Re: [Mesa-dev] [PATCH 1/4] i965/fs: Use sample interpolation for interpolateAtCentroid in persample mode
On Wednesday, September 14, 2016 10:45:24 AM PDT Jason Ekstrand wrote: > From the ARB_gpu_shader5 spec: > >The built-in functions interpolateAtCentroid() and interpolateAtSample() >will sample variables as though they were declared with the "centroid" >or "sample" qualifiers, respectively. > > When running with persample dispatch forced by the API, we interpolate > anything that isn't flat as if it's qualified by "sample". In order to > keep interpolateAtCentroid() consistent with the "centroid" qualifier, we > need to make interpolateAtCentroid() do sample interpolation instead. > Nothing in the GLSL spec guarantees that the result of > interpolateAtCentroid is uniform across samples in any way, so this is a > perfectly fine thing to do. > > Fixes 8 of the new dEQP-VK.pipeline.multisample_interpolation.* Vulkan CTS > tests that specifically validate consistency between the "sample" qualifier > and interpolateAtSample() > > Signed-off-by: Jason Ekstrand > --- > src/mesa/drivers/dri/i965/brw_fs.cpp | 26 ++ > 1 file changed, 26 insertions(+) Series is: Reviewed-by: Kenneth Graunke signature.asc Description: This is a digitally signed message part. ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] [PATCH 1/4] i965/fs: Use sample interpolation for interpolateAtCentroid in persample mode
On Wed, Sep 14, 2016 at 1:31 PM, Jason Ekstrand wrote: > > > On Wed, Sep 14, 2016 at 1:29 PM, Anuj Phogat wrote: >> >> On Wed, Sep 14, 2016 at 10:45 AM, Jason Ekstrand >> wrote: >> > From the ARB_gpu_shader5 spec: >> > >> >The built-in functions interpolateAtCentroid() and >> > interpolateAtSample() >> >will sample variables as though they were declared with the >> > "centroid" >> >or "sample" qualifiers, respectively. >> > >> > When running with persample dispatch forced by the API, we interpolate >> > anything that isn't flat as if it's qualified by "sample". In order to >> > keep interpolateAtCentroid() consistent with the "centroid" qualifier, >> > we >> > need to make interpolateAtCentroid() do sample interpolation instead. >> > Nothing in the GLSL spec guarantees that the result of >> > interpolateAtCentroid is uniform across samples in any way, so this is a >> > perfectly fine thing to do. >> > >> This explanation sounds good to me. To be consistent with what >> we do in case of per sample interpolation, shouldn't we do sample >> interpolation in case of InterpolateAtOffset() too? This series >> doesn't seem to include it. > > > No. interpolateAtOffset ask that the input be interpolated at a particular > offset relative to the pixel center. I believe we have to respect that. > Series is: Reviewed-by: Anuj Phogat >> >> > Fixes 8 of the new dEQP-VK.pipeline.multisample_interpolation.* Vulkan >> > CTS >> > tests that specifically validate consistency between the "sample" >> > qualifier >> > and interpolateAtSample() >> > >> > Signed-off-by: Jason Ekstrand >> > --- >> > src/mesa/drivers/dri/i965/brw_fs.cpp | 26 ++ >> > 1 file changed, 26 insertions(+) >> > >> > diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp >> > b/src/mesa/drivers/dri/i965/brw_fs.cpp >> > index 75642d3..9dbb699 100644 >> > --- a/src/mesa/drivers/dri/i965/brw_fs.cpp >> > +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp >> > @@ -6497,6 +6497,32 @@ brw_nir_set_default_interpolation(const struct >> > gen_device_info *devinfo, >> > var->data.sample = false; >> >} >> > } >> > + >> > + if (per_sample_interpolation) { >> > + nir_foreach_block(block, nir_shader_get_entrypoint(nir)) { >> > + nir_foreach_instr(instr, block) { >> > +if (instr->type != nir_instr_type_intrinsic) >> > + continue; >> > + >> > +nir_intrinsic_instr *intrin = >> > nir_instr_as_intrinsic(instr); >> > +if (intrin->intrinsic != >> > nir_intrinsic_interp_var_at_centroid) >> > + continue; >> > + >> > +nir_variable *var = intrin->variables[0]->var; >> > +if (var->data.interpolation == INTERP_MODE_FLAT) >> > + continue; >> > + >> > +/* The description of the interpolateAtCentroid intrinsic >> > is that >> > + * it interpolates the variable as if it had the "centroid" >> > + * qualifier. When executing with >> > per_sample_interpolation, this >> > + * is equivalent to having the "sample" qualifier. Just >> > convert >> > + * it to a load_var instead. >> > + */ >> > +assert(var->data.sample); >> > +intrin->intrinsic = nir_intrinsic_load_var; >> > + } >> > + } >> > + } >> > } >> > >> > /** >> > -- >> > 2.5.0.400.gff86faf >> > >> > ___ >> > mesa-dev mailing list >> > mesa-dev@lists.freedesktop.org >> > https://lists.freedesktop.org/mailman/listinfo/mesa-dev > > ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] [PATCH 1/4] i965/fs: Use sample interpolation for interpolateAtCentroid in persample mode
