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diff --git a/third_party/highway/hwy/examples/skeleton-inl.h b/third_party/highway/hwy/examples/skeleton-inl.h
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+// Copyright 2020 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Demo of functions that might be called from multiple SIMD modules (either
+// other -inl.h files, or a .cc file between begin/end_target-inl). This is
+// optional - all SIMD code can reside in .cc files. However, this allows
+// splitting code into different files while still inlining instead of requiring
+// calling through function pointers.
+
+// Per-target include guard. This is only required when using dynamic dispatch,
+// i.e. including foreach_target.h. For static dispatch, a normal include
+// guard would be fine because the header is only compiled once.
+#if defined(HIGHWAY_HWY_EXAMPLES_SKELETON_INL_H_) == defined(HWY_TARGET_TOGGLE)
+#ifdef HIGHWAY_HWY_EXAMPLES_SKELETON_INL_H_
+#undef HIGHWAY_HWY_EXAMPLES_SKELETON_INL_H_
+#else
+#define HIGHWAY_HWY_EXAMPLES_SKELETON_INL_H_
+#endif
+
+// It is fine to #include normal or *-inl headers.
+#include <stddef.h>
+
+#include "hwy/highway.h"
+
+HWY_BEFORE_NAMESPACE();
+namespace skeleton {
+namespace HWY_NAMESPACE {
+
+// Highway ops reside here; ADL does not find templates nor builtins.
+namespace hn = hwy::HWY_NAMESPACE;
+
+// Example of a type-agnostic (caller-specified lane type) and width-agnostic
+// (uses best available instruction set) function in a header.
+//
+// Computes x[i] = mul_array[i] * x_array[i] + add_array[i] for i < size.
+template <class D, typename T>
+HWY_MAYBE_UNUSED void MulAddLoop(const D d, const T* HWY_RESTRICT mul_array,
+                                 const T* HWY_RESTRICT add_array,
+                                 const size_t size, T* HWY_RESTRICT x_array) {
+  for (size_t i = 0; i < size; i += hn::Lanes(d)) {
+    const auto mul = hn::Load(d, mul_array + i);
+    const auto add = hn::Load(d, add_array + i);
+    auto x = hn::Load(d, x_array + i);
+    x = hn::MulAdd(mul, x, add);
+    hn::Store(x, d, x_array + i);
+  }
+}
+
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+}  // namespace skeleton
+HWY_AFTER_NAMESPACE();
+
+#endif  // include guard