There was an off-by-one error.
Fixes: 156306e5e6 ("nir/find_array_copies: Handle wildcards and overlapping copies")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This commit rewrites opt_find_array_copies to be able to handle
an array copy sequence with other intervening operations in between. In
particular, this handles the case where we OpLoad an array of structs
and then OpStore it, which generates code like:
foo[0].a = bar[0].a
foo[0].b = bar[0].b
foo[1].a = bar[1].a
foo[1].b = bar[1].b
...
that wasn't recognized by the previous pass.
In order to correctly handle copying arrays of arrays, and in particular
to correctly handle copies involving wildcards, we need to use a tree
structure similar to lower_vars_to_ssa so that we can walk all the
partial array copies invalidated by a particular write, including
ones where one of the common indices is a wildcard. I actually think
that when factoring in the needed hashing/comparing code, a hash table
based approach wouldn't be a lot smaller anyways.
All of the changes come from tessellation control shaders in Strange
Brigade, where we're able to remove the DXVK-inserted copy at the
beginning of the shader. These are the result for radv:
Totals from affected shaders:
SGPRS: 4576 -> 4576 (0.00 %)
VGPRS: 13784 -> 5560 (-59.66 %)
Spilled SGPRs: 0 -> 0 (0.00 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 8696 -> 6876 (-20.93 %) dwords per thread
Code Size: 329940 -> 263268 (-20.21 %) bytes
LDS: 0 -> 0 (0.00 %) blocks
Max Waves: 330 -> 898 (172.12 %)
Wait states: 0 -> 0 (0.00 %)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This lets passes easily detect derefs which have uses that fall outside
the standard load/store/copy pattern so they can bail appropriately.
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
It is possible and valid for a pointer to be selected based on a
conditional before used, and depending on the mode, those cases will
result in a phi with derefs as sources.
To achieve this, we don't rematerialize derefs that are used by phis.
As a consequence, when converting from SSA to regs, we may have phis
that come from different blocks and are used by phis. We now convert
those to regs too.
Validation was added to ensure only derefs of certain modes can be
used as phi sources. No extra validation is needed for the presence
of cast, any instruction that uses derefs will validate the
deref-chain is complete (ending in a cast or a var).
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
When looking at the dEQP nested_struct_array_dynamic_index_fragment code
after lowering, I was horrified at the amount of adding and multiplying by
0 we were doing. The builder _imm helpers handle that for you so that the
following optimization passes have less work to do. Plus, it's easier to
read.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
We were calcuating the offset for the field within the struct, and just
dropping it on the floor. Fixes a regression in
KHR-GLES3.shaders.struct.local.nested_struct_array_dynamic_index_fragment
and a few of its friends since the scratch lowering commit.
Fixes: e8e159e9df ("nir/deref: Add helpers for getting offsets")
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
llvm/spir-v spits out some struct a { struct b {} }, but it
doesn't deref, it casts (struct a) to (struct b), reconstruct
struct derefs instead of casts for these.
v2: use ssa_def_rewrite uses, rework the type restrictions (Jason)
v3: squish more stuff into one function, drop unused temp (Jason)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Not sure how ptr_stride should be taken into account if at all here
v2: reorder check to avoid src walking (Jason)
v3: remove is_cast_cast checks, keep going afterwards (Jason)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
If we get to two deref_var paths with different variables, we usually
know they don't alias. However, if both of the paths are marked
coherent, we don't have to worry about it.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
When nir_rematerialize_derefs_in_use_blocks_impl was first written, I
attempted to optimize things a bit by not bothering to re-materialize
the sources of deref instructions figuring that the final caller would
take care of that. However, in the case of more complex deref chains
where the first link or two lives in block A and then another link and
the load/store_deref intrinsic live in block B it doesn't work. The
code in rematerialize_deref_in_block looks at the tail of the chain,
sees that it's already in block B and skips it, not realizing that part
of the chain also lives in block A.
The easy solution here is to just rematerialize deref sources of deref
instructions as well. This may potentially lead to a few more deref
instructions being created by the conditions required for that to
actually happen are fairly unlikely and, thanks to the caching, it's all
linear time regardless.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109603
Fixes: 7d1d1208c2 "nir: Add a small pass to rematerialize derefs per-block"
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Replace calls to create hash tables and sets that use
_mesa_hash_pointer/_mesa_key_pointer_equal with the helpers
_mesa_pointer_hash_table_create() and _mesa_pointer_set_create().
