[onert] Remove frontend layout feature

[ragmani]

What

Let's remove frontend layout feature.

Why

onert supports only NHWC model(circle, tflite) and probably will supports only NHWC model in the future. If so, the feature is meaningless.

How

• Change default layout to ir::Layout::UNKNOWN
• Remove frontend_layout from ir::Graph.
• Remove layout from compiler::PermuteFactor.
• Remove layout from compiler::OperationLowerInfo.
• Add layout to compiler::OperandLowerInfo.
• Add layout to ir::Operand to support ops like Conv2D that has layout.
• Delegate dealing with layouts to backends.
  • Remove layout feature for each backend.
  • Enable each backend to update their partial graph

Draft #12224

[hseok-oh]

onert supports only NHWC model(circle, tflite) and probably will supports only NHWC model in the future

Then, will we remove data_format field in circle schema?

[glistening]

onert is not the only user of circle schema. Other tools (like ONE front end and/or NPU Compiler) may make use of data_format.

onert supports only NHWC model(circle, tflite)

I am not sure it is valid. We've supported some model in NHWC at least for some operators a long time ago.

[ragmani]

@hseok-oh

Then, will we remove data_format field in circle schema?

Thanks for your information. I didn't know circle schema has data_format. I will stop this task.

[ragmani]

@glistening

onert is not the only user of circle schema. Other tools (like ONE front end and/or NPU Compiler) may make use of data_format.

What is ONE front and NPU Compiler? onert get models from them? I didn't catch the reason why you are talking about other tools.

I am not sure it is valid. We've supported some model in NHWC at least for some operators a long time ago.

OK, I will stop this task.

[glistening]

@ragmani

What is ONE front and NPU Compiler? onert get models from them? I didn't catch the reason why you are talking about other tools.

It was my comment about @hseok-oh's

Then, will we remove data_format field in circle schema?

What is ONE front and NPU Compiler?

CFE in this repo, and NPU_Compiler in our internal repo.

[hseok-oh]

But if we don't use data_format field on compiler frontend and runtime (in other word, use NHWC only as default value), I think we can consider removing this feature from schema.

[ragmani]

But if we don't use data_format field on compiler frontend and runtime (in other word, use NHWC only as default value),

I also felt that compiler frontend converts models(i.g. ONNX model) to circle models in NHWC when I was working on compiler frontend.

[hseok-oh]

I talked with @seanshpark about this yesterday, and he also said that data_format is not used on compiler frontend and assume NHWC only. Let's deprecate this feature.

[seanshpark]

several modules in compiler has access to data_format but doesn't seem to do valid things. I'll check with a draft change.

[hseok-oh]

Now layout is removes in frontend and backend all, and layout is used for input/output setting only.