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Re: New approach to annex D of the 754-R proposal.



On 2007-06-15 09:40:12 +0000, Michel Hack wrote:
Looks good.  Some comments:

- tanpi x   ]-infty,infty[ \ { 1/2 + k, k in Z}

I suppose the reason for excluding half-integers is that the sign of
Infinity would be undetermined by the limit argument.  I wonder however
whether the rule used for the sign of x-x could not be used here: +Inf
except when rounding towards -Inf.

I don't think this would be a good idea. Note that one has +0 = -0 (so
that even if the sign of the zero is incorrect, one gets a value that
is equal to the "correct" value), but one does not have +inf = -inf.
So, the zeros and the infinities should not be treated in the same way.

-- 
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.org/>
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Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)

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