Commit 4434591bf5 caused substantially more URB messages in
geometry and tessellation shaders. Before we can really enable this
sort of optimization, We either need some way of combining them back
together into vectors or we need to do cross-stage vector element
elimination without splitting everything into scalars.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107510
Fixes: 4434591bf5 "intel/nir: Call nir_lower_io_to_scalar_early"
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Tested-by: Mark Janes <mark.a.janes@intel.com>
The NIR nir_lower_io_arrays_to_elements pass attempts to split I/O
variables which are arrays or matrices into a sequence of separate
variables. This can help link-time optimization by allowing us to
remove varyings at a more granular level.
Shader-db results on Kaby Lake:
total instructions in shared programs: 15177645 -> 15168494 (-0.06%)
instructions in affected programs: 79857 -> 70706 (-11.46%)
helped: 392
HURT: 0
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Some of the lowering passes, nir_lower_locals_to_regs for example, can
cause some previously live code to be dead. This pass in particular
leaves a bunch of nir_instr_type_deref instructions floating around.
This causes shader-db runs on Gen5 through Haswell to spew tons of
messages like:
VS instruction not yet implemented by NIR->vec4
UnrealEngine4/EffectsCaveDemo/239.shader_test is one shader that
generates these messages. Cleaning up the dead code fixes that.
To verify, I did a shader-db before and after. Even though all the
messages are gone, the results make my brain hurt. :(
Haswell
total cycles in shared programs: 411890163 -> 411891145 (<.01%)
cycles in affected programs: 57016 -> 57998 (1.72%)
helped: 3
HURT: 11
helped stats (abs) min: 2 max: 154 x̄: 96.67 x̃: 134
helped stats (rel) min: 0.08% max: 2.23% x̄: 1.42% x̃: 1.96%
HURT stats (abs) min: 18 max: 686 x̄: 115.64 x̃: 20
HURT stats (rel) min: 0.81% max: 7.12% x̄: 1.87% x̃: 0.93%
95% mean confidence interval for cycles value: -51.39 191.67
95% mean confidence interval for cycles %-change: -0.14% 2.46%
Inconclusive result (value mean confidence interval includes 0).
Ivy Bridge
total cycles in shared programs: 259114802 -> 259115032 (<.01%)
cycles in affected programs: 24034 -> 24264 (0.96%)
helped: 1
HURT: 9
helped stats (abs) min: 2 max: 2 x̄: 2.00 x̃: 2
helped stats (rel) min: 0.08% max: 0.08% x̄: 0.08% x̃: 0.08%
HURT stats (abs) min: 18 max: 48 x̄: 25.78 x̃: 20
HURT stats (rel) min: 0.80% max: 1.94% x̄: 1.08% x̃: 0.80%
95% mean confidence interval for cycles value: 12.42 33.58
95% mean confidence interval for cycles %-change: 0.54% 1.38%
Cycles are HURT.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Fixes: 5a02ffb733 nir: Rework lower_locals_to_regs to use deref instructions
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
According to RenderDoc, this shaves 99.6% of the run time off of the
ambient occlusion pass in Skyrim Special Edition when running under DXVK
and shaves 92% off the runtime for a reasonably representative frame.
When running the actual game, Skyrim goes from being a slide-show to a
very stable and playable framerate on my SKL GT4e machine.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This completely reworks the pass to support deref instructions and
delete support for old deref chains
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Now that it's rewritten for deref instructions, we can turn it back on.
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Everything else should already be handled.
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Since we had to rewrite the deref walking loop anyway, I took the
opportunity to make it a bit clearer and more efficient. In particular,
in the AoA case, we will now emit one minmax instead of one per array
level.
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This pass doesn't handle deref instructions yet. Making it handle both
legacy derefs and deref instructions would be painful. Since it's not
important for correctness, just disable it for now.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
These are not supported in hardware for 16-bit integers.
We do the lowering pass after the optimization loop to ensure that we
lower ALU operations injected by algebraic optimizations too.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
The Vertex Elements are now:
* VE 1: <BaseVertex/firstvertex, BaseInstance, VertexID, InstanceID>
* VE 2: <DrawID, is-indexed-draw, 0, 0>
VE1 is it kept as it was before, VE2 additionally contains the new
system value.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Until we set gl_BaseVertex to zero for non-indexed draw calls
both have an identical value.
