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encoding of binary qNaN/sNaN

To: stds-754@xxxxxxxx
Subject: encoding of binary qNaN/sNaN
From: Vincent Lefevre <vincent@xxxxxxxxxx>
Date: Thu, 2 Aug 2007 16:17:06 +0200
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It seems that the encoding of qNaN/sNaN is specified for the decimal
formats, but not for the binary ones (so that it makes difficult to
differentiate both forms of binary NaN without special support from
the language). Is there any reason? Is it because IEEE 754-1985
doesn't specify the encoding either, to avoid breaking the
compatibility with existing IEEE-754 implementations?

Sorry if this has been discussed recently (I couldn't follow every
discussion). If someone who knows could update

  http://en.wikipedia.org/wiki/NaN#NaN_encodings

(which is obsolete: Section 6.2.1 is no longer there in Draft 1.4.0),
this would be very useful. Thanks.

-- 
Vincent LefÃ¨vre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.org/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/>
Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)

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