Comme=
nt # 13
on bug 11124=
1
from Timothy Arceri
(In reply to Dieter N=C3=BCtzel from comment #12)
> (In reply to Pierre-Eric Pelloux-Prayer from comment #11)
> > (In reply to Dieter N=C3=BCtzel from comment #8)
> > > BTW
> > >=20
> > > Pierre-Eric can you look into this
> > >=20
> > > Shadertoy shader corruption, too?
> > > https://ww=
w.shadertoy.com/view/Xt3cWS
> > >
> >=20
> > The "Buffer A" shader doesn't write fragColor when uv.y=
is < 0.1 or > 0.9.
> >=20
> > So the content is undefined and may be black on some platform or =
random.
> >=20
> > radeonsi is correct here, but we might want to replace undef valu=
es with 0x0
> > to get a default value instead of random.
>=20
> Cool to have you around for bug hunting...;-)
>=20
> Any hints where I shoud change 'undef values with 0x0' for testing?
>=20
> And sorry that I 'hijacked' this thread - should I open a new ticket?<=
/span >
I don't think you need to open a bug for it at all. As its not a bug in Mesa
its a shader bug.
Closing this bug report as it should be fixed by:
commit 47cc660d9c19572e5ef2dce7c8ae1766a2ac9885
glsl: replace 'x + (-x)' with constant 0
This fixes a hang in shadertoy for radeonsi where a buffer was initializ=
ed
with:
value -=3D value
with value being undefined.
In this case LLVM replace the operation with an assignment to NaN.
Cc: 19.1 19.2 <mesa-stable@lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.=
cgi?id=3D111241
Reviewed-by: Marek Ol=C5=A1=C3=A1k <marek.olsak@amd.com>