This involves permuting the registers of barycentric vectors to have
the standard X[0-n] Y[0-n] layout at NIR translation time.
Barycentrics are converted to the format expected by the PLN
instruction in the lower_barycentrics() pass run after the
optimization loop.
Main reason is correctness of SIMD32 fragment shaders. The
shuffle_from_pln_layout() and shuffle_to_pln_layout() helpers used
during NIR translation are busted for SIMD32. This leads to serious
corruption at present with INTEL_DEBUG=do32, especially on Gen11+
where these helpers are hit more frequently due to the lack of a
hardware PLN instruction.
Of course one could have chosen to fix those helpers instead, but
there is another far more subtle issue that was reported during review
of the SIMD32 fragment shader codegen changes: The SIMD splitting pass
currently handles SIMD32 barycentric vectors as if they had the
standard X[0-n] Y[0-n] layout, even though they are interleaved for
the PLN instruction, which causes incorrect execution masks to be
applied to the MOVs unzipping barycentric vectors in cases where a
LINTERP instruction occurs under non-uniform control flow.
I'm not aware of any conformance regressions due to the latter issue
at present, but for our peace of mind let's move the conversion to the
PLN layout into the lower_barycentrics() pass run after
lower_simd_width().
This leads to the following shader-db improvements (including SIMD32
shaders) in combination with the previous back-end preparation changes
-- Without them (especially the copy propagation changes) this would
lead to a massive number of regressions. On ICL:
total instructions in shared programs: 20662316 -> 20466903 (-0.95%)
instructions in affected programs: 10538474 -> 10343061 (-1.85%)
helped: 68775
HURT: 6
total spills in shared programs: 8938 -> 8748 (-2.13%)
spills in affected programs: 376 -> 186 (-50.53%)
helped: 9
HURT: 5
total fills in shared programs: 8965 -> 8663 (-3.37%)
fills in affected programs: 965 -> 663 (-31.30%)
helped: 9
HURT: 6
LOST: 146
GAINED: 43
On SKL:
total instructions in shared programs: 18725867 -> 18614912 (-0.59%)
instructions in affected programs: 3876590 -> 3765635 (-2.86%)
helped: 27492
HURT: 2
LOST: 191
GAINED: 417
On SNB:
total instructions in shared programs: 14573613 -> 13980646 (-4.07%)
instructions in affected programs: 5199074 -> 4606107 (-11.41%)
helped: 29998
HURT: 0
LOST: 21
GAINED: 30
Results are somewhat less impressive but still significant without
SIMD32 fragment shaders enabled. On ICL:
total instructions in shared programs: 16148728 -> 16061659 (-0.54%)
instructions in affected programs: 6114788 -> 6027719 (-1.42%)
helped: 42046
HURT: 6
total spills in shared programs: 8218 -> 8028 (-2.31%)
spills in affected programs: 376 -> 186 (-50.53%)
helped: 9
HURT: 5
total fills in shared programs: 8953 -> 8651 (-3.37%)
fills in affected programs: 965 -> 663 (-31.30%)
helped: 9
HURT: 6
LOST: 0
GAINED: 3
On SKL:
total instructions in shared programs: 14927994 -> 14926738 (-0.01%)
instructions in affected programs: 168850 -> 167594 (-0.74%)
helped: 711
HURT: 2
On SNB:
total instructions in shared programs: 10770538 -> 10734403 (-0.34%)
instructions in affected programs: 2702172 -> 2666037 (-1.34%)
helped: 17818
HURT: 0
All of the hurt shaders are either spilling slightly more or emitting
additional NOP instructions due to the SIMD16 POW workaround for
Gen8-9 combined with differences in scheduling.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
We're about to change the layout of barycentric vectors, which will
involve permuting the GRFs of barycentrics fetched from the thread
payload. Make room for this in a function separate from the generic
fetch_payload_reg(), since the permutation will only be applicable to
barycentric vectors. This allows simplifying fetch_payload_reg(),
since there was no need for handling multiple-component payload
registers except for barycentrics.
This causes some minor shader-db noise due to the new helper emitting
a LOAD_PAYLOAD instruction unconditionally, but it will be cleaned up
shortly.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This prevents regressions on SNB due to the redundant MOVs lying
around in cases where fetch_payload_reg() returns a VGRF (currently
only in SIMD32 but soon in pretty much all cases). The MOVs can't be
register-coalesced due to their source being a FIXED_GRF, and they
can't be copy-propagated either due to the unlit centroid workaround
partial writes. They can be copy-propagated just fine into a SEL
instruction though.
