Commit Graph

1594 Commits

Author SHA1 Message Date
Marcin Ślusarz 97c3ec6116 intel/compiler: cache computed register pressure benefit
This halves the number of calls to get_register_pressure_benefit
and decreases shader-db CPU time by ~1.5%.

Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8741>
2021-01-29 11:31:39 +00:00
Jason Ekstrand f3a43e36e0 intel/fs: Add an ex_desc field to fs_inst for SHADER_OPCODE_SEND
I meant to do this years ago when I first added SHADER_OPCODE_SEND.  At
the time, the only use for the extended descriptor was bindless handles
which were always one thing and never non-constant.  However, it doesn't
actually require any extra instructions because we have to OR in ex_mlen
anyway.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8748>
2021-01-28 17:57:48 +00:00
Caio Marcelo de Oliveira Filho 9f3d5e99ea compiler: Use util/bitset.h for system_values_read
It is currently a bitset on top of a uint64_t but there are already
more than 64 values.  Change to use BITSET to cover all the
SYSTEM_VALUE_MAX bits.

Cc: mesa-stable
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Acked-by: Jesse Natalie <jenatali@microsoft.com>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Acked-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8585>
2021-01-26 20:20:47 +00:00
Connor Abbott 68969cbcb7 brw/vec4: Don't convert tex dest type to glsl_type
We were using nir_tex_instr::dest_type to a glsl_type, then passing it
to emit_texture(), only to just check the number of components. Just
pass the number of components directly. This lets us delete
brw_glsl_base_type_for_nir_type, which was asserting with
nir_texop_all_samples_equal because it didn't handle bool32.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7989>
2021-01-25 11:21:42 +01:00
Lionel Landwerlin 65f7b93435 intel: silence unused var warnings in release builds
v2: Use ASSERTED

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4162
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8681>
2021-01-25 09:04:32 +00:00
Jason Ekstrand 8c2543d037 intel/fs: Implement umin/umax shuffle
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:38 +00:00
Jason Ekstrand a6500236e3 intel/fs: Refactor our shuffle emit code
This adds an emit_scan_step helper which gives us a place to do
something a bit more interesting than emitting a single op.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:38 +00:00
Jason Ekstrand 44571c6a68 intel/fs: Properly lower 64-bit MUL on 64-bit-incapable platforms
There are two problems this commit solves:  First, is that the 64x64 MUL
lowering generates a Q MOV which, because of how late it runs in the
compile pipeline, it never gets removed.  Second, it generates 32x32
MULs and we have to run it a second time to lower those.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:38 +00:00
Jason Ekstrand c80db6611a intel/fs: Support 64-bit CLUSTER_BROADCAST on Gen11+
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:38 +00:00
Jason Ekstrand b90921ec0c intel/fs: Support 64-bit SHUFFLE on Gen11+
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:38 +00:00
Jason Ekstrand cdedc82329 intel/fs: Support 64-bit SEL_EXEC on Gen11+
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:37 +00:00
Jason Ekstrand 58bcb5401d intel/fs: QUAD_SWIZZLE requires packed data
We could probably support some strides if we tried hard enough but the
whole point of this opcode is to accelerate things with crazy Align16 or
crazy regions.  It's ok if we have to emit an extra MOV to get a packed
source.

