2 source instruction only support immediate for src1 operand, so no
point in adding optimization condition for src0 oprand.
v2:
- Update commit message and don't remove ADD optimization (Matt Turner)
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5341>
Gen9 and Cherryview have the ability to mark texture instructions with
the End-of-thread bit under some conditions, which allows the texture
result to be written to the render target directly, rather than
returning to the EU.
In order to handle overlapping primitives correctly, we have to use the
'sendc' instruction which stalls until other threads potentially writing
to the same locations in the render target are retired. Unfortunately,
this stall happens before the texture is sampled (rather than in
parallel with stall), so for some literal edge cases (like the diagonal
edge between two triangles forming a rectangle) there can be a
performance penalty. As a result, it's probably not a good idea to use
this optimization in general.
I had planned to leave it enabled only for BLORP, where we use rectangle
primitives and are typically clearing/blitting an entire render target
without any overlapping primitives, but I noticed that the optimization
wasn't applied in some normal cases anyway. For example, in the piglit
test tests/shaders/glsl-fs-texture2d-bias.shader_test it is applied to
one BLORP-blit shader but not another due to some kind of mishandling of
register types (the destination register type of the texture operation
is UD while the color source of the render target write is F).
Additionally the instruction scheduler assumed that the combined texture
and render target write operation took 0 cycles, leading to cycle
estimates that are wildly inaccurate. Since the optimization was not
implemented for SIMD32 and our decision whether to use the SIMD32
program is made by comparing the estimated performance with that of the
SIMD16 shader, we wrongly threw out a bunch of SIMD32 programs that are
likely profitable.
total cycles in shared programs: 472807891 -> 473784245 (0.21%)
cycles in affected programs: 108277 -> 1084631 (901.72%)
helped: 0
HURT: 1290
total sends in shared programs: 998955 -> 1000245 (0.13%)
sends in affected programs: 1400 -> 2690 (92.14%)
helped: 0
HURT: 1290
LOST: 0
GAINED: 33
This patch shows no performance changes in Intel's Mesa performance CI.
Given the problems, the lack of evidence that the pass improves
performance, and the fact that the hardware feature was removed from
subsequent GPU generations, I think that the pass is not valuable and
should be removed.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5412>
This will make the GL drivers pick the right SIMD variant for a given
group size set during dispatch. The heuristic implemented in
brw_cs_simd_size_for_group_size() is the same as in brw_compile_cs().
The cs_prog_data::simd_size field was removed. The generated SIMD
sizes are marked in a bitmask, which is already used via
brw_cs_simd_size_for_group_size() by the drivers.
When in variable group size, it is OK if larger SIMD shader spill,
since we'd need it for the cases where the smaller one can't hold all
the invocations.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5142>
Move the decision one level up, let brw_compile_*() functions use the
spilling information to decide whether or not a certain width
compilation can spill (passed via run_*() functions).
The min_dispatch_width was used to compare with the dispatch_width and
decide whether "a previous shader is already available, so don't
accept spill".
This is replaced by:
- Not calling run_*() functions if it is know beforehand a smaller width
already spilled -- since the larger width will spill and fail;
- Explicitly passing whether or not a shader is allowed to spill. For
the cases where the smaller width is available and haven't spilled,
the larger width will be compiled but is only useful if it won't
spill.
Moving the decision to this level will be useful later for variable
group size, which is a case where we want all the widths to be allowed
to spill.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5142>
The motivating factor is: this lowering may cause
nir_intrinsic_load_local_group_size intrinsics to be added to the
shader, and by moving this around we make possible for the drivers to
lower that intrinsic by themselves.
Iris will do just that in a later patch for implementing variable
group size.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4794>
Intrinsic to get the SIMD width, which not always the same as subgroup
size. Starting with a small scope (Intel), but we can rename it later
to generalize if this turns out useful for other drivers.
Change brw_nir_lower_cs_intrinsics() to use this intrinsic instead of
a width will be passed as argument. The pass also used to optimized
load_subgroup_id for the case that the workgroup fitted into a single
thread (it will be constant zero). This optimization moved together
with lowering of the SIMD.
