[ardour-dev] Denormalisation

Ross Vandegrift ross at willow.seitz.com
Tue Apr 27 07:41:31 PDT 2004

On Tue, Apr 27, 2004 at 11:16:58AM +0300, Sampo Savolainen wrote:
> I've a few had problems which seem like denormalisation issues. In case
> someone reading this doesn't know what it is, you should read 
> http://phonophunk.phreakin.com/p4denormal.php . In short, it's got to do
> with processors handling very very very small floating point numbers very
> slowly.

This problem should be easily fixable in software.  According to IEEE
754, denormalizing results in loss of significance and starts a gradual
underflow. (there's a version at:
http://www.cs.berkeley.edu/~wkahan/ieee754status/IEEE754.PDF - I'm
looking at pages 2 and 15)

If you're just going to set a register that sets denormals to zero, why
not do it right and detect underflows?  When an underflow happens, just
stop banging the processor against the wall.

No fancy register required!

Ross Vandegrift
ross at willow.seitz.com

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