Commit Graph

240 Commits (b7b7fd4959e1834274206d4c2666ebd87165bc85)

Author SHA1 Message Date
Sean Silva b7b7fd4959 Rewrite error reporting of e2e tests.
This now gives [much nicer output](https://gist.github.com/silvasean/f048e0f37b04542dae6469b86802bb3e).
Embarrassingly, we previously couldn't even report failures for two
different tests, and weren't able to report on compilation failures
(besides just crashing).
2021-05-20 11:28:20 -07:00
Sean Silva d66e8fe1f8 Get simple quantized model importing.
This is enough to import the program and get it through the compilation
pipeline. It of course fails at the VerifyBackendContract pass since
there is a lot missing, but the final IR for a simple quantized MLP is
looking pretty decent already:
[IR](https://gist.github.com/silvasean/f76bccd76e9b193d396cfb2f9a11f54d)

Main changes:
- Add support for importing torch quantized tensors, including
  `torch.per_tensor_affine.create` op and `!torch.qint8` element type.
- Add support for importing `LinearPackedParamsBase` (basically a weight
  + optional bias, but requires `torch.linear_params.create` op +
  `!torch.LinearParams` type to model it). This was less painful than I
  expected, as it has the necessary methods to opaquely unpack itself. I
  factored things so it should be easy to extend to other custom classes
  like `ConvPackedParamsBase`.
- Add minimal boilerplate for importing `quantized::*` ops, with
  `quantized::linear` being a motivating example.
- Add e2e test with simple quantized MLP (courtesy of @phoenix-meadowlark).

This is somewhat of an abuse of `!numpy.ndarray` / `tensor`, as
really the proper semantics of `!torch.qint8` dtype on a Torch tensor is
"check the quantizer object of the tensor for side data (scale/offset,
possibly per-channel) that defines the full semantics of the tensor". We
don't have any such notion of "side data" for `!numpy.ndarray` /
`tensor`, let alone anything that would have the associated behavior of
keying off the dtype to determine if the side data is present.
This will be fixed by a proper `!torch.tensor` type.
2021-05-20 11:28:20 -07:00
Sean Silva 2efda323ff Significantly restructure torch/aten import design.
This is a really major and invasive restructuring of the way we get
torch operators (`torch::jit::Operator` / `c10::OperatorHandle`) into
MLIR. Please forgive the challenging review, but due to the sheer
invasiveness, it wasn't really practical do do it in sane smaller
pieces.

This fully replaces everything that was already working on the
TorchScript path (actually, more -- we added tanh support to
TorchToLinalg in order to delete the older code paths). Additionally,
I've kept the lights on for the acap path too, including what little e2e
stuff was working before (for expediency I made a few tiny compromises
along the way that will be easy to undo when we give that path proper
attention).

Overview of the new design:
- The torch operator `somens::someunqualname.someoverloadname` is
  imported as `torch.somens.someunqualname.someoverloadname` (skip the
  last dotted part if the overload name is empty), OR, if we don't have
  such an op registered, it is imported as
  `torch.operator "somens.someunqualname.someoverloadname" (...) : ...`.
  - The addition of the "overload name" is a critical element here, as
    the `(ns,unqual,overload)` triple is unique, which solves a lot of
    problems we were having.
  - This involves having separate MLIR ops for the `trailing_` and
    `.out` variants and all the different overloads. This seemed
    necessary, because the set of overloads is so wild and varied and
    unstructured. The previous design was leaning into some underlying
    structure that just isn't there -- the default situation is
    the "random overload that we want to manage on the MLIR side",
    rather than that being an exception. E.g.  `aten::ne` (not-equal)
    has 21 overloads, only 4 of which are c10 dispatcher ops see
    [gist](https://gist.github.com/silvasean/190ba918c550c956260e21254e1b8aa1),
    and the "out" variant is really called `.Tensor_out` instead of
    `.out` as it frequently is for other ops.
  - Rationale for all being in `torch` namespace: the set of operators
    are so varied and unstructured that "dialect per namespace"
    doesn't result in anything resembling the typical MLIR dialect
    boundary expectations. We could maybe draw the boundary at
    dispatcher ops vs non-dispatcher ops, but that doesn't seem to
    really result in very much useful structure at this point in time.
  - Note: within the torch operator registry, we effectively have a
    mini-basicpy subdialect (already type-resolved), which is reasonably
    structured.
  - The existing Torch op interfaces are also removed -- now that we
    track the overload name, we can losslessly find the original
    operator.
- Instead of `ATenRecognizeKernelsPass`, we now have a
  `ReduceOpVariantsPass` that keys off certain traits (and perhaps
  eventually interfaces) to reduce variants of ops to a smaller set,
  ideally operating on immutable tensors and using surrounding ops to
  model the mutability/aliasing aspects.
  - Note: `torch.ns.unqual.overload` ops allow both immutable and
    mutable tensors (unlike the previous hard distinction in the common
    case). This is a premonition for a future change that will introduce a
    bona fide `!torch.tensor` type that will clean up a bunch of stuff.
- `TorchToLinalg` / `TorchToStd` supercede the existing
  "ATen->TCF->TCP->Linalg" path.
- The new `torch_ods_gen.py` supercedes `torch_signature_ods_gen.py`.
  It should look somewhat familiar, but the benefit of hindsight has
  allowed a lot of simplifications.

