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1/*2 * kmp_utils.h -- Utilities that used internally3 */4 5//===----------------------------------------------------------------------===//6//7// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.8// See https://llvm.org/LICENSE.txt for license information.9// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception10//11//===----------------------------------------------------------------------===//12#ifndef __KMP_UTILS_H__13#define __KMP_UTILS_H__14 15#include <cstddef>16 17#include "kmp.h"18 19/// A simple pure header implementation of VLA that aims to replace uses of20/// actual VLA, which can cause compile warning. This class by default creates a21/// stack buffer that can accomodate \p N elements. If the number of elements is22/// greater than \p N, then a heap buffer will be allocated and used to23/// accomodate the elements. Similar to the actual VLA, we don't check boundary24/// (for now), so we will not store the number of elements. We can always revise25/// it later.26template <typename T, unsigned N = 8> class SimpleVLA final {27 T StackBuffer[N];28 T *HeapBuffer = nullptr;29 T *Ptr = StackBuffer;30 31public:32 SimpleVLA() = delete;33 SimpleVLA(const SimpleVLA &) = delete;34 SimpleVLA(SimpleVLA &&) = delete;35 SimpleVLA &operator=(const SimpleVLA &) = delete;36 SimpleVLA &operator=(SimpleVLA &&) = delete;37 38 explicit SimpleVLA(unsigned NumOfElements) noexcept {39 if (NumOfElements > N) {40 HeapBuffer =41 reinterpret_cast<T *>(__kmp_allocate(NumOfElements * sizeof(T)));42 Ptr = HeapBuffer;43 }44 }45 46 ~SimpleVLA() {47 if (HeapBuffer)48 __kmp_free(HeapBuffer);49 }50 51 operator T *() noexcept { return Ptr; }52 operator const T *() const noexcept { return Ptr; }53};54 55#endif56