codeblock.cpp

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            int id0 = (++it)->u.operand;
            int r1 = (++it)->u.operand;
            printf("[%4d] push_new_scope \t%s, %s, %s\n", location, registerName(r0).c_str(), idName(id0, m_identifiers[id0]).c_str(), registerName(r1).c_str());
            break;
        }
        case op_jmp_scopes: {
            int scopeDelta = (++it)->u.operand;
            int offset = (++it)->u.operand;
            printf("[%4d] jmp_scopes\t^%d, %d(->%d)\n", location, scopeDelta, offset, locationForOffset(begin, it, offset));
            break;
        }
        case op_catch: {
            int r0 = (++it)->u.operand;
            printf("[%4d] catch\t\t %s\n", location, registerName(r0).c_str());
            break;
        }
        case op_throw: {
            int r0 = (++it)->u.operand;
            printf("[%4d] throw\t\t %s\n", location, registerName(r0).c_str());
            break;
        }
        case op_new_error: {
            int r0 = (++it)->u.operand;
            int errorType = (++it)->u.operand;
            int k0 = (++it)->u.operand;
            printf("[%4d] new_error\t %s, %d, %s\n", location, registerName(r0).c_str(), errorType, constantName(exec, k0, unexpectedConstant(k0)).c_str());
            break;
        }
        case op_jsr: {
            int retAddrDst = (++it)->u.operand;
            int offset = (++it)->u.operand;
            printf("[%4d] jsr\t\t %s, %d(->%d)\n", location, registerName(retAddrDst).c_str(), offset, locationForOffset(begin, it, offset));
            break;
        }
        case op_sret: {
            int retAddrSrc = (++it)->u.operand;
            printf("[%4d] sret\t\t %s\n", location, registerName(retAddrSrc).c_str());
            break;
        }
        case op_debug: {
            int debugHookID = (++it)->u.operand;
            int firstLine = (++it)->u.operand;
            int lastLine = (++it)->u.operand;
            printf("[%4d] debug\t\t %s, %d, %d\n", location, debugHookName(debugHookID), firstLine, lastLine);
            break;
        }
        case op_profile_will_call: {
            int function = (++it)->u.operand;
            printf("[%4d] profile_will_call %s\n", location, registerName(function).c_str());
            break;
        }
        case op_profile_did_call: {
            int function = (++it)->u.operand;
            printf("[%4d] profile_did_call\t %s\n", location, registerName(function).c_str());
            break;
        }
        case op_end: {
            int r0 = (++it)->u.operand;
            printf("[%4d] end\t\t %s\n", location, registerName(r0).c_str());
            break;
        }
    }
}

#endif // !defined(NDEBUG) || ENABLE(OPCODE_SAMPLING)

#if DUMP_CODE_BLOCK_STATISTICS
static HashSet<CodeBlock*> liveCodeBlockSet;
#endif

#define FOR_EACH_MEMBER_VECTOR(macro) \
    macro(instructions) \
    macro(globalResolveInfos) \
    macro(structureStubInfos) \
    macro(callLinkInfos) \
    macro(linkedCallerList) \
    macro(identifiers) \
    macro(functionExpressions) \
    macro(constantRegisters)

#define FOR_EACH_MEMBER_VECTOR_RARE_DATA(macro) \
    macro(regexps) \
    macro(functions) \
    macro(unexpectedConstants) \
    macro(exceptionHandlers) \
    macro(immediateSwitchJumpTables) \
    macro(characterSwitchJumpTables) \
    macro(stringSwitchJumpTables) \
    macro(functionRegisterInfos)

#define FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(macro) \
    macro(expressionInfo) \
    macro(lineInfo) \
    macro(getByIdExceptionInfo) \
    macro(pcVector)

template<typename T>
static size_t sizeInBytes(const Vector<T>& vector)
{
    return vector.capacity() * sizeof(T);
}

void CodeBlock::dumpStatistics()
{
#if DUMP_CODE_BLOCK_STATISTICS
    #define DEFINE_VARS(name) size_t name##IsNotEmpty = 0; size_t name##TotalSize = 0;
        FOR_EACH_MEMBER_VECTOR(DEFINE_VARS)
        FOR_EACH_MEMBER_VECTOR_RARE_DATA(DEFINE_VARS)
        FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(DEFINE_VARS)
    #undef DEFINE_VARS

    // Non-vector data members
    size_t evalCodeCacheIsNotEmpty = 0;

    size_t symbolTableIsNotEmpty = 0;
    size_t symbolTableTotalSize = 0;

    size_t hasExceptionInfo = 0;
    size_t hasRareData = 0;

    size_t isFunctionCode = 0;
    size_t isGlobalCode = 0;
    size_t isEvalCode = 0;

