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torch-mlir/frontends/pytorch/test/ivalue_import/methods.py

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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 08:35:44 +08:00
# -*- Python -*-
# This file is licensed under a pytorch-style license
# See frontends/pytorch/LICENSE for license information.
import typing
import torch
import torch_mlir
# RUN: %PYTHON %s | npcomp-opt | FileCheck %s
mb = torch_mlir.ModuleBuilder()
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](https://github.com/pytorch/pytorch/blob/1d6bd157902d4b1347a5d03122d02b407658e263/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).
2021-02-27 08:20:35 +08:00
# Function names in the Torch compilation unit are systematic -- they
# are effectively Python dotted paths. E.g. a Python module "foo" with a class
# "bar" with a method "baz" will result in a function in the compilation unit
# called "foo.bar.baz" when it gets `torch.jit.script`'ed.
# (with the exception that `__main__` is replaced with `__torch__`).
#
# Given how systematic this is, we don't treat the symbol names as opaque (i.e.
# we don't need to capture their names when FileCheck testing).
# CHECK-LABEL: func private @__torch__.TestModule.forward
# CHECK-SAME: (%[[SELF:.*]]: !torch.nn.Module<"__torch__.TestModule">, %[[X:.*]]: !numpy.ndarray<*:!numpy.any_dtype>) -> !numpy.ndarray<*:!numpy.any_dtype> {
# CHECK: return %[[X]] : !numpy.ndarray<*:!numpy.any_dtype>
# CHECK: }
#
# CHECK-LABEL: torch.class_type @__torch__.TestModule {
# CHECK: torch.method "forward", @__torch__.TestModule.forward
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 03:28:51 +08:00
# CHECK: }
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](https://github.com/pytorch/pytorch/blob/1d6bd157902d4b1347a5d03122d02b407658e263/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).
2021-02-27 08:20:35 +08:00
class TestModule(torch.nn.Module):
def __init__(self):
super().__init__()
def forward(self, x):
return x
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 08:35:44 +08:00
test_module = TestModule()
recursivescriptmodule = torch.jit.script(test_module)
# TODO: Automatically handle unpacking Python class RecursiveScriptModule into the underlying ScriptModule.
mb.import_module(recursivescriptmodule._c)
mb.module.operation.print()