Arm backend: Propagate node info from quantizer to backend (#15300)

Use the Node meta 'custom' field to propagate information from quantizer
to partitioner using a new ArmAnnotationInfo data class. This allows us
to track quantized node reliably which is useful in order to track which
nodes should 'fold' it's quantization parameter and which should be kept
in fp when mixing integer and float in a sub-graph.

Signed-off-by: Oscar Andersson <oscar.andersson@arm.com>
Co-authored-by: Per Åstrand <per.astrand@arm.com>

Author: oscarandersson8218

backends/arm/common/annotation_meta.py

@@ -0,0 +1,19 @@
+# Copyright 2025 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 dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class ArmAnnotationInfo:
+    """
+    Data class to carry Arm-specific annotation information through the pipeline.
+    This is intended to be attached to node.meta['custom'] and propagated
+    through partitioning and backend stages. As it's propagated through the pipeline,
+    it's intentionally minimal and only carries whether the node is quantized or not.
+    """
+
+    quantized: bool
+    CUSTOM_META_KEY: str = "_arm_annotation_info"

backends/arm/operator_support/tosa_supported_operators.py

@@ -21,6 +21,7 @@
     FuseQuantizedActivationPass,
 )
 from executorch.backends.arm._passes.insert_table_ops import TableOps
+from executorch.backends.arm.common.annotation_meta import ArmAnnotationInfo
 from executorch.backends.arm.constants import DQ_OPS, MAX_RANK, Q_OPS
 from executorch.backends.arm.operator_support.ethos_u55_support import (
     EthosU55CastCheck,
@@ -140,6 +141,7 @@ def tosa_support_factory(
     ]
 
     if not tosa_spec.support_float():
+        negative_checks.append(CheckArmQuantized(reporter))
         negative_checks.append(CheckProperQuantization(reporter))
     if tosa_spec.is_U55_subset:
         negative_checks.append(EthosU55NotSupported(reporter))
@@ -167,7 +169,6 @@ class TOSAProINTSupportList(OperatorSupportBase):
     def is_node_supported(
         self, submodules: typing.Mapping[str, torch.nn.Module], node: fx.Node
     ) -> bool:
-
         return node.op == "call_function" and node.target in TOSA_PRO_INT_SupportList
 
 
@@ -180,10 +181,80 @@ class TOSAProFPSupportList(OperatorSupportBase):
     def is_node_supported(
         self, submodules: typing.Mapping[str, torch.nn.Module], node: fx.Node
     ) -> bool:
-
         return node.op == "call_function" and node.target in TOSA_PRO_FP_SupportList
 
 
+class CheckArmQuantized(OperatorSupportBase):
+    """
+    Check if the node was marked as quantized in the Arm backend.
+    This is used to ensure that nodes that were quantized in the Arm backend
+    are only partitioned if they are supported by the TOSA backend.
+    """
+
+    def __init__(self, reporter: WhyNoPartitionReporter):
+        self.reporter = reporter
+
+    def _is_quantized(self, node: torch.fx.Node) -> bool:
+        """Checks if the node is quantized.
+
+        A node is considered quantized if at least one criteria is met:
+        - Its dtype is not floating point or complex => integer
+        - It is one of the special cases where the node has been created in to_edge, e.g.
+          .Scalar operations that have been promoted .Tensor operations
+          where the scalar is replaced by a full op.
+        - It has been marked as quantized in the ArmAnnotationInfo custom meta.
+
+        Args:
+            node (torch.fx.Node): The FX node to check.
+
+        Returns:
+            bool: True if the node is quantized, False otherwise.
+        """
+        node_dtype = get_first_fake_tensor(node).dtype
+        if not node_dtype.is_complex and not node_dtype.is_floating_point:
+            return True
+        if node.target in (
+            exir_ops.edge.aten.full_like.default,
+            *ComputeConstantOpsAOT.targeted_ops,
+        ):
+            # Special cases where nodes have been created in to_edge, e.g.
+            # .Scalar operations that have been promoted .Tensor operations
+            # where the scalar is replaced by a full op.
+            if all(user.target in Q_OPS for user in node.users):
+                return True
+            for user in node.users:
+                if (
+                    user.target
+                    == exir_ops.edge.dim_order_ops._to_dim_order_copy.default
+                ):
+                    dim_order_dtype = get_first_fake_tensor(user).dtype
+                    if dim_order_dtype.is_complex or dim_order_dtype.is_floating_point:
+                        return False
+                else:
+                    return False
+            return True
+        return (
+            ArmAnnotationInfo.CUSTOM_META_KEY in node.meta.get("custom", {})
+            and node.meta["custom"][ArmAnnotationInfo.CUSTOM_META_KEY].quantized
+        )
+
+    def is_node_supported(
+        self, submodules: typing.Mapping[str, torch.nn.Module], node: fx.Node
+    ) -> bool:
+        if node.op != "call_function":
+            return False
+
+        if node.target in (*DQ_OPS, *Q_OPS):
+            return True
+
+        if not self._is_quantized(node):
+            self.reporter.report_reject(
+                node, "Node was not marked as quantized in the Arm backend."
+            )
+            return False
+        return True
+
+
 class CheckProperQuantization(OperatorSupportBase):
     """
     For targeted nodes, check that it has been quantized as expected. In most cases this means that a pair of quantize
@@ -427,7 +498,6 @@ def is_node_supported(
 
