Arm backend: Add select operator

backends/arm/arm_partitioner.py

@@ -61,6 +61,7 @@ def is_node_supported(self, submodules, node: torch.fx.Node) -> bool:
             exir_ops.edge.aten.relu.default,
             exir_ops.edge.aten.rsqrt.default,
             exir_ops.edge.aten._softmax.default,
+            exir_ops.edge.aten.select_copy.int,
             exir_ops.edge.aten.slice_copy.Tensor,
             exir_ops.edge.aten.sub.Tensor,
             exir_ops.edge.aten.sum.dim_IntList,

backends/arm/operators/__init__.py

@@ -29,6 +29,7 @@
     op_relu,
     op_repeat,
     op_rsqrt,
+    op_select,
     op_sigmoid,
     op_slice,
     op_softmax,

backends/arm/operators/op_select.py

@@ -0,0 +1,69 @@
+# Copyright 2024 Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+from typing import List
+
+import serializer.tosa_serializer as ts
+from executorch.backends.arm.operators.node_visitor import (
+    NodeVisitor,
+    register_node_visitor,
+)
+
+from executorch.backends.arm.tosa_mapping import TosaArg
+
+from executorch.backends.arm.tosa_utils import build_reshape, tosa_shape
+from serializer.tosa_serializer import TosaOp
+from torch.fx import Node
+
+
+@register_node_visitor
+class SelectVisitor(NodeVisitor):
+    target = "aten.select_copy.int"
+
+    def __init__(self, *args):
+        super().__init__(*args)
+
+    def define_node(
+        self,
+        node: Node,
+        tosa_graph: ts.TosaSerializer,
+        inputs: List[TosaArg],
+        output: TosaArg,
+        is_quant_node: bool,
+    ) -> None:
+
+        assert len(inputs) == 3
+        input_node, dim, index = inputs
+        shape = input_node.shape
+        rank = len(shape)
+
+        dim = dim.number % rank if dim.number < 0 else dim.number
+        index = index.number % rank if index.number < 0 else index.number
+
+        # For aten.select_copy, the output will be rank[input_shape - 1]
+        # For TOSA rank(in) == rank(out).
+        # Add an intermediate with the same rank
+        expanded_shape = tuple(1 if i == dim else shape[i] for i in range(rank))
+        expanded_shape = tosa_shape(expanded_shape, input_node.dim_order)
+
+        output_reshaped = tosa_graph.addIntermediate(
+            expanded_shape, ts.DType.INT8 if is_quant_node else output.dtype
+        )
+
+        attr_slice = ts.TosaSerializerAttribute()
+
+        start_attr = [index if i == dim else 0 for i in input_node.dim_order]
+        size_attr = [
+            1 if i == dim else input_node.shape[i] for i in input_node.dim_order
+        ]
+
+        attr_slice.SliceAttribute(start_attr, size_attr)
+
+        tosa_graph.addOperator(
+            TosaOp.Op().SLICE, [input_node.name], [output_reshaped.name], attr_slice
+        )
+
+        # Reshape back to original rank of output.
+        build_reshape(tosa_graph, output_reshaped.name, output.shape, output.name)

backends/arm/quantizer/quantization_annotation/generic_annotator.py

@@ -34,6 +34,8 @@
     # torch.ops.aten.view_as_real.default,
     # torch.ops.aten.view_as_real_copy.default,
     torch.ops.aten.view_copy.default,
+    torch.ops.aten.select.int,
+    torch.ops.aten.select_copy.int,
     torch.ops.aten.slice.Tensor,
     torch.ops.aten.slice_copy.Tensor,
     # 'concat' should be handled separately as it has a sequence of inputs and

