interpreter.cpp

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            ASSERT(m_opcodeIDTable.size() == numOpcodeIDs);
        #endif // HAVE(COMPUTED_GOTO)
        return noValue();
    }

#if ENABLE(JIT)
    // Currently with CTI enabled we never interpret functions
    ASSERT_NOT_REACHED();
#endif

    JSGlobalData* globalData = &callFrame->globalData();
    JSValuePtr exceptionValue = noValue();
    HandlerInfo* handler = 0;

    Instruction* vPC = callFrame->codeBlock()->instructions().begin();
    Profiler** enabledProfilerReference = Profiler::enabledProfilerReference();
    unsigned tickCount = globalData->timeoutChecker.ticksUntilNextCheck();

#define CHECK_FOR_EXCEPTION() \
    do { \
        if (UNLIKELY(globalData->exception != noValue())) { \
            exceptionValue = globalData->exception; \
            goto vm_throw; \
        } \
    } while (0)

#if ENABLE(OPCODE_STATS)
    OpcodeStats::resetLastInstruction();
#endif

#define CHECK_FOR_TIMEOUT() \
    if (!--tickCount) { \
        if (globalData->timeoutChecker.didTimeOut(callFrame)) { \
            exceptionValue = jsNull(); \
            goto vm_throw; \
        } \
        tickCount = globalData->timeoutChecker.ticksUntilNextCheck(); \
    }
    
#if ENABLE(OPCODE_SAMPLING)
    #define SAMPLE(codeBlock, vPC) m_sampler->sample(codeBlock, vPC)
#else
    #define SAMPLE(codeBlock, vPC)
#endif

#if HAVE(COMPUTED_GOTO)
    #define NEXT_INSTRUCTION() SAMPLE(callFrame->codeBlock(), vPC); goto *vPC->u.opcode
#if ENABLE(OPCODE_STATS)
    #define DEFINE_OPCODE(opcode) opcode: OpcodeStats::recordInstruction(opcode);
#else
    #define DEFINE_OPCODE(opcode) opcode:
#endif
    NEXT_INSTRUCTION();
#else
    #define NEXT_INSTRUCTION() SAMPLE(callFrame->codeBlock(), vPC); goto interpreterLoopStart
#if ENABLE(OPCODE_STATS)
    #define DEFINE_OPCODE(opcode) case opcode: OpcodeStats::recordInstruction(opcode);
#else
    #define DEFINE_OPCODE(opcode) case opcode:
#endif
    while (1) { // iterator loop begins
    interpreterLoopStart:;
    switch (vPC->u.opcode)
#endif
    {
    DEFINE_OPCODE(op_new_object) {
        /* new_object dst(r)

           Constructs a new empty Object instance using the original
           constructor, and puts the result in register dst.
        */
        int dst = (++vPC)->u.operand;
        callFrame[dst] = JSValuePtr(constructEmptyObject(callFrame));

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_new_array) {
        /* new_array dst(r) firstArg(r) argCount(n)

           Constructs a new Array instance using the original
           constructor, and puts the result in register dst.
           The array will contain argCount elements with values
           taken from registers starting at register firstArg.
        */
        int dst = (++vPC)->u.operand;
        int firstArg = (++vPC)->u.operand;
        int argCount = (++vPC)->u.operand;
        ArgList args(callFrame->registers() + firstArg, argCount);
        callFrame[dst] = JSValuePtr(constructArray(callFrame, args));

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_new_regexp) {
        /* new_regexp dst(r) regExp(re)

           Constructs a new RegExp instance using the original
           constructor from regexp regExp, and puts the result in
           register dst.
        */
        int dst = (++vPC)->u.operand;
        int regExp = (++vPC)->u.operand;
        callFrame[dst] = JSValuePtr(new (globalData) RegExpObject(callFrame->scopeChain()->globalObject()->regExpStructure(), callFrame->codeBlock()->regexp(regExp)));

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_mov) {
        /* mov dst(r) src(r)

           Copies register src to register dst.
        */
        int dst = (++vPC)->u.operand;
        int src = (++vPC)->u.operand;
        callFrame[dst] = callFrame[src];

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_eq) {
        /* eq dst(r) src1(r) src2(r)

           Checks whether register src1 and register src2 are equal,
           as with the ECMAScript '==' operator, and puts the result
           as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src1 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr src2 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        if (JSFastMath::canDoFastBitwiseOperations(src1, src2))
            callFrame[dst] = JSFastMath::equal(src1, src2);
        else {
            JSValuePtr result = jsBoolean(JSValuePtr::equalSlowCase(callFrame, src1, src2));
            CHECK_FOR_EXCEPTION();
            callFrame[dst] = result;
        }

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_eq_null) {
        /* eq_null dst(r) src(r)

           Checks whether register src is null, as with the ECMAScript '!='
           operator, and puts the result as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src = callFrame[(++vPC)->u.operand].jsValue(callFrame);

        if (src.isUndefinedOrNull()) {
            callFrame[dst] = jsBoolean(true);
            ++vPC;
            NEXT_INSTRUCTION();
        }
        
        callFrame[dst] = jsBoolean(src.isCell() && src.asCell()->structure()->typeInfo().masqueradesAsUndefined());
        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_neq) {
        /* neq dst(r) src1(r) src2(r)