The overall trend seems to be to make the `torch` dialect a nice layer
independent of anything else. It feels like as a natural result of
various future changes we will be removing the reliance on basicpy+numpy
dialects and have a nice self-contained type system too that properly
models the TorchScript type system (including proper subtyping,
mutable/immutable tensors, optional dtype, etc.).

Recommended review order:
- Start at some of the new import IR, e.g. in
  `frontends/pytorch/test/node_import/prim.py`,
  `frontends/pytorch/test/acap_export/test_export_add3.py`, and other
  tests.
- `frontends/pytorch/python/torch_mlir_utils/codegen/torch_ods_gen.py`
  and associated generated files:
  - `include/npcomp/Dialect/Torch/IR/GeneratedAtenOps.td`
  - `include/npcomp/Dialect/Torch/IR/GeneratedPrimOps.td`
- Inspect `ReduceOpVariants.cpp` / `reduce-op-variants.mlir` and the new
  traits in `include/npcomp/Dialect/Torch/IR/TorchTraits.h`
- Various code changes in the import path in
  `frontends/pytorch/csrc/builder`. Probably most interesting is the new
  code in `torch_to_mlir_utils.cpp` that has the logic to create the
  `torch.operator` ops or `torch.ns.unqual.overload` ops.

This is the [new ResNet IR](https://gist.github.com/silvasean/5407aafb710d07612b7b5b92eabecebe),
just to be able to look at a substantial sample of IR in the new style.
2021-05-19 13:37:39 -07:00
Sean Silva 133bdf4b31 [cleanup] Add materializer for basicpy.singleton
This allows the canonicalizer to coalesce it like other constants.
2021-05-03 09:54:44 -07:00
Sean Silva 3d08c83580 Add flatten op recognition + shape refinement.
This op has complex aliasing semantics, so it is kept mutable for now.

With this, we reduce ResNet18 to a single BB with all aten operators
having rank + dtype:
https://gist.github.com/silvasean/2fcb1c6e4d4ae27461204a43ae9c5031
2021-05-03 09:54:44 -07:00
Sean Silva 122cae2ee3 Add aten::len.t, aten::size, and aten::gt.int primitive ops
Also add some canonicalizations that finally reduce ResNet down to a
single block.
2021-04-30 10:57:02 -07:00
Sean Silva ec6d06aa86 Add some more ResNet ops.
- aten::relu_, aten::max_pool2d, aten::adaptive_avg_pool2d, aten::batch_norm, aten::conv2d

No aten-to-linalg conversion for the latter ones, as they are fairly
substantial. At this point, I'm trying to get shape inference and stuff
working for them and the IR cleaned up.
2021-04-30 10:57:02 -07:00
Sean Silva 9257457d8a Add AllowsTypeRefinement trait and use it to improve RefineTypes
This trait lets us model the semantics of various aten/torch/numpy ops
that are insensitive to type refinements. This replaces
hardcoded/inconsistent checks for this property.

To show usage of this new trait, we fix up some old uses, and improve
RefineTypes to be smarter about rewriting with this trait.
2021-04-30 10:57:02 -07:00
Sean Silva 1c832604d2 Remove old aten-to-std / ATenLowering pass.
It was confusing now that we have `convert-aten-to-std`.
2021-04-30 10:57:02 -07:00
Sean Silva 55c3cc6624 Add recognition/folder/lowering for aten::__is__, aten::ne.int, and aten::dim
Interestingly, TorchScript has its own op (`torch::jit::Operator`)
registry separate from the dispatcher (it is a superset of the
dispatcher).

