Re: [hatari-devel] FPU update

[Thomas Huth <th.huth@xxxxxx>]

Am Wed, 8 Feb 2017 12:40:02 +0000
schrieb Douglas Little <doug694@xxxxxxxxxxxxxx>:

> Hi,
> 
> I'm not sure if there are any remaining problems in 6888x emulation.
> I am
> > thinking about what could be tested, but most things have been
> > tested through Douglas' great test utility and some things have
> > been tested by Toni separately.
> > I think 68040 might be incorrect for some conditions, especially
> > related to nonmaskable overflow and underflow exceptions (inexact
> > bit set, where it shouldn't). But it that makes more sense to test
> > and fix that while adding 68040 arithmetic exception handling.
> > So what is next? We need a SoftFloat routine to convert between
> > extended precision and packed decimal floats! This is commonly
> > used, but quite faulty with native floats. Any ideas?
> >  
> 
> I'll need to get a recent build with new changes brought into Hatari
> soon so I can see all the progress.
> 
> I'm quite interested to see if the HW-backed float support still has
> relevant bugs (other than precision differences which I accept should
> remain). I mean things like (0.5+/-epsilon) rounding up or down in
> different rounding modes, or common condition flags not being set, or
> being set inappropriately - that's the kind of thing that can cause
> breakage.

You could also try to compile with USE_SOFT_LONG_DOUBLE ... maybe that
helps with your precision problems, too?

 Thomas