Remove and clean up more code.

js/src/jit/BaselineIC.cpp

@@ -5365,13 +5365,6 @@ GetTemplateObjectForSimd(JSContext* cx, JSFunction* target, MutableHandleObject
     return true;
 }
 
-static void
-EnsureArrayGroupAnalyzed(JSContext* cx, JSObject* obj)
-{
-    if (PreliminaryObjectArrayWithTemplate* objects = obj->group()->maybePreliminaryObjects())
-        objects->maybeAnalyze(cx, obj->group(), /* forceAnalyze = */ true);
-}
-
 static bool
 GetTemplateObjectForNative(JSContext* cx, HandleFunction target, const CallArgs& args,
                            MutableHandleObject res, bool* skipAttach)
@@ -5403,10 +5396,7 @@ GetTemplateObjectForNative(JSContext* cx, HandleFunction target, const CallArgs&
             // With this and other array templates, analyze the group so that
             // we don't end up with a template whose structure might change later.
             res.set(NewFullyAllocatedArrayForCallingAllocationSite(cx, count, TenuredObject));
-            if (!res)
+            return !!res;
-                return false;
-            EnsureArrayGroupAnalyzed(cx, res);
-            return true;
         }
     }
 
@@ -5432,10 +5422,7 @@ GetTemplateObjectForNative(JSContext* cx, HandleFunction target, const CallArgs&
                 }
                 res.set(NewFullyAllocatedArrayTryReuseGroup(cx, &args.thisv().toObject(), 0,
                                                             TenuredObject));
-                if (!res)
+                return !!res;
-                    return false;
-                EnsureArrayGroupAnalyzed(cx, res);
-                return true;
             }
         }
     }
@@ -5452,10 +5439,7 @@ GetTemplateObjectForNative(JSContext* cx, HandleFunction target, const CallArgs&
         }
 
         res.set(NewFullyAllocatedArrayForCallingAllocationSite(cx, 0, TenuredObject));
-        if (!res)
+        return !!res;
-            return false;
-        EnsureArrayGroupAnalyzed(cx, res);
-        return true;
     }
 
     if (native == StringConstructor) {
@@ -5768,7 +5752,6 @@ CopyArray(JSContext* cx, HandleArrayObject arr, MutableHandleValue result)
     ArrayObject* nobj = NewFullyAllocatedArrayTryReuseGroup(cx, arr, length, TenuredObject);
     if (!nobj)
         return false;
-    EnsureArrayGroupAnalyzed(cx, nobj); //XXX
 	
     MOZ_ASSERT(arr->isNative());
     MOZ_ASSERT(nobj->isNative());

js/src/jit/MIR.h

@@ -9234,7 +9234,7 @@ class MLoadElement
     ALLOW_CLONE(MLoadElement)
 };
 
-// Load a value from the elements vector for a dense native or unboxed array.
+// Load a value from the elements vector of a native object.
 // If the index is out-of-bounds, or the indexed slot has a hole, undefined is
 // returned instead.
 class MLoadElementHole
@@ -9465,10 +9465,10 @@ class MStoreElement
     ALLOW_CLONE(MStoreElement)
 };
 
-// Like MStoreElement, but supports indexes >= initialized length, and can
+// Like MStoreElement, but supports indexes >= initialized length. The downside
-// handle unboxed arrays. The downside is that we cannot hoist the elements
+// is that we cannot hoist the elements vector and bounds check, since this
-// vector and bounds check, since this instruction may update the (initialized)
+// instruction may update the (initialized) length and reallocate the elements
-// length and reallocate the elements vector.
+// vector.
 class MStoreElementHole
   : public MAryInstruction<4>,
     public MStoreElementCommon,

js/src/jsarray.cpp

@@ -2261,9 +2261,6 @@ js::array_unshift(JSContext* cx, unsigned argc, Value* vp)
     if (args.length() > 0) {
         /* Slide up the array to make room for all args at the bottom. */
         if (length > 0) {
-            // Only include a fast path for boxed arrays. Unboxed arrays can'nt
-            // be optimized here because unshifting temporarily places holes at
-            // the start of the array.
             bool optimized = false;
             do {
                 if (!obj->is<ArrayObject>())
@@ -2323,10 +2320,10 @@ js::array_unshift(JSContext* cx, unsigned argc, Value* vp)
 }
 