 
 class CheckFloat64Inputs(OperatorSupportBase):
-
     def __init__(
         self, exported_program: ExportedProgram, reporter: WhyNoPartitionReporter
     ):

backends/arm/quantizer/arm_quantizer_utils.py

@@ -1,6 +1,6 @@
 # Copyright (c) Meta Platforms, Inc. and affiliates.
-# Copyright 2024-2025 Arm Limited and/or its affiliates.
 # All rights reserved.
+# Copyright 2024-2025 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.
@@ -14,6 +14,8 @@
 
 from typing import cast
 
+from executorch.backends.arm.common.annotation_meta import ArmAnnotationInfo
+
 from torch.fx import Node
 
 from torchao.quantization.pt2e.quantizer import QuantizationAnnotation
@@ -65,4 +67,10 @@ def mark_node_as_annotated(node: Node) -> None:
     """
     if Q_ANNOTATION_KEY not in node.meta:
         node.meta[Q_ANNOTATION_KEY] = QuantizationAnnotation()
+    annotation_info = ArmAnnotationInfo(
+        quantized=True,
+    )
     node.meta[Q_ANNOTATION_KEY]._annotated = True
+    meta_custom = node.meta.get("custom", {})
+    meta_custom[ArmAnnotationInfo.CUSTOM_META_KEY] = annotation_info
+    node.meta["custom"] = meta_custom

backends/arm/quantizer/quantization_annotator.py

@@ -394,6 +394,7 @@ def _match_pattern(
     torch.ops.aten.view.default,
     torch.ops.aten.view_as.default,
     torch.ops.aten.view_copy.default,
+    torch.ops.aten._unsafe_view.default,
     torch.ops.aten.select.int,
     torch.ops.aten.select_copy.int,
     torch.ops.aten.slice.Tensor,
@@ -426,6 +427,7 @@ def _match_pattern(
 ]
 
 _one_to_one_shared_input_or_input_act_qspec = [
+    torch.ops.aten.alias.default,
     torch.ops.aten.clone.default,
     torch.ops.aten.hardtanh.default,
     torch.ops.aten.hardtanh_.default,
@@ -693,10 +695,10 @@ def any_or_hardtanh_min_zero(n: Node):
         ]
         quant_properties.quant_output = None
     elif node.target in [
-        torch.ops.aten.scalar_tensor.default,
         torch.ops.aten.full.default,
         torch.ops.aten.full,
         torch.ops.aten.fill_.Scalar,
+        torch.ops.aten.scalar_tensor.default,
     ]:
         quant_properties.quant_inputs = []
         quant_properties.quant_output = _QuantProperty(0, output_act_qspec)

backends/arm/test/misc/test_int64.py

@@ -68,10 +68,6 @@ def forward(self, x: torch.Tensor):
         ConstAdd(torch.int64, 2**40),
         (torch.rand(10) - 0.5,),
     ),
-    "int64_in+float_const": (
-        ConstAdd(torch.float32),
-        (torch.randint(0, 10, (10,)),),
-    ),
     "fp32_in+int64_buffer_chain": (
         BufferChainAdd(torch.int64),
         (torch.rand(2, 5, 3) - 0.5,),
@@ -94,7 +90,7 @@ def test_int64_tosa_FP(test_data: Tuple):
         ArmTester(
             model,
             inputs,
-            common.get_tosa_compile_spec("TOSA-1.0+FP", custom_path="tosa/int64"),
+            common.get_tosa_compile_spec("TOSA-1.0+FP"),
         )
         .export()
         .to_edge_transform_and_lower()

