[Cfp-interest 1906] Re: cr_xxx functions

[Jim Thomas]

> On Jan 19, 2021, at 11:24 PM, Paul Zimmermann <Paul.Zimmermann at inria.fr> wrote:
> 
>       Hi,
> 
> I just checked the reserved names for correctly rounded functions in N2596
> (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2596.pdf) page 392.
> I have a few comments:
> 
> * why is cr_acosh before cr_acos? I would put cr_acos before cr_acosh and cr_acospi.

The ordering was done by the C editor. I’ll pass the question on to the current editor.
> 
> * the cr_sqrt function is missing

Before the prefix was changed from cr to cr_, crsqrt was not included to leave the name available for complex reciprocal square root (7.31.1). Since sqrt is already correctly rounded for all IEC 60559 implementations, that seemed reasonable. Now that the prefix is cr_, we could revisit it.
> 
> * are also missing: cr_cbrt, cr_erf, cr_erfc, cr_j0, cr_lgamma, cr_tgamma
>  (the Bessel functions j0, j1, jn, y0, y1, yn are not in the C standard,
>  thus it makes sense that the cr_xxx variants are not reserved)

These are not IEC 60559 operations, which is why they are not on the list. Of hand, I don’t see any significant downside to adding them.

I’ll put the last two issues on the agenda for the February CFP meeting.

Thanks for checking.

- Jim Thomas

> 
> Best regards,
> Paul
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