On SNB this prevents the following shader-db regressions (including
SIMD32 programs) in combination with the interpolation rework part of
this series:
total instructions in shared programs: 13996898 -> 14001982 (0.04%)
instructions in affected programs: 197461 -> 202545 (2.57%)
helped: 0
HURT: 1251
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Remove emit_alpha_to_coverage workaround from backend compiler and start
using ported workaround from NIR.
v2: Copy comment from brw_fs_visitor (Caio Marcelo de Oliveira Filho)
Fixes piglit test on HSW:
- arb_sample_shading-builtin-gl-sample-mask-mrt-alpha-to-coverage-combinations
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
The WAIT instruction has been removed, but SYNC.bar can be used
instead to wait for a notification on n0.0.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
We need this function to emit code that setups the control register
later with the defined execution mode for the shader. Therefore, we
emit it as the first instruction.
v2:
- Fix bug in setting the default mode mask in brw_rnd_mode_from_nir().
- Fix support for rounding modes in brw_rnd_mode_from_nir().
v3:
- Updated to renamed shader info member and enum values (Andres).
v4:
- Add actual emission as first instruction of emit_nir_code (Caio).
Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
This reverts commit c0504569ea. Now that
we're doing interpolation lowering in NIR, we can continue to stride the
FS input registers directly in the brw_fs_nir code like we did before.
This fixes SIMD32 fragment shaders which broke because lower_simd_width
depended on the 0 stride to split PLN instructions correctly.
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
It's not used by anything anymore now that so much lowering has been
moved into NIR. Sadly, we still need on in brw_compile_gs() for
geometry shaders on Sandy Bridge. Short of a lot of pointless work,
that one's probably not going away.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
It'll grow further, and we'd like to avoid adding an additional
parameter to fs_generator() for each new piece of data.
v2 (idr): Rebase on 17 months. Track a visitor instead of a cfg.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
This allows us to drop legacy userclip plane handling in both the vec4
and FS backends, and simplifies a few interfaces.
v2 (Jason Ekstrand):
- Move brw_nir_lower_legacy_clipping to brw_nir_uniforms.cpp because
it's i965-specific.
- Handle adding the params in brw_nir_lower_legacy_clipping
- Call brw_nir_lower_legacy_clipping from brw_codegen_vs_prog
Co-authored-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Right now, all keys have two things in common: a program string ID and a
sampler_prog_key_data. I'd like to add another thing or two and need a
place to put it. This commit adds a new brw_base_prog_key struct which
contains those two common bits.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
One cannot write the URB arbitrarily and therefore the message
has to be carefully constructed. The clever tricks originate
from Kenneth and Jason, I'm just writing the patch.
Fixes GPU hangs on ICL with Vulkan CTS.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Move the scalar-region conversion from the IR to the generator, so it
doesn't affect the Gen11 path. We need the non-scalar regioning
for a later lowering pass that we are adding.
v2: Better commit message (Matt)
Reviewed-by: Matt Turner <mattst88@gmail.com>
We add two new texture sources for bindless surface and sampler handles.
Bindless surface handles are expected to be pre-shifted so that the
20-bit surface state table index is in the top 20 bits of the 32-bit
handle. This lets us avoid any extra shifts in the shader. Bindless
sampler handles are 32-byte aligned byte offsets from general state base
address. We use 32-byte aligned instead of 16-byte aligned to avoid
having to use more indirect messages than needed. It means we can't
tightly pack samplers but that's probably not a big deal.
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
From "Alpha Coverage" section of SKL PRM Volume 7:
"If Pixel Shader outputs oMask, AlphaToCoverage is disabled in
hardware, regardless of the state setting for this feature."
From OpenGL spec 4.6, "15.2 Shader Execution":
"The built-in integer array gl_SampleMask can be used to change
the sample coverage for a fragment from within the shader."
From OpenGL spec 4.6, "17.3.1 Alpha To Coverage":
"If SAMPLE_ALPHA_TO_COVERAGE is enabled, a temporary coverage value
is generated where each bit is determined by the alpha value at the
corresponding sample location. The temporary coverage value is then
ANDed with the fragment coverage value to generate a new fragment
coverage value."
Similar wording could be found in Vulkan spec 1.1.100
"25.6. Multisample Coverage"
Thus we need to compute alpha to coverage dithering manually in shader
and replace sample mask store with the bitwise-AND of sample mask and
alpha to coverage dithering.