    HashSet<CodeBlock*>::const_iterator end = liveCodeBlockSet.end();
    for (HashSet<CodeBlock*>::const_iterator it = liveCodeBlockSet.begin(); it != end; ++it) {
        CodeBlock* codeBlock = *it;

        #define GET_STATS(name) if (!codeBlock->m_##name.isEmpty()) { name##IsNotEmpty++; name##TotalSize += sizeInBytes(codeBlock->m_##name); }
            FOR_EACH_MEMBER_VECTOR(GET_STATS)
        #undef GET_STATS

        if (!codeBlock->m_symbolTable.isEmpty()) {
            symbolTableIsNotEmpty++;
            symbolTableTotalSize += (codeBlock->m_symbolTable.capacity() * (sizeof(SymbolTable::KeyType) + sizeof(SymbolTable::MappedType)));
        }

        if (codeBlock->m_exceptionInfo) {
            hasExceptionInfo++;
            #define GET_STATS(name) if (!codeBlock->m_exceptionInfo->m_##name.isEmpty()) { name##IsNotEmpty++; name##TotalSize += sizeInBytes(codeBlock->m_exceptionInfo->m_##name); }
                FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(GET_STATS)
            #undef GET_STATS
        }

        if (codeBlock->m_rareData) {
            hasRareData++;
            #define GET_STATS(name) if (!codeBlock->m_rareData->m_##name.isEmpty()) { name##IsNotEmpty++; name##TotalSize += sizeInBytes(codeBlock->m_rareData->m_##name); }
                FOR_EACH_MEMBER_VECTOR_RARE_DATA(GET_STATS)
            #undef GET_STATS

            if (!codeBlock->m_rareData->m_evalCodeCache.isEmpty())
                evalCodeCacheIsNotEmpty++;
        }

        switch (codeBlock->codeType()) {
            case FunctionCode:
                ++isFunctionCode;
                break;
            case GlobalCode:
                ++isGlobalCode;
                break;
            case EvalCode:
                ++isEvalCode;
                break;
        }
    }

    size_t totalSize = 0;

    #define GET_TOTAL_SIZE(name) totalSize += name##TotalSize;
        FOR_EACH_MEMBER_VECTOR(GET_TOTAL_SIZE)
        FOR_EACH_MEMBER_VECTOR_RARE_DATA(GET_TOTAL_SIZE)
        FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(GET_TOTAL_SIZE)
    #undef GET_TOTAL_SIZE

    totalSize += symbolTableTotalSize;
    totalSize += (liveCodeBlockSet.size() * sizeof(CodeBlock));

    printf("Number of live CodeBlocks: %d\n", liveCodeBlockSet.size());
    printf("Size of a single CodeBlock [sizeof(CodeBlock)]: %zu\n", sizeof(CodeBlock));
    printf("Size of all CodeBlocks: %zu\n", totalSize);
    printf("Average size of a CodeBlock: %zu\n", totalSize / liveCodeBlockSet.size());

    printf("Number of FunctionCode CodeBlocks: %zu (%.3f%%)\n", isFunctionCode, static_cast<double>(isFunctionCode) * 100.0 / liveCodeBlockSet.size());
    printf("Number of GlobalCode CodeBlocks: %zu (%.3f%%)\n", isGlobalCode, static_cast<double>(isGlobalCode) * 100.0 / liveCodeBlockSet.size());
    printf("Number of EvalCode CodeBlocks: %zu (%.3f%%)\n", isEvalCode, static_cast<double>(isEvalCode) * 100.0 / liveCodeBlockSet.size());

    printf("Number of CodeBlocks with exception info: %zu (%.3f%%)\n", hasExceptionInfo, static_cast<double>(hasExceptionInfo) * 100.0 / liveCodeBlockSet.size());
    printf("Number of CodeBlocks with rare data: %zu (%.3f%%)\n", hasRareData, static_cast<double>(hasRareData) * 100.0 / liveCodeBlockSet.size());

    #define PRINT_STATS(name) printf("Number of CodeBlocks with " #name ": %zu\n", name##IsNotEmpty); printf("Size of all " #name ": %zu\n", name##TotalSize); 
        FOR_EACH_MEMBER_VECTOR(PRINT_STATS)
        FOR_EACH_MEMBER_VECTOR_RARE_DATA(PRINT_STATS)
        FOR_EACH_MEMBER_VECTOR_EXCEPTION_INFO(PRINT_STATS)
    #undef PRINT_STATS

    printf("Number of CodeBlocks with evalCodeCache: %zu\n", evalCodeCacheIsNotEmpty);
    printf("Number of CodeBlocks with symbolTable: %zu\n", symbolTableIsNotEmpty);

    printf("Size of all symbolTables: %zu\n", symbolTableTotalSize);

