Source/JavaScriptCore/bytecode/SharedJITStubSet.h

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#pragma once

#include "DOMJITGetterSetter.h"
#include "PropertyInlineCache.h"

namespace JSC {

#if ENABLE(JIT)

class SharedJITStubSet {
    WTF_DEPRECATED_MAKE_FAST_ALLOCATED(SharedJITStubSet);
public:
    SharedJITStubSet() = default;

    using PropertyInlineCacheKey = std::tuple<AccessType, bool, bool, bool, bool>;
    using StatelessCacheKey = std::tuple<PropertyInlineCacheKey, AccessCase::AccessType>;
    using DOMJITCacheKey = std::tuple<PropertyInlineCacheKey, const DOMJIT::GetterSetter*>;

    static PropertyInlineCacheKey propertyCacheKey(const PropertyInlineCache& propertyCache)
    {
        return std::tuple { propertyCache.accessType, static_cast<bool>(propertyCache.propertyIsInt32), static_cast<bool>(propertyCache.propertyIsString), static_cast<bool>(propertyCache.propertyIsSymbol), static_cast<bool>(propertyCache.prototypeIsKnownObject) };
    }

    struct Hash {
        struct Key {
            Key() = default;

            Key(PropertyInlineCacheKey propertyCacheKey, PolymorphicAccessJITStubRoutine* wrapped)
                : m_wrapped(wrapped)
                , m_propertyCacheKey(propertyCacheKey)
            { }

            Key(WTF::HashTableDeletedValueType)
                : m_wrapped(std::bit_cast<PolymorphicAccessJITStubRoutine*>(static_cast<uintptr_t>(1)))
            { }

            bool isHashTableDeletedValue() const { return m_wrapped == std::bit_cast<PolymorphicAccessJITStubRoutine*>(static_cast<uintptr_t>(1)); }

            friend bool operator==(const Key&, const Key&) = default;

            PolymorphicAccessJITStubRoutine* m_wrapped { nullptr };
            PropertyInlineCacheKey m_propertyCacheKey { };
        };

        using KeyTraits = SimpleClassHashTraits<Key>;

        static unsigned hash(const Key& p)
        {
            if (!p.m_wrapped)
                return 1;
            return p.m_wrapped->hash();
        }

        static bool equal(const Key& a, const Key& b)
        {
            return a == b;
        }

        static constexpr bool safeToCompareToEmptyOrDeleted = false;
    };

    struct Searcher {
        struct Translator {
            static unsigned hash(const Searcher& searcher)
            {
                return searcher.m_hash;
            }

            static bool equal(const Hash::Key a, const Searcher& b)
            {
                if (a.m_propertyCacheKey == b.m_propertyCacheKey && Hash::hash(a) == b.m_hash) {
                    if (a.m_wrapped->cases().size() != 1)
                        return false;
                    const auto& aCase = a.m_wrapped->cases()[0];
                    const auto& bCase = b.m_accessCase;
                    if (!AccessCase::canBeShared(aCase.get(), bCase.get()))
                        return false;
                    return true;
                }
                return false;
            }
        };

        Searcher(PropertyInlineCacheKey&& propertyCacheKey, Ref<AccessCase>&& accessCase)
            : m_propertyCacheKey(WTF::move(propertyCacheKey))
            , m_accessCase(WTF::move(accessCase))
            , m_hash(m_accessCase->hash())
        {
        }

        PropertyInlineCacheKey m_propertyCacheKey;
        const Ref<AccessCase> m_accessCase;
        unsigned m_hash { 0 };
    };

    struct PointerTranslator {
        static unsigned hash(const PolymorphicAccessJITStubRoutine* stub)
        {
            return stub->hash();
        }

        static bool equal(const Hash::Key& key, const PolymorphicAccessJITStubRoutine* stub)
        {
            return key.m_wrapped == stub;
        }
    };

    void add(Hash::Key&& key)
    {
        m_stubs.add(WTF::move(key));
    }

    void remove(PolymorphicAccessJITStubRoutine* stub)
    {
        auto iter = m_stubs.find<PointerTranslator>(stub);
        if (iter != m_stubs.end())
            m_stubs.remove(iter);
    }

    RefPtr<PolymorphicAccessJITStubRoutine> find(const Searcher& searcher)
    {
        auto entry = m_stubs.find<SharedJITStubSet::Searcher::Translator>(searcher);
        if (entry != m_stubs.end())
            return entry->m_wrapped;
        return nullptr;
    }

    RefPtr<PolymorphicAccessJITStubRoutine> getStatelessStub(StatelessCacheKey) const;
    void setStatelessStub(StatelessCacheKey, Ref<PolymorphicAccessJITStubRoutine>);

    MacroAssemblerCodeRef<JITStubRoutinePtrTag> getDOMJITCode(DOMJITCacheKey) const;
    void setDOMJITCode(DOMJITCacheKey, MacroAssemblerCodeRef<JITStubRoutinePtrTag>);

    RefPtr<InlineCacheHandler> getSlowPathHandler(AccessType) const;
    void setSlowPathHandler(AccessType, Ref<InlineCacheHandler>);

private:
    UncheckedKeyHashSet<Hash::Key, Hash, Hash::KeyTraits> m_stubs;
    UncheckedKeyHashMap<StatelessCacheKey, Ref<PolymorphicAccessJITStubRoutine>> m_statelessStubs;
    UncheckedKeyHashMap<DOMJITCacheKey, MacroAssemblerCodeRef<JITStubRoutinePtrTag>> m_domJITCodes;
    std::array<RefPtr<InlineCacheHandler>, numberOfAccessTypes> m_fallbackHandlers { };
    std::array<RefPtr<InlineCacheHandler>, numberOfAccessTypes> m_slowPathHandlers { };
};

#else

class PropertyInlineCache;

#endif // ENABLE(JIT)

} // namespace JSC