fix: Pad/AveragePool fusion (#23190)

### Description
Fusing Pad & AveragePool requires AveragePool to use
`count_include_pad=1`. If the AveragePool already set some padding and
`count_include_pad=0`, fusion can't happen.

This PR adds a condition to perform fusion depending on those
attributes. If fusion occurs, `count_include_pad` is always set to `1`.

### Motivation and Context
Fix #22177 (mislabelled as a performance issue but there's an actual bug
in the implementation)
Bug introduced in #21556

onnxruntime/core/optimizer/pad_fusion.cc

@@ -10,7 +10,7 @@ namespace onnxruntime {
 
 bool VerifyNotCastChild(const Node& child_node) {
   if (!graph_utils::IsSupportedOptypeVersionAndDomain(child_node, "Conv", {1, 11}) &&
-      !graph_utils::IsSupportedOptypeVersionAndDomain(child_node, "AveragePool", {1, 7, 10, 11, 19}) &&
+      !graph_utils::IsSupportedOptypeVersionAndDomain(child_node, "AveragePool", {7, 10, 11, 19}) &&
       !graph_utils::IsSupportedOptypeVersionAndDomain(child_node, "MaxPool", {1, 8, 10, 11, 12})) {
     return false;
   }
@@ -31,11 +31,32 @@ bool VerifyNotCastChild(const Node& child_node) {
     return false;
   }
 
+  if (child_node.OpType() == "AveragePool") {
+    // in case there's already padding and count_include_pad is 0, fusion can't be performed
+    auto has_pad = false;
+    if (child_node.GetAttributes().find("pads") != child_node.GetAttributes().end()) {
+      auto const& pads_values = child_node.GetAttributes().at("pads").ints();
+      if (!pads_values.empty()) {
+        has_pad = std::any_of(pads_values.begin(), pads_values.end(), [](int64_t value) { return value != 0; });
+      }
+    }
+    if (has_pad && child_node.GetAttributes().find("count_include_pad") != child_node.GetAttributes().end()) {
+      if (child_node.GetAttributes().at("count_include_pad").i() == 0) {
+        return false;
+      }
+    }
+  }
+
   return true;
 }
 
 void UpdatePaddingAttribute(Node& child_node, const std::vector<int64_t>& pads_values, const uint32_t pads_size) {
-  if (child_node.GetAttributes().find("pads") == child_node.GetAttributes().end()) {
+  auto reset_pads = true;
+  if (child_node.GetAttributes().find("pads") != child_node.GetAttributes().end()) {
+    /* pads can be empty, overwrite pads attribute in this case */
+    reset_pads = child_node.GetAttributes().at("pads").ints().empty();
+  }
+  if (reset_pads) {
     std::vector<int64_t> pads(pads_size - 4, 0);
     child_node.AddAttribute("pads", pads);
   }
@@ -49,6 +70,10 @@ void UpdatePaddingAttribute(Node& child_node, const std::vector<int64_t>& pads_v
     uint32_t mirrored_pad_index = pads_index + (pads_size / 2);
     child_pads->Set(mirrored_child_index, child_pads->Get(mirrored_child_index) + pads_values[mirrored_pad_index]);
   }
+
+  if (child_node.OpType() == "AveragePool") {
+    child_node.AddAttribute("count_include_pad", static_cast<int64_t>(1));
+  }
 }
 /*
  * Before:

onnxruntime/test/optimizer/graph_transform_test.cc

@@ -1622,6 +1622,128 @@ TEST_F(GraphTransformationTests, FusePadWithMaxPoolOpsetLessThan11) {
   }
 }
 
