+#if USE(GCC_COMPUTED_GOTO_WORKAROUND)
+ goto *(&&skip_id_getter_chain);
+#endif
+ DEFINE_OPCODE(op_get_by_id_getter_chain) {
+ /* op_get_by_id_getter_chain dst(r) base(r) property(id) structure(sID) structureChain(chain) count(n) offset(n)
+
+ Cached property access: Attempts to get a cached property from the
+ value base's prototype chain. If the cache misses, op_get_by_id_getter_chain
+ reverts to op_get_by_id.
+ */
+ int base = vPC[2].u.operand;
+ JSValue baseValue = callFrame->r(base).jsValue();
+
+ if (LIKELY(baseValue.isCell())) {
+ JSCell* baseCell = asCell(baseValue);
+ Structure* structure = vPC[4].u.structure;
+
+ if (LIKELY(baseCell->structure() == structure)) {
+ RefPtr<Structure>* it = vPC[5].u.structureChain->head();
+ size_t count = vPC[6].u.operand;
+ RefPtr<Structure>* end = it + count;
+
+ while (true) {
+ JSObject* baseObject = asObject(baseCell->structure()->prototypeForLookup(callFrame));
+
+ if (UNLIKELY(baseObject->structure() != (*it).get()))
+ break;
+
+ if (++it == end) {
+ int dst = vPC[1].u.operand;
+ int offset = vPC[7].u.operand;
+ if (GetterSetter* getterSetter = asGetterSetter(baseObject->getDirectOffset(offset).asCell())) {
+ JSObject* getter = getterSetter->getter();
+ CallData callData;
+ CallType callType = getter->getCallData(callData);
+ JSValue result = call(callFrame, getter, callType, callData, baseValue, ArgList());
+ CHECK_FOR_EXCEPTION();
+ callFrame->r(dst) = result;
+ } else
+ callFrame->r(dst) = jsUndefined();
+ vPC += OPCODE_LENGTH(op_get_by_id_getter_chain);
+ NEXT_INSTRUCTION();
+ }
+
+ // Update baseCell, so that next time around the loop we'll pick up the prototype's prototype.
+ baseCell = baseObject;
+ }
+ }
+ }
+ uncacheGetByID(callFrame->codeBlock(), vPC);
+ NEXT_INSTRUCTION();
+ }
+#if USE(GCC_COMPUTED_GOTO_WORKAROUND)
+ skip_id_getter_chain:
+#endif
+#if USE(GCC_COMPUTED_GOTO_WORKAROUND)
+ goto *(&&skip_id_custom_chain);
+#endif
+ DEFINE_OPCODE(op_get_by_id_custom_chain) {
+ /* op_get_by_id_custom_chain dst(r) base(r) property(id) structure(sID) structureChain(chain) count(n) offset(n)
+
+ Cached property access: Attempts to use a cached named property getter on the
+ value base's prototype chain. If the cache misses, op_get_by_id_custom_chain
+ reverts to op_get_by_id.
+ */
+ int base = vPC[2].u.operand;
+ JSValue baseValue = callFrame->r(base).jsValue();
+
+ if (LIKELY(baseValue.isCell())) {
+ JSCell* baseCell = asCell(baseValue);
+ Structure* structure = vPC[4].u.structure;
+
+ if (LIKELY(baseCell->structure() == structure)) {
+ RefPtr<Structure>* it = vPC[5].u.structureChain->head();
+ size_t count = vPC[6].u.operand;
+ RefPtr<Structure>* end = it + count;
+
+ while (true) {
+ JSObject* baseObject = asObject(baseCell->structure()->prototypeForLookup(callFrame));
+
+ if (UNLIKELY(baseObject->structure() != (*it).get()))
+ break;
+
+ if (++it == end) {
+ int dst = vPC[1].u.operand;
+ int property = vPC[3].u.operand;
+ Identifier& ident = callFrame->codeBlock()->identifier(property);
+
+ PropertySlot::GetValueFunc getter = vPC[7].u.getterFunc;
+ JSValue result = getter(callFrame, baseObject, ident);
+ CHECK_FOR_EXCEPTION();
+ callFrame->r(dst) = result;
+ vPC += OPCODE_LENGTH(op_get_by_id_custom_chain);
+ NEXT_INSTRUCTION();
+ }
+
+ // Update baseCell, so that next time around the loop we'll pick up the prototype's prototype.
+ baseCell = baseObject;
+ }
+ }
+ }
+ uncacheGetByID(callFrame->codeBlock(), vPC);
+ NEXT_INSTRUCTION();
+ }
+#if USE(GCC_COMPUTED_GOTO_WORKAROUND)
+ skip_id_custom_chain:
+#endif