The Vertex Elements are kept like that:
* VE 1: <BaseVertex/firstvertex, BaseInstance, VertexID, InstanceID>
* VE 2: <Draw ID, 0, 0, 0>
v2 (idr): Mark nir_intrinsic_load_first_vertex as "unreachable" in
emit_system_values_block and fs_visitor::nir_emit_vs_intrinsic.
This requires us to bump the subgroup size to 32 for all shader stages
because Vulkan requires that to be a physical device query.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Otherwise loop unrolling will fail to see the actual cost of
the unrolling operations when the loop body contains 64-bit integer
instructions, and very specially when the divmod64 lowering applies,
since its lowering is quite expensive.
Without this change, some in-development CTS tests for int64
get stuck forever trying to register allocate a shader with
over 50K SSA values. The large number of SSA values is the result
of NIR first unrolling multiple seemingly simple loops that involve
int64 instructions, only to then lower these instructions to produce
a massive pile of code (due to the divmod64 lowering in the unrolled
instructions).
With this change, loop unrolling will see the loops with the int64
code already lowered and will realize that it is too expensive to
unroll.
v2: Run nir_algebraic first so we can hopefully get rid of some of
the int64 instructions before we even attempt to lower them.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Older OpenGL defines two equations for converting from signed-normalized
to floating point data. These are:
f = (2c + 1)/(2^b - 1) (equation 2.2)
f = max{c/2^(b-1) - 1), -1.0} (equation 2.3)
Both OpenGL 4.2+ and OpenGL ES 3.0+ mandate that equation 2.3 is to be
used in all scenarios, and remove equation 2.2. DirectX uses equation
2.3 as well. Intel hardware only supports equation 2.3, so Gen7.5+
systems that use the vertex fetcher hardware to do the conversions
always get formula 2.3.
This can make a big difference for 10-10-10-2 formats - the 2-bit value
can represent 0 with equation 2.3, and cannot with equation 2.2.
Ivybridge and older were using equation 2.2 for OpenGL, and 2.3 for ES.
Now that Ivybridge supports OpenGL 4.2, this is wrong - we need to use
the new rules, at least in core profile. That would leave Gen4-6 doing
something different than all other hardware, which seems...lame.
With context version promotion, applications that requested a pre-4.2
context may get promoted to 4.2, and thus get the new rules. Zero cases
have been reported of this being a problem. However, we've received a
report that following the old rules breaks expectations. SuperTuxKart
apparently renders the cars red when following equation 2.2, and works
correctly when following equation 2.3:
https://github.com/supertuxkart/stk-code/issues/2885#issuecomment-353858405
So, this patch deletes the legacy equation 2.2 support entirely, making
all hardware and APIs consistently use the new equation 2.3 rules.
If we ever find an application that truly requires the old formula, then
we'd likely want that application to work on modern hardware, too. We'd
likely restore this support as a driconf option. Until then, drop it.
This commit will regress Piglit's draw-vertices-2101010 test on
pre-Haswell without the corresponding Piglit patch to accept either
formula (commit 35daaa1695ea01eb85bc02f9be9b6ebd1a7113a1):
draw-vertices-2101010: Accept either SNORM conversion formula.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Previously, if we were linking a vec4 VS with a SIMD8/16 FS, we wouldn't
lower indirects on the fragment shader which is wrong. Instead of using
a single indirect mask, take advantage of our new little helper.
Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>
Cc: mesa-stable@lists.freedesktop.org
The GL_ARB_shader_ballot spec says that gl_SubGroupSizeARB is declared
as a uniform. This means that it cannot change across an invocation
such as a draw call or a compute dispatch. For compute shaders, we're
ok because we only ever use one dispatch size. For fragment, however,
the hardware dynamically chooses between SIMD8 and SIMD16 which violates
the spec. Instead, let's just pick a subgroup size based on the shader
stage. The fixed size we choose for compute shaders is a bit higher
than strictly needed but there's no real harm in that. The advantage is
that, if they do anything interesting with the value, NIR will see it as
an immediate and can optimize better.
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Ballot intrinsics return a bitfield of subgroups. In GLSL and some
SPIR-V extensions, they return a uint64_t. In SPV_KHR_shader_ballot,
they return a uvec4. Also, some back-ends would rather pass around
32-bit values because it's easier than messing with 64-bit all the time.
