[Mesa-dev] [PATCH 00/61] nir: Move to using instructions for derefs
Jason Ekstrand
jason at jlekstrand.net
Thu Mar 29 00:16:53 UTC 2018
On March 28, 2018 16:54:33 Rob Clark <robdclark at gmail.com> wrote:
I had noticed the code to remove dead deref's in a few of the passes
(at least on your wip branch), and had wondered a bit about not just
requiring all the deref related lowering to happen in ssa and possibly
require dce after, although admittedly hadn't thought about it *too*
much yet..
Yeah. Like I said below, it should be ready enough to just have a tiny
clean-up pass instead of having to run full-on dce. Maybe just running dce
is the right choice; I'm not sure.
I kinda expected to use the dce clean things up once we are in a
deref-instruction world.. re: validation passes, could we not just
allow dead deref instructions to be ok. That seems like kind of a
natural thing..
Making validation ignore them is easy. The trickier bit is that they can
cause problems for any pass which works on all deref instructions as
opposed to working on texture instructions or intrinsics and tracing the
deref chain back. The later are ok because they'll never look at dead
derefs. There former (which are likely to be more efficient if we've CSEd
derefs) can run into trouble as it's not always obvious when a deref is dead.
I'm sure I'll get a better feel for this whole mess as I continue to progress.
--Jason
BR,
-R
On Wed, Mar 28, 2018 at 7:43 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
One interesting and unexpected side effect of this series has been that dead
code elimination is now required to clean up unused deref instructions.
This can be a problem for passes which alter and/or delete the variable
because they may leave invalid deref instructions lying around. This is a
bit troublesome because it causes validation issues and can confused later
passes if there are invalid deref instructions even if they are unused. I
have added a helper that allows you to easily check if a deref instruction
is in use and remove it and its ancestors if it is not. This seems to help a
bit but means that you have to manually clean up derefs whenever you alter
or remove a variable. Another option would be to write a simple dead deref
elimination pass that other optimization passes can run.
I'm not 100% sure what I think of that. On the balance, though, I think the
amount that removing deref chains simplifies the IR still makes it worth it.
On March 23, 2018 14:43:16 Jason Ekstrand <jason at jlekstrand.net> wrote:
This is something that Connor and I have been talking about for some time
now. The basic idea is to replace the current singly linked nir_deref
list
with deref instructions. This is similar to what LLVM does and it offers
quite a bit more freedom when we start getting more realistic pointers
from
compute applications.
This series implements an almost complete conversion for both i965 and
anv.
The two remaining gaps are nir_lower_locals_to_regs and
nir_lower_samplers.
The former will have to wait for ir3 to be converted and the later will
have to wait for radeonsi. I've got patches for nir_lower_samplers but
not
nir_lower_samplers_as_deref which is required by at least radeonsi. Once
those are in place, we should be able to drop the lowering pass from the
Intel back-end completely.
The next step (which I will start on next week) will be removing legacy
derefs from core NIR. This will also involve significant reworks in some
passes such as vars_to_ssa which still uses legacy derefs internally even
for things which use deref instructions.
Clearly, we can't remove anything until all of the other drivers are
converted. However, this series should be a good basis for anyone wanting
to work on converting another driver since almost all of the core NIR
passes now work with both types of derefs so you can convert in whatever
way makes sense.
This series can be found as a branch on gitlab:
https://gitlab.freedesktop.org/jekstrand/mesa/commits/review/nir-deref-instrs-v1
Cc: Rob Clark <robdclark at gmail.com>
Cc: Timothy Arceri <tarceri at itsqueeze.com>
Cc: Eric Anholt <eric at anholt.net>
Cc: Connor Abbott <cwabbott0 at gmail.com>
Cc: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
Cc: Karol Herbst <kherbst at redhat.com>
Jason Ekstrand (61):
nir: Add src/dest num_components helpers
nir: Return a cursor from nir_instr_remove
nir/vars_to_ssa: Remove copies from the correct set
nir/lower_indirect_derefs: Support interp_var_at intrinsics
intel/vec4: Set channel_sizes for MOV_INDIRECT sources
nir/validator: Validate that all used variables exist
nir: Add a deref instruction type
nir/builder: Add deref building helpers
nir: Add _deref versions of all of the _var intrinsics
nir: Add deref sources to texture instructions
nir: Add helpers for working with deref instructions
anv,i965,radv,st,ir3: Call nir_lower_deref_instrs
glsl/nir: Only claim to handle intrinsic functions
glsl/nir: Use deref instructions instead of dref chains
prog/nir: Simplify some load/store operations
prog/nir: Use deref instructions for params
nir/lower_atomics: Rework the main walker loop a bit
