1 //===-- Implementation header for rand utilities ----------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_LIBC_SRC_STDLIB_RAND_UTIL_H 10 #define LLVM_LIBC_SRC_STDLIB_RAND_UTIL_H 11 12 #include "src/__support/GPU/utils.h" 13 #include "src/__support/macros/attributes.h" 14 15 namespace LIBC_NAMESPACE { 16 17 #ifdef LIBC_TARGET_ARCH_IS_GPU 18 // Implement thread local storage on the GPU using local memory. Each thread 19 // gets its slot in the local memory array and is private to the group. 20 // TODO: We need to implement the 'thread_local' keyword on the GPU. This is an 21 // inefficient and incomplete stand-in until that is done. 22 template <typename T> class ThreadLocal { 23 private: 24 static constexpr long MAX_THREADS = 1024; 25 [[clang::loader_uninitialized]] static inline gpu::Local<T> 26 storage[MAX_THREADS]; 27 28 public: T()29 LIBC_INLINE operator T() const { return storage[gpu::get_thread_id()]; } 30 LIBC_INLINE void operator=(const T &value) { 31 storage[gpu::get_thread_id()] = value; 32 } 33 }; 34 35 extern ThreadLocal<unsigned long> rand_next; 36 #else 37 extern LIBC_THREAD_LOCAL unsigned long rand_next; 38 #endif 39 40 } // namespace LIBC_NAMESPACE 41 42 #endif // LLVM_LIBC_SRC_STDLIB_RAND_UTIL_H 43