Fixes: 8b4a5e641b "intel/fs: Add support for subgroup quad operations"
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:37 +00:00
Jason Ekstrand 69a3559efd intel/reg,fs: Handle immediates properly in subscript()
Just returning the original type isn't what we want in basically any
case.  Mask and shift the immediate as needed.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:37 +00:00
Jason Ekstrand e797daba53 intel/compiler: Move brw_reg_type_for_bit_size to brw_reg_type.h
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:37 +00:00
Jason Ekstrand 4c8cbe9b13 intel/compiler: Return 1 for immediates in regs_read
Previously, we were returning 2 whenever the source was a Q type.  As
far as I can tell, the only reason why this hasn't blown up before is
that it was only ever used for VGRFs until the SWSB pass landed which
uses it for everything.  This wasn't a problem because Q types generally
aren't a thing on TGL.  However, they are for a small handful of
instructions.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7329>
2021-01-22 18:38:37 +00:00
Caio Marcelo de Oliveira Filho 77aa86a521 intel/fs: Separate SLM size calculation from encoding
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8486>
2021-01-19 21:49:04 +00:00
Jason Ekstrand 369eab9420 intel/fs: Emit code for Gen12-HP indirect compute data
Reworks:
 * Jordan: Apply to gen > 12
 * Jordan: Adjust comment about loading constants

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8342>
2021-01-13 13:10:28 -08:00
Jason Ekstrand b4ffbf1521 intel/fs: Allow compute dispatch without a pushed subgroup ID on Gen12-HP
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8342>
2021-01-13 13:10:27 -08:00
Jordan Justen 9294193098 intel/compiler: Disable push constants on gen12-hp
We currently don't use push constants with the COMPUTE_WALKER command.
Make all uniforms to be pull constants.

The local group id previously was a push constant, but is now
available in R0.2[7:0].

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8342>
2021-01-13 13:10:27 -08:00
Daniel Schürmann bd8e84eb8d nir: replace .lower_sub with .has_fsub and .has_isub
This allows a more fine-grained control about whether
a backend supports one of these instructions.

Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6597>
2021-01-11 19:13:51 +00:00
Erico Nunes faaba0d6af nir/lower_vec_to_movs: don't vectorize unsupports ops
If the instruction being coalesced would be vectorized but the target
doesn't support vectorizing that op, skip coalescing.
Reuse the callbacks from alu_to_scalar to describe which ops should not
be vectorized.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6506>
2021-01-11 13:13:30 +00:00
Rhys Perry f199b7188b nir/load_store_vectorize: add data as callback args
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4202>
2021-01-07 16:34:53 +00:00
Rhys Perry 00c8bec47b nir: add nir_load_store_vectorize_options
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4202>
2021-01-07 16:34:53 +00:00
Christian Gmeiner c5a9270109 intel/compiler: use intrinsic builders
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8295>
2021-01-06 14:34:41 +00:00
Yevhenii Kolesnikov 5ad54d498c intel/fs: don't spill a register, set by undef
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3941
Signed-off-by: Yevhenii Kolesnikov <yevhenii.kolesnikov@globallogic.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8185>
2020-12-21 21:18:01 +00:00
Jason Ekstrand a1976e1cb2 intel/fs: Implement nir_jump_halt
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5071>
2020-12-01 16:19:18 -06:00
Jason Ekstrand 6992d2f625 intel/fs: Emit HALT_TARGET in emit_nir_code()
Instead of making it a fragment-specific thing based on uses_kill, track
whether or not we need one in fs_visitor and emit HALT_TARGET at the end
of emit_nir_code() if needed.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5071>
2020-12-01 16:19:14 -06:00
Jason Ekstrand 4a7f0aa2e0 intel/fs: Remove unnecessary HALT_TARGET in opt_redundant_halt()
This means the pass has to walk all the instructions but it was doing
that in a bunch of cases anyway when it didn't have a HALT_TARGET.
However, removing HALT_TARGET frees up the scheduler a bit because
HALT_TARGET is considered a scheduling barrier.  The shader-db results
are kind-of a wash but we're about to add HALT_TARGET unconditionally so
we want to be able to get rid of it.

