> Date: Mon, 18 Feb 2002 15:23:34 -0500 (EST)
> From: Stephen L Moshier <moshier@moshier.net>
> On Mon, 18 Feb 2002, Geoff Keating wrote:
>
> > ... actually, C99 seems to imply that all supported rounding
> > precisions should work for the math library
>
> Could you point out specifically where it says that?
It would have to specifically say that it doesn't, and I can't find
that. For example, in s. 7.12.1 para 4, it says that HUGE_VAL is
a guaranteed result only in the default rounding mode.
Appendix F says, in s. F.9 para 10, "Whether the [elementary]
functions honour the rounding direction mode is
implementation-defined." but this doesn't allow the functions to
produce invalid results, just to ignore the mode and use some other
mode instead. A good math library should honour the current rounding
mode, as this is what is most useful.
--
- Geoffrey Keating <geoffk@geoffk.org> <geoffk@redhat.com>
|