10b57cec5SDimitry Andric //===-- Atomic.cpp - Atomic Operations --------------------------*- C++ -*-===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric // 90b57cec5SDimitry Andric // This file implements atomic operations. 100b57cec5SDimitry Andric // 110b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 120b57cec5SDimitry Andric 130b57cec5SDimitry Andric #include "llvm/Support/Atomic.h" 140b57cec5SDimitry Andric #include "llvm/Config/llvm-config.h" 150b57cec5SDimitry Andric 160b57cec5SDimitry Andric using namespace llvm; 170b57cec5SDimitry Andric 180b57cec5SDimitry Andric #if defined(_MSC_VER) 190b57cec5SDimitry Andric #include <intrin.h> 200b57cec5SDimitry Andric 210b57cec5SDimitry Andric // We must include windows.h after intrin.h. 220b57cec5SDimitry Andric #include <windows.h> 230b57cec5SDimitry Andric #undef MemoryFence 240b57cec5SDimitry Andric #endif 250b57cec5SDimitry Andric 260b57cec5SDimitry Andric #if defined(__GNUC__) || (defined(__IBMCPP__) && __IBMCPP__ >= 1210) 270b57cec5SDimitry Andric #define GNU_ATOMICS 280b57cec5SDimitry Andric #endif 290b57cec5SDimitry Andric MemoryFence()300b57cec5SDimitry Andricvoid sys::MemoryFence() { 310b57cec5SDimitry Andric #if LLVM_HAS_ATOMICS == 0 320b57cec5SDimitry Andric return; 330b57cec5SDimitry Andric #else 340b57cec5SDimitry Andric # if defined(GNU_ATOMICS) 350b57cec5SDimitry Andric __sync_synchronize(); 360b57cec5SDimitry Andric # elif defined(_MSC_VER) 370b57cec5SDimitry Andric MemoryBarrier(); 380b57cec5SDimitry Andric # else 390b57cec5SDimitry Andric # error No memory fence implementation for your platform! 400b57cec5SDimitry Andric # endif 410b57cec5SDimitry Andric #endif 420b57cec5SDimitry Andric } 430b57cec5SDimitry Andric CompareAndSwap(volatile sys::cas_flag * ptr,sys::cas_flag new_value,sys::cas_flag old_value)440b57cec5SDimitry Andricsys::cas_flag sys::CompareAndSwap(volatile sys::cas_flag* ptr, 450b57cec5SDimitry Andric sys::cas_flag new_value, 460b57cec5SDimitry Andric sys::cas_flag old_value) { 470b57cec5SDimitry Andric #if LLVM_HAS_ATOMICS == 0 480b57cec5SDimitry Andric sys::cas_flag result = *ptr; 490b57cec5SDimitry Andric if (result == old_value) 500b57cec5SDimitry Andric *ptr = new_value; 510b57cec5SDimitry Andric return result; 520b57cec5SDimitry Andric #elif defined(GNU_ATOMICS) 530b57cec5SDimitry Andric return __sync_val_compare_and_swap(ptr, old_value, new_value); 540b57cec5SDimitry Andric #elif defined(_MSC_VER) 550b57cec5SDimitry Andric return InterlockedCompareExchange(ptr, new_value, old_value); 560b57cec5SDimitry Andric #else 570b57cec5SDimitry Andric # error No compare-and-swap implementation for your platform! 580b57cec5SDimitry Andric #endif 590b57cec5SDimitry Andric } 60