This is where the "prim" ops and some "aten" ops (that should probably
be renamed to "prim") live. In particular, `aten::__is__` is in that
latter category of "aten but really prim". This registry is also the
source of truth for what the TorchScript interpreter calls into when it
executes.

The bulk of the "not part of the dispatcher" ops live in
09feb5f579/torch/csrc/jit/runtime/register_prim_ops.cpp (L82)

And the registry itself lives in:
09feb5f579/torch/csrc/jit/runtime/operator.cpp (L196)

This fold further reduces the IR of ResNet by folding away some
more not-taken branches. These not-taken branches in ResNet require
first-class handling of the list type which we don't yet have on any
backend.
2021-04-30 10:57:02 -07:00
Sean Silva 7eb36b4ae7 Constant fold through basicpy.bool_cast.
This is the start of a push to getting ResNet running.

This involves throwing in the towel on an O0 pipelinie for now. See note
in the code. We keep an options struct with `optimize` flag, but it
default to true for now.
2021-04-30 10:57:02 -07:00
Sean Silva fb5f149e04 Reformat Passes.cpp and remove torch-globalize-pipeline.
The pipeline is subsumed by our lowering pipelines.
2021-04-30 10:57:02 -07:00
River Riddle 4678a7fedd Refactor RefineTypes to use the upstream ForwardDataFlowAnalysis engine
This removes the need for defining all of the custom propagation logic,
and also adds support for propagating value knowledge across branches,
through regions, and across calls.
2021-04-27 13:17:56 -07:00
Sean Silva 642482429c Bump llvm-project to 12011b5217929ef8a56c2099c6f3233934ea4fbc
- Rename FrozenRewritePatternList -> FrozenRewritePatternSet
2021-04-27 13:12:33 -07:00
Sean Silva 179105ca3e Add basic MLP's to the e2e curriculum.
These tests pass on the reference backend.

- Add aten.linear op + shape xfer function + ATen->Linalg lowering.
 - Note: this needs to be more automated, and needs to cover more cases.
 - Current not implemented caveats:
  - size-1 broadcasting for bias vector (either static-size-1 or ? case)
  - higher-rank aten.linear ops (not produced by torch.nn.Linear though)
  - type promotion (still don't even know the exact rules here)
- Add folder for torch.derefine op. Now the inliner can clean it up as
  it inlines. (call boundaries are a main place we need to insert
  torch.derefine) This is brittle -- the other important case is control
  flow which will need to be handled via an extension to
  RefineTypes.cpp (as will more robust call handling). River has an
  in-flight patch to update it to the new dataflow framework so I didn't
  want to do anything intrusive here.
    - Also adjust torch.derefine syntax to use the keyword `to` instead of
      `->`, as most type-only, cast-like ops do.
2021-04-27 12:18:54 -07:00
Sean Silva 9ba77c6e13 Add InlineGlobalSlots pass.
This inlines global slots if possible. This allows them to participate
in folding, canonicalization, shape inference, etc.

Example use cases:
- inlining weights and biases that are readonly during inference
- inlining the "training" bool to allow stuff to fold away

For training use cases (especially internal training loop), we will need
something smarter to get good performance. That would look like an "SSA
formation" which promotes the global slots to tensors in the program,
flushing them back to the slots at the minimal number of necessary
places. We might want to let backends do that transformation though.
This also interacts with shape inference (type bounds on the slots to
even lower them to backends in the first place).
2021-04-27 12:18:54 -07:00
Sean Silva 3a890aa26c Miscellaneous changes while trying to work on ResNet18
- Move frontend lowering pipelines to c++ (this helps with reproducing
  failures in npcomp-opt)
- Add debugging printouts when compilation fails on RefBackendTestConfig

The experience now when a test fails during MLIR lowering is now like this:
```
NPCOMP TorchScript Object Graph IR -> NPCOMP Backend IR lowering failed with the following diagnostics:
failed to legalize operation 'torch.global_slot'
Module does not conform to npcomp's backend contract. See dialect conversion legality information above.

Error can be reproduced with:
$ npcomp-opt -torchscript-to-npcomp-backend-pipeline /tmp/ResNet18Module.mlir
```

And when TorchScript->MLIR import fails it looks like this:
```
PyTorch TorchScript module -> NPCOMP Object Graph IR import failed with the following diagnostics:
unhandled prim operation: %18 : int = prim::min(%17) # /usr/local/google/home/silvasean/.local/lib/python3.9/site-packages/torch/nn/functional.py:4532:4
```

