Commit graph

242 commits

Author SHA1 Message Date
Matt Turner
e76772af6c intel/compiler: Lower 64-bit MOV/SEL operations 2019-01-09 16:42:40 -08:00
Francisco Jerez
230a8a541d intel/fs: Remove FS_OPCODE_UNPACK_HALF_2x16_SPLIT opcodes.
These are broken on a future platform, but it turns out we don't need
to fix them, since they're just type-converting moves with strided
source.  Kill them.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:09 -08:00
Francisco Jerez
2c99c7a56c intel/fs: Remove existing lower_conversions pass.
It's redundant with the functionality provided by lower_regioning now.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:09 -08:00
Francisco Jerez
efa4e4bc5f intel/fs: Introduce regioning lowering pass.
This legalization pass is meant to handle situations where the source
or destination regioning controls of an instruction are unsupported by
the hardware and need to be lowered away into separate instructions.
This should be more reliable and future-proof than the current
approach of handling CHV/BXT restrictions manually all over the
visitor.  The same mechanism is leveraged to lower unsupported type
conversions easily, which obsoletes the lower_conversions pass.

v2: Give conditional modifiers the same treatment as predicates for
    SEL instructions in lower_dst_modifiers() (Iago).  Special-case a
    couple of other instructions with inconsistent conditional mod
    semantics in lower_dst_modifiers() (Curro).

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:09 -08:00
Francisco Jerez
b94519971a intel/fs: Constify fs_inst::can_do_source_mods().
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:09 -08:00
Francisco Jerez
bc781a0323 intel/fs: Fix bug in lower_simd_width while splitting an instruction which was already split.
This seems to be a problem in combination with the lower_regioning
pass introduced by a future commit, which can modify a SIMD-split
instruction causing its execution size to become illegal again.  A
subsequent call to lower_simd_width() would hit this bug on a future
platform.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:08 -08:00
Francisco Jerez
812ede088f intel/fs: Implement quad swizzles on ICL+.
Align16 is no longer a thing, so a new implementation is provided
using Align1 instead.  Not all possible swizzles can be represented as
a single Align1 region, but some fast paths are provided for
frequently used swizzles that can be represented efficiently in Align1
mode.

Fixes ~90 subgroup quad swap Vulkan CTS tests.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:08 -08:00
Francisco Jerez
c5f9c0009d intel/fs: Handle source modifiers in lower_integer_multiplication().
lower_integer_multiplication() implements 32x32-bit multiplication on
some platforms by bit-casting one of the 32-bit sources into two
16-bit unsigned integer portions.  This can give incorrect results if
the original instruction specified a source modifier.  Fix it by
emitting an additional MOV instruction implementing the source
modifiers where necessary.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2019-01-09 12:03:08 -08:00
Ian Romanick
9a83c3d3b3 i965/fs: Eliminate unary op on operand of compare-with-zero
The (-abs(x) >= 0) => (x == 0) optimization is removed from the vec4 and
scalar parts. In the VS part, adding the new pattern was not
helpful. The pattern that is removed is really old, and it has been
handled by NIR for ages.

All Gen7+ platforms had similar results. (Broadwell shown)
total instructions in shared programs: 14715715 -> 14715709 (<.01%)
instructions in affected programs: 474 -> 468 (-1.27%)
helped: 6
HURT: 0
helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1
helped stats (rel) min: 1.12% max: 1.35% x̄: 1.28% x̃: 1.35%
95% mean confidence interval for instructions value: -1.00 -1.00
95% mean confidence interval for instructions %-change: -1.40% -1.15%
Instructions are helped.

total cycles in shared programs: 559569911 -> 559569809 (<.01%)
cycles in affected programs: 5963 -> 5861 (-1.71%)
helped: 6
HURT: 0
helped stats (abs) min: 16 max: 18 x̄: 17.00 x̃: 17
helped stats (rel) min: 1.45% max: 1.88% x̄: 1.73% x̃: 1.85%
95% mean confidence interval for cycles value: -18.15 -15.85
95% mean confidence interval for cycles %-change: -1.95% -1.51%
Cycles are helped.