This is a preparation for letting the drivers call it before the
brw_compile_cs() step.
No shader-db changes in BDW, SKL, ICL and TGL.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4794>
These should be more accurate than the current cycle counts, since
among other things they consider the effect of post-scheduling passes
like the software scoreboard on TGL. In addition it will enable us to
clean up some of the now redundant cycle-count estimation
functionality in the instruction scheduler.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This is useful in order to identify codegen issues caused by SIMD32.
It doesn't currently have any effect on compute shaders since SIMD32
dispatch is only enabled for CS when it's strictly necessary to do so
in order to support the workgroup size requested for the shader --
That might change in the future though when we hook up the SIMD32
heuristic to CS compilation.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The heuristic enables the SIMD32 fragment shader based on whether the
IR performance modeling pass predicts it to have greater throughput
than the SIMD16 and SIMD8 variants of the same shader. It would be
straightforward to do the same thing in order to control whether
SIMD16 dispatch is enabled, but it's pending additional performance
evaluation.
The INTEL_DEBUG=do32 option is left around in order to force the
SIMD32 shader to be used regardless of the result of the heuristic,
since it's useful as a debugging aid e.g. in order to identify
SIMD32-specific codegen issues which may be masked by the SIMD32
heuristic, or cases where the heuristic is incorrectly disabling
SIMD32 shaders that offer a performance advantage.
Currently this is only enabled on Gen6+, since SIMD32 codegen support
is incomplete on earlier platforms.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This makes brw_compile_fs() look a bit more similar to
brw_compile_cs(). It saves us three v*_shader_stats local variables,
and will save us additional triplicated declarations as we start
tracking IR performance analysis results.
The triplicated cfg pointers are left around because they're set to
NULL to mark specific dispatch modes as disabled (e.g. in order to
enforce hardware restrictions). Doing the same thing with the visitor
pointers would cause data leaks.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Makes more sense considering SIMD32. Relaxing the assertion in
brw_ir_fs.h will be required in order to avoid assertion failures on
SNB with SIMD32 fragment shaders.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
In Gen12 the Poly 0 Info DWORD containing the Viewport Index and
Render Target Index fields were moved from r0.0 to r1.1 in order to
make room for dual-polygon dispatch. The render target message format
was updated to expect that information in the same location, so we
didn't need to make any changes for framebuffer fetch to work with
SIMD8 and SIMD16 dispatch. Unfortunately that won't work with SIMD32,
since the render target message header is assembled from r0 and r2
instead of r1, and the r2 thread payload wasn't updated with an
additional copy of the same information. We need to fix things up
manually instead. This avoids a handful of
EXT_shader_framebuffer_fetch regressions in combination with SIMD32
fragment shaders.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The Gen12 docs are rather contradictory regarding the dispatch
configurations supported by the fragment shader -- The same table
present in previous generations seems to imply that only one dispatch
mode can be enabled when doing per-sample shading, but a restriction
documented in the 3DSTATE_PS_BODY page implies the opposite: That
SIMD32 can only be used in combination with some other dispatch mode.
The latter seems to match the behavior of real hardware as I could
tell from my testing: A bunch of multisample test-cases that do
per-sample shading hang if we only provide a SIMD32 shader.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This commit fixes performance regressions introduced by e03f965280
in which we started bounds checking our push constants. This added a
LOT of shader code to shaders which use the robustBufferAccess feature
and led to substantial spilling. The checking we just added to the FS
back-end is far more efficient for two reasons:
1. It can be done at a whole register granularity rather than per-
scalar and so we emit one SIMD8 SEL per 32B GRF rather than one
SIMD16 SEL (executed as two SELs) for each component loaded.
2. Because we do it with NoMask instructions, we can do it on whole
pushed GRFs without splatting them out to SIMD8 or SIME16 values.
This means that robust buffer access no longer explodes our register
pressure for no good reason.
