Add 16A8W linear ops support and test (pytorch#13922)

This PR was created by the merge bot to help merge the original PR into
the main branch.
ghstack PR number: pytorch#13899 by
@Ninja91
^ Please use this as the source of truth for the PR details, comments,
and reviews
ghstack PR base:
https://github.com/pytorch/executorch/tree/gh/Ninja91/18/base
ghstack PR head:
https://github.com/pytorch/executorch/tree/gh/Ninja91/18/head
Merge bot PR base: https://github.com/pytorch/executorch/tree/main
Merge bot PR head:
https://github.com/pytorch/executorch/tree/gh/Ninja91/18/orig
@diff-train-skip-merge

Co-authored-by: Nitin Jain <[email protected]>

Author: pytorchbot

backends/arm/operators/op_view.py

@@ -44,7 +44,13 @@ def define_node(
         validate_valid_dtype(
             self.target,
             [inputs[0], output],
-            [ts.DType.INT8, ts.DType.INT32, ts.DType.FP32, ts.DType.BOOL],
+            [
+                ts.DType.INT8,
+                ts.DType.INT16,
+                ts.DType.INT32,
+                ts.DType.FP32,
+                ts.DType.BOOL,
+            ],
             output.tosa_spec,
         )
 

backends/arm/test/ops/test_linear.py

@@ -9,9 +9,12 @@
 from typing import Tuple
 
 import pytest
-
 import torch
-from executorch.backends.arm.test import common
+from executorch.backends.arm.quantizer.arm_quantizer import (
+    get_symmetric_a16w8_quantization_config,
+    TOSAQuantizer,
+)
+from executorch.backends.arm.test import common, conftest
 
 from executorch.backends.arm.test.tester.test_pipeline import (
     EthosU55PipelineINT,
@@ -20,6 +23,8 @@
     TosaPipelineINT,
     VgfPipeline,
 )
+from executorch.backends.arm.tosa_specification import TosaSpecification
+from executorch.backends.xnnpack.test.tester import Quantize
 
 aten_op = "torch.ops.aten.linear.default"
 
@@ -143,7 +148,6 @@ def test_linear_tosa_FP(test_data: torch.Tensor):
     pipeline.run()
 
 
-@pytest.mark.flaky(reruns=5)  # TODO: Investigate flakyness.
 @common.parametrize("test_data", test_data_rank1_INT | test_data_rank4_INT)
 def test_linear_tosa_INT(test_data: torch.Tensor):
     test_data, out_features, has_bias, per_channel_quantization = test_data()
@@ -243,3 +247,64 @@ def test_linear_vgf_INT(test_data: torch.Tensor):
         per_channel_quantization=per_channel_quantization,
     )
     pipeline.run()
+
+
+def get_symmetric_a16w8_linear_quantizer(
+    u55_config=False, per_channel_quantization=False
+):
+    tosa_version = conftest.get_option("tosa_version")
+    tosa_profiles = {
+        "1.0": TosaSpecification.create_from_string("TOSA-1.0+INT+int16"),
+    }
+
+    quantizer = TOSAQuantizer(tosa_profiles[tosa_version])
+    quantizer.set_global(
+        get_symmetric_a16w8_quantization_config(is_per_channel=per_channel_quantization)
+    )
+    quantizer.set_module_type(
+        torch.nn.Linear,
+        get_symmetric_a16w8_quantization_config(
+            is_per_channel=per_channel_quantization
+        ),
+    )
+
+    return Quantize(
+        quantizer,
+        get_symmetric_a16w8_quantization_config(
+            is_per_channel=per_channel_quantization
+        ),
+    )
+
+
+@common.parametrize("test_data", test_data_rank1_INT | test_data_rank4_INT)
+@pytest.mark.xfail(
+    reason="missing int16 linear ops support; fails at TOSA reference model run with Invalid TOSA graph"
+)
+def test_linear_16a8w_tosa_INT(test_data: torch.Tensor):
+    """Test linear operation with 16A8W quantization (16-bit activations, 8-bit weights)"""
+    test_data, out_features, has_bias, per_channel_quantization = test_data()
+    in_features = test_data.shape[-1]
+
+    # Create pipeline with custom 16A8W quantization config
+    pipeline = TosaPipelineINT[input_t1](
+        Linear(
+            in_features=in_features,
+            out_features=out_features,
+            bias=has_bias,
+        ),
+        (test_data,),
+        aten_op,
+        exir_op=[],
+        per_channel_quantization=per_channel_quantization,
+        use_to_edge_transform_and_lower=True,
+        tosa_extensions=["int16"],
+    )
+
+    pipeline.change_args(
+        "quantize",
+        get_symmetric_a16w8_linear_quantizer(
+            per_channel_quantization=per_channel_quantization
+        ),
+    )
+    # Run the pipeline
+    pipeline.run()