nir: Support deref instructions in remove_dead_variables
nir: Add a pass for fixing deref modes
nir: Support deref instructions in lower_global_vars_to_local
nir: Support deref instructions in lower_io_to_temporaries
nir: Add a deref path helper struct
nir: Support deref instructions in lower_var_copies
nir: Support deref instructions in split_var_copies
nir: Support deref instructions in lower_vars_to_ssa
nir: Support deref instructions in lower_indirect_derefs
nir/deref: Add a deref cleanup function
nir: Support deref instructions in lower_system_values
nir: Support deref instructions in lower_clip_cull
nir: Support deref instructions in propagate_invariant
nir: Support deref instructions in gather_info
nir: Support deref instructions in lower_io
nir: Support deref instructions in lower_atomics
nir: Support deref instructions in lower_wpos_ytransform
nir: Support deref instructions in lower_pos_center
nir: Support deref instructions in remove_unused_varyings
intel,ir3: Disable nir_opt_copy_prop_vars
intel/nir: Fixup deref modes after lowering patch vertices
i965: Move nir_lower_deref_instrs to right before locals_to_regs
st/nir: Move lower_deref_instrs later
spirv: Use deref instructions for most variables
nir: Add a concept of per-member structs and a lowering pass
nir/lower_system_values: Support SYSTEM_VALUE_LOCAL_GROUP_SIZE
spirv: Use the LOCAL_GROUP_SIZE system value
nir/spirv: Pass nir_variable_data into apply_var_decoration
anv/pipeline: Lower more constant initializers earlier
spirv: Use NIR per-member splitting
spirv: Make push constants an offset-based pointer
spirv: Clean up vtn_pointer_to_offset
spirv: Allow pointers to have a deref at the base
spirv: Update vtn_pointer_to/from_ssa to handle deref pointers
spirv: Record the type of functions
spirv/cfg: Make the builder fully capable for both walks
nir,spirv: Rework function calls
anv/pipeline: Do less deref instruction lowering
anv/pipeline: Convert lower_input_attachments to deref instructions
anv/pipeline: Convert YCbCr lowering to deref instructiosn
anv/apply_pipeline_layout: Simplify extract_tex_src_plane
anv/pipeline: Convert apply_pipeline_layout to deref instructions
intel/fs: Use image_deref intrinsics instead of image_var
intel/nir: Only lower load/store derefs
src/amd/vulkan/radv_shader.c | 10 +
src/compiler/Makefile.sources | 3 +
src/compiler/glsl/glsl_to_nir.cpp | 265 ++++------
src/compiler/nir/meson.build | 3 +
src/compiler/nir/nir.c | 107 ++--
src/compiler/nir/nir.h | 175 +++++-
src/compiler/nir/nir_builder.h | 236 +++++++++
src/compiler/nir/nir_clone.c | 65 ++-
src/compiler/nir/nir_deref.c | 393 ++++++++++++++
src/compiler/nir/nir_deref.h | 55 ++
src/compiler/nir/nir_gather_info.c | 26 +-
src/compiler/nir/nir_inline_functions.c | 193 +------
src/compiler/nir/nir_instr_set.c | 78 +++
src/compiler/nir/nir_intrinsics.h | 88 ++++
src/compiler/nir/nir_linking_helpers.c | 50 +-
src/compiler/nir/nir_lower_atomics.c | 137 ++++-
.../nir/nir_lower_clip_cull_distance_arrays.c | 69 ++-
src/compiler/nir/nir_lower_global_vars_to_local.c | 62 ++-
src/compiler/nir/nir_lower_indirect_derefs.c | 169 +++++-
src/compiler/nir/nir_lower_io.c | 70 ++-
src/compiler/nir/nir_lower_io_to_temporaries.c | 2 +
src/compiler/nir/nir_lower_system_values.c | 23 +-
src/compiler/nir/nir_lower_var_copies.c | 90 +++-
src/compiler/nir/nir_lower_vars_to_ssa.c | 77 ++-
src/compiler/nir/nir_lower_wpos_center.c | 13 +-
src/compiler/nir/nir_lower_wpos_ytransform.c | 51 +-
src/compiler/nir/nir_opt_copy_prop_vars.c | 19 +-
src/compiler/nir/nir_opt_copy_propagate.c | 62 ++-
src/compiler/nir/nir_opt_dce.c | 7 +
src/compiler/nir/nir_print.c | 119 +++--
src/compiler/nir/nir_propagate_invariant.c | 23 +-
src/compiler/nir/nir_remove_dead_variables.c | 117 +++-
src/compiler/nir/nir_serialize.c | 137 +++--
src/compiler/nir/nir_split_per_member_structs.c | 289 ++++++++++
src/compiler/nir/nir_split_var_copies.c | 42 ++
src/compiler/nir/nir_sweep.c | 4 -
src/compiler/nir/nir_validate.c | 143 +++--
src/compiler/spirv/spirv_to_nir.c | 180 ++++---
src/compiler/spirv/vtn_cfg.c | 231 ++++----
src/compiler/spirv/vtn_glsl450.c | 19 +-
src/compiler/spirv/vtn_private.h | 28 +-
src/compiler/spirv/vtn_variables.c | 586
+++++++--------------
src/gallium/drivers/freedreno/ir3/ir3_cmdline.c | 3 +
src/gallium/drivers/freedreno/ir3/ir3_nir.c | 2 +-
src/intel/compiler/brw_fs.h | 2 +-
src/intel/compiler/brw_fs_nir.cpp | 157 +++---
src/intel/compiler/brw_nir.c | 4 +-
src/intel/compiler/brw_vec4.cpp | 5 +-
src/intel/vulkan/anv_nir_apply_pipeline_layout.c | 187 +++----
src/intel/vulkan/anv_nir_lower_input_attachments.c | 31 +-
src/intel/vulkan/anv_nir_lower_ycbcr_textures.c | 34 +-
src/intel/vulkan/anv_pipeline.c | 19 +-
src/mesa/drivers/dri/i965/brw_nir_uniforms.cpp | 2 +
src/mesa/drivers/dri/i965/brw_program.c | 1 +
src/mesa/program/prog_to_nir.c | 65 +--
src/mesa/state_tracker/st_glsl_to_nir.cpp | 2 +
56 files changed, 3451 insertions(+), 1579 deletions(-)
create mode 100644 src/compiler/nir/nir_deref.c
create mode 100644 src/compiler/nir/nir_deref.h
create mode 100644 src/compiler/nir/nir_split_per_member_structs.c
--
2.5.0.400.gff86faf
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