The current scheduling algorithm favors parallelism a bit too
aggressively and sometimes generates shaders that fail register
allocation. This happens even if the threshold is set to zero to force
it to always use the CSR instruction choosing algorithm.
This patch adds an option to use an even more aggressive fallback that
just always picks the instruction with the shortest maximum delay in the
hope that that will generate the least register pressure. The intention
is to use this as a last resort after register allocation fails in order
to at least have a working shader.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Acked-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5953>
Adds a callback function to nir_schedule_options to give the backend a
chance to add custom dependencies between certain intrinsics. The
callback can assign a class number to the intrinsic and then set a read
or write dependency on that class.
v2: Use a linked-list of schedule nodes for the dependency classes
instead of a fixed-sized array.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5953>
nir_schedule already has a struct for options which makes it more than
just a function declaration. Later patches intend to add more structs to
complement these options. In order to make the code easier to manage,
this moves the nir_scheduler-related parts out of nir.h to their own
header.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5953>
Previously, objects of type OpTypeImage or OpTypeSampler were treated as
vtn_pointers and objects of type OpTypeSampledImage were a special-use
vtn_sampled_image struct. This commit changes that so that all of those
objects are stored in vtn_ssa_values. Each of images, samplers, and
sampled images, are stored as a scalar or vector nir_ssa_def whose
components are NIR deref values. We now use vtn_type_get_nir_type to
re-resolve those as-needed into GLSL sampler types for NIR.
This simplification has a number of benefits:
1. We can git rid of the rest of our special-cases for handling images
and samplers in function arguments. Now that they're treated as
structs at the glsl_type level, the generic paths can handle images
and samplers.
2. We can now construct composite values containing images and samplers
internally. It's unclear from the SPIR-V spec whether or not this
is allowed and it's not a pattern that GLSLang currently generates
thanks to GLSL rules. However, if we do start seeing SPIR-V that
contains such composites, we should now be able to handle it.
3. SPIR-V OpNull and OpUndef instructions can now create samplers,
images, and sampled images. The NIR generated won't likely be fully
valid but, given a NIR pass to do something sensible, it should be a
thing we can compile.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
There are a few cases, atomic counters being one example, where the type
used by vtn_ssa_value is not the same as the type we want NIR to use in
derefs and variables. To solve this, we add a helper which converts
between the types for us. In the next commit, we'll be adding another
major user of this: images and samplers.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
Previously, we created our vtn_ssa_value in _vtn_variable_load_store
manually as we did the recursive load/store. Instead, we now create the
SSA value before calling into the recursive function. This is a tiny
bit less efficient but it removes a case of hand-rolling vtn_ssa_value
creation. For symmetry, we make _vtn_block_load_store assume the value
is already created. Finally, we remove a trivial hand-rolled case in
vtn_composite_extract.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
For three different functions which create vtn_ssa_values, we had three
completely different implementations. This unifies them all to roughly
the same algorithm. While we're at it, we take advantage of the
nir_build_imm helper to avoid some extra code in vtn_const_ssa_value.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
The w++ is to handle a differences between the KHR extension and Vulkan
1.1 feature where the Vulkan 1.1 instructions take an scope parameter.
While incrementing w technically works, it's really subtle and very easy
to miss when reading the code.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
For some reason, we were doing a signed shift vectors and an unsigned
shift for scalars. We then plug it into i2b so it should make no
difference whatsoever. The fact that we're doing different things for
vectors vs. scalars is bonkers. Let's simplify the code a bit.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
The original implementation of SPV_EXT_descriptor_indexing was extremely
paranoid about the NonUniform qualifier, trying to fetch it from every
possible location and propagate it through access chains etc. However,
the Vulkan spec is quite nice to us on this and has very strict rules
for where the NonUniform decoration has to be placed. For image and
texture operations, we can search for the decoration on the spot when we
process the image or texture op. For pointers, we continue putting it
on the pointer but we don't bother trying to do anything silly like
propagate it through casts.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5278>
This adds a nir_unsigned_upper_bound() helper which does something similar
to nir_analyze_range() except it tries to obtain the largest possible
value instead of it's relation to zero.
It also adds nir_addition_might_overflow(), which uses this helper to try
to prove that an unsigned addition does not wrap around.
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2720>
Neil Roberts