1 /* 2 * Copyright (c) Meta Platforms, Inc. and affiliates. 3 * All rights reserved. 4 * 5 * This source code is licensed under the BSD-style license found in the 6 * LICENSE file in the root directory of this source tree. 7 */ 8 9 #pragma once 10 11 #include <executorch/runtime/platform/compiler.h> 12 13 // Utility to guaruntee complete unrolling of a loop where the bounds are known 14 // at compile time. Various pragmas achieve similar effects, but are not as 15 // portable across compilers. 16 17 // Example: ForcedUnroll<4>{}(f); is equivalent to f(0); f(1); f(2); f(3); 18 19 namespace executorch { 20 namespace utils { 21 22 template <int n> 23 struct ForcedUnroll { 24 template <typename Func> operatorForcedUnroll25 ET_INLINE void operator()(const Func& f) const { 26 ForcedUnroll<n - 1>{}(f); 27 f(n - 1); 28 } 29 }; 30 31 template <> 32 struct ForcedUnroll<1> { 33 template <typename Func> 34 ET_INLINE void operator()(const Func& f) const { 35 f(0); 36 } 37 }; 38 39 } // namespace utils 40 } // namespace executorch 41