Discord Thread:
https://discord.com/channels/636084430946959380/1238330633328005243
## Context:
[This](https://github.com/llvm/torch-mlir/blob/main/python/torch_mlir/fx.py#L61)
was updated to support e2e tests for the TorchDynamo frontend in
Torch-MLIR, where we run FX decompositions and import the FX IR to
generate Torch dialect, followed by
`torch-function-to-torch-backend-pipeline`, skipping only the shape/type
refinement for now. However, we should be able to skip many of the torch
simplification passes, as depicted in the [frontend
roadmap](https://github.com/llvm/torch-mlir/blob/main/docs/images/roadmap_frontend.png).
Based on IREE's TorchDynamo
[pipeline](https://github.com/iree-org/iree/blob/main/compiler/plugins/input/Torch/InputConversion/Passes.cpp#L29),
the only two passes we seem to require are: `ReduceOpVariantsPass` and
`DecomposeComplexOpsPass`. This is inline with our findings as well
based on initial exploration.
This PR creates a dedicated frontend simplification pipeline for
TorchDynamo / FX Importer which calls only `ReduceOpVariantsPass` and
`DecomposeComplexOpsPass`. We rely on the e2e fx_importer tests to
ensure we're not regressing by removing many of the passes that were
historically needed for TorchScript.
One notable change here is that we do not call the
`LowerToBackendContractPass` anymore, which used to call
`TorchSimplificationPipeline` iteratively until VerifyBackendContract
was clean. Some of this was required for the shape/type refinement to
converge, which seems a non-issue for Dynamo frontend. Do we anticipate
this (the iterative invocation of TorchSimplificationPipeline followed
by VerifyBackendContract) to be worth retaining in the Dynamo frontend
pipeline? If so, I can make those changes, PLMK.
This commit fixes the onnx.MaxPool op lowering which was lacking the
indices result support.
Signed-Off By: Vivek Khandelwal <vivekkhandelwal1424@gmail.com>
The old lowering only had logic for 2d (i.e. images). this patch allows
interpolation for n spatial dims, which is required for some 3d vision
models such as
- onnx/models/pytorch-3dunet_vaiq_int8
which successfully compiles and runs with this patch.
* not to decompose `aten.amax` on `stablehlo` backend. Because it could
be lowering to `stablehlo.reduce` directly.
* lowering `aten.max.dim` to `stablehlo.reduce apply max` when
`AtenMaxDimOp.getIndices()` doesn't have users. It's more simple.
In constant folding progress, a new constant op will be created
according to the origin op's result type.
See the code in TorchDialect.cpp.
```cpp
Operation *TorchDialect::materializeConstant(OpBuilder &builder,
Attribute value, Type type,
Location loc) {
if (auto integerType = dyn_cast<Torch::IntType>(type))
return builder.create<Torch::ConstantIntOp>(loc, cast<IntegerAttr>(value));
if (auto floatType = dyn_cast<Torch::FloatType>(type))
return builder.create<Torch::ConstantFloatOp>(loc, cast<FloatAttr>(value));
if (auto numberType = dyn_cast<Torch::NumberType>(type)) {
if (auto floatValue = dyn_cast<mlir::FloatAttr>(value)) {
return builder.create<Torch::ConstantNumberOp>(loc, floatValue);
} else if (auto intValue = dyn_cast<mlir::IntegerAttr>(value)) {
return builder.create<Torch::ConstantNumberOp>(loc, intValue);
}
}
if (isa<Torch::BoolType>(type)) {
return builder.create<Torch::ConstantBoolOp>(loc, cast<IntegerAttr>(value));
}
if (isa<Torch::NoneType>(type))
return builder.create<ConstantNoneOp>(loc);
if (auto stringAttr = dyn_cast<StringAttr>(value))
return builder.create<ConstantStrOp>(loc, stringAttr);
if (auto elementsAttr = dyn_cast<ElementsAttr>(value)) {
// Only !torch.vtensor can be constant folded. !torch.tensor has
// non-trivial aliasing semantics which prevent deduplicating it.
assert(isa<ValueTensorType>(type) && "should be a vtensor type!");
return builder.create<ValueTensorLiteralOp>(loc, elementsAttr);
}
return nullptr;
}
```
So when the op has a tensor result type, it must be "ValueTensorType"
due to the **assert** statement. However, many fold methods in
TorchOps.cpp only have a judgment of "BaseTensorType".
As mentioned in issue #3290 , the difference between onnx.Transpose in
versions 1 and 13 is minimal, and therefore should be supported with the
same conversion pattern.
After running the model tests in SHARK-TestSuite, I noticed a few model
failures due to half-fusion.
Notably, RDN_pytorch_vaiq_int8 had a depth=5 convolution chain with
multiple AtenViewOp's.
This change enables more customization with operand quantization, and
generalizes the patterns QuantizeOperands and QuantizeTransposeOperands
to QuantizeOperandsPastCommutingOps.
This allows for passing quantization through operations which are
functionally unaffected by quantization, such as view-like ops. The
purpose of this change is to address a myriad of quantization issues
seen in quantized onnx models that have some reshape-like operations
sandwiched in between a dequant and something like a matmul (whose other
operand is immediately quantizable).
* Enables assume_strict_symbolic_shapes on fx_importer imported
programs, indicating strict shape semantics.
* Reworks the view->reshape lowering to take advantage of strict mode
and do one of:
* Collapse to 0D
* Flatten/Unflatten when there is an inferred dim.
* Fallback to tensor.reshape
* Splits some test cases up and adds an attribute to control the old
pattern (so new corners can be tested in strict mode in isolation).
* Dynamic inferred mode needs upstream work to generalize expand_shape
(so that case is suppressed here).
* Deletes the assert from the existing tensor.reshape lowering if strict
shape mode is enabled (since the condition it is dynamically asserting
cannot happen).
Sambhav Jain
Aart Bik
RattataKing
penguin_wwy
Vivek Khandelwal
zjgarvey
lialan
Wu Yuan
Yuanqiang Liu
Andrew Woloszyn
Xida Ren (Cedar)
Suraj Sudhir
Xinyu Yang
Peiming Liu
Aaron St George
NeverRaR
Archana Ramalingam
Stella Laurenzo
Andreas Falkenberg
jinchen
Angel Zhang