The following formula is used to compute final sample mask:
m = int(16.0 * clamp(src0_alpha, 0.0, 1.0))
dither_mask = 0x1111 * ((0xfea80 >> (m & ~3)) & 0xf) |
0x0808 * (m & 2) | 0x0100 * (m & 1)
sample_mask = sample_mask & dither_mask
Credits to Francisco Jerez <currojerez@riseup.net> for creating it.
It gives a number of ones proportional to the alpha for 2, 4, 8 or 16
least significant bits of the result.
GEN6 hardware does not have issue with simultaneous usage of sample mask
and alpha to coverage however due to the wrong sending order of oMask
and src0_alpha it is still affected by it.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109743
Signed-off-by: Danylo Piliaiev <danylo.piliaiev@globallogic.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
The sampler will be ignored since the underlying 'ld_mcs' operation
won't use it, so just fill the field with 0 instead of the texture to
make it clearer that's the case.
This will also avoid is_high_sampler() to kick in unnecessarily, in
case we are using the operation for a texture with index >= 16.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This helps us to compact original instruction:
mul(8) g3<1>D g6<8,8,1>UD 0x00000006UD { align1 1Q };
So now we emit:
mul(8) g3<1>UD g6<8,8,1>UD 0x00000006UD { align1 1Q compacted };
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
There's no reason for us to emit it a pile of times and then have a
whole pass to clean it up. Just emit it once like we really want.
Reviewed-by: Matt Turner <mattst88@gmail.com>
This generalizes the unlit centroid workaround so it's less code and now
supports SIMD32.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
While we're here, we change to using horiz_offset() instead of abusing
half().
v2 (Jason Ekstrand):
- Use horiz_offset() instead of half()
Reviewed-by: Matt Turner <mattst88@gmail.com>
This prevents a crash in some arb_enhanced_layouts tests that would be
caused by the next commit.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
When using multiple RT write messages to the same RT such as for
dual-source blending or all RT writes in SIMD32, we have to set the
"Last Render Target Select" bit on all write messages that target the
last RT but only set EOT on the last RT write in the shader.
Special-casing for dual-source blend works today because that is the
only case which requires multiple RT write messages per RT. When we
start doing SIMD32, this will become much more common so we add a
dedicated bit for it.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
This replaces the special magic opcodes which implicitly read inputs
with explicit use of the ATTR file.
v2 (Jason Ekstrand):
- Break into multiple patches
- Change the units of the FS ATTR to be in logical scalars
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
This should shut up some Valgrind errors during pre-regalloc
scheduling. The errors were harmless since they could only have led
to the estimation of the bank conflict penalty of an instruction
pre-regalloc, which is inaccurate at that point of the program
compilation, but no less accurate than the intended "return 0"
fall-back path. The scheduling pass is normally re-run after regalloc
with a well-defined grf_used value and accurate bank conflict
information.
Fixes: acf98ff933 "intel/fs: Teach instruction scheduler about GRF bank conflict cycles."
Reported-by: Eero Tamminen <eero.t.tamminen@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Originally we tried to handle this case based on slots_valid. However,
there are a number of ways that this can go wrong. For one, we throw
away any trailing slots which either aren't written or are set to
VARYING_SLOT_PAD. Second, even if PSIZ is a valid slot, we may not
actually write anything there. Between the lot of these, it was
possible to end up in a case where we tried to do a regular URB write
but ended up with a length of 1 which is invalid. This commit moves it
to the end and makes it based on a new boolean flag urb_written.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Cc: mesa-stable@lists.freedesktop.org
It's 8 for everything except compute shaders. For compute shaders,
there's no need to duplicate the computation and it's just a possible
source of error.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Instead of requiring the caller of brw_compile_vs to figure it out, just
grow the param array on-demand.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This moves us away to the array of pointers model and onto a model where
each param is represented by a generic uint32_t handle. We reserve 2^16
of these handles for builtins that get generated by somewhere inside the
compiler and have well-defined meanings. Generic params have handles
whose meanings are defined by the driver.
The primary downside to this new approach is that it moves a little bit
of the work that we would normally do at compile time to draw time. On
my laptop this hurts OglBatch6 by no more than 1% and doesn't seem to
have any measurable affect on OglBatch7. So, while this may come back
to bite us, it doesn't look too bad.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.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>
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>
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>
