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c++ - Denormalization (OT)

reply Ilya Minkov <midiclub 8ung.at> writes:
Hello Wizards.

I'm sorry for posting such a general question on such a specific 
newsgroup, but i believe here are people who might know how to help.

The usual problem in sound processing using floating-point is 
denormalization. The bad thing is, it usually happens not to one value, 
but to thousands at once. Is there any way to deal with it without a 
huge penalty? It is not necessary to try to treat de-normals carefully, 
it is enough to zero them out. Is there an efficient way to implement 
this? I know there is within SIMD2 (Pentium4), but the code has to stay 
at least Pentium3/Athlon compatible.

Does the program start-up code set the FP control word? Are the FP 
exceptions enabled or disabled?

Thanks in advance,
-i.
May 09 2003
parent "Walter" <walter digitalmars.com> writes:
"Ilya Minkov" <midiclub 8ung.at> wrote in message
news:b9h8uf$187i$1 digitaldaemon.com...
 The usual problem in sound processing using floating-point is
 denormalization. The bad thing is, it usually happens not to one value,
 but to thousands at once. Is there any way to deal with it without a
 huge penalty? It is not necessary to try to treat de-normals carefully,
 it is enough to zero them out. Is there an efficient way to implement
 this? I know there is within SIMD2 (Pentium4), but the code has to stay
 at least Pentium3/Athlon compatible.

The easiest way is to switch to 80 bit reals. That gives you more room before you lose bits to denormalization.
 Does the program start-up code set the FP control word?

Yes.
 Are the FP
 exceptions enabled or disabled?

Disabled.
May 09 2003