 /*
- * Returns true if this is a dense or unboxed array whose |count| properties
+ * Returns true if this is a dense array whose properties ending at |endIndex|
- * starting from |startingIndex| may be accessed (get, set, delete) directly
+ * (exclusive) may be accessed (get, set, delete) directly through its
- * through its contiguous vector of elements without fear of getters, setters,
+ * contiguous vector of elements without fear of getters, setters, etc. along
- * etc. along the prototype chain, or of enumerators requiring notification of
+ * the prototype chain, or of enumerators requiring notification of
  * modifications.
  */
 static inline bool
@@ -3550,10 +3547,10 @@ js::NewDenseCopyOnWriteArray(JSContext* cx, HandleArrayObject templateObject, gc
     return arr;
 }
 
-// Return a new boxed or unboxed array with the specified length and allocated
+// Return a new array with the specified length and allocated capacity (up to
-// capacity (up to maxLength), using the specified group if possible. If the
+// maxLength), using the specified group if possible. If the specified group
-// specified group cannot be used, ensure that the created array at least has
+// cannot be used, ensure that the created array at least has the given
-// the given [[Prototype]].
+// [[Prototype]].
 template <uint32_t maxLength>
 static inline ArrayObject*
 NewArrayTryUseGroup(ExclusiveContext* cx, HandleObjectGroup group, size_t length,
@@ -3561,10 +3558,7 @@ NewArrayTryUseGroup(ExclusiveContext* cx, HandleObjectGroup group, size_t length
 {
     MOZ_ASSERT(newKind != SingletonObject);
 
-    if (group->maybePreliminaryObjects())
+    if (group->shouldPreTenure())
-        group->maybePreliminaryObjects()->maybeAnalyze(cx, group);
-
-    if (group->shouldPreTenure() || group->maybePreliminaryObjects())
         newKind = TenuredObject;
 
     RootedObject proto(cx, group->proto().toObject());
@@ -3579,9 +3573,6 @@ NewArrayTryUseGroup(ExclusiveContext* cx, HandleObjectGroup group, size_t length
     if (res->length() > INT32_MAX)
         res->setLength(cx, res->length());
 
-    if (PreliminaryObjectArray* preliminaryObjects = group->maybePreliminaryObjects())
-        preliminaryObjects->registerNewObject(res);
-
     return res;
 }
 
@@ -3601,10 +3592,7 @@ js::NewPartlyAllocatedArrayTryUseGroup(ExclusiveContext* cx, HandleObjectGroup g
 // Return a new array with the default prototype and specified allocated
 // capacity and length. If possible, try to reuse the group of the input
 // object. The resulting array will either reuse the input object's group or
-// will have unknown property types. Additionally, the result will have the
+// will have unknown property types.
-// same boxed/unboxed elements representation as the input object, unless
-// |length| is larger than the input object's initialized length (in which case
-// UnboxedArrayObject::MaximumCapacity might be exceeded).
 template <uint32_t maxLength>
 static inline ArrayObject*
 NewArrayTryReuseGroup(JSContext* cx, JSObject* obj, size_t length,

js/src/jsarray.h

@@ -75,8 +75,6 @@ NewDenseFullyAllocatedArrayWithTemplate(JSContext* cx, uint32_t length, JSObject
 extern ArrayObject*
 NewDenseCopyOnWriteArray(JSContext* cx, HandleArrayObject templateObject, gc::InitialHeap heap);
 
-// The methods below can create either boxed or unboxed arrays.
-
 extern ArrayObject*
 NewFullyAllocatedArrayTryUseGroup(ExclusiveContext* cx, HandleObjectGroup group, size_t length,
                                   NewObjectKind newKind = GenericObject);

js/src/vm/Interpreter.cpp

@@ -4933,7 +4933,7 @@ js::NewObjectOperation(JSContext* cx, HandleScript script, jsbytecode* pc,
             newKind = TenuredObject;
     }
 
-    RootedObject obj(cx);
+    RootedPlainObject obj(cx);
 
     if (*pc == JSOP_NEWOBJECT) {
         RootedPlainObject baseObject(cx, &script->getObject(pc)->as<PlainObject>());
@@ -5011,9 +5011,6 @@ js::NewArrayOperation(JSContext* cx, HandleScript script, jsbytecode* pc, uint32
         MOZ_ASSERT(obj->isSingleton());
     } else {
         obj->setGroup(group);
-
-        if (PreliminaryObjectArray* preliminaryObjects = group->maybePreliminaryObjects())
-            preliminaryObjects->registerNewObject(obj);
     }
 
     return obj;

js/src/vm/ObjectGroup.cpp

@@ -838,17 +838,6 @@ ObjectGroup::newArrayObject(ExclusiveContext* cx,
 
         AddTypePropertyId(cx, group, nullptr, JSID_VOID, elementType);
 
