Re: Why do some math functions return -0

[Mike McGonagle <mjmogo@...>]

On Mon, Sep 20, 2010 at 9:35 AM, KHMan <keinhong@gmail.com> wrote:
> In libm, the software implementation of floor() seems normal enough. Looking
> at i387 assembly code in libm, the rounding mode is indeed changed, but it
> is restored, pretty standard stuff -- no one in the right mind would have
> left it as changed.
>
> Since there is nothing amiss on Tony Finch's Mac OS version of Lua, I don't
> think Mac OS or FreeBSD developers would have missed such a simple thing.
>
> I guess that the 'something' is likely to be found in additional libraries
> or code that the OP is using, like a heavy maths library that can have its
> floating point modes adjusted and assumes that it is king of its
> environment.

I don't think this could be it, as I don't have anything other than
the base install for 5.1.4 running. I can only assume that this might
stem from how the G4 (an IBM chip) as opposed to the Intel that the
Mac now uses.

Mike

>
> --
> Cheers,
> Kein-Hong Man (esq.)
> Kuala Lumpur, Malaysia
>
>