1 //===-- Atomic.cpp - Atomic Operations --------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file implements atomic operations.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Support/Atomic.h"
15 #include "llvm/Config/llvm-config.h"
16 #if defined(ANDROID_TARGET_BUILD)
17 #include "cutils/atomic.h"
27 void sys::MemoryFence() {
28 #if LLVM_HAS_ATOMICS == 0
31 # if defined(__GNUC__)
33 # elif defined(_MSC_VER)
36 # error No memory fence implementation for your platform!
41 sys::cas_flag sys::CompareAndSwap(volatile sys::cas_flag* ptr,
42 sys::cas_flag new_value,
43 sys::cas_flag old_value) {
44 #if LLVM_HAS_ATOMICS == 0
45 sys::cas_flag result = *ptr;
46 if (result == old_value)
49 #elif defined(ANDROID_TARGET_BUILD)
50 return android_atomic_cmpxchg((int32_t)old_value, (int32_t)new_value,
52 #elif defined(__GNUC__)
53 return __sync_val_compare_and_swap(ptr, old_value, new_value);
54 #elif defined(_MSC_VER)
55 return InterlockedCompareExchange(ptr, new_value, old_value);
57 # error No compare-and-swap implementation for your platform!
61 sys::cas_flag sys::AtomicIncrement(volatile sys::cas_flag* ptr) {
62 #if LLVM_HAS_ATOMICS == 0
65 #elif defined(ANDROID_TARGET_BUILD)
66 return android_atomic_inc((volatile int*)ptr);
67 #elif defined(__GNUC__)
68 return __sync_add_and_fetch(ptr, 1);
69 #elif defined(_MSC_VER)
70 return InterlockedIncrement(ptr);
72 # error No atomic increment implementation for your platform!
76 sys::cas_flag sys::AtomicDecrement(volatile sys::cas_flag* ptr) {
77 #if LLVM_HAS_ATOMICS == 0
80 #elif defined(ANDROID_TARGET_BUILD)
81 return android_atomic_dec((volatile int*)ptr);
82 #elif defined(__GNUC__)
83 return __sync_sub_and_fetch(ptr, 1);
84 #elif defined(_MSC_VER)
85 return InterlockedDecrement(ptr);
87 # error No atomic decrement implementation for your platform!
91 sys::cas_flag sys::AtomicAdd(volatile sys::cas_flag* ptr, sys::cas_flag val) {
92 #if LLVM_HAS_ATOMICS == 0
95 #elif defined(ANDROID_TARGET_BUILD)
96 return android_atomic_add((int32_t)val, (volatile int*)ptr);
97 #elif defined(__GNUC__)
98 return __sync_add_and_fetch(ptr, val);
99 #elif defined(_MSC_VER)
100 return InterlockedExchangeAdd(ptr, val) + val;
102 # error No atomic add implementation for your platform!
106 sys::cas_flag sys::AtomicMul(volatile sys::cas_flag* ptr, sys::cas_flag val) {
107 sys::cas_flag original, result;
110 result = original * val;
111 } while (sys::CompareAndSwap(ptr, result, original) != original);
116 sys::cas_flag sys::AtomicDiv(volatile sys::cas_flag* ptr, sys::cas_flag val) {
117 sys::cas_flag original, result;
120 result = original / val;
121 } while (sys::CompareAndSwap(ptr, result, original) != original);