-        if (elementType != TypeSet::UnknownType()) {
-            // Keep track of the initial objects we create with this type.
-            // If the initial ones have a consistent shape and property types, we
-            // will try to use an unboxed layout for the group.
-            PreliminaryObjectArrayWithTemplate* preliminaryObjects =
-                cx->new_<PreliminaryObjectArrayWithTemplate>(nullptr);
-            if (!preliminaryObjects)
-                return nullptr;
-            group->setPreliminaryObjects(preliminaryObjects);
-        }
-
         if (!p.add(cx, *table, ObjectGroupCompartment::ArrayObjectKey(elementType), group))
             return nullptr;
     }
@@ -856,9 +845,6 @@ ObjectGroup::newArrayObject(ExclusiveContext* cx,
     // The type of the elements being added will already be reflected in type
     // information.
     ShouldUpdateTypes updateTypes = ShouldUpdateTypes::DontUpdate;
-    if (group->maybePreliminaryObjects())
-        group->maybePreliminaryObjects()->maybeAnalyze(cx, group);
-
     return NewCopiedArrayTryUseGroup(cx, group, vp, length, newKind, updateTypes);
 }
 
@@ -868,27 +854,13 @@ GiveObjectGroup(ExclusiveContext* cx, JSObject* source, JSObject* target)
 {
     MOZ_ASSERT(source->group() != target->group());
 
-    if (!target->is<ArrayObject>())
+    if (!target->is<ArrayObject>() || !source->is<ArrayObject>()) {
-        return true;
-
-    if (target->group()->maybePreliminaryObjects()) {
-        bool force = IsInsideNursery(source);
-        target->group()->maybePreliminaryObjects()->maybeAnalyze(cx, target->group(), force);
-    }
-
-    ObjectGroup* sourceGroup = source->group();
-
-    if (source->is<ArrayObject>()) {
-        source->setGroup(target->group());
-    } else {
         return true;
     }
 
-    if (sourceGroup->maybePreliminaryObjects())
+    source->setGroup(target->group());
-        sourceGroup->maybePreliminaryObjects()->unregisterObject(source);
+
-    if (target->group()->maybePreliminaryObjects())
+    for (size_t i = 0; i < source->as<ArrayObject>().getDenseInitializedLength(); i++) {
-        target->group()->maybePreliminaryObjects()->registerNewObject(source);
-     for (size_t i = 0; i < source->as<ArrayObject>().getDenseInitializedLength(); i++) {
         Value v = source->as<ArrayObject>().getDenseElement(i);
         AddTypePropertyId(cx, source->group(), source, JSID_VOID, v);
     }

js/src/vm/TypeInference.cpp

@@ -3393,7 +3393,7 @@ JSFunction::setTypeForScriptedFunction(ExclusiveContext* cx, HandleFunction fun,
 /////////////////////////////////////////////////////////////////////
 
 void
-PreliminaryObjectArray::registerNewObject(JSObject* res)
+PreliminaryObjectArray::registerNewObject(PlainObject* res)
 {
     // The preliminary object pointers are weak, and won't be swept properly
     // during nursery collections, so the preliminary objects need to be
@@ -3411,7 +3411,7 @@ PreliminaryObjectArray::registerNewObject(JSObject* res)
 }
 
 void
-PreliminaryObjectArray::unregisterObject(JSObject* obj)
+PreliminaryObjectArray::unregisterObject(PlainObject* obj)
 {
     for (size_t i = 0; i < COUNT; i++) {
         if (objects[i] == obj) {

js/src/vm/TypeInference.h

@@ -814,8 +814,8 @@ class PreliminaryObjectArray
   public:
     PreliminaryObjectArray() = default;
 
-    void registerNewObject(JSObject* res);
+    void registerNewObject(PlainObject* res);
-    void unregisterObject(JSObject* obj);
+    void unregisterObject(PlainObject* obj);
 
     JSObject* get(size_t i) const {
         MOZ_ASSERT(i < COUNT);