godot/thirdparty/embree/common/sys/atomic.h

60 lines
1.3 KiB
C++

// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include <atomic>
#include "intrinsics.h"
namespace embree
{
/* compiler memory barriers */
#if defined(__INTEL_COMPILER)
//#define __memory_barrier() __memory_barrier()
#elif defined(__GNUC__) || defined(__clang__)
# define __memory_barrier() asm volatile("" ::: "memory")
#elif defined(_MSC_VER)
# define __memory_barrier() _ReadWriteBarrier()
#endif
template <typename T>
struct atomic : public std::atomic<T>
{
atomic () {}
atomic (const T& a)
: std::atomic<T>(a) {}
atomic (const atomic<T>& a) {
this->store(a.load());
}
atomic& operator=(const atomic<T>& other) {
this->store(other.load());
return *this;
}
};
template<typename T>
__forceinline void atomic_min(std::atomic<T>& aref, const T& bref)
{
const T b = bref.load();
while (true) {
T a = aref.load();
if (a <= b) break;
if (aref.compare_exchange_strong(a,b)) break;
}
}
template<typename T>
__forceinline void atomic_max(std::atomic<T>& aref, const T& bref)
{
const T b = bref.load();
while (true) {
T a = aref.load();
if (a >= b) break;
if (aref.compare_exchange_strong(a,b)) break;
}
}
}