Iron Lake and Sandy Bridge had similar results. (Iron Lake shown)
total instructions in shared programs: 7780915 -> 7780913 (<.01%)
instructions in affected programs: 246 -> 244 (-0.81%)
helped: 2
HURT: 0

total cycles in shared programs: 177876108 -> 177876106 (<.01%)
cycles in affected programs: 3636 -> 3634 (-0.06%)
helped: 1
HURT: 0

GM45
total instructions in shared programs: 4799152 -> 4799151 (<.01%)
instructions in affected programs: 126 -> 125 (-0.79%)
helped: 1
HURT: 0

total cycles in shared programs: 122052654 -> 122052652 (<.01%)
cycles in affected programs: 3640 -> 3638 (-0.05%)
helped: 1
HURT: 0

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
2018-12-17 13:47:06 -08:00
Jason Ekstrand
cb98e0755f intel/fs: Support min_lod parameters on texture instructions
We have to lower some shadow instructions because they don't exist in
hardware and we have to lower txb+offset+clamp because the message gets
too big and we run into the sampler message length limit of 11 regs.

Acked-by: Ian Romanick <ian.d.romanick@intel.com>
2018-12-11 21:26:23 -06:00
Matt Turner
f447a13032 i965/fs: Handle V/UV immediates in dump_instructions() 2018-12-10 10:46:56 -08:00
Iago Toral Quiroga
453570cd8c intel/compiler: fix indentation style in opt_algebraic() 2018-11-27 09:53:09 +01:00
Kenneth Graunke
562448b75a i965: Do NIR shader cloning in the caller.
This moves nir_shader_clone() to the driver-specific compile function,
rather than the shared src/intel/compiler code.  This allows i965 to do
key-specific passes before calling brw_compile_*.  Vulkan should not
need this cloning as it doesn't compile multiple variants.

We do need to continue cloning in the compute shader code because we
lower various things in NIR based on the SIMD width.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
2018-11-20 15:53:46 -08:00
Jason Ekstrand
d3a0d8b750 intel/compiler: Stop assuming the entrypoint is called "main"
This isn't true for Vulkan so we have to whack it to "main" in anv which
is silly.  Instead of walking the list of functions and asserting that
everything is named "main" and hoping there's only one function named
"main", just use the nir_shader_get_entrypoint() helper which has better
assertions anyway.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-10-30 20:14:52 -05:00
Topi Pohjolainen
a11cafbd7a intel/compiler/icl: Use invocation id bits 22:16 instead of 23:17
Identifier bits in the dispatch header have changed. See Bspec:

SINGLE_PATCH Payload:

3D Pipeline Stages - 3D Pipeline Geometry -
Hull Shader (HS) Stage IVB+ - Payloads IVB+

Fixes: KHR-GL46.tessellation_shader.tessellation_shader_tc_barriers.barrier_guarded_read_write_calls

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
2018-10-17 21:19:57 +03:00
Matt Turner
58a51d0a67 i965/fs: Add 64-bit int immediate support to dump_instructions()
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2018-10-16 17:48:17 -07:00
Jason Ekstrand
4ba445e011 intel: Don't propagate conditional modifiers if a UD source is negated
This fixes a bug uncovered by my NIR integer division by constant
optimization series.

Fixes: 19f9cb72c8 "i965/fs: Add pass to propagate conditional..."
Fixes: 627f94b72e "i965/vec4: adding vec4_cmod_propagation..."
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2018-10-10 13:13:12 -05:00
Dylan Baker
8396043f30 Replace uses of _mesa_bitcount with util_bitcount
and _mesa_bitcount_64 with util_bitcount_64. This fixes a build problem
in nir for platforms that don't have popcount or popcountll, such as
32bit msvc.

v2: - Fix additional uses of _mesa_bitcount added after this was
      originally written

Acked-by: Eric Engestrom <eric.engestrom@intel.com> (v1)
Acked-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2018-09-07 10:21:26 -07:00
Jason Ekstrand
09f1de97a7 anv,i965: Lower away image derefs in the driver
Previously, the back-end compiler turn image access into magic uniform
reads and there was a complex contract between back-end compiler and
driver about setting up and filling out those params.  As of this
commit, both drivers now lower image_deref_load_param_intel intrinsics
to load_uniform intrinsics controlled by the driver and lower the other
image_deref_* intrinsics to image_* intrinsics which take an actual
binding table index.  There are still "magic" uniforms but they are now
added and controlled entirely by the driver and that contract no longer
spans components.