#else
    printf("Dumping CodeBlock statistics is not enabled.\n");
#endif
}


CodeBlock::CodeBlock(ScopeNode* ownerNode, CodeType codeType, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset)
    : m_numCalleeRegisters(0)
    , m_numConstants(0)
    , m_numVars(0)
    , m_numParameters(0)
    , m_ownerNode(ownerNode)
    , m_globalData(0)
#ifndef NDEBUG
    , m_instructionCount(0)
#endif
    , m_needsFullScopeChain(ownerNode->needsActivation())
    , m_usesEval(ownerNode->usesEval())
    , m_isNumericCompareFunction(false)
    , m_codeType(codeType)
    , m_source(sourceProvider)
    , m_sourceOffset(sourceOffset)
    , m_exceptionInfo(new ExceptionInfo)
{
    ASSERT(m_source);

#if DUMP_CODE_BLOCK_STATISTICS
    liveCodeBlockSet.add(this);
#endif
}

CodeBlock::~CodeBlock()
{
#if !ENABLE(JIT)
    for (size_t size = m_globalResolveInstructions.size(), i = 0; i < size; ++i)
        derefStructures(&m_instructions[m_globalResolveInstructions[i]]);

    for (size_t size = m_propertyAccessInstructions.size(), i = 0; i < size; ++i)
        derefStructures(&m_instructions[m_propertyAccessInstructions[i]]);
#else
    for (size_t size = m_globalResolveInfos.size(), i = 0; i < size; ++i) {
        if (m_globalResolveInfos[i].structure)
            m_globalResolveInfos[i].structure->deref();
    }

    for (size_t size = m_structureStubInfos.size(), i = 0; i < size; ++i)
        m_structureStubInfos[i].deref();

    for (size_t size = m_callLinkInfos.size(), i = 0; i < size; ++i) {
        CallLinkInfo* callLinkInfo = &m_callLinkInfos[i];
        if (callLinkInfo->isLinked())
            callLinkInfo->callee->removeCaller(callLinkInfo);
    }

    unlinkCallers();
#endif

#if DUMP_CODE_BLOCK_STATISTICS
    liveCodeBlockSet.remove(this);
#endif
}

#if ENABLE(JIT) 
void CodeBlock::unlinkCallers()
{
    size_t size = m_linkedCallerList.size();
    for (size_t i = 0; i < size; ++i) {
        CallLinkInfo* currentCaller = m_linkedCallerList[i];
        JIT::unlinkCall(currentCaller);
        currentCaller->setUnlinked();
    }
    m_linkedCallerList.clear();
}
#endif

void CodeBlock::derefStructures(Instruction* vPC) const
{
    Interpreter* interpreter = m_globalData->interpreter;

    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self)) {
        vPC[4].u.structure->deref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto)) {
        vPC[4].u.structure->deref();
        vPC[5].u.structure->deref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_chain)) {
        vPC[4].u.structure->deref();
        vPC[5].u.structureChain->deref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_transition)) {
        vPC[4].u.structure->deref();
        vPC[5].u.structure->deref();
        vPC[6].u.structureChain->deref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_replace)) {
        vPC[4].u.structure->deref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global)) {
        if(vPC[4].u.structure)
            vPC[4].u.structure->deref();
        return;
    }
    if ((vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto_list))
        || (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self_list))) {
        PolymorphicAccessStructureList* polymorphicStructures = vPC[4].u.polymorphicStructures;
        polymorphicStructures->derefStructures(vPC[5].u.operand);
        delete polymorphicStructures;
        return;
    }

    // These instructions don't ref their Structures.
    ASSERT(vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id) || vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_put_by_id_generic) || vPC[0].u.opcode == interpreter->getOpcode(op_get_array_length) || vPC[0].u.opcode == interpreter->getOpcode(op_get_string_length));
}

void CodeBlock::refStructures(Instruction* vPC) const
{
    Interpreter* interpreter = m_globalData->interpreter;

    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_self)) {
        vPC[4].u.structure->ref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_proto)) {
        vPC[4].u.structure->ref();
        vPC[5].u.structure->ref();
        return;
    }
    if (vPC[0].u.opcode == interpreter->getOpcode(op_get_by_id_chain)) {
        vPC[4].u.structure->ref();
        vPC[5].u.structureChain->ref();
        return;