Public Comment Number PC-UK0161

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: F.9.4.3

Title: pow(+-inf,+-0) or pow(NaN,+-0) and IEEE


Detailed description:

Defining pow(+-inf,+-0) and pow(NaN,+-0) to return a finite value and not
raise the invalid exception is mathematically incorrect and incompatible
with robust code.  I suggest changing these cases to do the correct thing:

    pow(+-inf,+-0) returns a NaN and raises the invalid exception.
    pow(NaN,+-0) returns its NaN argument.