This also has the side-effect of making most image use compile-time
binding table indices.  Previously, all image access pulled the binding
table index from a uniform.  Part of the reason for this was that the
magic uniforms made it difficult to decouple binding table indices from
the uniforms and, since they are indexed completely differently
(especially in Vulkan), it was hard to pull them apart.  Now that the
driver is handling both, it's trivial to decouple the two and provide
actual binding table indices.

Shader-db results on Kaby Lake:

    total instructions in shared programs: 15166872 -> 15164293 (-0.02%)
    instructions in affected programs: 115834 -> 113255 (-2.23%)
    helped: 191
    HURT: 0

    total cycles in shared programs: 571311495 -> 571196465 (-0.02%)
    cycles in affected programs: 4757115 -> 4642085 (-2.42%)
    helped: 73
    HURT: 67

    total spills in shared programs: 10951 -> 10926 (-0.23%)
    spills in affected programs: 742 -> 717 (-3.37%)
    helped: 7
    HURT: 0

    total fills in shared programs: 22226 -> 22201 (-0.11%)
    fills in affected programs: 1146 -> 1121 (-2.18%)
    helped: 7
    HURT: 0

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-08-29 14:04:03 -05:00
Ian Romanick
d515c75463 intel/compiler: Implement untyped atomic float min, max, and compare-swap dataport messages
v2: Split changes to the message type field to another patch.  Suggested
by Caio.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
2018-08-22 20:31:32 -07:00
Kenneth Graunke
08a5c395ab intel: Fix SIMD16 unaligned payload GRF reads on Gen4-5.
When the SIMD16 Gen4-5 fragment shader payload contains source depth
(g2-3), destination stencil (g4), and destination depth (g5-6), the
single register of stencil makes the destination depth unaligned.

We were generating this instruction in the RT write payload setup:

   mov(16)   m14<1>F   g5<8,8,1>F   { align1 compr };

which is illegal, instructions with a source region spanning more than
one register need to be aligned to even registers.  This is because the
hardware implicitly does (nr | 1) instead of (nr + 1) when splitting the
compressed instruction into two mov(8)'s.

I believe this would cause the hardware to load g5 twice, replicating
subspan 0-1's destination depth to subspan 2-3.  This showed up as 2x2
artifact blocks in both TIS-100 and Reicast.

Normally, we rely on the register allocator to even-align our virtual
GRFs.  But we don't control the payload, so we need to lower SIMD widths
to make it work.  To fix this, we teach lower_simd_width about the
restriction, and then call it again after lower_load_payload (which is
what generates the offending MOV).

Fixes: 8aee87fe4c (i965: Use SIMD16 instead of SIMD8 on Gen4 when possible.)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107212
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=13728
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Tested-by: Diego Viola <diego.viola@gmail.com>
2018-08-09 12:33:41 -07:00
Jason Ekstrand
57804efa88 i965/fs: Flag all slots of a flat input as flat
Otherwise, only the first vec4 of a matrix or other complex type will
get marked as flat and we'll interpolate the others.  This was caught by
a dEQP test which started failing because it did a SSO vs. non-SSO
comparison.  Previously, we did the interpolation wrong consistently in
both versions.  However, with one of Tim Arceri's NIR linkingpatches, we
started splitting the matrix input into vectors at link time in the
non-SSO version and it started getting correctly interpolated which
didn't match the broken SSO version.  As of this commit, they both get
correctly interpolated.

