diff options
Diffstat (limited to 'js/src/vm/UnboxedObject.cpp')
| -rw-r--r-- | js/src/vm/UnboxedObject.cpp | 400 |
1 files changed, 0 insertions, 400 deletions
diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp index 3018ace677..d7ad91de41 100644 --- a/js/src/vm/UnboxedObject.cpp +++ b/js/src/vm/UnboxedObject.cpp @@ -1655,227 +1655,12 @@ const Class UnboxedArrayObject::class_ = { // API ///////////////////////////////////////////////////////////////////// -static bool -UnboxedTypeIncludes(JSValueType supertype, JSValueType subtype) -{ - if (supertype == JSVAL_TYPE_DOUBLE && subtype == JSVAL_TYPE_INT32) - return true; - if (supertype == JSVAL_TYPE_OBJECT && subtype == JSVAL_TYPE_NULL) - return true; - return false; -} - -static bool -CombineUnboxedTypes(const Value& value, JSValueType* existing) -{ - JSValueType type = value.isDouble() ? JSVAL_TYPE_DOUBLE : value.extractNonDoubleType(); - - if (*existing == JSVAL_TYPE_MAGIC || *existing == type || UnboxedTypeIncludes(type, *existing)) { - *existing = type; - return true; - } - if (UnboxedTypeIncludes(*existing, type)) - return true; - return false; -} - -// Return whether the property names and types in layout are a subset of the -// specified vector. -static bool -PropertiesAreSuperset(const UnboxedLayout::PropertyVector& properties, UnboxedLayout* layout) -{ - for (size_t i = 0; i < layout->properties().length(); i++) { - const UnboxedLayout::Property& layoutProperty = layout->properties()[i]; - bool found = false; - for (size_t j = 0; j < properties.length(); j++) { - if (layoutProperty.name == properties[j].name) { - found = (layoutProperty.type == properties[j].type); - break; - } - } - if (!found) - return false; - } - return true; -} - -static bool -CombinePlainObjectProperties(PlainObject* obj, Shape* templateShape, - UnboxedLayout::PropertyVector& properties) -{ - // All preliminary objects must have been created with enough space to - // fill in their unboxed data inline. This is ensured either by using - // the largest allocation kind (which limits the maximum size of an - // unboxed object), or by using an allocation kind that covers all - // properties in the template, as the space used by unboxed properties - // is less than or equal to that used by boxed properties. - MOZ_ASSERT(gc::GetGCKindSlots(obj->asTenured().getAllocKind()) >= - Min(NativeObject::MAX_FIXED_SLOTS, templateShape->slotSpan())); - - if (obj->lastProperty() != templateShape || obj->hasDynamicElements()) { - // Only use an unboxed representation if all created objects match - // the template shape exactly. - return false; - } - - for (size_t i = 0; i < templateShape->slotSpan(); i++) { - Value val = obj->getSlot(i); - - JSValueType& existing = properties[i].type; - if (!CombineUnboxedTypes(val, &existing)) - return false; - } - - return true; -} - -static bool -CombineArrayObjectElements(ExclusiveContext* cx, ArrayObject* obj, JSValueType* elementType) -{ - if (obj->inDictionaryMode() || - obj->lastProperty()->propid() != AtomToId(cx->names().length) || - !obj->lastProperty()->previous()->isEmptyShape()) - { - // Only use an unboxed representation if the object has no properties. - return false; - } - - for (size_t i = 0; i < obj->getDenseInitializedLength(); i++) { - Value val = obj->getDenseElement(i); - - // For now, unboxed arrays cannot have holes. - if (val.isMagic(JS_ELEMENTS_HOLE)) - return false; - - if (!CombineUnboxedTypes(val, elementType)) - return false; - } - - return true; -} - -static size_t -ComputePlainObjectLayout(ExclusiveContext* cx, Shape* templateShape, - UnboxedLayout::PropertyVector& properties) -{ - // Fill in the names for all the object's properties. - for (Shape::Range<NoGC> r(templateShape); !r.empty(); r.popFront()) { - size_t slot = r.front().slot(); - MOZ_ASSERT(!properties[slot].name); - properties[slot].name = JSID_TO_ATOM(r.front().propid())->asPropertyName(); - } - - // Fill in all the unboxed object's property offsets. - uint32_t offset = 0; - - // Search for an existing unboxed layout which is a subset of this one. - // If there are multiple such layouts, use the largest one. If we're able - // to find such a layout, use the same property offsets for the shared - // properties, which will allow us to generate better code if the objects - // have a subtype/supertype relation and are accessed at common sites. - UnboxedLayout* bestExisting = nullptr; - for (UnboxedLayout* existing : cx->compartment()->unboxedLayouts) { - if (PropertiesAreSuperset(properties, existing)) { - if (!bestExisting || - existing->properties().length() > bestExisting->properties().length()) - { - bestExisting = existing; - } - } - } - if (bestExisting) { - for (size_t i = 0; i < bestExisting->properties().length(); i++) { - const UnboxedLayout::Property& existingProperty = bestExisting->properties()[i]; - for (size_t j = 0; j < templateShape->slotSpan(); j++) { - if (existingProperty.name == properties[j].name) { - MOZ_ASSERT(existingProperty.type == properties[j].type); - properties[j].offset = existingProperty.offset; - } - } - } - offset = bestExisting->size(); - } - - // Order remaining properties from the largest down for the best space - // utilization. - static const size_t typeSizes[] = { 8, 4, 1 }; - - for (size_t i = 0; i < ArrayLength(typeSizes); i++) { - size_t size = typeSizes[i]; - for (size_t j = 0; j < templateShape->slotSpan(); j++) { - if (properties[j].offset != UINT32_MAX) - continue; - JSValueType type = properties[j].type; - if (UnboxedTypeSize(type) == size) { - offset = JS_ROUNDUP(offset, size); - properties[j].offset = offset; - offset += size; - } - } - } - - // The final offset is the amount of data needed by the object. - return offset; -} - -static bool -SetLayoutTraceList(ExclusiveContext* cx, UnboxedLayout* layout) -{ - // Figure out the offsets of any objects or string properties. - Vector<int32_t, 8, SystemAllocPolicy> objectOffsets, stringOffsets; - for (size_t i = 0; i < layout->properties().length(); i++) { - const UnboxedLayout::Property& property = layout->properties()[i]; - MOZ_ASSERT(property.offset != UINT32_MAX); - if (property.type == JSVAL_TYPE_OBJECT) { - if (!objectOffsets.append(property.offset)) - return false; - } else if (property.type == JSVAL_TYPE_STRING) { - if (!stringOffsets.append(property.offset)) - return false; - } - } - - // Construct the layout's trace list. - if (!objectOffsets.empty() || !stringOffsets.empty()) { - Vector<int32_t, 8, SystemAllocPolicy> entries; - if (!entries.appendAll(stringOffsets) || - !entries.append(-1) || - !entries.appendAll(objectOffsets) || - !entries.append(-1) || - !entries.append(-1)) - { - return false; - } - int32_t* traceList = cx->zone()->pod_malloc<int32_t>(entries.length()); - if (!traceList) - return false; - PodCopy(traceList, entries.begin(), entries.length()); - layout->setTraceList(traceList); - } - - return true; -} - static inline Value NextValue(Handle<GCVector<Value>> values, size_t* valueCursor) { return values[(*valueCursor)++]; } -static bool -GetValuesFromPreliminaryArrayObject(ArrayObject* obj, MutableHandle<GCVector<Value>> values) -{ - if (!values.append(Int32Value(obj->length()))) - return false; - if (!values.append(Int32Value(obj->getDenseInitializedLength()))) - return false; - for (size_t i = 0; i < obj->getDenseInitializedLength(); i++) { - if (!values.append(obj->getDenseElement(i))) - return false; - } - return true; -} - void UnboxedArrayObject::fillAfterConvert(ExclusiveContext* cx, Handle<GCVector<Value>> values, size_t* valueCursor) @@ -1901,16 +1686,6 @@ UnboxedArrayObject::fillAfterConvert(ExclusiveContext* cx, JS_ALWAYS_TRUE(initElement(cx, i, NextValue(values, valueCursor))); } -static bool -GetValuesFromPreliminaryPlainObject(PlainObject* obj, MutableHandle<GCVector<Value>> values) -{ - for (size_t i = 0; i < obj->slotSpan(); i++) { - if (!values.append(obj->getSlot(i))) - return false; - } - return true; -} - void UnboxedPlainObject::fillAfterConvert(ExclusiveContext* cx, Handle<GCVector<Value>> values, size_t* valueCursor) @@ -1921,181 +1696,6 @@ UnboxedPlainObject::fillAfterConvert(ExclusiveContext* cx, JS_ALWAYS_TRUE(setValue(cx, layout().properties()[i], NextValue(values, valueCursor))); } -bool -js::TryConvertToUnboxedLayout(ExclusiveContext* cx, AutoEnterAnalysis& enter, Shape* templateShape, - ObjectGroup* group, PreliminaryObjectArray* objects) -{ - bool isArray = !templateShape; - - // Unboxed arrays are nightly only for now. The getenv() call will be - // removed when they are on by default. See bug 1153266. - if (isArray) { -#ifdef NIGHTLY_BUILD - if (!getenv("JS_OPTION_USE_UNBOXED_ARRAYS")) { - if (!cx->options().unboxedArrays()) - return true; - } -#else - return true; -#endif - } else { - if (jit::JitOptions.disableUnboxedObjects) - return true; - } - - MOZ_ASSERT_IF(templateShape, !templateShape->getObjectFlags()); - - if (group->runtimeFromAnyThread()->isSelfHostingGlobal(cx->global())) - return true; - - if (!isArray && templateShape->slotSpan() == 0) - return true; - - UnboxedLayout::PropertyVector