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Re: Kahan's Floating Point Test


"Tim Prince" <tprince@computer.org> writes:

> ----- Original Message -----
> From: "Stephen L Moshier" <moshier@mediaone.net>
> To: "Michael Price" <mprice@atl.imco.com>
> Cc: <gcc@gcc.gnu.org>

> One of the necessary modifications to Paranoia to make it work with
> extended width register architectures (which go back at least 20 years
> prior to x86) is to force storage to memory at strategic places.  I don't
> totally understand why Kahan didn't do this, as he was (AFAIK) an advocate
> of such architectures and their incorporation into IEEE standards. As
> Stephen points out, failing to do this, even after setting precision mode,
> will produce inconsistencies in exponent range.  I expect the same would
> happen on some PowerPC architectures. 

Even those (old) PowerPC architectures where all computations are done
in double precision should have single-precision IEEE arithmetic fully
supported in GCC; GCC will add appropriate rounding instructions when
necessary.

-- 
- Geoffrey Keating <geoffk@geoffk.org>


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