Previously, if a group was nested in another group such that it didn't
start on a dword boundary, we would decode it as if it started at the
start of its first dword. This changes things to work even more in
terms of bits so that we can properly decode these structs. This
affects MOCS, attribute swizzles, and several other things.
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
We can write to the same output but in different components, like
in this example:
layout(location = 0, component = 0) out ivec2 dEQP_FragColor_0;
layout(location = 0, component = 2) out ivec2 dEQP_FragColor_1;
Therefore, they are not two different outputs but only one.
Fixes:
dEQP-VK.glsl.440.linkage.varying.component.frag_out.*
v3:
- Remove FRAG_RESULT_MAX.
- Add const and use sizeof (Ian).
- Do three-pass to set properly the locations of fragment
outputs when having arrays (Jason).
Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Push constants on Intel hardware are significantly more performant than
pull constants. Since most Vulkan applications don't actively use push
constants on Vulkan or at least don't use it heavily, we're pulling way
more than we should be. By enabling pushing chunks of UBOs we can get
rid of a lot of those pulls.
On my SKL GT4e, this improves the performance of Dota 2 and Talos by
around 2.5% and improves Aztec Ruins by around 2%.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
In Vulkan, we don't support classic pull constants and everything the
client asks us to push, we push. However, for pushed UBOs, we still
want to fall back to conventional pulls if we run out of space.
Push constants work in terms of 32-byte chunks so if we want to be able
to push UBOs, every thing needs to be 32-byte aligned. Currently, we
only require 16-byte which is too small.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
In order to do this we have to modify push constant set up to handle
ranges. We also have to tweak the way we handle dirty bits a bit so
that we re-push whenever a descriptor set changes.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
There are several places where we look up opcodes in an array of stages.
Assert that the we don't end up going out-of-bounds.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
We want to call brw_nir_analyze_ubo_ranges immedately after
anv_nir_apply_pipeline_layout and it badly wants constants. We could
run an optimization step and let constant folding do it but that's way
more expensive than needed. It's really easy to just handle constants
in apply_pipeline_layout.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
This rewires the logic for assigning uniform locations to work in terms
of "complex alignments". The basic idea is that, as we walk the list of
instructions, we keep track of the alignment and continuity requirements
of each slot and assert that the alignments all match up. We then use
those alignments in the compaction stage to ensure that everything gets
placed at a properly aligned register. The old mechanism handled
alignments by special-casing each of the bit sizes and placing 64-bit
values first followed by 32-bit values.
The old scheme had the advantage of never leaving a hole since all the
64-bit values could be tightly packed and so could the 32-bit values.
However, the new scheme has no type size special cases so it handles not
only 32 and 64-bit types but should gracefully extend to 16 and 8-bit
types as the need arises.
Tested-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
The testing for this extension is currently very poor. The CTS tests
only test accessing UBOs and SSBOs at dynamic offsets so none of our
constant-offset paths get triggered at all. Also, there's an assertion
in our handling of nir_intrinsic_load_uniform that offset % 4 == 0 which
is never triggered indicating that nothing every gets loaded from an
offset which is not a dword. Both push constants and the constant
offset pull paths are complex enough, we really don't want to ship
without tests. We'll turn the extension back on once we have decent
tests.
This addresses a long-standing back-end compiler bug that could lead
to cross-channel data corruption in loops executed non-uniformly. In
some cases live variables extending through a loop divergence point
(e.g. a non-uniform break) into a convergence point (e.g. the end of
the loop) wouldn't be considered live along all physical control flow
paths the SIMD thread could possibly have taken in between due to some
channels remaining in the loop for additional iterations.
This patch fixes the problem by extending the CFG with physical edges
that don't exist in the idealized non-vectorized program, but
represent valid control flow paths the SIMD EU may take due to the
divergence of logical threads. This makes sense because the i965 IR
is explicitly SIMD, and it's not uncommon for instructions to have an
influence on neighboring channels (e.g. a force_writemask_all header
setup), so the behavior of the SIMD thread as a whole needs to be
considered.
No changes in shader-db.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This makes the dataflow propagation logic of the copy propagation pass
more intelligent in cases where the destination of a copy is known to
be undefined for some incoming CFG edges, building upon the
definedness information provided by the last patch. Helps a few
programs, and avoids a handful shader-db regressions from the next
patch.
shader-db results on ILK:
total instructions in shared programs: 6541547 -> 6541523 (-0.00%)
instructions in affected programs: 360 -> 336 (-6.67%)
helped: 8
HURT: 0
LOST: 0
GAINED: 10
shader-db results on BDW:
total instructions in shared programs: 8174323 -> 8173882 (-0.01%)
instructions in affected programs: 7730 -> 7289 (-5.71%)
helped: 5
HURT: 2
LOST: 0
GAINED: 4
shader-db results on SKL:
total instructions in shared programs: 8185669 -> 8184598 (-0.01%)
instructions in affected programs: 10364 -> 9293 (-10.33%)
helped: 5
HURT: 2
LOST: 0
GAINED: 2
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Currently the liveness analysis pass would extend a live interval up
to the top of the program when no unconditional and complete
definition of the variable is found that dominates all of its uses.
This can lead to a serious performance problem in shaders containing
many partial writes, like scalar arithmetic, FP64 and soon FP16
operations. The number of oversize live intervals in such workloads
can cause the compilation time of the shader to explode because of the
worse than quadratic behavior of the register allocator and scheduler
when running out of registers, and it can also cause the running time
of the shader to explode due to the amount of spilling it leads to,
which is orders of magnitude slower than GRF memory.
This patch fixes it by computing the intersection of our current live
intervals with the subset of the program that can possibly be reached
from any definition of the variable. Extending the storage allocation
of the variable beyond that is pretty useless because its value is
guaranteed to be undefined at a point that cannot be reached from any
definition.
According to Jason, this improves performance of the subgroup Vulkan
CTS tests significantly (e.g. the runtime of the dvec4 broadcast test
improves by nearly 50x).
No significant change in the running time of shader-db (with 5%
statistical significance).
shader-db results on IVB:
total cycles in shared programs: 61108780 -> 60932856 (-0.29%)
cycles in affected programs: 16335482 -> 16159558 (-1.08%)
helped: 5121
HURT: 4347
total spills in shared programs: 1309 -> 1288 (-1.60%)
spills in affected programs: 249 -> 228 (-8.43%)
helped: 3
HURT: 0
total fills in shared programs: 1652 -> 1597 (-3.33%)
fills in affected programs: 262 -> 207 (-20.99%)
helped: 4
HURT: 0
LOST: 2
GAINED: 209
shader-db results on BDW:
total cycles in shared programs: 67617262 -> 67361220 (-0.38%)
cycles in affected programs: 23397142 -> 23141100 (-1.09%)
helped: 8045
HURT: 6488
total spills in shared programs: 1456 -> 1252 (-14.01%)
spills in affected programs: 465 -> 261 (-43.87%)
helped: 3
HURT: 0
total fills in shared programs: 1720 -> 1465 (-14.83%)
fills in affected programs: 471 -> 216 (-54.14%)
helped: 4
HURT: 0
LOST: 2
GAINED: 162
shader-db results on SKL:
total cycles in shared programs: 65436248 -> 65245186 (-0.29%)
cycles in affected programs: 22560936 -> 22369874 (-0.85%)
helped: 8457
HURT: 6247
total spills in shared programs: 437 -> 437 (0.00%)
spills in affected programs: 0 -> 0
helped: 0
HURT: 0
total fills in shared programs: 870 -> 854 (-1.84%)
fills in affected programs: 16 -> 0
helped: 1
HURT: 0
LOST: 0
GAINED: 107
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This should allow the post-RA scheduler to do a slightly better job at
hiding latency in presence of instructions incurring bank conflicts.
The main purpuse of this patch is not to improve performance though,
but to get conflict cycles to show up in shader-db statistics in order
to make sure that regressions in the bank conflict mitigation pass
don't go unnoticed.
Acked-by: Matt Turner <mattst88@gmail.com>
Unnecessary GRF bank conflicts increase the issue time of ternary
instructions (the overwhelmingly most common of which is MAD) by
roughly 50%, leading to reduced ALU throughput. This pass attempts to
minimize the number of bank conflicts by rearranging the layout of the
GRF space post-register allocation. It's in general not possible to
eliminate all of them without introducing extra copies, which are
typically more expensive than the bank conflict itself.
In a shader-db run on SKL this helps roughly 46k shaders:
total conflicts in shared programs: 1008981 -> 600461 (-40.49%)
conflicts in affected programs: 816222 -> 407702 (-50.05%)
helped: 46234
HURT: 72
The running time of shader-db itself on SKL seems to be increased by
roughly 2.52%±1.13% with n=20 due to the additional work done by the
compiler back-end.
On earlier generations the pass is somewhat less effective in relative
terms because the hardware incurs a bank conflict anytime the last two
sources of the instruction are duplicate (e.g. while trying to square
a value using MAD), which is impossible to avoid without introducing
copies. E.g. for a shader-db run on SNB:
total conflicts in shared programs: 944636 -> 623185 (-34.03%)
conflicts in affected programs: 853258 -> 531807 (-37.67%)
helped: 31052
HURT: 19
And on BDW:
total conflicts in shared programs: 1418393 -> 987539 (-30.38%)
conflicts in affected programs: 1179787 -> 748933 (-36.52%)
helped: 47592
HURT: 70
On SKL GT4e this improves performance of GpuTest Volplosion by 3.64%
±0.33% with n=16.
NOTE: This patch intentionally disregards some i965 coding conventions
for the sake of reviewability. This is addressed by the next
squash patch which introduces an amount of (for the most part
boring) boilerplate that might distract reviewers from the
non-trivial algorithmic details of the pass.
The following patch is squashed in:
SQUASH: intel/fs/bank_conflicts: Roll back to the nineties.
Acked-by: Matt Turner <mattst88@gmail.com>
The handle type in the case statement is supposed to be VK_EXTERNAL_-
MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT.
Fixes: ab18e8e59b ("anv: Implement VK_EXT_external_memory_dma_buf")
Signed-off-by: Fredrik Höglund <fredrik@kde.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
SSBO loads were using byte_scattered read messages as they allow
reading 16-bit size components. byte_scattered messages can only
operate one component at a time so we needed to emit as many messages
as components.
But for vec2 and vec4 of 16-bit, being multiple of 32-bit we can use the
untyped_surface_read message to read pairs of 16-bit components using only
one message. Once each pair is read it is unshuffled to return the proper
16-bit components. vec3 case is assimilated to vec4 but the 4th component
is ignored.
16-bit scalars are read using one byte_scattered_read message.
v2: Removed use of stride = 2 on sources (Jason Ekstrand)
Rework optimization using unshuffle 16 reads (Chema Casanova)
v3: Use W and D types insead of HF and F in shuffle to avoid rounding
erros (Jason Ekstrand)
Use untyped_surface_read for 16-bit vec3. (Jason Ekstrand)
v4: Use subscript insead of chaging type and stride (Jason Ekstrand)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Currently, we use byte-scattered write messages for storing 16-bit
into an SSBO. This is because untyped surface messages have a fixed
32-bit size.
This patch optimizes these 16-bit writes by combining 2 values (e.g,
two consecutive components aligned with 32-bits) into a 32-bit register,
packing the two 16-bit words.
16-bit single component values will continue to use byte-scattered
write messages. The same will happens when the first consecutive
component is not aligned 32-bits.
This optimization reduces the number of SEND messages used for storing
16-bit values potentially by 2 or 4, which cuts down execution time
significantly because byte-scattered writes are an expensive
operation as they only write a component for message.
v2: Removed use of stride = 2 on sources (Jason Ekstrand)
Rework optimization using shuffle 16 write and enable writes
of 16bit vec4 with only one message of 32-bits. (Chema Casanova)
v3: - Fix coding style (Eduardo Lima)
- Reorganize code to avoid duplication. (Jason Ekstrand)
- Include new comments to explain the length calculations to
fix alignment issues of components. (Jason Ekstrand)
- Fix issues with writemask yz with 16-bit writes. (Jason Ektrand)
v4: (Jason Ekstrand)
- Reorganize 64-bit ssbo-writes to avoid using slots_per_component.
- Comment about why suffle is needed when using byte_scattered_write.
Signed-off-by: Eduardo Lima <elima@igalia.com>
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Enables SPV_KHR_16bit_storage on gen 8+.
VK_KHR_16bit_storage is enabled for SSBO/UBO using the
VK_KHR_get_physical_device_properties2 functionality to expose
if the extension is supported or not.
v2: update due rebase against master (Alejandro)
v3: (Jason Ekstrand)
- Move this patch up in VK_KHR_16bit_storage series enabling only
storageBuffer16BitAccess and uniformAndStorageBuffer16BitAccess.
- Only expose VK_KHR_16bit_storage on Gen8+
v4: (Jason Ekstrand)
- Squash enable SPV_KHR_16bit_storage into VK_KHR_16bit_storage
enablement for SSBO/UBO.
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Signed-off-by: Eduardo Lima Mitev <elima@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
load_ubo is using 32-bit loads as uniforms surfaces have a 32-bit
surface format defined. So when reading 16-bit components with the
sampler we need to unshuffle two 16-bit components from each 32-bit
component.
Using the sampler avoids the use of the byte_scattered_read message
that needs one message for each component and is supposed to be
slower.
v2: (Jason Ekstrand)
- Simplify component selection and unshuffling for different bitsizes
- Remove SKL optimization of reading only two 32-bit components when
reading 16-bits types.
Reviewed-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
This helpers are used to load/store 16-bit types from/to 32-bit
components.
The functions shuffle_32bit_load_result_to_16bit_data and
shuffle_16bit_data_for_32bit_write are implemented in a similar
way than the analogous functions for handling 64-bit types.
v1: Explain need of temporary in shuffle operations. (Jason Ekstrand)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Used to enable 16-bit reads at do_untyped_vector_read, that is used on
the following intrinsics:
* nir_intrinsic_load_shared
* nir_intrinsic_load_ssbo
v2: Removed use of stride = 2 on 16-bit sources (Jason Ekstrand)
v3: - Add bitsize to scattered read operation (Jason Ekstrand)
- Remove implementation of 16-bit UBO read from this patch.
- Avoid assertion at opt_algebraic caused by ADD of two IMM with
offset with BRW_REGISTER_TYPE_UD type found on matrix tests.
(Jose Maria Casanova)
v4: (Jason Ekstrand)
- Put if case for 16-bits at the beginning of the if ladder.
- Use type_sz(dest.type) * 8 as bit_size parameter for scattered read.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
v2: Fix alignment style (Topi Pohjolainen)
(Jason Ekstrand)
- Enable bit_size parameter to scattered messages to enable different
bitsizes byte/word/dword.
- Remove use of brw_send_indirect_scattered_message in favor of
brw_send_indirect_surface_message.
- Move scattered messages to surface messages namespace.
- Assert align1 for scattered messages and assume Gen8+.
- Inline brw_set_dp_byte_scattered_read.
v3: (Jason Ekstrand)
- Use renamed brw_byte_scattered_data_element_from_bit_size method
- Assert scattered read for Gen8+ and Haswell.
- Use conditional expresion at components_read.
- Include comment about params for scattered opcodes.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
While on Untyped Surface messages the bits of the execution mask are
ANDed with the corresponding bits of the Pixel/Sample Mask, that is
not the case for byte scattered writes. That is needed to avoid ssbo
stores writing on helper invocations. So when that can affect, we load
the sample mask, and predicate the send message.
Note: the need for this patch was tested with a custom test. Right now
the 16 bit storage CTS tests doesnt need this path in order to get a
full pass.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
We need to rely on byte scattered writes as untyped writes are 32-bit
size. We could try to keep using 32-bit messages when we have two or
four 16-bit elements, but for simplicity sake, we use the same message
for any component number. We revisit this aproach in the follwing
patches.
v2: Removed use of stride = 2 on 16-bit sources (Jason Ekstrand)
v3: (Jason Ekstrand)
- Include bit_size to scattered write message and remove namespace
- specific for scattered messages.
- Move comment to proper place.
- Squashed with i965/fs: Adjust type_size/type_slots on store_ssbo.
(Jose Maria Casanova)
- Take into account that get_nir_src returns now WORD types for
16-bit sources instead of DWORD.
v4: (Jason Ekstrand)
- Rename lenght variable to num_components.
- Include assertions before emit_untyped_write.
- Remove type_slot in favor of num_slot and first_slot.
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
v2: (Jason Ekstrand)
- Enable bit_size parameter to scattered messages to enable different
bitsizes byte/word/dword.
- Remove use of brw_send_indirect_scattered_message in favor of
brw_send_indirect_surface_message.