Also,
- Add `--filter=<regex>` to e2e test harness to filter tests.
- Add a few prim ops that were needed to import ResNet18
- Fix torch.prim.Loop.condition assemblyFormat (it previously would not
  round-trip in the case of no loop-carried variables)
2021-04-27 11:51:11 -07:00
Sean Silva 544cb4ef54 Bump llvm-project to 484b6648fdd4b104eaf7a2504dd07b60af2c9f8d
- add_mlir_doc arg order
- fix some dependent dialects on passes that were now causing errors
- "encoding" attribute on mlirRankedTensorTypeGetChecked
2021-04-22 18:12:55 -07:00
Sean Silva fef1733e12 Fix issue with unused functions in torch::jit::CompilationUnit
As described in the code comment:

```
When we import TorchScript IR, we import their entire "compilation unit",
which can contain numerous functions unrelated to the current program,
which breaks torch-globalization-pipeline; for example, there can be
random functions referencing types that haven't been imported
as part of the root `torch.nn.Module` we imported. Those will
be unreferenced private functions which symbol-dce will clean up nicely.
```

This situation is really easy to hit in jupyter notebooks, where the
same cell is evaluated multiple times. That results in the same
class name (at the Python level, e.g. class `Foo` in the top-level
main module). Internally to PyTorch, it handles this situation by
mangling in a unique number to the names of ClassType's and such. When
we import the new ClassType's, we see not just the new
torch::jit::Function's in the CompilationUnit, but, also all the old
ones, which reference ClassType's that are not reachable from the
`torch.nn.Module` that we imported.

Note: there is no way to avoid importing the whole CompilationUnit
(including these old remnants) without doing a fairly complicated call
graph reachability analysis of which functions are reachable from the
methods of the ClassType's we imported. It turns out that once we are
inside MLIR, we model visibility correctly so that `symbol-dce`
"Just Works" for this use case. That is to say, this is not a quick
hack, but rather seems like a totally palatable long-term solution.
2021-04-20 12:00:35 -07:00
Sean Silva c4123d4d4d Add npcomp-verify-backend-contract pass.
This pass verifies that a given module satisfies the contract that we
have for backends. This is phrased as an "allowlist", because we want to
keep this interface tight. Also, this gives much better diagnostics than
a backend randomly crashing or failing to compile would (though they
could still be improved).

This was especially painful because if we had
`tensor<?x!numpy.any_dtype>` slip through, at some point RefBackend
would convert it to a memref type and trip the "verify type invariants"
assertion which gives no location or anything and crashed the process,
which was very unpleasant.

We implement this with the dialect conversion framework, which works
reasonably well and was quick to put together and familiar, but is still
very "op oriented". We probably want to make this hand-rolled
eventually, especially the error reporting (the most useful kind of
error for a dialect conversion user is not necessarily the best for this
use case). Also, in production, these error will go to users, and need
to be surfaced carefully such as "the compiler needs a type annotation
on this function parameter" which in general requires some special
analysis, wordsmithing, and overall awareness of the e2e use case (such
as how much we can lean into certain source locations) to provide a
meaningful user-level diagnostic.

Also, add `inline` to the current frontend lowering pass pipeline to
allow slightly more complicated programs that otherwise would fail on
shape inference.
2021-04-20 12:00:35 -07:00
Sean Silva f5dfa02523 Add `aten.mm` to linalg lowering.
This is our first op with error semantics, and stresses the system.

There are a few design notes of special interest:
- RefineTypes.cpp's note about shape inference in the presence of code
  that dynamically produces and error, and it is provable statically.
- ATenToLinalg.cpp's notes about future automation of the ATen->linalg
  path.
- The notes in Passes.td about using low-tech `std.assert` ops instead
  of `shape.assuming`.

Note: Doesn't work on IREE yet due to the `std.assert` op (needs to be
lowered to `vm.fail` on the IREE side).
2021-04-16 12:03:31 -07:00
Sean Silva 28a0f02746 Add support for compiling through IREE.
Recommended review order:
- Changes in frontends/pytorch/examples/
- Changes in python/npcomp/compiler/pytorch/backend/
- Boilerplate for the `npcomp-iree-backend-lower-linkage` pass.

This change separates out a
`npcomp.compiler.pytorch.backend.frontend_lowering` module that does the
common lowering for all backends. The individual compiler backends
`npcomp.compiler.pytorch.backend.{refjit,iree}` now accept a loosely
defined "TCP + scalar code" IR mix that will be formalized in the
future as the interface to codegen backends.

