Re: [ros-dev] [ros-diffs] [tkreuzer] 67709: [D3DX9_36/WINED3D] - Remove useless copysignf invocation and the wrong defines for it - BrokenHacksOnTopOfBrokenCode--; - Should be sent upstream

[Thomas Faber]

On 2015-05-14 06:00, tkreuzer(a)svn.reactos.org wrote:
>   -    int sign = (copysignf(1, in) < 0);
>  +    int sign = (in < 0); 

>   -    if (copysignf(1.0f, value) < 0.0f)
>  +    if (value < 0.0f)
>            ++idx; 

I believe the behavior would be different here for negative zero:
copysignf(1.0f, -0.0f) should be < 0.0f
-0.0f should be == 0.0f

Maybe that's the reason for having these calls?

[David Quintana (gigaherz)]

Judging by the involved macro, if -0.0 is not < 0, then the old code
had exactly the same bug.

On 14 May 2015 at 14:50, Thomas Faber &lt;thomas.faber(a)reactos.org&gt; wrote:
>   On 2015-05-14 06:00, tkreuzer(a)svn.reactos.org wrote:
> >  
> >  -    int sign = (copysignf(1, in) < 0);
> >  +    int sign = (in < 0); 
>
>
> >   -    if (copysignf(1.0f, value) < 0.0f)
> >  +    if (value < 0.0f)
> >            ++idx; 
>
>
>  I believe the behavior would be different here for negative zero:
>  copysignf(1.0f, -0.0f) should be < 0.0f
>  -0.0f should be == 0.0f
>
>  Maybe that's the reason for having these calls?
>
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>  Ros-dev(a)reactos.org
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[Thomas Faber]

Yes it did. Except that macro was a ROS-Diff in the first place ;)

On 2015-05-14 11:12, David Quintana (gigaherz) wrote:
>   Judging by the involved macro, if -0.0 is not < 0,
> then the old code
>  had exactly the same bug.
>
>  On 14 May 2015 at 14:50, Thomas Faber &lt;thomas.faber(a)reactos.org&gt; wrote:
> > On 2015-05-14 06:00, tkreuzer(a)svn.reactos.org wrote:
> >>
> >> -    int sign = (copysignf(1, in) < 0);
> >> +    int sign = (in < 0);
> >
> >
> >
> >> -    if (copysignf(1.0f, value) < 0.0f)
> >> +    if (value < 0.0f)
> >>            ++idx;
> >
> >
> >
> > I believe the behavior would be different here for negative zero:
> > copysignf(1.0f, -0.0f) should be < 0.0f
> > -0.0f should be == 0.0f
> >
> > Maybe that's the reason for having these calls?

[Timo Kreuzer]

ok, I'll bring it back after some cleanup.

Am 14.05.2015 um 18:18 schrieb Thomas Faber:
>   Yes it did. Except that macro was a ROS-Diff in the
> first place ;)
>
>  On 2015-05-14 11:12, David Quintana (gigaherz) wrote:
> >   Judging by the involved macro, if -0.0 is not
> > < 0, then the old code
> >  had exactly the same bug.
> >
> >  On 14 May 2015 at 14:50, Thomas Faber &lt;thomas.faber(a)reactos.org&gt; wrote:
> > > On 2015-05-14 06:00, tkreuzer(a)svn.reactos.org wrote:
> > >>
> > >> -    int sign = (copysignf(1, in) < 0);
> > >> +    int sign = (in < 0);
> > >
> > >
> > >
> > >> -    if (copysignf(1.0f, value) < 0.0f)
> > >> +    if (value < 0.0f)
> > >>            ++idx;
> > >
> > >
> > >
> > > I believe the behavior would be different here for negative zero:
> > > copysignf(1.0f, -0.0f) should be < 0.0f
> > > -0.0f should be == 0.0f
> > >
> > > Maybe that's the reason for having these calls? 
>
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