properties; - if (!isArray) { - if (!properties.appendN(UnboxedLayout::Property(), templateShape->slotSpan())) - return false; - } - JSValueType elementType = JSVAL_TYPE_MAGIC; - - size_t objectCount = 0; - for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) { - JSObject* obj = objects->get(i); - if (!obj) - continue; - - if (obj->isSingleton() || obj->group() != group) - return true; - - objectCount++; - - if (isArray) { - if (!CombineArrayObjectElements(cx, &obj->as<ArrayObject>(), &elementType)) - return true; - } else { - if (!CombinePlainObjectProperties(&obj->as<PlainObject>(), templateShape, properties)) - return true; - } - } - - size_t layoutSize = 0; - if (isArray) { - // Don't use an unboxed representation if we couldn't determine an - // element type for the objects. - if (UnboxedTypeSize(elementType) == 0) - return true; - } else { - if (objectCount <= 1) { - // If only one of the objects has been created, it is more likely - // to have new properties added later. This heuristic is not used - // for array objects, where we might want an unboxed representation - // even if there is only one large array. - return true; - } - - for (size_t i = 0; i < templateShape->slotSpan(); i++) { - // We can't use an unboxed representation if e.g. all the objects have - // a null value for one of the properties, as we can't decide what type - // it is supposed to have. - if (UnboxedTypeSize(properties[i].type) == 0) - return true; - } - - // Make sure that all properties on the template shape are property - // names, and not indexes. - for (Shape::Range<NoGC> r(templateShape); !r.empty(); r.popFront()) { - jsid id = r.front().propid(); - uint32_t dummy; - if (!JSID_IS_ATOM(id) || JSID_TO_ATOM(id)->isIndex(&dummy)) - return true; - } - - layoutSize = ComputePlainObjectLayout(cx, templateShape, properties); - - // The entire object must be allocatable inline. - if (UnboxedPlainObject::offsetOfData() + layoutSize > JSObject::MAX_BYTE_SIZE) - return true; - } - - UniquePtr<UnboxedLayout>& layout = enter.unboxedLayoutToCleanUp; - MOZ_ASSERT(!layout); - layout = group->zone()->make_unique<UnboxedLayout>(); - if (!layout) - return false; - - if (isArray) { - layout->initArray(elementType); - } else { - if (!layout->initProperties(properties, layoutSize)) - return false; - - // The unboxedLayouts list only tracks layouts for plain objects. - cx->compartment()->unboxedLayouts.insertFront(layout.get()); - - if (!SetLayoutTraceList(cx, layout.get())) - return false; - } - - // We've determined that all the preliminary objects can use the new layout - // just constructed, so convert the existing group to use the unboxed class, - // and update the preliminary objects to use the new layout. Do the - // fallible stuff first before modifying any objects. - - // Get an empty shape which we can use for the preliminary objects. - const Class* clasp = isArray ? &UnboxedArrayObject::class_ : &UnboxedPlainObject::class_; - Shape* newShape = EmptyShape::getInitialShape(cx, clasp, group->proto(), 0); - if (!newShape) { - cx->recoverFromOutOfMemory(); - return false; - } - - // Accumulate a list of all the values in each preliminary object, and - // update their shapes. - Rooted<GCVector<Value>> values(cx, GCVector<Value>(cx)); - for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) { - JSObject* obj = objects->get(i); - if (!obj) - continue; - - bool ok; - if (isArray) - ok = GetValuesFromPreliminaryArrayObject(&obj->as<ArrayObject>(), &values); - else - ok = GetValuesFromPreliminaryPlainObject(&obj->as<PlainObject>(), &values); - - if (!ok) { - cx->recoverFromOutOfMemory(); - return false; - } - } - - if (TypeNewScript* newScript = group->newScript()) - layout->setNewScript(newScript); - - for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) { - if (JSObject* obj = objects->get(i)) - obj->as<NativeObject>().setLastPropertyMakeNonNative(newShape); - } - - group->setClasp(clasp); - group->setUnboxedLayout(layout.release()); - - size_t valueCursor = 0; - for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) { - JSObject* obj = objects->get(i); - if (!obj) - continue; - - if (isArray) - obj->as<UnboxedArrayObject>().fillAfterConvert(cx, values, &valueCursor); - else - obj->as<UnboxedPlainObject>().fillAfterConvert(cx, values, &valueCursor); - } - - MOZ_ASSERT(valueCursor == values.length()); - return true; -} - DefineBoxedOrUnboxedFunctor6(SetOrExtendBoxedOrUnboxedDenseElements, ExclusiveContext*, JSObject*, uint32_t, const Value*, uint32_t, ShouldUpdateTypes); |