/* * Copyright (C) 2015-2019 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #pragma once #if ENABLE(DFG_JIT) #include <wtf/PrintStream.h> namespace JSC { namespace DFG { // Utility class for epoch-based analyses. class Epoch { public: Epoch() : m_epoch(s_none) { } static Epoch fromUnsigned(unsigned value) { Epoch result; result.m_epoch = value; return result; } unsigned toUnsigned() const { return m_epoch; } static Epoch first() { Epoch result; result.m_epoch = s_first; return result; } bool operator!() const { return m_epoch == s_none; } Epoch next() const { Epoch result; result.m_epoch = m_epoch + 1; return result; } void bump() { *this = next(); } bool operator==(const Epoch& other) const { return m_epoch == other.m_epoch; } bool operator!=(const Epoch& other) const { return !(*this == other); } bool operator<(const Epoch& other) const { return m_epoch < other.m_epoch; } bool operator>(const Epoch& other) const { return other < *this; } bool operator<=(const Epoch& other) const { return !(*this > other); } bool operator>=(const Epoch& other) const { return !(*this < other); } void dump(PrintStream&) const; private: static constexpr unsigned s_none = 0; static constexpr unsigned s_first = 1; unsigned m_epoch; }; } } // namespace JSC::DFG #endif // ENABLE(DFG_JIT)