On Wed, Sep 14, 2016 at 1:29 PM, Anuj Phogat wrote: > On Wed, Sep 14, 2016 at 10:45 AM, Jason Ekstrand > wrote: > > From the ARB_gpu_shader5 spec: > > > >The built-in functions interpolateAtCentroid() and > interpolateAtSample() > >will sample variables as though they were declared with the "centroid" > >or "sample" qualifiers, respectively. > > > > When running with persample dispatch forced by the API, we interpolate > > anything that isn't flat as if it's qualified by "sample". In order to > > keep interpolateAtCentroid() consistent with the "centroid" qualifier, we > > need to make interpolateAtCentroid() do sample interpolation instead. > > Nothing in the GLSL spec guarantees that the result of > > interpolateAtCentroid is uniform across samples in any way, so this is a > > perfectly fine thing to do. > > > This explanation sounds good to me. To be consistent with what > we do in case of per sample interpolation, shouldn't we do sample > interpolation in case of InterpolateAtOffset() too? This series > doesn't seem to include it. > No. interpolateAtOffset ask that the input be interpolated at a particular offset relative to the pixel center. I believe we have to respect that. > > Fixes 8 of the new dEQP-VK.pipeline.multisample_interpolation.* Vulkan > CTS > > tests that specifically validate consistency between the "sample" > qualifier > > and interpolateAtSample() > > > > Signed-off-by: Jason Ekstrand > > --- > > src/mesa/drivers/dri/i965/brw_fs.cpp | 26 ++ > > 1 file changed, 26 insertions(+) > > > > diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp > b/src/mesa/drivers/dri/i965/brw_fs.cpp > > index 75642d3..9dbb699 100644 > > --- a/src/mesa/drivers/dri/i965/brw_fs.cpp > > +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp > > @@ -6497,6 +6497,32 @@ brw_nir_set_default_interpolation(const struct > gen_device_info *devinfo, > > var->data.sample = false; > >} > > } > > + > > + if (per_sample_interpolation) { > > + nir_foreach_block(block, nir_shader_get_entrypoint(nir)) { > > + nir_foreach_instr(instr, block) { > > +if (instr->type != nir_instr_type_intrinsic) > > + continue; > > + > > +nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); > > +if (intrin->intrinsic != nir_intrinsic_interp_var_at_ > centroid) > > + continue; > > + > > +nir_variable *var = intrin->variables[0]->var; > > +if (var->data.interpolation == INTERP_MODE_FLAT) > > + continue; > > + > > +/* The description of the interpolateAtCentroid intrinsic > is that > > + * it interpolates the variable as if it had the "centroid" > > + * qualifier. When executing with > per_sample_interpolation, this > > + * is equivalent to having the "sample" qualifier. Just > convert > > + * it to a load_var instead. > > + */ > > +assert(var->data.sample); > > +intrin->intrinsic = nir_intrinsic_load_var; > > + } > > + } > > + } > > } > > > > /** > > -- > > 2.5.0.400.gff86faf > > > > ___ > > mesa-dev mailing list > > mesa-dev@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/mesa-dev > ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] [PATCH 1/4] i965/fs: Use sample interpolation for interpolateAtCentroid in persample mode
