Backends can normally handle shader inputs solely by looking at
load_input intrinsics, and ignore the nir_variables in nir->inputs.
One exception is fragment shader inputs. load_input doesn't capture
the necessary interpolation information - flat, smooth, noperspective
mode, and centroid, sample, or pixel for the location. This means
that backends have to interpolate based on the nir_variables, then
associate those with the load_input intrinsics (say, by storing a
map of which variables are at which locations).
With GL_ARB_enhanced_layouts, we're going to have multiple varyings
packed into a single vec4 location. The intrinsics make this easy:
simply load N components from location <loc, component>. However,
working with variables and correlating the two is very awkward; we'd
much rather have intrinsics capture all the necessary information.
Fragment shader input interpolation typically works by producing a
set of barycentric coordinates, then using those to do a linear
interpolation between the values at the triangle's corners.
We represent this by introducing five new load_barycentric_* intrinsics:
- load_barycentric_pixel (ordinary variable)
- load_barycentric_centroid (centroid qualified variable)
- load_barycentric_sample (sample qualified variable)
- load_barycentric_at_sample (ARB_gpu_shader5's interpolateAtSample())
- load_barycentric_at_offset (ARB_gpu_shader5's interpolateAtOffset())
Each of these take the interpolation mode (smooth or noperspective only)
as a const_index, and produce a vec2. The last two also take a sample
or offset source.
We then introduce a new load_interpolated_input intrinsic, which
is like a normal load_input intrinsic, but with an additional
barycentric coordinate source.
The intention is that flat inputs will still use regular load_input
intrinsics. This makes them distinguishable from normal inputs that
need fancy interpolation, while also providing all the necessary data.
This nicely unifies regular inputs and interpolateAt functions.
Qualifiers and variables become irrelevant; there are just
load_barycentric intrinsics that determine the interpolation.
v2: Document the interp_mode const_index value, define a new
BARYCENTRIC() helper rather than using SYSTEM_VALUE() for
some of them (requested by Jason Ekstrand).
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Likewise, rename the enum type to glsl_interp_mode.
Beyond the GLSL front-end, talking about "interpolation modes" seems
more natural than "interpolation qualifiers" - in the IR, we're removed
from how exactly the source language specifies how to interpolate an
input. Also, SPIR-V calls these "decorations" rather than "qualifiers".
Generated by:
$ find . -regextype egrep -regex '.*\.(c|cpp|h)' -type f -exec sed -i \
-e 's/INTERP_QUALIFIER_/INTERP_MODE_/g' \
-e 's/glsl_interp_qualifier/glsl_interp_mode/g' {} \;
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Dave Airlie <airlied@redhat.com>
This will be used to select the plane to sample from for planar
textures.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Caller can pass a hashtable mapping NIR object (currently instr or var,
but I guess others could be added as needed) to annotation msg to print
inline with the shader dump. As the annotation msg is printed, it is
removed from the hashtable to give the caller a way to know about any
unassociated msgs.
This is used in the next patch, for nir_validate to try to associate
error msgs to nir_print dump.
Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Intel hardware does a form of multisample compression that involves an
auxilary surface called the MCS. When an MCS is in use, you have to first
sample from the MCS with a special opcode and then pass the result of that
operation into the next sample instrucion. Normally, we just do this
ourselves in the back-end, but we want to expose that functionality to NIR
so that we can use MCS values directly in NIR-based blorp.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This matches the "foreach x in container" pattern found in many other
programming languages.
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
This matches the "foreach x in container" pattern found in many other
programming languages. Generated by the following regular expression:
s/nir_foreach_phi_src(\([^,]*\),\s*\([^,]*\))/nir_foreach_phi_src(\2, \1)/
and a similar expression for nir_foreach_phi_src_safe.
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
This matches the "foreach x in container" pattern found in many other
programming languages. Generated by the following regular expression:
s/nir_foreach_instr(\([^,]*\),\s*\([^,]*\))/nir_foreach_instr(\2, \1)/
and similar expressions for nir_foreach_instr_safe etc.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
nir_variable_mode is currently a bitflag enum, while
nir_print::print_var_decl() assumes is still a numbered list.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This is used to facilitate the Vulkan binding model where each resource is
described by a (descriptor set, binding, array index) tuple.
Reviewed-by: Rob Clark <robdclark@gmail.com>
v2:
- Squash the printing doubles related patches into one patch (Sam).
v3:
- Print using PRIx64 format: long is 32-bit on some 32-bit platforms but long
long is basically always 64-bit (Jason).
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Previously we were receiving shared variable accesses via a lowered
intrinsic function from glsl. This change allows us to send in
variables instead. For example, when converting from SPIR-V.
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Since we aren't going to put the function parameters or the return variable
in the list of locals, it won't get a proper declaration. This changes
nir_print to print the type along with each parameter or return variable.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Otherwise, we have a problem when we go to print functions with arguments
because their names get added to the hash table during declaration which
happens after we print the prototype.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
When NIR was originally drafted, there was no easy way to determine if
something was constant or not. The result was that we had lots of
special-casing for constant values such as this. Now that load_const
instructions are SSA-only, it's really easy to find constants and this
isn't really needed anymore.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Rob Clark <robclark@gmail.com>
This commit adds the capability to NIR to support separate textures and
samplers. As it currently stands, glsl_to_nir only sets the texture deref
and leaves the sampler deref alone as it did before and nir_lower_samplers
assumes this. Backends can still assume that they are combined and only
look at only at the texture index. Or, if they wish, they can assume that
they are separate because nir_lower_samplers, tgsi_to_nir, and prog_to_nir
all set both texture and sampler index whenever a sampler is required (the
two indices are the same in this case).
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
We're about to separate the two concepts. When we do, the sampler will
become optional. Doing a rename first makes the separation a bit more
safe because drivers that depend on GLSL or TGSI behaviour will be fine to
just use the texture index all the time.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Direct access to intr->const_index[n], where different slots have
different meanings, is somewhat confusing.
Instead, let's put some extra info in nir_intrinsic_infos[] about which
slots map to what, and add some get/set helpers. The helpers validate
that the field being accessed (base/writemask/etc) is applicable for the
intrinsic opc, for some extra safety. And nir_print can use this to
dump out decoded const_index fields.
Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Kenneth Graunke
Timothy Arceri
Kristian Høgsberg Kristensen
Rob Clark
Jason Ekstrand
Eduardo Lima Mitev
Jose Fonseca
Connor Abbott
Iago Toral Quiroga
Jordan Justen
Emil Velikov