As a tiny side-benefit, we're now using can use AND instead of SEL which
means no need for the flag and better scheduling.
Vulkan pipeline database results on ICL:
Instructions in all programs: 293586059 -> 238009118 (-18.9%)
SENDs in all programs: 13568515 -> 13568515 (+0.0%)
Loops in all programs: 149720 -> 149720 (+0.0%)
Cycles in all programs: 88499234498 -> 84348917496 (-4.7%)
Spills in all programs: 1229018 -> 184339 (-85.0%)
Fills in all programs: 1348397 -> 246061 (-81.8%)
This also improves the performance of a few apps:
- Shadow of the Tomb Raider: +4%
- Witcher 3: +3.5%
- UE4 Shooter demo: +2%
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4447>
At this point all drivers are doing this math on their own -- since
most of them need to cover the variable group size case, in which at
compile time the group size (and number of threads) is not defined.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4504>
Add new builtin parameters that are used to keep track of the group
size. This will be used to implement ARB_compute_variable_group_size.
The compiler will use the maximum group size supported to pick a
suitable SIMD variant. A later improvement will be to keep all SIMD
variants (like FS) so the driver can select the best one at dispatch
time.
When variable workgroup size is used, the small workgroup optimization
is disabled as it we can't prove at compile time that the barriers
won't be needed.
Extracted from original i965 patch with additional changes by
Caio Marcelo de Oliveira Filho.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4504>
The push.total field had three values but only one was directly
used (size). Replace it with a helper function that explicitly takes
the cs_prog_data and the number of threads -- and use that in the
drivers.
This is a preparation for ARB_compute_variable_group_size where the
number of threads (hence the total size for push constants) is not
defined at compile time (not cs_prog_data->threads).
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4504>
Change brw_compute_vue_map() to also take the number of pos slots. If
more than one slot is used, the VARYING_SLOT_POS is treated as an
array.
When using Primitive Replication, instead of a single position, the
VUE must contain an array of positions. Padding might be
necessary (after clip distance) to ensure rest of attributes start
aligned.
v2: Add note about array in the commit message and assert that
pos_slots >= 1 to make clear 0 is invalid. (Jason)
Move padding to be after the clip distance.
v3: Apply the correct offset when gathering the sources from outputs.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> [v2]
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Rafael Antognolli <rafael.antognolli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2313>
Store the fragment shader inputs in the program data so we can use them
later when required without needing the NIR shader.
Cc: mesa-stable@lists.freedesktop.org
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Ivan Briano <ivan.briano@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2010>
Avoid looping over all VARYING_SLOT_MAX urb_setup array
entries from genX_upload_sbe. Prepare an array indirection
to the active entries of urb_setup already in the compile
step. On upload only walk the active arrays.
v2: Use uint8_t to store the attribute numbers.
v3: Change loop to build up the array indirection.
v4: Rebase.
v5: Style fix.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/308>
Passing shader_stats to the fs_generator constructor means that the
SIMD8 shader stats from the visitor (such as the scheduler mode) will be
reported out for the SIMD16/SIMD32 versions as well.
As you can see, we are now passing 'shader_stats' and 'stats' to
generate_code(), which is obviously odd looking. Ian rebased and
committed an old patch of mine which added the shader_stats struct on
July 30 in commit dabb5d4bee (i965/fs: Add a shader_stats struct.) and
shortly after on August 12 Jason added the brw_compile_stats struct in
commit 134607760a (intel/compiler: Fill a compiler statistics struct).
I'd like to combine the two, but I'm not sure how. shader_stats is an
input to generate_code() while brw_compile_stats is an output and is
only used by the Vulkan driver. Leave it as is for now...
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4093>
This defines a new BRW_ANALYSIS object which wraps the register
pressure computation code along with its result. For the rationale
see the previous commits converting the liveness and dominance
analysis passes to the IR analysis framework.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This involves wrapping fs_live_variables in a BRW_ANALYSIS object and
hooking it up to invalidate_analysis() so it's properly invalidated.
