Fixed point matrix representation considered harmful

Marc Balmer marc at
Thu Mar 20 11:10:59 PDT 2008

Daniel Stone wrote:
> On Thu, Mar 20, 2008 at 06:48:23PM +0100, Joerg Sonnenberger wrote:
>> On Wed, Mar 19, 2008 at 09:55:34AM -0700, Keith Packard wrote:
>>> On Wed, 2008-03-19 at 16:59 +0100, Joerg Sonnenberger wrote:
>>>> OK, so you basically want to specify a 32bit (or whatever) IEEE format
>>>> without all the nasty parts? E.g. subnormals and exception values?
>>> Exception values (NaN, +/-inf) should be invalid, but denorms shouldn't
>>> cause any issues for us.
>> Except that it complicates decoding for non-IEEE platforms. Think VAX.
> Are we actually designing for VAX these days? There aren't many other
> non-IEEE platforms that I know of: even lame embedded/consumer chips are
> pretty much all IEEE now, TTBOMK.

Of course...  The BSDs run happily on Vaxen and a Vax still deserves
a modern operating system and a decent graphics environment.

The world is not all IEEE, as much as it is not Linux/i386 only..;)

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