This also required adding a small pass
`npcomp-iree-backend-lower-linkage` which adds `iree.module.export` onto
functions, and layering that into the frontend flow. The pass doesn't
require a C++-level dependency on IREE, which is nice for now. TBD how
we are going to handle lists (we hope we can get away with sneakerneting
some td files and relying on loose IR compatibility).

Running through IREE requires the ability to import `iree.compiler` and
`iree.runtime`, which can be obtained as follows:
```
python3 -m pip install iree-compiler-snapshot iree-runtime-snapshot -f https://github.com/google/iree/releases/tag/snapshot-20210406.200
PYTHONPATH="${PYTHONPATH}:${MY_IREE_BUILD}/bindings/python/"
```

This patch makes it painfully clear that we don't have any e2e testing
harness to really plug into, and also don't have a usable Python API to
our compiler stack (something usable in a jupyter notebook).
That will be addressed in subsequent commits. We've been flying by the
seat of our pants with this `examples` directory that isn't subject to
any kind of testing or real usability concerns.
2021-04-09 13:15:07 -07:00
Aaron J Arthurs f9d9518f6e Declare TCP dialect dependency in TCFToTCP conversion 2021-04-07 14:23:56 -07:00
Sean Silva 927546b3c5 Add RefinePublicReturn pass.
This pass allows shape information to be propagated to return types,
which is nontrivial and cannot be cleanly put anywhere else as it
changes the public ABI, which is a concern that we want to keep
concentrated in one place.
2021-04-07 11:06:34 -07:00
Sean Silva 1e357ae680 Add simple type refinement pass.
Currently implemented as a simple intraprocedural dataflow analysis over
a standard ShapedType lattice (hasRank, sizes, and elementType).

It currently hardcodes a few key pieces of information:
- shape transfer functions
- whether it is legal to update the operand type of an op

This needs to be made pluggable obviously and the core propagation logic
moved somewhere agnostic.
2021-04-07 11:06:34 -07:00
Sean Silva 6431b0f11f Add primitive ArrayToTensor (numpy-array-to-tensor) pass.
The current implementation is just sufficient to do a unary aten.tanh
from the e2e spike, and just applies some local rewrite patterns.  I've
sketched out the more full explanation of where this pass eventually
need to go in the pass docs.

Adding this required adding `numpy.tensor_static_info_cast`, which is
the tensor analog of `numpy.static_info_cast`. This op encapsulates the
same numpy-specific "no runtime code" casting semantics, in particular
the interpretation of `!numpy.any_dtype`. The
`numpy.tensor_static_info_cast` I see in practice now are "information
erasing" and will be removed by a later pass that exploits the fact that
aten ops are agnostic to the static info in the operand types (so
substituting a type with more static info is fine).

Side note: we *need* to do dtype and rank inference before aten->tcf
(which will eventually mostly be aten->linalg+guards), because each aten
op is idiosyncratically overloaded based on dtype and rank. Without
copying that idiosyncratic overloading into lower layers (layering
violation), we cannot really lower it to anything until we do that.
2021-04-05 17:56:35 -07:00
Sean Silva 30356c41c8 Add torch-adjust-calling-conventions pass.
This pass incorporates torch.type_bound info and also removes NoneType
returns (eventually it will rewrite tuple types too, but can't yet
because !basicpy.TupleType doesn't track element types).

Recommend looking at adjust-calling-conventions.mlir first to see what
it is doing, and holding your nose for the implementation of the pass.
I decided to implement this with the conversion framework, because it
gives us *some* goodies for type conversion -- mainly avoiding large
amounts of tricky RAUW dances. Unfortunately, the conversion framework
isn't a perfect fit for a couple reasons:
- the incorporation of torch.type_bound is a context-sensitive rewrite
  (requires looking at the arg attr, not just the type).
- NoneType conversion is 1->0, which requires some special handling
- (not implemented yet) 1->N tuple type conversions require special
  handling.
It's a little bit scary, but on balance doing it the other way would
have its own downsides.
2021-04-05 17:56:35 -07:00
Sean Silva 464feacba9 Bump llvm-project to 223dcdcfbe23affdf17ada7f023ee1872fd76160
- ModuleOp no longer has a terminator.
2021-04-05 17:56:35 -07:00
Sean Silva e749074bae Basic infra for annotate shapes and dtypes on arguments.
These allow users to annotate a known "type bound" on the argument,
which can seed shape/dtype inference. We don't rewrite the function
types as part of the import process (it will happen in a
yet-to-be-written pass) because:

1. We would need to interprocedurally rewrite all calls to keep the IR
   consistent. Currently, we have a place after GlobalizeObjectGraph but
   before we convert to tensors where this is convenient to do. Ideally,
   we would do this on the object graph representation.

