Arm backend: Add GLU decomposition pass and test (#13270)

Decomposes the gated linear unit function.

Signed-off-by: Teo Bergkvist <[email protected]>

Author: tbergkvist

backends/arm/_passes/__init__.py

@@ -36,6 +36,7 @@
 from .decompose_div_pass import DecomposeDivPass  # noqa
 from .decompose_embedding_pass import DecomposeEmbeddingPass  # noqa  # noqa
 from .decompose_gelu_pass import DecomposeGeluPass  # noqa
+from .decompose_glu_pass import DecomposeGluPass  # noqa
 from .decompose_grouped_conv import DecomposeGroupedConv  # noqa
 from .decompose_groupnorm_pass import DecomposeGroupNormPass  # noqa
 from .decompose_layernorm_pass import DecomposeLayerNormPass  # noqa

backends/arm/_passes/arm_pass_manager.py

@@ -41,6 +41,7 @@
     DecomposeDivPass,
     DecomposeEmbeddingPass,
     DecomposeGeluPass,
+    DecomposeGluPass,
     DecomposeGroupedConv,
     DecomposeGroupNormPass,
     DecomposeLayerNormPass,
@@ -184,6 +185,7 @@ def _tosa_FP_pipeline(self, exported_program: ExportedProgram) -> GraphModule:
         self.add_pass(ConvertSplitToSlicePass())
         self.add_pass(FuseBatchnorm2DPass(exported_program))
         self.add_pass(ConvertMmToBmmPass())
+        self.add_pass(DecomposeGluPass())
         self.add_pass(DecomposeLinearPass())
         self.add_pass(DecomposeLeakyReLUPass())
         self.add_pass(DecomposeGroupNormPass())
@@ -264,6 +266,7 @@ def transform_for_annotation_pipeline(self, graph_module: GraphModule):
         self.add_pass(DecomposeMeanDimPass(graph_module, self.tosa_spec))
         self.add_pass(DecomposeNotEqualPass())
         self.add_pass(DecomposeCosineSimilarityPass())
+        self.add_pass(DecomposeGluPass())
         self.add_pass(DecomposeDivPass())
         self.add_pass(DecomposeLeakyReLUPass())
         self.add_pass(DecomposeLinearVectorNormPass())

backends/arm/_passes/decompose_glu_pass.py

@@ -0,0 +1,75 @@
+# 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._passes import ArmPass
+from executorch.exir.dialects._ops import ops as exir_ops
+
+
+# For FP case
+edge_glu = exir_ops.edge.aten.glu.default
+
+# For INT case
+aten_glu = torch.ops.aten.glu.default
+
+
+def get_ops(op):
+    """Returns the appropriate operator functions based on the input operator."""
+    if op == edge_glu:
+        return (
+            exir_ops.edge.aten.mul.Tensor,
+            exir_ops.edge.aten.sigmoid.default,
+            exir_ops.edge.aten.slice_copy.Tensor,
+        )
+    elif op == aten_glu:
+        return (
+            torch.ops.aten.mul.Tensor,
+            torch.ops.aten.sigmoid.default,
+            torch.ops.aten.slice_copy.Tensor,
+        )
+    else:
+        raise ValueError(f"Unsupported operator: {op}")
+
+
+class DecomposeGluPass(ArmPass):
+    """Decomposes the GLU operator into hadamard product and sigmoid."""
+
+    def call_operator(self, op, args, kwargs, meta):
+        if op not in [edge_glu, aten_glu]:
+            return super().call_operator(op, args, kwargs, meta)
+
+        hadamard_prod, sigmoid, slice_op = get_ops(op)
+        X = args[0]
+
+        dim = args[1] if len(args) > 1 else kwargs.get("dim", -1)
+
+        if "val" not in X.node.meta:
+            raise Exception("Could not get dimension metadata in input.")
+
+        if dim < 0:
+            dim += X.node.meta["val"].dim()
+
+        n = X.node.meta["val"].size(dim)
+
+        if n % 2:
+            raise RuntimeError(
+                f"glu expects an even split along dim={dim}, got size {n}"
+            )
+
+        middle = n // 2
+
+        T1 = super().call_operator(
+            slice_op, (X, dim, 0, middle), {}, meta, updated=True
+        )
+
+        T2 = super().call_operator(
+            slice_op, (X, dim, middle, n), {}, meta, updated=True
+        )
+
+        T2_sigmoid = super().call_operator(sigmoid, (T2,), {}, meta, updated=True)
+
+        return super().call_operator(
+            hadamard_prod, (T1, T2_sigmoid), {}, meta, updated=True
+        )

