Commit Graph

143 Commits (9afaacedbdff9487749b7d043c56f1bce6e98766)

Author SHA1 Message Date
Sean Silva 784156a998 Add `!torch.bool` type.
This finishes removing the dependence on the basicpy dialect!

Changes:
- Add `!torch.bool` type and replace use of `!basicpy.BoolType` in
  Torch-related code.
- Rename BuiltinTensorize to BackendTypeConversion since now it handles
  bool conversions (and, when we add !torch.int and !torch.float, it
  will handle those as well), and generalize the related utilities (I
  also moved them to Torch/Transforms since they aren't really part of
  Torch/IR).
  - Add `torch.to_i1` and `torch.from_i1` ops for materializations
- [cleanup] Reorganize `torch.constant.*` ops in TorchOps.td
- Remove dependency of `torch` dialect on `basicpy` dialect and also
  `std` dialect. For `std`, we use some call related ops, but the
  `torch` dialect itself never produces them (we have passes that do
  though).

This is fairly mechanical. Recommended review order:
- New stuff in Torch/IR
- New BuiltinTypeConversion files.
- Mechnical fixups elsewhere.
2021-06-16 13:22:00 -07:00
Sean Silva 3ccf6002af Add `torch.constant.int` and `torch.constant.float`.
- This removes reliance on basicpy.numeric_constant.
- Also, add OpAsmOpInterface to the `torch.constant.none` and
  `torch.constant.str` ops.
2021-06-15 15:29:42 -07:00
Sean Silva 2e850ecb72 Add !torch.str type.
- Remove dependence on `!basicpy.BytesType`.
- Add `torch.constant.str "s"` analogous to `torch.constant.none`.
2021-06-15 10:10:59 -07:00
Sean Silva 92ee0fa98f Add `!torch.tuple<T1, T2>` type.
This further eliminates the need for the `basicpy` dependency.

This required adding `torch.prim.TupleConstruct` to replace
`basicpy.build_tuple`.
2021-06-15 08:15:22 -07:00
Sean Silva db282fd1b4 Introduce native `!torch.none` type.
- Add `torch.constant.none` op to construct it (naming is chosen to be
  analogous to Torch's representation of a prim::Constant with
  NoneType, rather than using the "singleton" terminology of Basicpy).
2021-06-14 13:30:58 -07:00
Sean Silva 81bcd7fb12 Move Torch type implementation code into TorchTypes.cpp 2021-06-10 16:46:47 -07:00
Yi Zhang e0ff5248fb Add TorchList type and prim::ListConstruct #218 2021-06-10 14:31:35 -07:00
Sean Silva 370e3270ab Introduce `!torch.tensor` / `!torch.vtensor` types.
This removes our reliance on the numpy dialect and avoids our off-label
use of the builtin tnesor type for modeling unknown dtypes.  The
`!torch.vtensor` (`ValueTensorType`) type is a value-semantic tensor.
The `!torch.tensor` (`NonValueTensorType`) type is a non-value-semantic
tensor. The new types look as follows syntactically:

```
// Least-static-information, non-value-semantic tensor.
!torch.tensor
// Explicit form of least-static-information variant.
!torch.tensor<*,unk>
// Least-static-information, value-semantic tensor.
!torch.vtensor
// Explicit form of least-static-information variant.
!torch.vtensor<*,unk>
// Fixed-set of allowable element types, with first-class support for
// Torch's frontend signedness semantics.
!torch.tensor<*,si32>
// First-class support for unknown dtypes.
!torch.tensor<[?,?,?],unk>
// Standard MLIR representation of `?` for unknown dimensions.
!torch.tensor<[?,2,?,4],unk>
// Statically shaped / dtyped example.
!torch.vtensor<[1,2,3,4],f32>
```

This required fairly significant changes throughout the compiler, but
overall it is a big cleanup. We now have a much clearer layering of "the
Torch frontend lowering" vs "lowering to std + linalg + etc.".

At the C++ level, there is `ValueTensorType`, `NonValueTensorType`.
We also have a helper `BaseTensorType` (kind of like ShapedType) which
interoperates with those two.

Included changes:
- New `torch.tensor(dense<0.0> : tensor<5xf32>) : !torch.tensor` op for
  creating torch tensor literals in the frontend.
- Consistently use signedness for the types (except i1 which I didn't
  touch -- we need to sort out the situation with !basicpy.BoolType
  there anyway so will be attending to that soon)
- Frontend can annotate whether an argument to the function has value
  semantics. We currently require this, as our backend contract does not
  currently allow us to even model the non-value-semantic case. Before,
  the value-semantic assumption was randomly injected in the middle of
  the pass pipeline.
- Move ArrayToTensor (now called MaximizeValueSemantics) and
  RefinePublicReturn passes to torch dialect.
- The TorchToStd and TorchToLinalg passes are now type conversions from
  `!torch.vtensor` to `tensor` and use the dialect conversion infra.
  The overall conversion pipeline is set up following the best practices
  of the "Type Conversions the Not-So-Hard Way" talk. This required
  introducing `torch-func-builtin-tensorize` and
  `torch-finalizing-builtin-tensorize` passes analogous to the upstream
  bufferization passes with the corresponding names (mostly just
  copypasta from there).
- Misc Torch-level canonicalizations -- we now cleanly layer the
  lowering to std later in the pipeline, so we are gradually lessening
  our reliance on random std constant folding before we get to that
  point.

