|
| 1 | +# Copyright 2025 Arm Limited and/or its affiliates. |
| 2 | +# |
| 3 | +# This source code is licensed under the BSD-style license found in the |
| 4 | +# LICENSE file in the root directory of this source tree. |
| 5 | + |
| 6 | +from __future__ import annotations |
| 7 | + |
| 8 | +import numbers |
| 9 | +from typing import Set, Type |
| 10 | + |
| 11 | +import torch |
| 12 | +from executorch.backends.arm._passes import ArmPass |
| 13 | +from executorch.exir.dialects._ops import ops as exir_ops |
| 14 | +from executorch.exir.pass_base import ExportPass |
| 15 | + |
| 16 | + |
| 17 | +_ADD_OPS = ( |
| 18 | + exir_ops.edge.aten.add.Tensor, |
| 19 | + torch.ops.aten.add.Tensor, |
| 20 | +) |
| 21 | + |
| 22 | +_SUB_OPS = ( |
| 23 | + exir_ops.edge.aten.sub.Tensor, |
| 24 | + torch.ops.aten.sub.Tensor, |
| 25 | +) |
| 26 | + |
| 27 | + |
| 28 | +def _get_ops(op): |
| 29 | + if op in _ADD_OPS: |
| 30 | + if op is exir_ops.edge.aten.add.Tensor: |
| 31 | + return ( |
| 32 | + exir_ops.edge.aten.mul.Tensor, |
| 33 | + exir_ops.edge.aten.full.default, |
| 34 | + exir_ops.edge.aten.add.Tensor, |
| 35 | + ) |
| 36 | + return ( |
| 37 | + torch.ops.aten.mul.Tensor, |
| 38 | + torch.ops.aten.full.default, |
| 39 | + torch.ops.aten.add.Tensor, |
| 40 | + ) |
| 41 | + if op in _SUB_OPS: |
| 42 | + if op is exir_ops.edge.aten.sub.Tensor: |
| 43 | + return ( |
| 44 | + exir_ops.edge.aten.mul.Tensor, |
| 45 | + exir_ops.edge.aten.full.default, |
| 46 | + exir_ops.edge.aten.sub.Tensor, |
| 47 | + ) |
| 48 | + return ( |
| 49 | + torch.ops.aten.mul.Tensor, |
| 50 | + torch.ops.aten.full.default, |
| 51 | + torch.ops.aten.sub.Tensor, |
| 52 | + ) |
| 53 | + raise RuntimeError(f"Unsupported operator {op}") |
| 54 | + |
| 55 | + |
| 56 | +def _should_decompose(alpha) -> bool: |
| 57 | + if isinstance(alpha, numbers.Number): |
| 58 | + return alpha != 1 |
| 59 | + return False |
| 60 | + |
| 61 | + |
| 62 | +class DecomposeAddSubAlphaPass(ArmPass): |
| 63 | + """Rewrite add/sub with alpha into a mul followed by add/sub.""" |
| 64 | + |
| 65 | + _passes_required_after: Set[Type[ExportPass]] = set() |
| 66 | + |
| 67 | + def call_operator(self, op, args, kwargs, meta, updated: bool | None = False): |
| 68 | + if op not in _ADD_OPS + _SUB_OPS: |
| 69 | + return super().call_operator(op, args, kwargs, meta, updated) |
| 70 | + |
| 71 | + alpha = kwargs.get("alpha", 1) |
| 72 | + if not _should_decompose(alpha): |
| 73 | + return super().call_operator(op, args, kwargs, meta, updated) |
| 74 | + |
| 75 | + mul_op, full_op, binary_op = _get_ops(op) |
| 76 | + lhs, rhs = args |
| 77 | + |
| 78 | + alpha_full = super().call_operator( |
| 79 | + full_op, ((1,), float(alpha)), {}, meta, updated=True |
| 80 | + ) |
| 81 | + scaled_rhs = super().call_operator( |
| 82 | + mul_op, |
| 83 | + (rhs, alpha_full), |
| 84 | + {}, |
| 85 | + meta, |
| 86 | + updated=True, |
| 87 | + ) |
| 88 | + return super().call_operator( |
| 89 | + binary_op, |
| 90 | + (lhs, scaled_rhs), |
| 91 | + {}, |
| 92 | + meta, |
| 93 | + updated=True, |
| 94 | + ) |
0 commit comments