+TEST_F(GraphTransformationTests, FusePadWithAvgPool) {
+  constexpr const ORTCHAR_T* model_uri = MODEL_FOLDER "fusion/fuse-pad-avgpool.onnx";
+
+  std::shared_ptr<Model> p_model;
+  ASSERT_STATUS_OK(Model::Load(model_uri, p_model, nullptr, *logger_));
+  Graph& graph = p_model->MainGraph();
+
+  std::vector<int64_t> expected_pads;
+  GraphViewer graphViewer(graph);
+  for (auto& node_index : graphViewer.GetNodesInTopologicalOrder()) {
+    auto& node = *graph.GetNode(node_index);
+    if (node.OpType() == "Pad") {
+      auto const& pads_proto = node.GetAttributes().at("pads").ints();
+      gsl::span<const int64_t> pads_values = gsl::make_span(pads_proto.data(), pads_proto.size());
+      expected_pads.resize(pads_values.size() - 4);
+      for (uint32_t pads_index = 2, index = 0; pads_index < pads_values.size() / 2; pads_index++, index++) {
+        expected_pads[index] = pads_values[pads_index];
+        expected_pads[index + (expected_pads.size() / 2)] = pads_values[pads_index + (pads_values.size() / 2)];
+      }
+    }
+  }
+
+  onnxruntime::GraphTransformerManager graph_transformation_mgr{5};
+  auto rule_transformer_L1 = std::make_unique<RuleBasedGraphTransformer>("RuleTransformerL1");
+  ASSERT_STATUS_OK(rule_transformer_L1->Register(std::make_unique<PadFusion>()));
+  ASSERT_STATUS_OK(graph_transformation_mgr.Register(std::move(rule_transformer_L1), TransformerLevel::Level1));
+
+  ASSERT_STATUS_OK(graph_transformation_mgr.ApplyTransformers(graph, TransformerLevel::Level1, *logger_));
+
+  std::map<std::string, int> op_to_count = CountOpsInGraph(graph);
+  ASSERT_EQ(op_to_count["Pad"], 0);
+  ASSERT_EQ(op_to_count["AveragePool"], 1);
+
+  for (auto& node : graph.Nodes()) {
+    if (node.OpType() == "AveragePool") {
+      auto const& child_pads = node.GetAttributes().at("pads").ints();
+      auto const& count_include_pad = node.GetAttributes().at("count_include_pad");
+      ASSERT_NE(count_include_pad.i(), 0) << "fusion should ensure count_include_pad!=0";
+      ASSERT_EQ(child_pads.size(), static_cast<int32_t>(expected_pads.size()))
+          << "fusion should produce the same size of pads integer as the AvgPool node";
+      for (uint32_t index = 0; index < expected_pads.size(); index++) {
+        ASSERT_EQ(expected_pads[index], child_pads.Get(index))
+            << "fusion does not produce correct padding value";
+      }
+    }
+  }
+}
+
+TEST_F(GraphTransformationTests, FusePadWithAvgPoolWithPad) {
+  constexpr const ORTCHAR_T* model_uri = MODEL_FOLDER "fusion/fuse-pad-avgpool_with_pad.onnx";
+
+  std::shared_ptr<Model> p_model;
+  ASSERT_STATUS_OK(Model::Load(model_uri, p_model, nullptr, *logger_));
+  Graph& graph = p_model->MainGraph();
+
+  std::vector<int64_t> expected_pads;
+  GraphViewer graphViewer(graph);
+  for (auto& node_index : graphViewer.GetNodesInTopologicalOrder()) {
+    auto& node = *graph.GetNode(node_index);
+    if (node.OpType() == "Pad") {
+      auto const& pads_proto = node.GetAttributes().at("pads").ints();
+      gsl::span<const int64_t> pads_values = gsl::make_span(pads_proto.data(), pads_proto.size());
+      expected_pads.resize(pads_values.size() - 4);
+
+      for (uint32_t pads_index = 2, index = 0; pads_index < pads_values.size() / 2; pads_index++, index++) {
+        expected_pads[index] = pads_values[pads_index];
+        expected_pads[index + (expected_pads.size() / 2)] = pads_values[pads_index + (pads_values.size() / 2)];
+      }
+    } else if (node.OpType() == "AveragePool") {
+      auto const& child_pads = node.GetAttributes().at("pads").ints();
+      for (uint32_t index = 0; index < expected_pads.size(); index++) {
+        expected_pads[index] += child_pads.Get(index);
+      }
+    }
+  }
+
+  onnxruntime::GraphTransformerManager graph_transformation_mgr{5};
+  auto rule_transformer_L1 = std::make_unique<RuleBasedGraphTransformer>("RuleTransformerL1");
+  ASSERT_STATUS_OK(rule_transformer_L1->Register(std::make_unique<PadFusion>()));
+  ASSERT_STATUS_OK(graph_transformation_mgr.Register(std::move(rule_transformer_L1), TransformerLevel::Level1));
+
+  ASSERT_STATUS_OK(graph_transformation_mgr.ApplyTransformers(graph, TransformerLevel::Level1, *logger_));
+
+  std::map<std::string, int> op_to_count = CountOpsInGraph(graph);
+  ASSERT_EQ(op_to_count["Pad"], 0);
+  ASSERT_EQ(op_to_count["AveragePool"], 1);
+
+  for (auto& node : graph.Nodes()) {
+    if (node.OpType() == "AveragePool") {
+      auto const& child_pads = node.GetAttributes().at("pads").ints();
+      auto const& count_include_pad = node.GetAttributes().at("count_include_pad");
+      ASSERT_NE(count_include_pad.i(), 0) << "fusion should ensure count_include_pad!=0";
+      ASSERT_EQ(child_pads.size(), static_cast<int32_t>(expected_pads.size()))
+          << "fusion should produce the same size of pads integer as the AvgPool node";
+      for (uint32_t index = 0; index < expected_pads.size(); index++) {
+        ASSERT_EQ(expected_pads[index], child_pads.Get(index))
+            << "fusion does not produce correct padding value";
+      }
+    }
+  }
+}
+
+// should not fuse
+TEST_F(GraphTransformationTests, FusePadWithAvgPoolWithPadNoInclude) {
+  constexpr const ORTCHAR_T* model_uri = MODEL_FOLDER "fusion/fuse-pad-avgpool_with_pad-nofuse.onnx";
+
+  std::shared_ptr<Model> p_model;
+  ASSERT_STATUS_OK(Model::Load(model_uri, p_model, nullptr, *logger_));
+  Graph& graph = p_model->MainGraph();
+
+  onnxruntime::GraphTransformerManager graph_transformation_mgr{5};
+  auto rule_transformer_L1 = std::make_unique<RuleBasedGraphTransformer>("RuleTransformerL1");
+  ASSERT_STATUS_OK(rule_transformer_L1->Register(std::make_unique<PadFusion>()));
+  ASSERT_STATUS_OK(graph_transformation_mgr.Register(std::move(rule_transformer_L1), TransformerLevel::Level1));
+
+  ASSERT_STATUS_OK(graph_transformation_mgr.ApplyTransformers(graph, TransformerLevel::Level1, *logger_));
+
+  std::map<std::string, int> op_to_count = CountOpsInGraph(graph);
+  ASSERT_EQ(op_to_count["Pad"], 1);
+  ASSERT_EQ(op_to_count["AveragePool"], 1);
+}
+
 TEST_F(GraphTransformationTests, FuseMatmulBNWithInBetweenNodes) {
   constexpr const ORTCHAR_T* model_uri = MODEL_FOLDER "fusion/fuse-matmul-bn-with-reshape.onnx";
 