Shader-db results on Ice Lake:

    total instructions in shared programs: 19935623 -> 19935623 (0.00%)
    instructions in affected programs: 0 -> 0
    helped: 0
    HURT: 0

    total cycles in shared programs: 976758472 -> 976766135 (<.01%)
    cycles in affected programs: 11097707 -> 11105370 (0.07%)
    helped: 1750
    HURT: 875
    helped stats (abs) min: 1 max: 866 x̄: 26.39 x̃: 4
    helped stats (rel) min: <.01% max: 39.24% x̄: 1.25% x̃: 0.46%
    HURT stats (abs)   min: 1 max: 1678 x̄: 61.54 x̃: 10
    HURT stats (rel)   min: <.01% max: 65.69% x̄: 1.86% x̃: 0.42%
    95% mean confidence interval for cycles value: -2.48 8.32
    95% mean confidence interval for cycles %-change: -0.40% -0.03%
    Inconclusive result (value mean confidence interval includes 0).

    LOST:   62
    GAINED: 46

All of the lost/gained programs are SIMD32 fragment shaders.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5071>
2020-12-01 16:19:10 -06:00
Jason Ekstrand f9d549b2bf intel/fs: Use BRW_OPCODE_HALT for discards
We're about to start using it to implement nir_jump_halt which has
nothing inherently to do with fragment shaders or discards.  May as well
name it for the HW instruction it generates.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5071>
2020-12-01 16:19:08 -06:00
Jason Ekstrand e76e359007 intel/fs: Rename PLACEHOLDER_HALT to HALT_TARGET
It's a bit more explicit and will play more nicely with what we're about
to do.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5071>
2020-12-01 16:18:50 -06:00
Jordan Justen 071fd55381 intel/compiler: Add GEN125 to enum gen
Recommended-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7757>
2020-12-01 19:06:22 +00:00
Jason Ekstrand 73c6899285 intel/fs: DISCARD_JUMP does not have side-effects
This accidentally snuck into 75209d5bd1 due to a rebase fail.

Fixes: 75209d5bd1 "intel/fs: Add and implement intel-specific..."
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3897
Tested-by: Mark Janes <mark.a.janes@intel.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7839>
2020-11-30 20:33:48 +00:00
Jason Ekstrand b70847a389 nir: Use the right argument order for load_scratch_base_ptr
Fixes: c9bcad2573 "nir: add generated intrinsic builders"
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7836>
2020-11-30 12:03:33 -06:00
Rhys Perry c9bcad2573 nir: add generated intrinsic builders
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6587>
2020-11-26 17:50:38 +00:00
Caio Marcelo de Oliveira Filho ff9ea469f6 intel/disasm: Don't rely on FALLTHROUGHTs to print unsupported SFID
The code works but is a bit fragile if we ever add a case that has a
less strict requirement (a smaller gen) than the case above.  To avoid
having to reason about this, refactor code to use a variable to
indicate whether the SFID is supported or not.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7742>
2020-11-25 16:46:16 +00:00
Jason Ekstrand 9fa1cdfe7f intel/rt: Implement push constants as global memory reads
They're not really "push" anymore but that's because there is no such
thing as push constants in bindless shaders on Intel.  They should be
fast enough, though.  There is some room for debate here as to whether
we want to do the pull in NIR or push it into the back-end.  The
advantage of doing it in the back-end is that it'd be easier to use
MOV_INDIRECT for indirect push constant access rather than falling back
to a dataport message.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand f7e24e559f intel/rt: Add support for hit attributes
For triangle geometry, the hit attributes are always two floats which
contain the barycentric coordinates of the hit.  For procedural
geometry, they're an arbitrary blob of data passed from the intersection
shader to the hit shaders.  In our implementation, we stash that data
right after the HW RayQuery in the ray stack.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 96fde5518b intel/rt: Add a helper to create the raygen trampoline shader
Unlike graphics and compute pipelines, Vulkan ray-tracing pipelines do
not have a single entrypoint.  Instead, the raygen shader is specified
as a one-element shader binding table in the vkCmdTraceRay call.  This
means that raygen shaders have to be bindless shaders just like any
other ray tracing shader.  To launch them, we have a tiny compute shader
that acts as a trampoline and sets up the hotzone and uses btd_spawn to
fire off the raygen shader.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 303378e1dd intel/rt: Add lowering for combined intersection/any-hit shaders
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand cb261b03e5 intel/rt: Add lowering for ray-walk intrinsics in any-hit shaders
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand c3ddefa000 intel/rt: Add support for shader buffer record memory
Most of the work for this is done for us by spirv_to_nir which gives us
a load_global from a memory address based on the shader_record_ptr
system values.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 9ba7d459a3 intel/rt: Implement the new ray-tracing system values
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 7ce7c93755 intel/rt: Implement traceRay()
This is a little bit more work than executeCallable() because we also
have to set up the MemRay data structure which the ray traversal
hardware uses to keep its state.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 75209d5bd1 intel/fs: Add and implement intel-specific ray-tracing intrinsics
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 1f6ae809ef intel/rt: Implement support for shader call payloads
Both traceRay() and executeCallable() take a payload parameter which
gets passed from the caller to the callee and which the callee can write
to pass data back to the caller.  We implement these by passing a
pointer to the data structure in the callee to the caller as the second
QWord on its stack.  Coming out of spirv_to_nir, the incoming call
payloads get the nir_var_shader_call_data variable mode allowing us to
easily identify them.  Outgoing call payloads get assigned the
nir_var_shader_temp mode and will have been turned into function_temp by
nir_lower_global_vars_to_local.  All we have to do is crawl the shader
looking for references to the nir_var_shader_call_data variable and
rewrite those to use the passed in pointer.  nir_lower_explicit_io will
do the rest for us.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 72354b0e9d intel/rt: Add a helper to create a trivial return shader
These are required for ray-tracing.  There are many cases where the
ray-tracing hardware may decide to execute some but not all of our
shaders.  In these cases, it needs a shader to execute at the end which
will pop the stack back to the shader which called traceRay().