Seems like a lot of churn but it's fairly straightforward. The
fs_visitor invalidate_ and calculate_live_intervals() methods are no
longer necessary after this change.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This moves the following methods that are currently defined in
fs_visitor (even though they are side products of the liveness
analysis computation) and are already implemented in
brw_fs_live_variables.cpp:
> bool virtual_grf_interferes(int a, int b) const;
> int *virtual_grf_start;
> int *virtual_grf_end;
It makes sense for them to be part of the fs_live_variables object,
because they have the same lifetime as other liveness analysis results
and because this will allow some extra validation to happen wherever
they are accessed in order to make sure that we only ever use
up-to-date liveness analysis results.
This shortens the virtual_grf prefix in order to compensate for the
slightly increased lexical overhead from the live_intervals pointer
dereference.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
Have fun reading through the whole back-end optimizer to verify
whether I've missed any dependency flags -- Or alternatively, just
trust that any mistake here will trigger an assertion failure during
analysis pass validation if it ever poses a problem for the
consistency of any of the analysis passes managed by the framework.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
The invalidate_analysis() method knows what analysis passes there are
in the back-end and calls their invalidate() method to report changes
in the IR. For the moment it just calls invalidate_live_intervals()
(which will eventually be fully replaced by this function) if anything
changed.
This makes all optimization passes invalidate DEPENDENCY_EVERYTHING,
which is clearly far from ideal -- The dependency classes passed to
invalidate_analysis() will be refined in a future commit.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
Our current GPGPU_WALKER code only supports up to 64 threads.
On HSW we could use up to 70 and TGL up to 112, but only if the walker
is adjusted so the width does not exceed 64. Work to support this is
in progress.
Previous to this change, we might try to downgrade to SIMD8 if the
SIMD16 shader spilled. Since HSW and TGL have the max number of
threads above 64, we would then try to emit an invalid GPGPU walker
command.
Fixes: 932045061b ("i965/cs: Emit compute shader code and upload programs")
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
At this point this simply involves fixing the initialization of the
sample mask flag register to take the right dispatch mask from the
thread payload, and fixing sample_mask_reg() to return f1.1 for the
second half of a SIMD32 thread. This improves Manhattan 3.1
performance by 2.4%±0.31% (N>40) on my ICL with SIMD32 enabled
relative to falling back to SIMD16 for the shaders that use discard.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
In SIMD32 programs that don't use discard, the upper 16 bits of the UD
result of sample_mask_reg() don't contain the sample mask of the upper
16 channels as one would expect. Stop pretending we are returning a
valid 32-bit mask.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
FIND_LIVE_CHANNEL was using f1.0-f1.1 as temporary flag register on
Gen7, instead use f0.0-f0.1. In order to avoid collision with the
discard sample mask, move the latter to f1.0-f1.1. This makes room
for keeping track of the sample mask of the second half of SIMD32
programs that use discard.
Note that some MOVs of the sample mask into f1.0 become redundant now
in lower_surface_logical_send() and lower_a64_logical_send().
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>x
Use it instead of hard-coding f0.1 for the sample mask of programs
that use discard. This will make the task easier when we replace f0.1
with another flag register location in order to support discard with
SIMD32 shaders.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
It's only really useful there. This will avoid confusion with another
helper with a similar purpose I'm about to introduce that will be
useful in multiple files from the FS back-end.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Currently the "Source0 Alpha Present to RenderTarget" bit of the RT
write message header is derived from brw_wm_prog_data::replicate_alpha.
However the src0_alpha payload is provided anytime it's specified to
the logical message. This could theoretically lead to an
inconsistency if somebody provided a src0_alpha value while
brw_wm_prog_data::replicate_alpha was false, as I'm planning to do in
a future commit in order to implement a hardware workaround.
Instead calculate the header bit based on whether a src0_alpha value
was provided to the logical message, which guarantees the same
behavior on pre-ICL and ICL+ (the latter used an extended descriptor
bit for this which didn't suffer from the same issue). Remove the
brw_wm_prog_data::replicate_alpha flag.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
