llvm / llvm/torch-mlir

How to lower the pattern `torch.aten.Int.Scalar(torch.aten.item(rank0_tensor))`?

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Description

I want to lower `torch.dialect` module something like the following:
```mlir
module {
func @main(%arg0: !torch.vtensor<[?,?,?,?],f32>, %arg1: !torch.vtensor<[],si64>) -> !torch.vtensor<[?,?,?,?],f32> {
%int1 = torch.constant.int 1
%int3 = torch.constant.int 3
%int2 = torch.constant.int 2
%int0 = torch.constant.int 0
%0 = torch.aten.item %arg1 : !torch.vtensor<[],si64> -> !torch.number
%1 = torch.aten.Int.Scalar %0 : !torch.number -> !torch.int
%2 = torch.aten.add.Scalar %arg0, %1, %int1 : !torch.vtensor<[?,?,?,?],f32>, !torch.int, !torch.int -> !torch.vtensor<[?,?,?,?],f32>
return %2 : !torch.vtensor<[?,?,?,?],f32>
}
}
```

But I can't add a per-Op converter to somewhere like [`lib/Conversion/TorchToTosa/TorchToTosa.cpp`](https://github.com/llvm/torch-mlir/blob/main/lib/Conversion/TorchToTosa/TorchToTosa.cpp), since there is no `TypeConverter` between `!torch.number` and `!torch.int`.

Is there anyone knows how to lower the IR module?

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Research direction

Start with lib/Conversion/TorchToTosa/TorchToTosa.cpp and inspect how the shown torch.aten.item and torch.aten.Int.Scalar operations are handled. A resolution would need to establish a supported lowering for the sample IR and demonstrate that the resulting module can be lowered successfully.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
20/100

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