backends/arm/test/misc/test_quant_custom_meta.py

@@ -0,0 +1,100 @@
+# Copyright 2025 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.
+
+import torch
+from executorch.backends.arm.quantizer import (
+    get_symmetric_quantization_config,
+    TOSAQuantizer,
+)
+from executorch.backends.arm.test.tester.test_pipeline import TosaPipelineINT
+from executorch.backends.arm.tosa import TosaSpecification
+from executorch.backends.xnnpack.test.tester import Quantize
+
+
+class AddSigmoidMul(torch.nn.Module):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.sigmoid = torch.nn.Sigmoid()
+
+    def forward(self, x, y):
+        return self.sigmoid(x + y) * x
+
+
+def get_selective_quantizer(modules):
+    quantizer = TOSAQuantizer(TosaSpecification.create_from_string("TOSA-1.0+INT"))
+    quantizer.set_global(get_symmetric_quantization_config())
+    for module in modules:
+        quantizer.set_module_type(module, None)
+
+    return Quantize(quantizer, get_symmetric_quantization_config())
+
+
+def test_qdq_squeezed_fp_op():
+    """Test that a float operation surrounded by quantize-dequantize pairs
+    is correctly handled by the partitioner and the TOSA backend.
+    Pattern:
+    q -> dq -> add -> q -> dq -> sigmoid -> q -> dq -> mul -> dq -> q
+                        |_____Non-delegated____|
+    """
+    aten_op = "torch.ops.aten.add.Tensor"
+    exir_op = "executorch_exir_dialects_edge__ops_aten_add_Tensor"
+    module = AddSigmoidMul()
+    x = torch.randn(2, 3, 4)
+    y = torch.randn(2, 3, 4)
+    pipeline = TosaPipelineINT(
+        module=module, test_data=(x, y), aten_op=aten_op, exir_op=exir_op
+    )
+    pipeline.change_args("quantize", get_selective_quantizer([torch.nn.Sigmoid]))
+    pipeline.change_args(
+        "check_count.exir",
+        {
+            "torch.ops.higher_order.executorch_call_delegate": 2,
+            "executorch_exir_dialects_edge__ops_aten_sigmoid_default": 1,
+            "executorch_exir_dialects_edge__ops_quantized_decomposed_dequantize_per_tensor_default": 2,
+            "executorch_exir_dialects_edge__ops_quantized_decomposed_quantize_per_tensor_default": 3,
+        },
+    )
+    pipeline.run()
+
+
+class MulAddSigmoidConv(torch.nn.Module):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.sigmoid = torch.nn.Sigmoid()
+        self.conv = torch.nn.Conv1d(3, 3, 1)
+
+    def forward(self, x, y):
+        return self.conv(self.sigmoid(x + y * x))
+
+
+def test_quantized_to_float_transition():
+    """Test that a model executing quantized ops followed by float ops
+    is correctly handled by the partitioner and the TOSA backend.
+    Pattern:
+    q -> dq -> mul -> q -> dq -> add -> q -> dq -> sigmoid -> conv
+                                           |____Non-delegated___|
+    """
+    aten_op = "torch.ops.aten.add.Tensor"
+    exir_op = "executorch_exir_dialects_edge__ops_aten_add_Tensor"
+    module = MulAddSigmoidConv()
+    x = torch.randn(2, 3, 4)
+    y = torch.randn(2, 3, 4)
+    pipeline = TosaPipelineINT(
+        module=module, test_data=(x, y), aten_op=aten_op, exir_op=exir_op
+    )
+    pipeline.change_args(
+        "quantize", get_selective_quantizer([torch.nn.Sigmoid, torch.nn.Conv1d])
+    )
+    pipeline.change_args(
+        "check_count.exir",
+        {
+            "torch.ops.higher_order.executorch_call_delegate": 1,
+            "executorch_exir_dialects_edge__ops_aten_sigmoid_default": 1,
+            "executorch_exir_dialects_edge__ops_aten_convolution_default": 1,
+            "executorch_exir_dialects_edge__ops_quantized_decomposed_dequantize_per_tensor_default": 1,
+            "executorch_exir_dialects_edge__ops_quantized_decomposed_quantize_per_tensor_default": 2,
+        },
+    )
+    pipeline.run()

backends/arm/test/models/stable_diffusion/test_SD3Transformer2DModel.py

@@ -39,7 +39,8 @@ class TestSD3Transformer2DModel:
 
     ops_after_partitioner_INT = {
         "executorch_exir_dialects_edge__ops_dim_order_ops__to_dim_order_copy_default": 2,
-        "torch.ops.higher_order.executorch_call_delegate": 2,
+        "torch.ops.higher_order.executorch_call_delegate": 3,
+        "executorch_exir_dialects_edge__ops_aten_permute_copy_default": 1,
     }
 
     def _prepare_inputs(

backends/arm/test/models/test_nn_functional.py

@@ -102,7 +102,6 @@ def test_nn_functional_FP(test_data):
 @parametrize(
     "test_data",
     module_tests,
-    {"normalize": "MLETORCH-1255: Unsupported dtype in InsertTableOpsPass"},
 )
 def test_nn_functional_INT(test_data):
     module, inputs = test_data

backends/arm/test/models/test_torch_functions.py

@@ -126,10 +126,12 @@ def test_torch_fns_FP(test_data):
     xfails={
         "nonzero": "torch.fx.experimental.symbolic_shapes.GuardOnDataDependentSymNode: Could not guard on data-dependent expression Eq(u4, 0). "
         "Requires dynamic output shape.",
+        "eye": "ValueError: Failed processing buffer placeholder: aten_arange_start_step_1_pre_computed_common. "
+        "Is the original torch function supported?",
         "topk": "NotImplementedError: No registered serialization name for <class 'torch.return_types.topk'> found",
         "sort": "NotImplementedError: No registered serialization name for <class 'torch.return_types.sort'> found",
     },
-    strict=False,
+    strict=True,
 )
 def test_torch_fns_INT(test_data):
     module, inputs = test_data

backends/arm/test/ops/test_eye.py

@@ -95,7 +95,7 @@ def test_eye_u85_INT(test_data: test_data_t):
         input_data(),
         EyeAdd.aten_op,
         use_to_edge_transform_and_lower=True,
-    ).dump_artifact("to_edge_transform_and_lower")
+    )
     pipeline.pop_stage("check.quant_nodes")
     pipeline.run()