cheers ... tim