1. We don't necessarily know that adjusting the function type is a legal
   calling convention change. The pass will have blessed knowledge (by
   the pass pipeline author) that adjusting the argument type based on
   the type bound is safe (which it frequently is).

2. Note that in principle, a type bound could be a fairly general thing
   (such as maximum sizes of dimensions, unions of multiple concrete
   types, etc.). The pass will in principle have logic to interpret the
   type bounds and to determine a suitable "best" (and legal) argument
   type.
2021-04-01 18:40:03 -07:00
Sean Silva 7a4043b7c4 Add ability to compile from object graph ir. 2021-03-31 09:25:13 -07:00
Sean Silva c6d56fed8a Add unary tanh lowering. 2021-03-30 16:39:49 -07:00
Sean Silva 641098be54 Clean up some compiler warnings on my machine. 2021-03-23 14:29:05 -07:00
Sean Silva 99178a167d Bump llvm-project to 0524a09cc7e1a0797982feacf505825231efbee7
- renames of OwningRewritePatternList -> RewritePatternSet
  - also `insert` to `add`
- RewritePatternSet holds a context now
- memref dialect split from std
2021-03-23 14:29:05 -07:00
Bryce Arden 4591884d06 [refbackrt] Scalar arg support
* Adds f32 scalar argument support across the ABI boundary.
* Adds support for passing input type / shape information
  across the ABI boundary
* Adds support for parsing / creating input FloatAttr's in
  `npcomp-run-mlir`
2021-03-23 13:16:44 -07:00
Sean Silva 703428eff4 Add support for "trailing_" and "out" variants of various ops.
We already had the `promoteTrailingOutTensor` flag, but weren't using
it. A inplaceVariantKernelName flag needed to be added.

This change is a little dissatisfying, as the conversions done by the
RecognizeKernelsPass are currently non-orthogonal. In particular,
`kDropResultAndAliasArg0` probably won't work as intended if mixed with
these (we probably need to promote kDropResultAndAliasArg0 to not be an
arg-level thing anyway, as we have done with promoteTrailingOutTensor).

This involved adding a new op `numpy.overwrite_array`.

```
numpy.overwrite_array %arg2 overwrites %arg0 : tensor<2x3xf32>, !numpy.ndarray<[2,3]:f32>
```

This models the destructive update behavior. Note that in the above op,
we cannot simply RAUW %arg0 with a suitably conveted %arg2 (for example,
%arg0 might have uses that are not dominated by %arg2, or might have an
alias relation with some other array in the program). In general, we
need a pass analogous to "SSA-formation" which knows how to see through
these to uncover an underlying tensor program.

Also, add tanh_out_e2e.py/div_inplace_e2e.py and fix some bitrot in
refjit.py which is my running example I'm trying to get working.
2021-03-19 10:34:50 -07:00
Aaron Arthurs 4fd9b4afb5
Import ATen conv2d conversion and test (#180)
* Import ATen conv2d conversion and test

This is a first attempt at expanding ATen-to-TCF conversion for the
conv2d operator. Eventually, this will come in use when lowering a
high-level conv-based model.
2021-03-12 17:21:16 -08:00
Sean Silva 58c7030104 Support multiple instances of a class in GlobalizeObjectGraph.
This happens in practice with e.g. ResNet from torchvision (multiple
instances of the same BatchNorm class).

The key observation is that for this program, and the expected set of
programs, we can convert the program to the same globalized form with a
bit more static analysis and effort to suitably monomorphize the
program. Though what we are doing here is fairly annoying to implement,
it saves any nontrivial later pass from having to do similar analyses
(or worse). E.g. shape inference would need to be object-graph aware,
mutation/lifetime analyses would have to be aware, etc. Additionally, it
would make us front-load what it means to have a !torch.nn.Module type
on an ABI boundary, which we are just not ready to handle.

I'm really, really hoping that in practice we can get away with
this, otherwise it's going to be really rough designing a representation
(and implementing everything to back it) that is convenient to transform
and gracefully scales from full object graph (in the most dynamic case)
down to a fixed set of global slots like we have here (in the most
static case, which we presume a lot of practical programs fall into).