backends/arm/operator_support/tosa_supported_operators.py

@@ -258,6 +258,7 @@ def is_node_supported(
             exir_ops.edge.aten.masked_fill.Scalar,
             exir_ops.edge.aten.asinh.default,
             exir_ops.edge.aten.cosh.default,
+            exir_ops.edge.aten.glu.default,
         ]
 
         return supported
@@ -299,6 +300,7 @@ def is_node_supported(
             exir_ops.edge.aten.leaky_relu.default: None,
             exir_ops.edge.aten.round.default: None,
             exir_ops.edge.aten.addmm.default: None,
+            exir_ops.edge.aten.glu.default: None,
         }
 
         if node.target in needs_decomp_dict:

backends/arm/test/ops/test_glu.py

@@ -0,0 +1,130 @@
+# 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 typing import Tuple
+
+import torch
+import torch.nn.functional as F
+from executorch.backends.arm.test import common
+from executorch.backends.arm.test.tester.test_pipeline import (
+    EthosU55PipelineINT,
+    EthosU85PipelineINT,
+    TosaPipelineFP,
+    TosaPipelineINT,
+    VgfPipeline,
+)
+
+aten_op = "torch.ops.aten.glu.default"
+exir_op = "executorch_exir_dialects_edge__ops_aten__glu_default"
+
+
+input_t1 = Tuple[torch.Tensor]
+
+test_data_suite = {
+    "zeros": [torch.zeros(10, 10, 2), -1],
+    "ones": [torch.ones(10, 10, 2), -1],
+    "rand": [torch.rand(10, 10, 2) - 0.5, -1],
+    "randn_pos": [torch.randn(10, 2) + 10, -1],
+    "randn_neg": [torch.randn(10, 2) - 10, -1],
+    "ramp": [torch.linspace(-16, 15.8, 160).reshape(-1, 2), -1],
+    "zeros_custom_dim": [torch.zeros(7, 10, 5), 1],
+    "rand_custom_dim": [torch.rand(10, 3, 3) - 0.5, 0],
+}
+
+
+class Glu(torch.nn.Module):
+
+    def forward(self, a: torch.Tensor, dim: int) -> torch.Tensor:
+        return F.glu(a, dim=dim)
+
+
+@common.parametrize(
+    "test_data",
+    test_data_suite,
+)
+def test_glu_tosa_FP(test_data: Tuple):
+    pipeline = TosaPipelineFP[input_t1](
+        Glu(),
+        (*test_data,),
+        aten_op,
+        exir_op,
+    )
+    pipeline.run()
+
+
+@common.parametrize(
+    "test_data",
+    test_data_suite,
+)
+def test_glu_tosa_INT(test_data: Tuple):
+    pipeline = TosaPipelineINT[input_t1](
+        Glu(),
+        (*test_data,),
+        aten_op=[],
+        exir_op=exir_op,
+    )
+    pipeline.run()
+
+
+@common.parametrize(
+    "test_data",
+    test_data_suite,
+)
+@common.XfailIfNoCorstone300
+def test_glu_u55_INT(test_data: Tuple):
+    pipeline = EthosU55PipelineINT[input_t1](
+        Glu(),
+        (*test_data,),
+        aten_ops=[],
+        exir_ops=exir_op,
+    )
+    pipeline.run()
+
+
+@common.parametrize(
+    "test_data",
+    test_data_suite,
+)
+@common.XfailIfNoCorstone320
+def test_glu_u85_INT(test_data: Tuple):
+    pipeline = EthosU85PipelineINT[input_t1](
+        Glu(),
+        (*test_data,),
+        aten_ops=[],
+        exir_ops=exir_op,
+    )
+    pipeline.run()
+
+
+@common.parametrize(
+    "test_data",
+    test_data_suite,
+)
+@common.SkipIfNoModelConverter
+def test_glu_vgf_FP(test_data: input_t1):
+    pipeline = VgfPipeline[input_t1](
+        Glu(),
+        (*test_data,),
+        [],
+        [],
+        tosa_version="TOSA-1.0+FP",
+    )
+    pipeline.run()
+
+
+@common.parametrize(
+    "test_data",
+    test_data_suite,
+)
+@common.SkipIfNoModelConverter
+def test_glu_vgf_INT(test_data: input_t1):
+    pipeline = VgfPipeline[input_t1](
+        Glu(),
+        (*test_data,),
+        [],
+        [],
+        tosa_version="TOSA-1.0+INT",
+    )
+    pipeline.run()