On Wed, Sep 14, 2016 at 10:45 AM, Jason Ekstrand wrote: > From the ARB_gpu_shader5 spec: > >The built-in functions interpolateAtCentroid() and interpolateAtSample() >will sample variables as though they were declared with the "centroid" >or "sample" qualifiers, respectively. > > When running with persample dispatch forced by the API, we interpolate > anything that isn't flat as if it's qualified by "sample". In order to > keep interpolateAtCentroid() consistent with the "centroid" qualifier, we > need to make interpolateAtCentroid() do sample interpolation instead. > Nothing in the GLSL spec guarantees that the result of > interpolateAtCentroid is uniform across samples in any way, so this is a > perfectly fine thing to do. > This explanation sounds good to me. To be consistent with what we do in case of per sample interpolation, shouldn't we do sample interpolation in case of InterpolateAtOffset() too? This series doesn't seem to include it. > Fixes 8 of the new dEQP-VK.pipeline.multisample_interpolation.* Vulkan CTS > tests that specifically validate consistency between the "sample" qualifier > and interpolateAtSample() > > Signed-off-by: Jason Ekstrand > --- > src/mesa/drivers/dri/i965/brw_fs.cpp | 26 ++ > 1 file changed, 26 insertions(+) > > diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp > b/src/mesa/drivers/dri/i965/brw_fs.cpp > index 75642d3..9dbb699 100644 > --- a/src/mesa/drivers/dri/i965/brw_fs.cpp > +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp > @@ -6497,6 +6497,32 @@ brw_nir_set_default_interpolation(const struct > gen_device_info *devinfo, > var->data.sample = false; >} > } > + > + if (per_sample_interpolation) { > + nir_foreach_block(block, nir_shader_get_entrypoint(nir)) { > + nir_foreach_instr(instr, block) { > +if (instr->type != nir_instr_type_intrinsic) > + continue; > + > +nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); > +if (intrin->intrinsic != nir_intrinsic_interp_var_at_centroid) > + continue; > + > +nir_variable *var = intrin->variables[0]->var; > +if (var->data.interpolation == INTERP_MODE_FLAT) > + continue; > + > +/* The description of the interpolateAtCentroid intrinsic is that > + * it interpolates the variable as if it had the "centroid" > + * qualifier. When executing with per_sample_interpolation, this > + * is equivalent to having the "sample" qualifier. Just convert > + * it to a load_var instead. > + */ > +assert(var->data.sample); > +intrin->intrinsic = nir_intrinsic_load_var; > + } > + } > + } > } > > /** > -- > 2.5.0.400.gff86faf > > ___ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
[Mesa-dev] [PATCH 1/4] i965/fs: Use sample interpolation for interpolateAtCentroid in persample mode
From the ARB_gpu_shader5 spec: The built-in functions interpolateAtCentroid() and interpolateAtSample() will sample variables as though they were declared with the "centroid" or "sample" qualifiers, respectively. When running with persample dispatch forced by the API, we interpolate anything that isn't flat as if it's qualified by "sample". In order to keep interpolateAtCentroid() consistent with the "centroid" qualifier, we need to make interpolateAtCentroid() do sample interpolation instead. Nothing in the GLSL spec guarantees that the result of interpolateAtCentroid is uniform across samples in any way, so this is a perfectly fine thing to do. Fixes 8 of the new dEQP-VK.pipeline.multisample_interpolation.* Vulkan CTS tests that specifically validate consistency between the "sample" qualifier and interpolateAtSample() Signed-off-by: Jason Ekstrand --- src/mesa/drivers/dri/i965/brw_fs.cpp | 26 ++ 1 file changed, 26 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 75642d3..9dbb699 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -6497,6 +6497,32 @@ brw_nir_set_default_interpolation(const struct gen_device_info *devinfo, var->data.sample = false; } } + + if (per_sample_interpolation) { + nir_foreach_block(block, nir_shader_get_entrypoint(nir)) { + nir_foreach_instr(instr, block) { +if (instr->type != nir_instr_type_intrinsic) + continue; + +nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); +if (intrin->intrinsic != nir_intrinsic_interp_var_at_centroid) + continue; + +nir_variable *var = intrin->variables[0]->var; +if (var->data.interpolation == INTERP_MODE_FLAT) + continue; + +/* The description of the interpolateAtCentroid intrinsic is that + * it interpolates the variable as if it had the "centroid" + * qualifier. When executing with per_sample_interpolation, this + * is equivalent to having the "sample" qualifier. Just convert + * it to a load_var instead. + */ +assert(var->data.sample); +intrin->intrinsic = nir_intrinsic_load_var; + } + } + } } /** -- 2.5.0.400.gff86faf ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev