Using HALT to immediately jump to the end of the shader is required to
implement GL_EXT_gpu_shader4 and OpenGL 3.0. However, vanilla OpenGL
1.2 doesn't forbid it and it likely makes something somewhere faster.
We should be consistent and implement the same discard behavior on all
hardware if we can.
The rules for HALT on Gen4-5 are a bit different from Gen6+. On the
older hardware, there is no stack for HALT; instead it's up to software
to save and restore mask registers. However, there's no real saving
needed since we only use HALT to jump to the end of the program where
we're about about to do our FB writes. All we need to do is reset AMask
to DMask, the value it was initialized to at the start of the thread.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5244>
Instead of emitting the stall MOV "inside" the
SHADER_OPCODE_MEMORY_FENCE generation, use the scheduling fences when
creating the IR.
For IvyBridge, every (data cache) fence is accompained by a render
cache fence, that now is explicit in the IR, two
SHADER_OPCODE_MEMORY_FENCEs are emitted (with different SFIDs).
Because Begin and End interlock intrinsics are effectively memory
barriers, move its handling alongside the other memory barrier
intrinsics. The SHADER_OPCODE_INTERLOCK is still used to distinguish
if we are going to use a SENDC (for Begin) or regular SEND (for End).
This change is a preparation to allow emitting both SENDs in Gen11+
before we can stall on them.
Shader-db results for IVB (i965):
total instructions in shared programs: 11971190 -> 11971200 (<.01%)
instructions in affected programs: 11482 -> 11492 (0.09%)
helped: 0
HURT: 8
HURT stats (abs) min: 1 max: 3 x̄: 1.25 x̃: 1
HURT stats (rel) min: 0.03% max: 0.50% x̄: 0.14% x̃: 0.10%
95% mean confidence interval for instructions value: 0.66 1.84
95% mean confidence interval for instructions %-change: 0.01% 0.27%
Instructions are HURT.
Unlike the previous code, that used the `mov g1 g2` trick to force
both `g1` and `g2` to stall, the scheduling fence will generate `mov
null g1` and `mov null g2`. During review it was decided it was not
worth keeping the special codepath for the small effect will have.
Shader-db results for HSW (i965), BDW and SKL don't have a change
on instruction count, but do report changes in cycles count, showing
SKL results below
total cycles in shared programs: 341738444 -> 341710570 (<.01%)
cycles in affected programs: 7240002 -> 7212128 (-0.38%)
helped: 46
HURT: 5
helped stats (abs) min: 14 max: 1940 x̄: 676.22 x̃: 154
helped stats (rel) min: <.01% max: 2.62% x̄: 1.28% x̃: 0.95%
HURT stats (abs) min: 2 max: 1768 x̄: 646.40 x̃: 362
HURT stats (rel) min: <.01% max: 0.83% x̄: 0.28% x̃: 0.08%
95% mean confidence interval for cycles value: -777.71 -315.38
95% mean confidence interval for cycles %-change: -1.42% -0.83%
Cycles are helped.
This seems to be the effect of allocating two registers separatedly
instead of a single one with size 2, which causes different register
allocation, affecting the cycle estimates.
while ICL also has not change on instruction count but report changes
negative changes in cycles
total cycles in shared programs: 352665369 -> 352707484 (0.01%)
cycles in affected programs: 9608288 -> 9650403 (0.44%)
helped: 4
HURT: 104
helped stats (abs) min: 24 max: 128 x̄: 88.50 x̃: 101
helped stats (rel) min: <.01% max: 0.85% x̄: 0.46% x̃: 0.49%
HURT stats (abs) min: 2 max: 2016 x̄: 408.36 x̃: 48
HURT stats (rel) min: <.01% max: 3.31% x̄: 0.88% x̃: 0.45%
95% mean confidence interval for cycles value: 256.67 523.24
95% mean confidence interval for cycles %-change: 0.63% 1.03%
Cycles are HURT.
AFAICT this is the result of the case above.
Shader-db results for TGL have similar cycles result as ICL, but also
affect instructions
total instructions in shared programs: 17690586 -> 17690597 (<.01%)
instructions in affected programs: 64617 -> 64628 (0.02%)
helped: 55
HURT: 32
helped stats (abs) min: 1 max: 16 x̄: 4.13 x̃: 3
helped stats (rel) min: 0.05% max: 2.78% x̄: 0.86% x̃: 0.74%
HURT stats (abs) min: 1 max: 65 x̄: 7.44 x̃: 2
HURT stats (rel) min: 0.05% max: 4.58% x̄: 1.13% x̃: 0.69%
95% mean confidence interval for instructions value: -2.03 2.28
95% mean confidence interval for instructions %-change: -0.41% 0.15%
Inconclusive result (value mean confidence interval includes 0).
Now that more is done in the IR, more dependencies are visible and
more SWSB annotations are emitted. Mixed with different register
allocation decisions like above, some shaders will see more `sync
nops` while others able to avoid them.
Most of the new `sync nops` are also redundant and could be dropped,
which will be fixed in a separate change.
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3278>
Change brw_memory_fence to return the number of messages emitted, and
use that to update the send_count statistic in code generation.
This will fix the book-keeping for IVB since the memory fences will
result in two SEND messages.
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4646>
The instruction encoding for SENDS changed on Gen12 and it now supports
embedding the entire extended message descriptor in the instruction if
it's an immediate. Stop falling back to doing an indirect SEND just
because we had something in [15:12] of ex_desc.ud.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3547>
Gen4/5's rounding instructions operate differently than later Gens'.
They all return the floor of the input and the "Round-increment"
conditional modifier answers whether the result should be incremented by
1.0 to get the appropriate result for the operation (and thus its
behavior is determined by the round opcode; e.g., RNDZ vs RNDE).
Since this requires a second instruciton (a predicated ADD) that
consumes the result of the round instruction, the round instruction
cannot write its result directly to the (write-only) message registers.
By emitting the ADD in the generator, the backend thinks it's safe to
store the round's result directly to the message register file.
To avoid this, we move the emission of the ADD instruction to the NIR
translator so that the backend has the information it needs.
I suspect this also fixes code generated for RNDZ.SAT but since
Gen4/5 don't support GLSL 1.30 which adds the trunc() function, I
couldn't write a piglit test to confirm. My thinking is that if x=-0.5:
sat(trunc(-0.5)) = 0.0
But on Gen4/5 where sat(trunc(x)) is implemented as
rndz.r.f0 result, x // result = floor(x)
// set f0 if increment needed
(+f0) add result, result, 1.0 // fixup so result = trunc(x)
then putting saturate on both instructions will give the wrong result.
floor(-0.5) = -1.0
sat(floor(-0.5)) = 0.0
// +1 increment would be needed since floor(-0.5) != trunc(-0.5)
sat(sat(floor(-0.5)) + 1.0) = 1.0
Fixes: 6f394343b1 ("nir/algebraic: i2f(f2i()) -> trunc()")
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/2355
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3459>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3459>
Alignment requirements may have changed the horizontal stride already,
so don't set it if not required to avoid breaking said requirements.
Fixes several tests such as
dEQP-VK.subgroups.vote.graphics.subgroupallequal_int8_t
Signed-off-by: Iván Briano <ivan.briano@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
On Gen >= 12, if src0 or src2 holds immediate value, we need set
src[0/2]_is_imm bits instead of register file.
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
On Gen >= 10, Either src0 or src2 can use 16-bit immediate value, but
not both.
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Apparently this field was removed on SKL, and according to the
hardware docs for previous platforms "This field is only valid for a
ForwardMsg message. It is ignored for other messages. The BarrierMsg
message always increments the N0 notification counter".
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewers are encouraged to audit the code generation pass
independently for the case I missed some potential data hazard or new
code has been added in the meantime.
v2: Add SYNC instruction to cr0 workaround in brw_float_controls_mode().
v3: Drop likely redundant (and potentially harmful) RegDist SWSB
annotation from ce0 read in brw_find_live_channel() (Caio).
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
An effect similar to the one formerly provided by setting thread
control to "switch" can be achieved now by setting a RegDist of 1 on
the SWSB field.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
A future lowering pass will simulate the same behavior originally
provided by NoDDChk/NoDDClr at the IR level by using appropriate SWSB
annotations.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The new SEND instruction behaves like the former SENDS instruction.
The original single-payload SEND instruction is gone.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The SEND instruction is now four-source. The descriptor is no longer
part of source 1, so avoid touching it to avoid corruption while
initializing the descriptor.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Change brw_inst_set_opcode() and brw_inst_opcode() to call
brw_opcode_encode/decode() transparently in order to translate between
hardware and IR opcodes, and update the EU compaction code in order to
do the same as needed, so we can eventually drop the one-to-one
correspondence between hardware and IR opcodes.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The brw_inst opcode accessors are going away in one of the following
commits. We could potentially replace them with the new helpers that
do opcode remapping, but that would lead to a circular dependency
between brw_inst.h and brw_eu.h. This way we also avoid ordering
issues that can cause the semantics of the ex_desc accessors to change
depending on whether the ex_desc field is set after or before the
opcode instruction field.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
v2:
- Fix bug in defining BRW_CR0_FP_MODE_MASK.
v3:
- Update comment (Caio).
v4:
- Split the patch into the helper (this one) and the new
opcode (Caio).
Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Annoyingly, these bits exist in some extended message descriptors
(in particular render target writes), but they don't have any
corresponding bits in the ISA encoding. So we can't use an immediate
and have to fall back to an indirect extended descriptor.
Thanks to Jason Ekstrand for reminding me that you can still set these
bits via an indirect descriptor, even if they don't exist in the ISA.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
src0 vstride and type overlap with bits of the extended descriptor.
brw_set_desc() also sets the extended descriptor to 0. So by setting
the descriptor, then setting src0, we were accidentally setting a bunch
of extended descriptor bits unintentionally.
When using this infrastructure for framebuffer writes (in a future
patch), this ended up setting the extended descriptor bit 20, which is
"Null Render Target" on Icelake, causing nothing to be written to the
framebuffer.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Gen11 SLM is not on L3 anymore, so now the hardware has two separate
fences. Add a way to control which fence types to use.
At this time, we don't have enough information in NIR to control the
visibility of the memory being fenced, so for now be conservative and
assume that fences will need a stall. With more information later
we'll be able to reduce those.
Fixes Vulkan CTS tests in ICL:
dEQP-VK.memory_model.message_passing.core11.u32.coherent.fence_fence.atomicwrite.device.payload_nonlocal.workgroup.guard_local.buffer.comp
dEQP-VK.memory_model.message_passing.core11.u32.coherent.fence_fence.atomicwrite.device.payload_local.buffer.guard_nonlocal.workgroup.comp
dEQP-VK.memory_model.message_passing.core11.u32.coherent.fence_fence.atomicwrite.device.payload_local.image.guard_nonlocal.workgroup.comp
dEQP-VK.memory_model.message_passing.core11.u32.coherent.fence_fence.atomicwrite.workgroup.payload_local.buffer.guard_nonlocal.workgroup.comp
dEQP-VK.memory_model.message_passing.core11.u32.coherent.fence_fence.atomicwrite.workgroup.payload_local.image.guard_nonlocal.workgroup.comp
The whole set of supported tests in dEQP-VK.memory_model.* group
should be passing in ICL now.
v2: Pass BTI around instead of having an enum. (Jason)
Emit two SHADER_OPCODE_MEMORY_FENCE instead of one that gets
transformed into two. (Jason)
List tests fixed. (Lionel)
v3: For clarity, split the decision of which fences to emit from the
emission code. (Jason)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
v2: 1) Drop changes for vec4 backend as on Gen11+ we don't support
align16 mode (Matt Turner)
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
We set header_present but then pass it some random garbage. Give it g0
instead. I'm not actually sure this does anything but g0 is the usual
header data and this is what the windows driver does so it seems like a
good idea.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The hardware only allows a stride of 1 on a Byte destination for raw
byte MOV instructions. This is required even when the destination
is the NULL register.
Rather than making sure that we emit a proper NULL:B destination
every time we need one, just fix it at emission time.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Source0 and Destination extract the floating-point precision automatically
from the SrcType and DstType instruction fields respectively when they are
set to types :F or :HF. For Source1 and Source2 operands, we use the new
1-bit fields Src1Type and Src2Type, where 0 means normal precision and 1
means half-precision. Since we always use the type of the destination for
all operands when we emit 3-source instructions, we only need set Src1Type
and Src2Type to 1 when we are emitting a half-precision instruction.
v2:
- Set the bit separately for each source based on its type so we can
do mixed floating-point mode in the future (Topi).
v3:
- Use regular citation style for the comment referencing the PRM (Matt).
- Decided not to add asserts in the emission code to check that only
mixed HF/F types are used since such checks would break negative tests
for brw_eu_validate.c (Matt)
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Extended math with half-float operands is only supported since gen9,
but it is limited to SIMD8. In gen8 we lower it to 32-bit.
v2: quashed together the following patches (Jason):
- intel/compiler: allow extended math functions with HF operands
- intel/compiler: lower 16-bit extended math to 32-bit prior to gen9
- intel/compiler: extended Math is limited to SIMD8 on half-float
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
(allow extended math functions with HF operands,
extended Math is limited to SIMD8 on half-float)
For split indirect sends we have to put the EOT parameter in the
extended descriptor as well as the instruction itself so just calling
brw_inst_set_eot is insufficient. Moving the EOT handling handling into
the send_indirect_[split]_message helper lets us handle it properly.
We're about to add some more if cases so let's have the giant re-indent
in it's own patch to make review easier.
Acked-by: Iago Toral Quiroga <itoral@igalia.com>
This commit pulls the surface descriptor helpers out into brw_eu.h and
makes them no longer depend on the codegen infrastructure. This should
allow us to use them directly from the IR code instead of the generator.
This change is unfortunately less mechanical than perhaps one would like
but it should be fairly straightforward.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Instead of magically falling back to SIMD8 for atomics and typed
messages on Ivy Bridge, explicitly figure out the exec size and pass
that into brw_surface_payload_size.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
emit_uniformize() emits SHADER_OPCODE_FIND_LIVE_CHANNEL with its
flag_subreg set, so that the IR knows which flag is accessed. However
the flag is only used on Gen7 in Align1 mode.
To avoid setting unnecessary bits in the instruction words, get the
information we need and reset the default flag register. This allows
round-tripping through the assembler/disassembler.
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
For a long time, we based exec sizes on destination register widths.
We've not been doing that since 1ca3a94427 but a few remnants
accidentally remained.
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
A follow on patch will move the 'nr' field to the union containing the
immediate field, so prepare by checking that we're only testing these
assertions if the .file is correct.
The assertions with != ARF were kind of silly to begin with because the
<128 check is specifically only for things in the GRF.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
I triggered this bug while prototyping code for a future platform on
IVB. Could be a problem today though if a strided move is
copy-propagated into a type-converting move with DF destination.
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
When RepCtrl is set, the swizzle field is ignored by the hardware. In
order to ensure a 1-to-1 correspondence between the human-readable
disassembly and the binary instruction encoding always set the swizzle
to XXXX (all zeros) when it is unused due to RepCtrl
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
To have uniform behavior while disassembling send(c) instruction use
register type of unsigned doubleword for src1 when message descriptor is
immediate value. Bspec does not specifiy anything for src1 immediate
default type.
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
