- do not create new storage on clear if not really necessary

- in dict.update() check changes on others only based on size

Author: tomasstupka

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/common/DynamicObjectStorage.java

@@ -341,7 +341,9 @@ private static Object runNode(DynamicObjectStorage self, Object key, Object acc,
     @ExportMessage
     @TruffleBoundary
     public HashingStorage clear() {
-        return new DynamicObjectStorage();
+        store.setShapeAndResize(store.getShape(), EMPTY_SHAPE);
+        store.updateShape();
+        return this;
     }
 
     @Override

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/common/EconomicMapStorage.java

@@ -372,16 +372,17 @@ static HashingStorage delItemWithStateWithSideEffect(EconomicMapStorage self, Ob
     static class Clear {
 
         @Specialization(guards = "!hasSideEffect(self)")
-        static HashingStorage clear(@SuppressWarnings("unused") EconomicMapStorage self) {
-            return create();
+        static HashingStorage clear(EconomicMapStorage self) {
+            self.map.clear();
+            return self;
         }
 
         @Specialization
         static HashingStorage clearWithSideEffect(EconomicMapStorage self,
                         @Exclusive @Cached LookupInheritedAttributeNode.Dynamic lookup,
                         @Exclusive @Cached CallUnaryMethodNode callNode) {
             if (self.map.size() == 0) {
-                return create();
+                return self;
             }
             Object[] entries = new Object[self.map.size() * 2];
             MapCursor<DictKey, Object> cursor = self.map.getEntries();
@@ -398,7 +399,7 @@ static HashingStorage clearWithSideEffect(EconomicMapStorage self,
                     callNode.executeObject(lookup.execute(o, __DEL__), o);
                 }
             }
-            return create();
+            return self;
         }
 
     }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/dict/DictBuiltins.java

@@ -574,11 +574,12 @@ private HashingStorage addAll(PDict self, PDict other, GetDictStorageNode getSto
             HashingStorage selfStorage = getStorage.execute(self);
             HashingStorage otherStorage = getStorage.execute(other);
             HashingStorageIterator<DictEntry> itOther = libOther.entries(otherStorage).iterator();
+            int initialSize = libOther.length(otherStorage);
             HashingStorage newStorage = selfStorage;
             while (itOther.hasNext()) {
                 DictEntry next = itOther.next();
                 newStorage = libSelf.setItem(selfStorage, next.key, next.value);
-                if (otherStorage != getStorage.execute(other)) {
+                if (initialSize != libOther.length(otherStorage)) {
                     throw raise(RuntimeError, ErrorMessages.MUTATED_DURING_UPDATE, "dict");
                 }
             }