onnxruntime/test/testdata/transform/fusion/fuse-pad-avgpool-gen.py

@@ -0,0 +1,68 @@
+from pathlib import Path
+
+import numpy as np
+import onnx
+
+HERE = Path(__file__).parent.resolve(strict=True)
+TEST = False
+
+if TEST:
+    import onnxruntime
+
+
+def generate_fuse_pad_avgpool():
+    parameters = {
+        "fuse-pad-avgpool": (
+            {},
+            [[1.333333, 2.333333, 1.777778], [3.0, 5.0, 3.666667], [2.666667, 4.333333, 3.111111]],
+        ),
+        "fuse-pad-avgpool_with_pad": (
+            {"pads": [1, 1, 0, 0], "count_include_pad": 1},
+            [
+                [0.111111, 0.333333, 0.666667, 0.555556],
+                [0.555556, 1.333333, 2.333333, 1.777778],
+                [1.333333, 3.0, 5.0, 3.666667],
+                [1.222222, 2.666667, 4.333333, 3.111111],
+            ],
+        ),
+        "fuse-pad-avgpool_with_pad-nofuse": (
+            {"pads": [1, 1, 0, 0]},
+            [
+                [0.25, 0.5, 1.0, 0.833333],
+                [0.833333, 1.333333, 2.333333, 1.777778],
+                [2.0, 3.0, 5.0, 3.666667],
+                [1.833333, 2.666667, 4.333333, 3.111111],
+            ],
+        ),
+    }
+    for name in parameters:
+        model_path = HERE / f"{name}.onnx"
+        input_ = onnx.helper.make_tensor_value_info("input", onnx.TensorProto.FLOAT, (1, 1, 3, 3))
+        pad = onnx.helper.make_node("Pad", ["input"], ["tp"], mode="constant", pads=[0, 0, 1, 1, 0, 0, 1, 1])
+        pool = onnx.helper.make_node("AveragePool", ["tp"], ["output"], kernel_shape=[3, 3], **parameters[name][0])
+        nodes = [pad, pool]
+        output_shape = (1, 1, 3, 3) if name == "fuse-pad-avgpool" else (1, 1, 4, 4)
+        output_ = onnx.helper.make_tensor_value_info("output", onnx.TensorProto.FLOAT, output_shape)
+        graph = onnx.helper.make_graph(nodes, name, [input_], [output_])
+        model = onnx.helper.make_model(graph, opset_imports=[onnx.helper.make_opsetid("", 7)])
+        onnx.checker.check_model(model)
+        onnx.save_model(model, model_path)
+        if TEST:
+            input_array = np.array([[[[1, 2, 3], [4, 5, 6], [7, 8, 9]]]], dtype=np.float32)
+            expected = np.array(parameters[name][1], dtype=np.float32)
+            session_options = onnxruntime.SessionOptions()
+            session_options.execution_mode = onnxruntime.ExecutionMode.ORT_SEQUENTIAL
+            session_options.graph_optimization_level = onnxruntime.GraphOptimizationLevel.ORT_DISABLE_ALL
+            session = onnxruntime.InferenceSession(model_path, session_options)
+            out = session.run(["output"], {"input": input_array})
+            actual = out[0].squeeze()
+            np.testing.assert_allclose(actual, expected, rtol=1e-5, atol=0.0)
+            session_options.graph_optimization_level = onnxruntime.GraphOptimizationLevel.ORT_ENABLE_ALL
+            session = onnxruntime.InferenceSession(model_path, session_options)
+            out = session.run(["output"], {"input": input_array})
+            actual = out[0].squeeze()
+            np.testing.assert_allclose(actual, expected, rtol=1e-5, atol=0.0)
+
+
+if __name__ == "__main__":
+    generate_fuse_pad_avgpool()