This also involved introducing a
`torch-prepare-for-globalize-object-graph` pass that does a minimal set of
lowerings to simplify the IR into a more orthogonal and analyzable form,
and a `torch-globalize-pipeline` helper.

Recommended review order:
- updated documentation in Passes.td
- new tests in `globalize-object-graph-multiple-instances*.mlir`
- implementation of GlobalizeObjectGraph.cpp
- PrepareForGlobalizeObjectGraph.cpp + prepare-for-globalize-object-graph.mlir
- misc stuff like torch-globalize-pipeline pipeline definition.

With this, we can import, globalize, and inline resnet18 from
torchvision:
https://gist.github.com/silvasean/821586afc19b67d9fb72030b2e0adeb8
2021-03-11 19:21:07 -08:00
Sean Silva 2750d2084c Add prim::device and handle derefining for prim::CallMethod 2021-03-11 14:10:09 -08:00
Bairen Yi 5fed296904 Address missing default label in switch statement
Signed-off-by: Bairen Yi <yibairen.byron@bytedance.com>
2021-03-11 11:55:59 -08:00
Bairen Yi 5315598947 Update .getAttrs to ->getAttrs as it is deprecated.
Signed-off-by: Bairen Yi <yibairen.byron@bytedance.com>
2021-03-11 11:55:59 -08:00
Bryce Arden e7a8fd76e2
[refbackrt] Update Invoke API to support more than just Tensor's (#181) 2021-03-10 15:39:26 -08:00
Bairen Yi 53b01cb9ba Bump llvm-project to e31c77b1827fa4dd3511f21af11cfab18ecf6d38
Signed-off-by: Bairen Yi <yibairen.byron@bytedance.com>
2021-03-10 11:01:16 -08:00
Sean Silva 43dba03afd Properly model "derefinement".
In terms of IR structure, TorchScript allows types to vary in many
circumstances where MLIR requires pointer-identical types. In particular,
it is valid to pass any subtype in place of a type. For example, if an
`Optional[int]` is required somewhere in the IR, it is legal to pass a
value of just `int` (but not the other way around; see
`torch.prim.unchecked_cast`). In effect, every *use* can have a different
type.

We introduce a new op `torch.derefine` that models that impedance
mismatch. This op allows casting a value from one type to a type that it
is a subtype of to model this behavior.

Recommended review order:
- TorchOps.td for new torch.derefine (and updated docs for
  `torch.prim.unchecked_cast`)
- new test code in if.py, loop.py, function-derefine.py
- new code in node_importer.cpp for handling derefinement insertion
- function_importer.cpp and utils changes in torch_to_mlir_utils.cpp

Properly handling derefinement on function boundaries required
relayering the code so that graph_importer.cpp/.h is now
function_importer.cpp/.h because only the `torch::jit::Function`
(actually the `c10::FunctionSchema` it holds) knows the derefined types that are
actually needed at the boundary (see `function-derefine.py` for a test).

Annoyingly, this churns all the functions which are now prefixed with
`__torch__.` but that is more correct anyway (that is their linkage name
in the `torch::jit::CompilationUnit`; the previous `mb.import_function`
was actually buggy in the case of functions calling each other as it
would reference their unqualified name).

With this change, we can import `resnet18` from `torchvision` :)
IR: https://gist.github.com/silvasean/6426a5272d8a6c7caae533fce05ab704
2021-03-03 15:09:44 -08:00
Sean Silva 939d36906f Add support for prim::Loop op.
This is a funny one. It combines a `for` and `while` loop in one op. We
will need to write some conversions to `scf`.
2021-03-02 16:01:34 -08:00
Sean Silva c837dbb077 Properly import the entire torch::jit::CompilationUnit
This primarily unlocks proper handling of free functions (that is,
functions that are not methods of any torch.nn.Module).

Recommended review order:
- `ivalue_importer.cpp` + `ivalue_import/functions*.py`
- `GlobalizeObjectGraph.cpp` + test case
- misc other stuff

The `torch::jit::CompilationUnit` is basically a backing store or
"context" holding all the possible functions in the program. The
previous code was not explicitly accessing this data structure, since it
just imported the `torch::jit::Function`'s that it saw attached to
methods.