To solve this mess, we make nir_lower_subgroups take a new parameter
called ballot_bit_size and it lowers whichever thing it gets in from the
source language (uint64_t or uvec4) to a scalar with the specified
number of bits. This replaces a chunk of the old lowering code.
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
This commit pulls nir_lower_read_invocations_to_scalar along with most
of the guts of nir_opt_intrinsics (which mostly does subgroup lowering)
into a new nir_lower_subgroups pass. There are various other bits of
subgroup lowering that we're going to want to do so it makes a bit more
sense to keep it all together in one pass. We also move it in i965 to
happen after nir_lower_system_values to ensure that because we want to
handle the subgroup mask system value intrinsics here.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Specifically, constant fold intrinsics from ARB_shader_group_vote, but I
suspect it'll be useful for other things in the future.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
We're already doing this in the FS back-end. This just does the same
thing in the vec4 back-end.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The NIR pass already handles remapping system values to attributes for
us so we delete the system value code as part of the conversion.
We also change nir_lower_vs_inputs to take an explicit inputs_read
bitmask and pass in the inputs_read from prog_data instead from pulling
it out of NIR. This is because the version in prog_data may get
EDGEFLAG added to it on some old platforms.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
NIR calls these system values but they come in from the VF unit as
vertex data. It's terribly convenient to just be able to treat them as
such in the back-end.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The vec4 backend will want to count in units of vec4s, not scalar
components. The simplest solution is to move the multiplication by 4
into the scalar backend. This also improves consistency with how we
count varyings.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Now that we have nice block iterators, there's no good reason for this
to be off on it's own. While we're here, we convert to using the NIR
const index getters/setters instead of whacking const_index values
directly.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Commit e1af20f18a changed the shader_info
from being embedded into being just a pointer. The idea was that
sharing the shader_info between NIR and GLSL would be easier if it were
a pointer pointing to the same shader_info struct. This, however, has
caused a few problems:
1) There are many things which generate NIR without GLSL. This means
we have to support both NIR shaders which come from GLSL and ones
that don't and need to have an info elsewhere.
2) The solution to (1) raises all sorts of ownership issues which have
to be resolved with ralloc_parent checks.
3) Ever since 00620782c9, we've been
using nir_gather_info to fill out the final shader_info. Thanks to
cloning and the above ownership issues, the nir_shader::info may not
point back to the gl_shader anymore and so we have to do a copy of
the shader_info from NIR back to GLSL anyway.
All of these issues go away if we just embed the shader_info in the
nir_shader. There's a little downside of having to copy it back after
calling nir_gather_info but, as explained above, we have to do that
anyway.
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This shuffles constants down in the reverse of what the previous
patch does and applies some simpilifications that may be made
possible from doing so.
Shader-db results BDW:
total instructions in shared programs: 12980814 -> 12977822 (-0.02%)
instructions in affected programs: 281889 -> 278897 (-1.06%)
helped: 1231
HURT: 128
total cycles in shared programs: 246562852 -> 246567288 (0.00%)
cycles in affected programs: 11271524 -> 11275960 (0.04%)
helped: 1630
HURT: 1378
V2: mark float opts as inexact
Reviewed-by: Elie Tournier <elie.tournier@collabora.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
We want to be able to check the progress of each pass and dump the NIR
for debugging purposes if it changed.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Mostly a dummy git mv with a couple of noticable parts:
- With the earlier header cleanups, nothing in src/intel depends
files from src/mesa/drivers/dri/i965/
- Both Autoconf and Android builds are addressed. Thanks to Mauro and
Tapani for the fixups in the latter
- brw_util.[ch] is not really compiler specific, so it's moved to i965.
v2:
- move brw_eu_defines.h instead of brw_defines.h
- remove no-longer applicable includes
- add missing vulkan/ prefix in the Android build (thanks Tapani)
v3:
- don't list brw_defines.h in src/intel/Makefile.sources (Jason)
- rebase on top of the oa patches
[Emil Velikov: commit message, various small fixes througout]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Jason Ekstrand
Jose Maria Casanova Crespo
Ian Romanick
Iago Toral Quiroga
Antia Puentes
Timothy Arceri
Kenneth Graunke
Matt Turner
Johnson Lin
Timothy Arceri