Fixes: e61cc87c75 "i965/fs: Add a flat_inputs field to prog_data"
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-08-01 18:02:28 -07:00
Caio Marcelo de Oliveira Filho
4a29ee1861 intel/compiler: fix -Wsign-compare warning
Explicitly convert to signed integer. Conversion is valid since is the
same (implicitly) used to initialize the loop. Avoids the warning:

../../src/intel/compiler/brw_fs.cpp: In member function ‘bool fs_visitor::lower_simd_width()’:
../../src/intel/compiler/brw_fs.cpp:5761:45: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]
             split_inst.eot = inst->eot && i == n - 1;
                                           ~~^~~~~~~~

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
2018-07-18 08:29:51 -07:00
Caio Marcelo de Oliveira Filho
7df5f62768 intel/compiler: silence -Wclass-memaccess warnings
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
2018-07-18 08:29:51 -07:00
Francisco Jerez
48d6fc5eb6 intel/fs: Initialize mlen for gen7 varying pull constant load messages.
This makes the message length available at the IR level, which should
save some guesswork in a future commit.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-07-09 23:46:58 -07:00
Iago Toral Quiroga
81ca08e030 intel/compiler: remove unused function
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
2018-07-09 13:21:48 +02:00
Ian Romanick
f8e54d02f7 intel/compiler: Relax mixed type restriction for saturating immediates
At the time of commit 7bc6e455e2 (i965: Add support for saturating
immediates.) we thought mixed type saturates would be impossible.  We
were only thinking about type converting moves from D to F, for
example.  However, type converting moves w/saturate from F to DF are
definitely possible.  This change minimally relaxes the restriction to
allow cases that I have been able trigger via piglit tests.

Fixes new piglit tests:
 - arb_gpu_shader_fp64/execution/built-in-functions/fs-sign-sat-neg-abs.shader_test
 - arb_gpu_shader_fp64/execution/built-in-functions/vs-sign-sat-neg-abs.shader_test

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
2018-07-06 16:20:10 -07:00
Francisco Jerez
c2c803be7b intel/fs: Build 32-wide FS shaders.
Co-authored-by: Jason Ekstrand <jason@jlekstrand.net>
2018-06-28 13:25:21 -07:00
Jason Ekstrand
e208bc3bb7 intel/fs: Get rid of MOV_DISPATCH_TO_FLAGS
We can just emit the MOV in the two places where we use this.

Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Jason Ekstrand
5e3028d826 intel/fs: Emit MOV_DISPATCH_TO_FLAGS once for the centroid workaround
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>
2018-06-28 13:19:38 -07:00
Francisco Jerez
1d381731e0 intel/fs: Fix sample id setup for SIMD32.
v2 (Jason Ekstrand):
 - Disallow gl_SampleId in SIMD32 on gen7

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
2fd0aed89a intel/fs: Fix Gen7 compressed source region alignment restriction for SIMD32
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
6909aed90e intel/fs: Implement 32-wide FS payload setup on Gen6+
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
f6c4aace22 intel/fs: Extend thread payload layout to SIMD32
And handle 32-wide payload register reads in fetch_payload_reg().

v2 (Jason Ekstrand);
 - Fix some whitespace and brace placement

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
8f143f70d6 intel/fs: Wrap FS payload register look-up in a helper function.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
38aee1a06d intel/fs: Simplify fs_visitor::emit_samplepos_setup
The original code manually handled splitting the MOVs to 8-wide to
handle various regioning restrictions.  Now that we have a SIMD width
splitting pass that handles these things, we can just emit everything at
the full width and let the SIMD splitting pass handle it.  We also now
have a useful "subscript" helper which is designed exactly for the case
where you want to take a W type and read it as a vector of Bs so we may
as well use that too.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
244a0ff3a8 i965: Add plumbing for shader time in 32-wide FS dispatch mode.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
2d7d652d5c intel/fs: Disable opt_sampler_eot() in 32-wide dispatch.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
73d60455e9 intel/fs: Rework INTERPOLATE_AT_PER_SLOT_OFFSET
This reworks INTERPOLATE_AT_PER_SLOT_OFFSET to work more like an ALU
operation and less like a send.  This is less code over-all and, as a
side-effect, it now properly handles execution groups and lowering so
SIMD32 support just falls out.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
2aefa5e19f intel/fs: Fix FB read header setup for SIMD32.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
e06f5b30cc intel/fs: Fix logical FB write lowering for SIMD32
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Jason Ekstrand
d5b617a28e intel/fs: Split instructions low to high in lower_simd_width
Commit 0d905597f fixed an issue with the placement of the zip and unzip
instructions.  However, as a side-effect, it reversed the order in which
we were emitting the split instructions so that they went from high
group to low instead of low to high.  This is fine for most things like
texture instructions and the like but certain render target writes
really want to be emitted low to high.  This commit just switches the
order back around to be low to high.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Fixes: 0d905597f "intel/fs: Be more explicit about our placement of [un]zip"
2018-06-28 13:19:38 -07:00
Jason Ekstrand
0b830081f0 intel/fs: Rework KSP data to be SIMD width-based
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
5b6e91dd35 intel/fs: Remove program key argument from generator.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Jason Ekstrand
a14fb0184a intel/fs: Set up FB write message headers in the visitor
Doing instruction header setup in the generator is awful for a number
of reasons.  For one, we can't schedule the header setup at all.  For
another, it means lots of implied writes which the instruction scheduler
and other passes can't properly read about.  The second isn't a huge
problem for FB writes since they always happen at the end.  We made a
similar change to sampler handling in ff4726077d.

Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
dda31a7bbc intel/fs: Fix implied_mrf_writes() for headerless FB writes.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Francisco Jerez
90643689aa intel/fs: Fix fs_inst::flags_written() for Gen4-5 FB writes.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Jason Ekstrand
b1cc9a9ae1 intel/fs: Properly track implied header regs read by FB writes
The FB write opcode on gen4-5 does implied copies from g0 and g1 to the
message payload.  With this commit, we start tracking that as part of
the IR by having the FB write read from g0-1.

Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-06-28 13:19:38 -07:00
Jose Maria Casanova Crespo
a0891eabca intel/fs: Use shuffle_from_32bit_read at VARYING_PULL_CONSTANT_LOAD
shuffle_from_32bit_read can manage the shuffle/unshuffle needed
for different 8/16/32/64 bit-sizes at VARYING PULL CONSTANT LOAD.
To get the specific component the first_component parameter is used.

In the case of the previous 16-bit shuffle, the shuffle operation was
generating not needed MOVs where its results where never used. This
behaviour passed unnoticed on SIMD16 because dead_code_eliminate
pass removed the generated instructions but for SIMD8 they cound't be
removed because of being partial writes.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-06-16 22:39:08 +02:00
Ian Romanick
284b563fb0 i965/fs: Optimize OR with 0 into a MOV
fs_visitor::set_gs_stream_control_data_bits generates some code like
"control_data_bits | stream_id << ((2 * (vertex_count - 1)) % 32)" as
part of EmitVertex.  The first time this (dynamically) occurs in the
shader, control_data_bits is zero.  Many times we can determine this
statically and various optimizations will collaborate to make one of the
OR operands literal zero.

Converting the OR to a MOV usually allows it to be copy-propagated away.
However, this does not happen in at least some shaders (in the assembly
output of shaders/closed/UnrealEngine4/EffectsCaveDemo/301.shader_test,
search for shl).

All of the affected shaders are geometry shaders.

Broadwell and Skylake had similar results. (Skylake shown)
total instructions in shared programs: 14375452 -> 14375413 (<.01%)
instructions in affected programs: 6422 -> 6383 (-0.61%)
helped: 39
HURT: 0
helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1
helped stats (rel) min: 0.14% max: 2.56% x̄: 1.91% x̃: 2.56%
95% mean confidence interval for instructions value: -1.00 -1.00
95% mean confidence interval for instructions %-change: -2.26% -1.57%
Instructions are helped.

total cycles in shared programs: 531981179 -> 531980555 (<.01%)
cycles in affected programs: 27493 -> 26869 (-2.27%)
helped: 39
HURT: 0
helped stats (abs) min: 16 max: 16 x̄: 16.00 x̃: 16
helped stats (rel) min: 0.60% max: 7.92% x̄: 5.94% x̃: 7.92%
95% mean confidence interval for cycles value: -16.00 -16.00
95% mean confidence interval for cycles %-change: -6.98% -4.90%
Cycles are helped.

No changes on earlier platforms.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
2018-06-15 17:22:27 -07:00