Public Comment Number PC-UK0147

ISO/IEC CD 9899 (SC22N2620) Public Comment

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Date: 1998-02-25
Author: N.M Maclaren
Author Affiliation: Self
Postal Address:
    University of Cambridge,
    Computer Laboratory,
    New Museums Site,
    Pembroke Street,
    Cambridge CB3 3QG,
    United Kingdom
E-mail Address: <nmm1@cam.ac.uk>
Telephone Number: +44 1223 334761
Fax Number:       +44 1223 334679
Number of individual comments: 1


Comment 1. 

Category: Normative change to existing feature retaining the original intent

Committee Draft subsection: 7.7.11.1

Title: Ambiguity in the copysign function


Detailed description:

What does "treat negative zero consistently" mean?  Does IBM 370 arithmetic
do it?  Does VAX?  Does Intel?  Does IEEE?  I suggest replacing the
sentence "On implementations ... the sign of zero as positive." by

    Unless __STD_IEC_559__ is defined (see Annex F), it is
    implementation-defined whether any representations of zero are regarded
    as negative by this function and, if so, which.