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Eric Engestrom <eric@engestrom.ch>
NIR metadata validation verifies that the debug bit was unset (by a call
to nir_metadata_preserve) if a NIR optimization pass made progress on
the shader. With the expectation that the NIR shader consists of only a
single main function, it has been safe to call nir_metadata_preserve()
iff progress was made.
However, most optimization passes calculate progress per-function and
then return the union of those calculations. In the case that an
optimization pass makes progress only on a subset of the functions in
the shader metadata validation will detect the debug bit is still set on
any unchanged functions resulting in a failed assertion.
This patch offers a quick solution (short of a larger scale refactoring
which I do not wish to undertake as part of this series) that simply
unsets the debug bit on unchanged functions.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
I think this was copy-and-paste mistake -- nir_opt_large_constants was
passing in glsl_get_natural_size_align_bytes() given brw_nir.c's arguments
to the opt pass.
I wanted to reuse this function for handling constant offsets of arrays of
images in V3D.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Rob Clark <robdclark@gmail.com>
This pass is used when, for instance, we lazily change the mode of
variables rather than replacing the variable with a new one. Since we
only do this in cases where we know we have full deref chains, it's ok
to just skip them in fixup_deref_modes.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
The code which constructs deref paths already gives you the path
starting at the nearest deref_cast or deref_var. All we need to do for
casts is handle the case where the start of the path isn't a deref_var.
For ptr_as_array derefs, we just bail if we have any after the
divergence point between the two derefs. We may be able to do better in
the future but this works for now.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
When handling casts, we can't blindly propagate the parent of a cast
into a ptr_as_array deref because doing so might loose the stride
information from the cast. Instead, before we can propagate into
ptr_as_array derefs, we need to check that the cast is a cast of an
array deref and that the stride matches. For other types of derefs, we
can continue to propagate casts as normal because they don't need the
stride. We also add an optimization which can combine a ptr_as_array
deref with it parent if it is also an array deref of some form.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
These correspond directly to SPIR-V's OpPtrAccessChain. As such, they
treat whatever their parent gives them as if it's the first element in
some array and dereferences that array. If the parent is, itself, an
array deref, then the two indices can just be added together to get the
final array deref. However, it can also be used in cases where what you
have is a dereference to some random vec2 value somewhere. In this
case, we require a cast before the ptr_as_array and use the ptr_stride
field in the cast to provide a stride for the ptr_as_array derefs.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
We're going to want to do more deref optimizations going forward and
this gives us a central place to do them. Also, cast propagation will
get a bit more complicated with the addition of ptr_as_array derefs.
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
CC: Jason Ekstrand <jason@jlekstrand.net>
Fixes: 82799a5d1b8 ("nir: Add a small pass to rematerialize derefs
per-block")
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
This pass re-materializes deref instructions on a per-block basis to
ensure that every use of a deref occurs in the same block as the
instruction which uses it.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Cc: "18.2" <mesa-stable@lists.freedesktop.org>
Deref paths may share the same deref instructions in their chains,
e.g.
ssa_100 = deref_var A
ssa_101 = deref_struct "array_field" of ssa_100
ssa_102 = deref_array "[1]" of ssa_101
ssa_103 = deref_struct "field_a" of ssa_102
ssa_104 = deref_struct "field_a" of ssa_103
when comparing the two last deref instructions, their paths will share
a common sequence ssa_100, ssa_101, ssa_102. This patch skips to next
iteration if the deref instructions are the same. Path[0] (the var)
is still handled specially, so in the case above, only ssa_101 and
ssa_102 will be skipped.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
These are very similar to the related function in nir_lower_io except
that they don't handle per-vertex or packed things (that could be added,
in theory) and they take a more detailed size/align function pointer.
One day, we should consider switching nir_lower_io over to using the
more detailed size/align functions and then we could make it use these
helpers instead of having its own.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This commit introduces a new nir_deref.h header for helpers that are
less common and really only needed by a few heavy-duty passes. In this
header is a new struct for representing a full deref path which can be
walked in either direction.
v2 (Jason Ekstrand):
- Assert that deref != NULL (Caio)
- Fill _short_path with 0xdeadbeef in debug builds when not used (Caio)
- Make nir_deref_path a typedef (Rob)
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This will be needed by anything which changes variable modes without
rewriting derefs.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This will be removed at the end of the transition, but add some tracking
plus asserts to help ensure that lowering passes are called at the
correct point (pre or post deref instruction lowering) as passes are
converted and the point where lower_deref_instrs() is called is moved.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Sometimes it's useful for a pass to be able to clean up its own derefs
instead of waiting for DCE. This little helper makes it very easy.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This commit adds a pass for lowering deref instructions to deref chains
as well as some smaller helpers to ease the transition.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
