Merge pull request #1091 from MoonchildProductions/remove-unboxed

Remove unboxed objects phase 1

8 files changed, 5 insertions, 445 deletions

diff --git a/js/src/vm/Interpreter-inl.h b/js/src/vm/Interpreter-inl.h
index 5f476c4ff..710f1d89b 100644
--- a/js/src/vm/Interpreter-inl.h
+++ b/js/src/vm/Interpreter-inl.h
@@ -22,7 +22,6 @@
 #include "vm/EnvironmentObject-inl.h"
 #include "vm/Stack-inl.h"
 #include "vm/String-inl.h"
-#include "vm/UnboxedObject-inl.h"
 
 namespace js {
 
@@ -337,14 +336,10 @@ InitGlobalLexicalOperation(JSContext* cx, LexicalEnvironmentObject* lexicalEnvAr
 inline bool
 InitPropertyOperation(JSContext* cx, JSOp op, HandleObject obj, HandleId id, HandleValue rhs)
 {
-    if (obj->is<PlainObject>() || obj->is<JSFunction>()) {
-        unsigned propAttrs = GetInitDataPropAttrs(op);
-        return NativeDefineProperty(cx, obj.as<NativeObject>(), id, rhs, nullptr, nullptr,
-                                    propAttrs);
-    }
-
-    MOZ_ASSERT(obj->as<UnboxedPlainObject>().layout().lookup(id));
-    return PutProperty(cx, obj, id, rhs, false);
+  MOZ_ASSERT(obj->is<PlainObject>() || obj->is<JSFunction>());
+  unsigned propAttrs = GetInitDataPropAttrs(op);
+  return NativeDefineProperty(cx, obj.as<NativeObject>(), id, rhs,
+                              nullptr, nullptr, propAttrs);
 }
 
 inline bool
diff --git a/js/src/vm/Interpreter.cpp b/js/src/vm/Interpreter.cpp
index e6d6630c4..3cf2deb83 100644
--- a/js/src/vm/Interpreter.cpp
+++ b/js/src/vm/Interpreter.cpp
@@ -4111,7 +4111,7 @@ CASE(JSOP_INITHOMEOBJECT)
     /* Load the home object */
     ReservedRooted<JSObject*> obj(&rootObject0);
     obj = &REGS.sp[int(-2 - skipOver)].toObject();
-    MOZ_ASSERT(obj->is<PlainObject>() || obj->is<UnboxedPlainObject>() || obj->is<JSFunction>());
+    MOZ_ASSERT(obj->is<PlainObject>() || obj->is<JSFunction>());
 
     func->setExtendedSlot(FunctionExtended::METHOD_HOMEOBJECT_SLOT, ObjectValue(*obj));
 }
@@ -4927,15 +4927,10 @@ js::NewObjectOperation(JSContext* cx, HandleScript script, jsbytecode* pc,
             return nullptr;
         if (group->maybePreliminaryObjects()) {
             group->maybePreliminaryObjects()->maybeAnalyze(cx, group);
-            if (group->maybeUnboxedLayout())
-                group->maybeUnboxedLayout()->setAllocationSite(script, pc);
         }
 
         if (group->shouldPreTenure() || group->maybePreliminaryObjects())
             newKind = TenuredObject;
-
-        if (group->maybeUnboxedLayout())
-            return UnboxedPlainObject::create(cx, group, newKind);
     }
 
     RootedObject obj(cx);
diff --git a/js/src/vm/ReceiverGuard.cpp b/js/src/vm/ReceiverGuard.cpp
index 97df908c3..11c2d0727 100644
--- a/js/src/vm/ReceiverGuard.cpp
+++ b/js/src/vm/ReceiverGuard.cpp
@@ -7,7 +7,6 @@
 #include "vm/ReceiverGuard.h"
 
 #include "builtin/TypedObject.h"
-#include "vm/UnboxedObject.h"
 #include "jsobjinlines.h"
 
 using namespace js;
diff --git a/js/src/vm/ReceiverGuard.h b/js/src/vm/ReceiverGuard.h
index 459cc0012..c14f0d83b 100644
--- a/js/src/vm/ReceiverGuard.h
+++ b/js/src/vm/ReceiverGuard.h
@@ -28,11 +28,6 @@ namespace js {
 // TypedObject: The structure of a typed object is determined by its group.
 //   All typed objects with the same group have the same class, prototype, and
 //   own properties.
-//
-// UnboxedPlainObject: The structure of an unboxed plain object is determined
-//   by its group and its expando object's shape, if there is one. All unboxed
-//   plain objects with the same group and expando shape have the same
-//   properties except those stored in the expando's dense elements.
 
