(j3.2006) J3/09-292 - J3 Fortran interp letter ballot #19 - due19-Oct-2009

[Bill Long]

Added Comment for F03/0039:

There is no HYPOT intrinsic function in Fortran 2003. It is a Fortran 
2008 feature. I think this interp is out of order.  Suggestions for 
changes to HYPOT should be in the form of a J3 paper of a FCD ballot 
comment.

[I retain my NO vote, and suggest the interp should be rejected.]

Cheers,
Bill




Bill Long wrote:
>
> -----------------------------------
> Comments:
> 
> 
> F03/0039:
> ---------
> 
> The text in the IEEE 754-2008 standard says (bottom of page 43):
> 
> "For the hypot function, hypot(?0, ?0) is +0, hypot(??, qNaN) is +?,
> and hypot(qNaN, ??) is +?. "
> 
> If the argument for changing the rules for IEEE_LOGB() in Interp
> F03/0034 is to make the Fortran rules match the IEEE rules, then the
> same argument would seem to apply here.  Yet the changes I see
> proposed do not result in HYPOT returning the IEEE-required results
> when one of the arguments is a NaN and the other is an Infinity.
> 
> If we really want the results to be NaN, then the interp should
> clearly state that the values we require contradict the IEEE rules.
> 

-- 
Bill Long                                   longb at cray.com
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