- Move scattered messages to surface messages namespace.
- Assert align1 for scattered messages and assume Gen8+.
- Inline brw_set_dp_byte_scattered_write.
v3: - Remove leftover newline (Topi Pohjolainen)
- Rename brw_data_size to brw_scattered_data_element and use
defines instead of an enum (Jason Ekstrand)
- Assert scattered write for Gen8+ and Haswell (Jason Ekstrand)
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Although from SPIR-V point of view, rounding modes are attached to the
operation/destination, on i965 it is a status, so we don't need to
explicitly set the rounding mode if the one we want is already set.
Taking into account that the default mode is RTE, one possible
optimization would be optimize out the first RTE set for each
block. For in order to work, we would need to take into account block
interrelationships. At this point, it is not worth to complicate the
optimization for such small gain.
v2: Use a single SHADER_OPCODE_RND_MODE opcode taking an immediate
with the rounding mode (Curro)
v3: Reset optimization for every block. (Jason Ekstrand)
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
By default we don't set the rounding mode. We only set
round-to-near-even or round-to-zero mode if explicitly set from nir.
v2: Use a single SHADER_OPCODE_RND_MODE opcode taking an immediate
with the rounding mode (Curro)
v3: Use new helper brw_rnd_mode_from_nir_op (Jason Ekstrand)
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Although it is possible to emit them directly as AND/OR on brw_fs_nir,
having a specific opcode makes it easier to remove duplicate settings
later.
v2: (Curro)
- Set thread control to 'switch' when using the control register
- Use a single SHADER_OPCODE_RND_MODE opcode taking an immediate
with the rounding mode.
- Avoid magic numbers setting rounding mode field at control register.
v3: (Curro)
- Remove redundant and add missing whitespace lines.
- Match printing instruction to IR opcode "rnd_mode"
v4: (Topi Pohjolainen)
- Fix code style.
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Control register cr0 in i965 can be used to change the rounding modes
in 32-bit to 16-bit floating-point conversions.
From intel Skylake PRM, vol 07, section "Register and Tegister Regions",
subsection "Control Register" (page 754):
"Subregister cr0.0:ud contains normal operation control fields such as the
floating-point mode ... "
Floating-point Rounding mode is changed at bits 5:4 of cr0.0:
"Rounding Mode. This field specifies the FPU rounding mode. It is
initialized by Thread Dispatch."
00b = Round to Nearest or Even (RTNE)
01b = Round Up, toward +inf (RU)
10b = Round Down, toward -inf (RD)
11b = Round Toward Zero (RTZ)"
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Conversions to 16-bit need having aligment between the 16-bit
and 32-bit types. So the conversion operations unpack 16-bit types
to with an stride=2 and then applies a MOV with the conversion.
v2 (Jason Ekstrand):
- Avoid the general use of stride=2 for 16-bit register types.
v3 (Topi Pohjolainen)
- Code style fix
(Jason Ekstrand)
- Now nir_op_f2f16 was renamed to nir_op_f2f16_undef
because conversion to f16 with undefined rounding is explicit
Signed-off-by: Eduardo Lima <elima@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Note that we don't remove the assert at i965/vec4. At this point half
float support is only for the scalar backend.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
These types have similar vec4 sizes as their 32-bit counterparts.
The vec4 backend doesn't support 16-bit types and probably never will,
but this method is called by the scalar backend at
fs_visitor::nir_setup_outputs(), so we still need to provide valid vec4
sizes for 16-bit types. In the future, something different should be
implemented to avoid this dependency.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Not to be confused with variablePointersStorageBuffer which is the
subset of VK_KHR_variable_pointers required to enable the extension.
This means we now have "full" support for variable pointers.
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
The reference value in gen_device_info isn't going to be acurate on
Gen10+. We should query it from the kernel, which reads a couple of
register to compute the actual value.
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Rafael Antognolli <rafael.antognolli@intel.com>
Now that we have anv_device_init/finish functions, there's no reason to
have the individual driver do any more work than that.
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Chad Versace <chadversary@chromium.org>
This drops the unneeded callbacks struct as well as the queue_get_family
callback we were using before we'd pulled QueuePresent inside.
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Chad Versace <chadversary@chromium.org>
This lets us move wsi_interface to wsi_common_private.h
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Chad Versace <chadversary@chromium.org>
