(torch.compiler_ir)=

# IRs

PyTorch 2.0 offers two set of IRs for backends to interface with: Core Aten IR and Prims IR.

## Core Aten IR

Core aten ops is the core subset of aten operators that can be used to compose other operators.
Core aten IR is fully functional, and there is no `inplace` or `_out` variants in this opset.
In contrast to Prims IR, core aten ops reuses the existing aten ops in "native_functions.yaml",
and it doesn't further decompose ops into explicit type promotion and broadcasting ops.
This opset is designed to serve as the functional IR to interface with backends.

```{warning}
  This opset is still under active development, more ops will be added in the future.
```

```{csv-table}
   :file: ../../../build/ir/aten_ops.csv
   :widths: auto
   :header-rows: 1
```

## Prims IR

Prims IR is a set of primitive operators that can be used to compose other operators.
Prims IR is a lower level opset than core aten IR, and it further decomposes ops into explicit
type promotion and broadcasting ops: prims.convert_element_type and prims.broadcast_in_dim.
This opset is designed to interface with compiler backends.

```{warning}
  This opset is still under active development, more ops will be added in the future.
```

```{csv-table}
   :file: ../../../build/ir/prims_ops.csv
   :widths: auto
   :header-rows: 1
```
