(j3.2006) (SC22WG5.4177) [ukfortran] Urgent: letter ballot on interps

Malcolm Cohen malcolm
Thu Feb 11 19:41:50 EST 2010

Bill Long wrote:
> N.M. Maclaren wrote:
>> On Feb 10 2010, Bill Long wrote:
>>> Comment for F03/0039 - HYPOT()
>>> Nick's comments about the IEEE nonconformance of the proposed change
>>> might be considered for 13.7.69 "HYPOT (X, Y)" in F08
>>> 09-007r3[353:18-27].  The HYPOT defined in Note 14.7 is not really
>>> claimed to be the official IEEE HYPOT, but rather is a contrivance to
>>> illustrate the setting and getting of IEEE flags.
>> Ah!  That confused me.
>>> would result in a NaN result.  It might also make Fred Tydeman happier
>>> if the Note pointed out that the example is not an implementation of
>>> the IEEE HYPOT function (at least it's not a valid one).  I believe
>>> that Fred (and maybe Nick) would be happy of the name of the function
>>> were something other than HYPOT, to avoid confusion with the IEEE
>>> HYPOT function.
>> It would assuredly be less confusing.
> The potential for confusion is  greater in F08.

No, the potential for confusion is zero in F08.

>  In the context of the F03 standard (against which the interp is formally 
> filed),  one could argue that only "experts" who knew about HYPOT from 
> elsewhere would be confused.  In F08 we actually have an intrinsic function 
> with this name and the same argument list.  The temptation to assume the Note 
> is referring to the same function as the one specified in Clause 13 seems 
> quite high to me.

No, there is no temptation and no possibility for confusion.

That is because the Note in question does not exist in F08.  We deleted it 
specifically because it created more confusion than enlightenment.

................................Malcolm Cohen, Nihon NAG, Tokyo.

More information about the J3 mailing list