[Mesa-dev] [PATCH RFC 0/2] nir/lower_tex: Fix progress report when called in a loop

[Boris Brezillon]

On Mon, 17 Jun 2019 10:54:20 -0500
Jason Ekstrand <jason at jlekstrand.net> wrote:

> Why do you need to call it in a loop?

Well, I need to call it at least twice (first pass to lower TEX(RECT)
into TXS(LOD)+TEX(2D) and the second pass to lower TXS(LOD) into
TXS(0)>>LOD) and I thought doing that in a do {} while (progress) loop
would be more future proof (in case things need to be done in more than
2 passes at some point). This being said, I wasn't sure about this
solution, hence the RFC ;-). I'm perfectly fine calling
NIR_PASS(nir_lower_tex) twice if that's what you recommend.

> 
> On Mon, Jun 17, 2019 at 5:21 AM Boris Brezillon <
> boris.brezillon at collabora.com> wrote:  
> 
> > Hello,
> >
> > I've recently been working on adding a new lowering option to the
> > lower_tex() logic and found out that doing
> >
> >         do progress = nir_lower_tex(); while (progress);
> >
> > is not working well (nir_lower_tex() keeps returning true and lowering
> > the same instructions over and over again).
> >
> > The 2 patches in this series seem to fix my issues, but I'm only using
> > txp and rect lowering, and looking at the rest of the code I fear there
> > are other places that could lower things twice of keep reporting that
> > things have progressed even if it's not true (yuv to rgb conversion is
> > of these). So, my question is, are nir_lower_tex() users supposed to
> > clear options flags manually after this pass and limit the number
> > of passes (through some experimenting) or should we try to fix
> > nir_lower_tex()?
> >
> > Regards,
> >
> > Boris
> >
> > Boris Brezillon (2):
> >   nir/lower_tex: Actually report when projector lowering happened
> >   nir/lower_tex: Update ->sampler_dim value before calling
> >     get_texture_size()
> >
> >  src/compiler/nir/nir_lower_tex.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > --
> > 2.20.1
> >
> >