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand fad81a3968 intel/rt: Add a pass to lower shader call instructions
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand ca88cd8e5a intel/rt: Add return instructions at the end of ray-tracing shaders
Each callable ray-tracing shader shader stage has to perform a return
operation at the end.  In the case of raygen shaders, it retires the
bindless thread because the raygen shader is always the root of the call
tree.  In the case of any-hit shaders, the default action is accep the
hit.  For callable, miss, and closest-hit shaders, it does a return
operation.  The assumption is that the calling shader has placed a
BINDLESS_SHADER_RECORD address for the return in the first QWord of the
callee's scratch space.  The return operation simply loads this value
and calls a btd_spawn intrinsic to jump to it.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 49778a7253 intel/rt: Add support for scratch in ray-tracing shaders
In ray-tracing shader stages, we have a real call stack and so we can't
use the normal scratch mechanism.  Instead, the invocation's stack lives
in a memory region of the RT scratch buffer that sits after the HW ray
stacks.  We handle this by asking nir_lower_io to lower local variables
to 64-bit global memory access.  Unlike nir_lower_io for 32-bit offset
scratch, when 64-bit global access is requested, nir_lower_io generates
an address calculation which starts from a load_scratch_base_ptr.  We
then lower this intrinsic to the appropriate address calculation in
brw_nir_lower_rt_intrinsics.

When a COMPUTE_WALKER command is sent to the hardware with the BTD Mode
bit set to true, the hardware generates a set of stack IDs, one for each
invocation.  These then get passed along from one shader invocation to
the next as we trace the ray.  We can use those stack IDs to figure out
which stack our invocation needs to access.  Because we may not be the
first shader in the stack, there's a per-stack offset that gets stored
in the "hotzone".

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00
Jason Ekstrand 2b3f6cdc6c intel/rt: Add lowering functions for each ray-tracing stage
These will eventually contain per-stage lowering for various ray-tracing
things.  This is separate from brw_nir_lower_rt_intrinsics because, for
reasons that will become apparent later, brw_nir_lower_rt_intrinsics has
to be run very late in the compile process, right before brw_compile_bs.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
2020-11-25 05:37:10 +00:00