Subtly, any time a TorchScript module called into a free function, the
free function gets incorporated into the torch::jit::CompilationUnit,
but doesn't show up anywhere when dumping the module, except in the
curious pattern:

```
%5 : Function = prim::Constant[name="adaptive_avg_pool2d"]()
%6 : Tensor = prim::CallFunction(%5, %input.1, %4)
```

That is, calls are indirect calls, and are accessed via `prim::Constant`
materializing a function object. Even stranger, the `name` attribute here
doesn't really even tell the full story -- it doesn't correspond to
anything. It turns out that the c10::FunctionType itself actually holds
a pointer to the `torch::jit::Function` in the compilation unit
directly (so there is actually no indirection in prim::CallMethod,
because any two values of the same FunctionType call the same
function!). E.g. when converting the IR to bytecode, the "name" is
ignored [code link](1d6bd15790/torch/csrc/jit/runtime/interpreter.cpp (L937)).
We do import `prim::CallFunction` as a `std.call_indirect` though
because it's more braindead to do it that way (it gets canonicalized to
a direct call easily).
2021-03-01 12:08:01 -08:00
Sean Silva 79a3f639bf Give torch.global_slot an initializer region.
This is a much simpler representation than the ad-hoc initializer
function we had before. It is also less general, but given the rationale
in Passes.td it seems like the right tradeoff right now.

We can probably carry this representation for quite a while, and when we
can't, it likely means that TorchScript has fixed their object identity
bug and we probably need to just upgrade to a more general object graph
modeling (more general than GlobalizeObjectGraph).

In particular, we don't want to deal with defining and carrying around
this initializer function concept until we need it. For example, if we
want to constant-fold the global slots into uses, this is a much better
representation, and it plays better with symbol-dce (the initializer
function counts as a "use" of the symbol).

(the alternative would have been to write a pass that converts the
initializer function to this form when possible, but I realized that
lots of information had been lost which made that fairly annoying -- it
was all self-inflicted anyway, so best to just go to the source
(GlobalizeObjectGraph) before the information is lost)

Now symbol-dce works nicely (no more "training" bools)
```
pt_util ~/tmp/classifier.pt --import --exported-name forward \
| npcomp-opt -torch-globalize-object-graph -inline -symbol-dce
```
IR: https://gist.github.com/silvasean/8abe63d70d24e29d6db9170ccc8d512b
2021-02-26 16:24:19 -08:00
Sean Silva a375ccf9da Add ability to annotate TorchScript classes.
The first use case is to annotate certain program constructs as either
exported or private. In this commit we plumb it down to
GlobalizeObjectGraph which makes use of this information.

Recommended review order:
1. class_annotator.h/.cpp + `test/module_import/annotations/*`
    - New abstractions to communicate with Python code and annotate.
2. IR changes in TorchOps.td
    - Adding "private" attribute to various things.
3. ivalue_import.cpp changes
    - Module + ClassAnnotator = annotated IR
4. GlobalizeObjectGraph.cpp + tests
    - use new "private" attributes to create "private" IR.
    - also, tweak some of the op deleting mechanics, which was triggering
      some memory errors / assertions

With this, we can run the classifier through and inline it as follows:
```
frontends/pytorch/utils/pt_util.py --import --exported-name forward ~/tmp/classifier.pt \
| npcomp-opt -torch-globalize-object-graph -inline
```
IR: https://gist.github.com/silvasean/32dcad9f6270557f412094a77cecdd69
2021-02-25 11:28:34 -08:00
Sean Silva c424c24ed8 Bump llvm-project to c68d2895a1f4019b387c69d1e5eec31b0eb5e7b0
- dialect registration
- StringAttr::get: order of context arg
- math dialect
- LogicalResult nodiscard
- error message for invalid broadcast
2021-02-22 12:23:24 -08:00
Sean Silva 8486968925 Add trivial inliner interfaces.
With this + manually setting private visibility on everything, a simple
classifier can be reduced to this IR, which is looking pretty lean and
mean:
https://gist.github.com/silvasean/19e7e2e21a61ff197aeac0dd864d188f

Also, include a utility script for importing `.pt` models.

```
pt_util.py --import classifier.pt | npcomp-opt -torch-globalize-object-graph
```
2021-02-22 10:40:38 -08:00
Sean Silva 1b769f7841 Extend GlobalizeObjectGraph to handle torch.prim.GetAttr returning NnModuleType
This happens in practice. With this, we can globalize slots for the
non-trivial classifier layer obtained from
https://github.com/NVIDIA/NeMo/blob/main/tutorials/nlp/Joint_Intent_and_Slot_Classification.ipynb

This also adds support for tuple return types, which were needed by that
model.
2021-02-19 10:23:25 -08:00