backends/arm/test/ops/test_select.py

@@ -0,0 +1,198 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# Copyright 2024 Arm Limited and/or its affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+import unittest
+
+import torch
+
+from executorch.backends.arm.test import common
+from executorch.backends.arm.test.tester.arm_tester import ArmTester
+from executorch.exir.backend.compile_spec_schema import CompileSpec
+from parameterized import parameterized
+
+test_data_t = tuple[torch.Tensor, int, int]
+
+test_data_suite: list[tuple[test_data_t]] = [
+    # (test_data, dim, index)
+    ((torch.zeros(5, 3, 20), -1, 0),),
+    ((torch.zeros(5, 3, 20), 0, -1),),
+    ((torch.zeros(5, 3, 20), 0, 4),),
+    ((torch.ones(10, 10, 10), 0, 2),),
+    ((torch.rand(5, 3, 20, 2), 0, 2),),
+    ((torch.rand(10, 10) - 0.5, 0, 0),),
+    ((torch.randn(10) + 10, 0, 1),),
+    ((torch.randn(10) - 10, 0, 2),),
+    ((torch.arange(-16, 16, 0.2), 0, 1),),
+]
+
+
+class TestSelect(unittest.TestCase):
+    class SelectCopy(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+
+        def forward(self, x, dim: int, index: int):
+            return torch.select_copy(x, dim=dim, index=index)
+
+    class SelectInt(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+
+        def forward(self, x, dim: int, index: int):
+            return torch.select(x, dim=dim, index=index)
+
+    def _test_select_tosa_MI_pipeline(
+        self,
+        module: torch.nn.Module,
+        test_data: test_data_t,
+        export_target: str,
+    ):
+        # For 4D tensors, do not permute to NHWC
+        permute = False if len(test_data[0].shape) == 4 else True
+        (
+            ArmTester(
+                module,
+                example_inputs=test_data,
+                compile_spec=common.get_tosa_compile_spec(
+                    permute_memory_to_nhwc=permute
+                ),
+            )
+            .export()
+            .check([export_target])
+            .check_not(["torch.ops.quantized_decomposed"])
+            .to_edge()
+            .partition()
+            .check_count({"torch.ops.higher_order.executorch_call_delegate": 1})
+            .to_executorch()
+            .run_method_and_compare_outputs(inputs=test_data)
+        )
+
+    def _test_select_tosa_BI_pipeline(
+        self,
+        module: torch.nn.Module,
+        test_data: test_data_t,
+        export_target: str,
+    ):
+        # For 4D tensors, do not permute to NHWC
+        permute = False if len(test_data[0].shape) == 4 else True
+        (
+            ArmTester(
+                module,
+                example_inputs=test_data,
+                compile_spec=common.get_tosa_compile_spec(
+                    permute_memory_to_nhwc=permute
+                ),
+            )
+            .quantize()
+            .export()
+            .check([export_target])
+            .check(["torch.ops.quantized_decomposed"])
+            .to_edge()
+            .partition()
+            .dump_artifact()
+            .dump_operator_distribution()
+            .check_count({"torch.ops.higher_order.executorch_call_delegate": 1})
+            .to_executorch()
+            .run_method_and_compare_outputs(inputs=test_data)
+        )
+
+    def _test_select_ethos_BI_pipeline(
+        self,
+        compile_spec: list[CompileSpec],
+        module: torch.nn.Module,
+        test_data: test_data_t,
+        export_target: str,
+    ):
+        (
+            ArmTester(
+                module,
+                example_inputs=test_data,
+                compile_spec=compile_spec,
+            )
+            .quantize()
+            .export()
+            .check([export_target])
+            .check(["torch.ops.quantized_decomposed"])
+            .to_edge()
+            .partition()
+            .dump_artifact()
+            .dump_operator_distribution()
+            .check_count({"torch.ops.higher_order.executorch_call_delegate": 1})
+            .to_executorch()
+        )
+
+    def _test_select_tosa_u55_BI_pipeline(
+        self, module: torch.nn.Module, test_data: test_data_t, export_target: str
+    ):
+        # For 4D tensors, do not permute to NHWC
+        permute = False if len(test_data[0].shape) == 4 else True
+        self._test_select_ethos_BI_pipeline(
+            common.get_u55_compile_spec(permute_memory_to_nhwc=permute),
+            module,
+            test_data,
+            export_target,
+        )
+
+    def _test_select_tosa_u85_BI_pipeline(
+        self, module: torch.nn.Module, test_data: test_data_t, export_target: str
+    ):
+        # For 4D tensors, do not permute to NHWC
+        permute = False if len(test_data[0].shape) == 4 else True
+        self._test_select_ethos_BI_pipeline(
+            common.get_u85_compile_spec(permute_memory_to_nhwc=permute),
+            module,
+            test_data,
+            export_target,
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_copy_tosa_MI(self, test_data: test_data_t):
+        self._test_select_tosa_MI_pipeline(
+            self.SelectCopy(), test_data, export_target="torch.ops.aten.select_copy.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_int_tosa_MI(self, test_data: test_data_t):
+        self._test_select_tosa_MI_pipeline(
+            self.SelectInt(), test_data, export_target="torch.ops.aten.select.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_copy_tosa_BI(self, test_data: test_data_t):
+        self._test_select_tosa_BI_pipeline(
+            self.SelectCopy(), test_data, export_target="torch.ops.aten.select_copy.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_int_tosa_BI(self, test_data: test_data_t):
+        self._test_select_tosa_BI_pipeline(
+            self.SelectInt(), test_data, export_target="torch.ops.aten.select.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_copy_tosa_u55_BI(self, test_data: test_data_t):
+        self._test_select_tosa_u55_BI_pipeline(
+            self.SelectCopy(), test_data, export_target="torch.ops.aten.select_copy.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_int_tosa_u55_BI(self, test_data: test_data_t):
+        self._test_select_tosa_u55_BI_pipeline(
+            self.SelectInt(), test_data, export_target="torch.ops.aten.select.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_copy_tosa_u85_BI(self, test_data: test_data_t):
+        self._test_select_tosa_u85_BI_pipeline(
+            self.SelectCopy(), test_data, export_target="torch.ops.aten.select_copy.int"
+        )
+
+    @parameterized.expand(test_data_suite)
+    def test_select_int_tosa_u85_BI(self, test_data: test_data_t):
+        self._test_select_tosa_u85_BI_pipeline(
+            self.SelectInt(), test_data, export_target="torch.ops.aten.select.int"
+        )