/* * Copyright (C) 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 #include "TinyBloomFilter.h" #include <wtf/text/UniquedStringImpl.h> namespace JSC { struct GetByValHistory { void observeNonUID() { uintptr_t count = Options::getByValICMaxNumberOfIdentifiers() + 1; update(count, filter()); } void observe(const UniquedStringImpl* impl) { if (!impl) { observeNonUID(); return; } uintptr_t count = this->count(); uintptr_t filter = this->filter(); TinyBloomFilter bloomFilter(filter); uintptr_t implBits = bitwise_cast<uintptr_t>(impl); ASSERT(((static_cast<uint64_t>(implBits) << 8) >> 8) == static_cast<uint64_t>(implBits)); if (bloomFilter.ruleOut(implBits)) { bloomFilter.add(implBits); ++count; update(count, bloomFilter.bits()); } } uintptr_t count() const { return static_cast<uintptr_t>(m_payload >> 56); } private: uintptr_t filter() const { return static_cast<uintptr_t>((m_payload << 8) >> 8); } void update(uint64_t count, uint64_t filter) { ASSERT(((filter << 8) >> 8) == filter); m_payload = (count << 56) | filter; } uint64_t m_payload { 0 }; }; } // namespace JSC