           Checks whether register src1 and register src2 are not
           equal, as with the ECMAScript '!=' operator, and puts the
           result as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src1 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr src2 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        if (JSFastMath::canDoFastBitwiseOperations(src1, src2))
            callFrame[dst] = JSFastMath::notEqual(src1, src2);
        else {
            JSValuePtr result = jsBoolean(!JSValuePtr::equalSlowCase(callFrame, src1, src2));
            CHECK_FOR_EXCEPTION();
            callFrame[dst] = result;
        }

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_neq_null) {
        /* neq_null dst(r) src(r)

           Checks whether register src is not null, as with the ECMAScript '!='
           operator, and puts the result as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src = callFrame[(++vPC)->u.operand].jsValue(callFrame);

        if (src.isUndefinedOrNull()) {
            callFrame[dst] = jsBoolean(false);
            ++vPC;
            NEXT_INSTRUCTION();
        }
        
        callFrame[dst] = jsBoolean(!src.isCell() || !asCell(src)->structure()->typeInfo().masqueradesAsUndefined());
        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_stricteq) {
        /* stricteq dst(r) src1(r) src2(r)

           Checks whether register src1 and register src2 are strictly
           equal, as with the ECMAScript '===' operator, and puts the
           result as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src1 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr src2 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        callFrame[dst] = jsBoolean(JSValuePtr::strictEqual(src1, src2));

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_nstricteq) {
        /* nstricteq dst(r) src1(r) src2(r)

           Checks whether register src1 and register src2 are not
           strictly equal, as with the ECMAScript '!==' operator, and
           puts the result as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src1 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr src2 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        callFrame[dst] = jsBoolean(!JSValuePtr::strictEqual(src1, src2));

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_less) {
        /* less dst(r) src1(r) src2(r)

           Checks whether register src1 is less than register src2, as
           with the ECMAScript '<' operator, and puts the result as
           a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src1 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr src2 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr result = jsBoolean(jsLess(callFrame, src1, src2));
        CHECK_FOR_EXCEPTION();
        callFrame[dst] = result;

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_lesseq) {
        /* lesseq dst(r) src1(r) src2(r)

           Checks whether register src1 is less than or equal to
           register src2, as with the ECMAScript '<=' operator, and
           puts the result as a boolean in register dst.
        */
        int dst = (++vPC)->u.operand;
        JSValuePtr src1 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr src2 = callFrame[(++vPC)->u.operand].jsValue(callFrame);
        JSValuePtr result = jsBoolean(jsLessEq(callFrame, src1, src2));
        CHECK_FOR_EXCEPTION();
        callFrame[dst] = result;

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_pre_inc) {
        /* pre_inc srcDst(r)

           Converts register srcDst to number, adds one, and puts the result
           back in register srcDst.
        */
        int srcDst = (++vPC)->u.operand;
        JSValuePtr v = callFrame[srcDst].jsValue(callFrame);
        if (JSFastMath::canDoFastAdditiveOperations(v))
            callFrame[srcDst] = JSValuePtr(JSFastMath::incImmediateNumber(v));
        else {
            JSValuePtr result = jsNumber(callFrame, v.toNumber(callFrame) + 1);
            CHECK_FOR_EXCEPTION();
            callFrame[srcDst] = result;
        }

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_pre_dec) {
        /* pre_dec srcDst(r)

           Converts register srcDst to number, subtracts one, and puts the result
           back in register srcDst.
        */
        int srcDst = (++vPC)->u.operand;
        JSValuePtr v = callFrame[srcDst].jsValue(callFrame);
        if (JSFastMath::canDoFastAdditiveOperations(v))
            callFrame[srcDst] = JSValuePtr(JSFastMath::decImmediateNumber(v));
        else {
            JSValuePtr result = jsNumber(callFrame, v.toNumber(callFrame) - 1);
            CHECK_FOR_EXCEPTION();
            callFrame[srcDst] = result;
        }

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_post_inc) {
        /* post_inc dst(r) srcDst(r)

           Converts register srcDst to number. The number itself is
           written to register dst, and the number plus one is written
           back to register srcDst.
        */
        int dst = (++vPC)->u.operand;
        int srcDst = (++vPC)->u.operand;
        JSValuePtr v = callFrame[srcDst].jsValue(callFrame);
        if (JSFastMath::canDoFastAdditiveOperations(v)) {
            callFrame[dst] = v;
            callFrame[srcDst] = JSValuePtr(JSFastMath::incImmediateNumber(v));
        } else {
            JSValuePtr number = callFrame[srcDst].jsValue(callFrame).toJSNumber(callFrame);
            CHECK_FOR_EXCEPTION();
            callFrame[dst] = number;
            callFrame[srcDst] = JSValuePtr(jsNumber(callFrame, number.uncheckedGetNumber() + 1));
        }

        ++vPC;
        NEXT_INSTRUCTION();
    }
    DEFINE_OPCODE(op_post_dec) {
        /* post_dec dst(r) srcDst(r)

           Converts register srcDst to number. The number itself is
           written to register dst, and the number minus one is written
           back to register srcDst.
        */
        int dst = (++vPC)->u.operand;
        int srcDst = (++vPC)->u.operand;
        JSValuePtr v = callFrame[srcDst].jsValue(callFrame);
        if (JSFastMath::canDoFastAdditiveOperations(v)) {
            callFrame[dst] = v;
            callFrame[srcDst] = JSValuePtr(JSFastMath::decImmediateNumber(v));