 class HeapReceiverGuard;
 class RootedReceiverGuard;
diff --git a/js/src/vm/TypeInference.cpp b/js/src/vm/TypeInference.cpp
index 4775a2dea..9e0342382 100644
--- a/js/src/vm/TypeInference.cpp
+++ b/js/src/vm/TypeInference.cpp
@@ -1995,17 +1995,6 @@ TypeSet::ObjectKey::watchStateChangeForTypedArrayData(CompilerConstraintList* co
                                     ConstraintDataFreezeObjectForTypedArrayData(tarray)));
 }
 
-void
-TypeSet::ObjectKey::watchStateChangeForUnboxedConvertedToNative(CompilerConstraintList* constraints)
-{
-    HeapTypeSetKey objectProperty = property(JSID_EMPTY);
-    LifoAlloc* alloc = constraints->alloc();
-
-    typedef CompilerConstraintInstance<ConstraintDataFreezeObjectForUnboxedConvertedToNative> T;
-    constraints->add(alloc->new_<T>(alloc, objectProperty,
-                                    ConstraintDataFreezeObjectForUnboxedConvertedToNative()));
-}
-
 static void
 ObjectStateChange(ExclusiveContext* cxArg, ObjectGroup* group, bool markingUnknown)
 {
@@ -3577,7 +3566,6 @@ PreliminaryObjectArrayWithTemplate::maybeAnalyze(ExclusiveContext* cx, ObjectGro
         }
     }
 
-    TryConvertToUnboxedLayout(cx, enter, shape(), group, preliminaryObjects);
     if (group->maybeUnboxedLayout())
         return;
 
@@ -3861,10 +3849,6 @@ TypeNewScript::maybeAnalyze(JSContext* cx, ObjectGroup* group, bool* regenerate,
         PodCopy(initializerList, initializerVector.begin(), initializerVector.length());
     }
 
-    // Try to use an unboxed representation for the group.
-    if (!TryConvertToUnboxedLayout(cx, enter, templateObject()->lastProperty(), group, preliminaryObjects))
-        return false;
-
     js_delete(preliminaryObjects);
     preliminaryObjects = nullptr;
 
diff --git a/js/src/vm/TypeInference.h b/js/src/vm/TypeInference.h
index 0f1cd4936..04fed448c 100644
--- a/js/src/vm/TypeInference.h
+++ b/js/src/vm/TypeInference.h
@@ -262,7 +262,6 @@ class TypeSet
         bool hasStableClassAndProto(CompilerConstraintList* constraints);
         void watchStateChangeForInlinedCall(CompilerConstraintList* constraints);
         void watchStateChangeForTypedArrayData(CompilerConstraintList* constraints);
-        void watchStateChangeForUnboxedConvertedToNative(CompilerConstraintList* constraints);
         HeapTypeSetKey property(jsid id);
         void ensureTrackedProperty(JSContext* cx, jsid id);
 
diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp
index 3018ace67..d7ad91de4 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);
diff --git a/js/src/vm/UnboxedObject.h b/js/src/vm/UnboxedObject.h
index ecff8be5b..779dd14c7 100644
--- a/js/src/vm/UnboxedObject.h
+++ b/js/src/vm/UnboxedObject.h
@@ -317,13 +317,6 @@ class UnboxedPlainObject : public JSObject
     }
 };
 
-// Try to construct an UnboxedLayout for each of the preliminary objects,
-// provided they all match the template shape. If successful, converts the
-// preliminary objects and their group to the new unboxed representation.
-bool
-TryConvertToUnboxedLayout(ExclusiveContext* cx, AutoEnterAnalysis& enter, Shape* templateShape,
-                          ObjectGroup* group, PreliminaryObjectArray* objects);
-
 inline gc::AllocKind
 UnboxedLayout::getAllocKind() const
 {