XNNPACK graph runtime: in-tree operator interface

backends/xnnpack/runtime/operators/operator.cpp

@@ -0,0 +1,20 @@
+#include <executorch/backends/xnnpack/runtime/operators/operator.h>
+
+#include <executorch/runtime/platform/log.h>
+
+namespace executorch::backends::xnnpack::operators {
+
+std::unique_ptr<Operator> create_operator(graph::Operator op) {
+  // No in-tree operators are available yet; the graph runtime currently
+  // supports only XNNPACK-delegated subgraphs. Reaching this point means a
+  // node was routed to an in-tree kernel that has not been added. Return null
+  // so the caller can fail cleanly rather than aborting.
+  ET_LOG(
+      Error,
+      "No in-tree kernel for operator %d; only XNNPACK-delegated nodes are "
+      "supported",
+      static_cast<int>(op));
+  return nullptr;
+}
+
+} // namespace executorch::backends::xnnpack::operators

backends/xnnpack/runtime/operators/operator.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <executorch/backends/xnnpack/runtime/core/tensor.h>
+#include <executorch/backends/xnnpack/runtime/graph/node.h>
+#include <executorch/backends/xnnpack/runtime/graph/operator.h>
+#include <executorch/backends/xnnpack/runtime/graph/tensor_spec.h>
+#include <executorch/runtime/core/span.h>
+
+#include <memory>
+
+namespace executorch::backends::xnnpack::operators {
+
+class Operator {
+ public:
+  virtual void setup(runtime::Span<const graph::ConstantArg> constant_args) {};
+  virtual void prepare(
+      runtime::Span<core::Tensor*> inputs,
+      runtime::Span<core::Tensor*> outputs) {};
+  virtual void reshape(runtime::Span<const graph::TensorSpec> input_specs) {};
+  virtual void execute(
+      runtime::Span<core::Tensor*> inputs,
+      runtime::Span<core::Tensor*> outputs) = 0;
+  virtual ~Operator() = default;
+};
+
+std::unique_ptr<Operator> create_operator(graph::Operator op);
+
+} // namespace executorch::backends::xnnpack::operators

shim_et/xplat/executorch/build/build_variables.bzl

@@ -484,6 +484,7 @@ XNNPACK_BACKEND_BUCK_SRCS = [
     "runtime/core/quant_params.cpp",
     "runtime/graph/graph.cpp",
     "runtime/graph/graph_builder.cpp",
+    "runtime/operators/operator.cpp",
 ]
 
 XNNPACK_BACKEND_SRCS = ["backends/xnnpack/" + x for x in XNNPACK_BACKEND_BUCK_SRCS]