SkBarriers_x86.h revision 448e2a3b3935d91e7bf84dc5b0367b92d2e2a518 
1/*
2 * Copyright 2014 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkBarriers_x86_DEFINED
9#define SkBarriers_x86_DEFINED
10
11#ifdef SK_BUILD_FOR_WIN
12#  include <intrin.h>
13static inline void sk_compiler_barrier() { _ReadWriteBarrier(); }
14#else
15static inline void sk_compiler_barrier() { asm volatile("" : : : "memory"); }
16#endif
17
18template <typename T>
19T sk_acquire_load(T* ptr) {
20    T val = *ptr;
21    // On x86, all loads are acquire loads, so we only need a compiler barrier.
22    sk_compiler_barrier();
23    return val;
24}
25
26template <typename T>
27void sk_release_store(T* ptr, T val) {
28    // On x86, all stores are release stores, so we only need a compiler barrier.
29    sk_compiler_barrier();
30    *ptr = val;
31}
32
33#endif//SkBarriers_x86_DEFINED
34