Recommended review order:
- New types in TorchTypes.td/TorchTypes.h/TorchDialect.cpp
- New ops in TorchOps.td / TorchOps.cpp
- Less important / more mechanical stuff
  - Frontend changes.
  - Pass changes/additions in `Torch/Transforms` and `Conversion/`
2021-06-10 10:56:48 -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 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 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 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 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 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 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 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 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
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
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
Sean Silva 158c5c484d Implement GlobalizeObjectGraph transformation.
This required restructuring of how we model TorchScript on import. The
main difference is that now we split out a `torch.class_type` that holds
methods and declarations of the types of each slot. This is more
consistent with TorchScript (our previous representation was
"denormalized").

Recommended reading order:
1. check out the description of `torch.class_type` in `TorchOps.td` and
   look at `test/Dialect/Torch/ops.mlir` and
   `frontends/pytorch/test/module_import/` to familiarize with the new
   representation.
   - Just look at the new IR. The diff between the old names and new
     names is confusing.
2. check out `test/Dialect/Torch/globalize-object-graph*.mlir`
   and read along with the pass description in
   `include/npcomp/Dialect/Torch/Transforms/Passes.td`
3. Read the code in `GlobalizeObjectGraph.cpp` and miscellaneous changes
   in `ivalue_importer.cpp`, `TorchOps.cpp`, etc.
2021-02-18 18:18:47 -08:00
Sean Silva 689b40c7a6 Add initial TorchScript module importer
It turns out that this was easiest to structure as a general IValue
importer, since torch module are just one of the possible IValue's.

We import the IValue object graph in a braindead fashion into basicpy
ops and a new `torch.nn_module` op that is used to model the
attributes/methods of a torch::jit::Module IValue. See `Torch/ops.mlir`
for an example, and also check out the .py import tests in
`frontends/pytorch/test/module_import`.

As part of this change, a few housekeeping tasks:
- extract some helpers from graph_importer.cpp
- more helpers around the C API
- misc touchups
2021-01-28 11:55:17 -08:00
Stella Laurenzo 510f226df2 Expose signature metadata to ops and implement ATenRecognizeKernelsPass pass.
* Two op interfaces, one for querying instance metadata and one for getting static data needed to construct an op from a generic form.
* For torch.generic_kernel ops, metadata is splatted in during capture from Torch (it comes from the op registry, which will work for either device capture or graph import).
* Moved the 'add' out of the generated set so I can experiment on it. It implements the TorchBuildableKernelOpInterface interface which provides its metadata.
* The ATenRecognizeKernelsPass pass generically lowers from a torch.generic_kernel to recognized ops that implement the TorchBuildableKernelOpInterface, handling the various types of transformations that we allow at this stage.
2020-10-26 20:31:45 -07:00
Stella Laurenzo af4edb63ae Start reworking towards a shared library build.
* Need to have a dag of shared library deps in order to interop across python extensions (as presented in ODM).
* Introduced add_npcomp_library and friends to mirror the MLIR setup.
* Adds a libNPCOMP.so shared library.
* Redirects tools and extensions to link against libNPCOMP.so (instead of static libs).
* Moves all libraries to lib/, all binaries to bin/ and all python extensions to python/. The invariant is that the rpaths are setup to have a one level directory structure.
* Reworks the _torch_mlir extension to build like the others (still need to come up with a consolidated rule to do this instead of open coded).
* Includes an upstream version bump to pick up needed changes.

Sizes with dynamic linking (stripped, release, asserts enabled):
  libNPCOMP.so: 43M (includes much of the underlying LLVM codegen deps)
  libMLIR.so: 31M
  _npcomp.so: 1.6M (python extension)
  _torch_mlir.so: 670K (python extension)
  npcomp-capi-ir-test: 6.3K
  npcomp-opt: 351K
  npcomp-run-mlir: 461K
  mnist-playground: 530K

Still more can be done to normalize and optimize but this gets us structurally to the starting point.
2020-10-09 16:02:58 -07:00
Stella Laurenzo 3d74337be0 Add a torch.kernel_call op and associated predicates. 2020-09-29 15:10:38 -07:00
Stella Laurenzo 2c9ca79c89 Add boilerplate for Torch dialect. 2020-09-28 15:26:17 -07:00