Re: Geometry test on NetBSD (was Re: [HACKERS] RC1?)

Tom, can you clarify why -0 is valid. Is it for _small_ near zero
values that are indeed negative?

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Tom Lane wrote:
> Patrick Welche <prlw1(at)newn(dot)cam(dot)ac(dot)uk> writes:
> > On Tue, Nov 19, 2002 at 10:53:59AM -0500, Tom Lane wrote:
> >> Presumably that was put in because it was correct on i86. How do you
> >> feel about changing that entry to
> >> geometry/i.86-.*-netbsd=geometry-positive-zeros
> >> rather than deleting it?
>
> > I was under the impression until now that it was geometry.out for i86 using
> > the libm387 math library, and geometry-positive-zeros for everyone else, but
> > this acorn32 box is also giving geometry.out, so I must be wrong, in fact
> > I've just tried not using libm387 on an i386, and it gives geometry.out
> > too, so we might as well delete it...
>
> Hm. Another possibility is that the existing resultmap entry is correct
> for some prior netbsd version, but is correct no longer.
>
> AFAIK, all modern hardware claims compliance to the IEEE floating-point
> arithmetic standard, so failure to print minus zero as minus zero is
> very likely to be a software issue not hardware. That suggests strongly
> that the issue is netbsd version (specifically libc version) and not the
> hardware platform.
>
> If we knew which netbsd version the behavior changed at, we could put in
> some version-specific resultmap entries. But unless someone can provide
> datapoints on that, I guess we'll just have to update resultmap to match
> recent versions --- ie, take out the entry pointing to
> geometry-positive-zeros.
>
> Any objections out there?
>
> regards, tom lane
>
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