Move data members specific to ElementRareData out of NodeRareData

https://bugs.webkit.org/show_bug.cgi?id=253461 Reviewed by Darin Adler. Move data members specific to ElementRareData out of NodeRareData. Those were put in NodeRareData for better packing but we can achieve the same packing by reordering data members. I have verified that sizeof(NodeRareData)=32 and sizeof(ElementRareDate)=232 before and after my change. * Source/WebCore/dom/ElementRareData.cpp: * Source/WebCore/dom/ElementRareData.h: (WebCore::ElementRareData::useTypes const): * Source/WebCore/dom/NodeRareData.cpp: * Source/WebCore/dom/NodeRareData.h: (WebCore::NodeRareData::isElementRareData const): (WebCore::NodeRareData::useTypes const): (WebCore::NodeRareData::isElementRareData): Deleted. Canonical link: https://commits.webkit.org/261308@main
WebKit · Mar 7, 2023 · 11ece51 · 11ece51
1 parent 68217ea
commit 11ece51
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Showing 4 changed files with 10 additions and 14 deletions.
diff --git a/Source/WebCore/dom/ElementRareData.cpp b/Source/WebCore/dom/ElementRareData.cpp
@@ -34,6 +34,8 @@
 namespace WebCore {
 
 struct SameSizeAsElementRareData : NodeRareData {
+    unsigned short m_childIndex;
+    int m_tabIndex;
     IntPoint savedLayerScrollPosition;
     Vector<std::unique_ptr<ElementAnimationRareData>> animationRareData;
     void* pointers[16];

diff --git a/Source/WebCore/dom/ElementRareData.h b/Source/WebCore/dom/ElementRareData.h
@@ -193,11 +193,16 @@ class ElementRareData : public NodeRareData {
             result.add(UseType::ExplicitlySetAttrElementsMap);
         if (m_popoverData)
             result.add(UseType::Popover);
+        if (m_childIndex)
+            result.add(UseType::ChildIndex);
         return result;
     }
 #endif
 
 private:
+    unsigned short m_childIndex { 0 }; // Keep on top for better bit packing with NodeRareData.
+    int m_unusualTabIndex { 0 }; // Keep on top for better bit packing with NodeRareData.
+
     IntPoint m_savedLayerScrollPosition;
     std::unique_ptr<RenderStyle> m_computedStyle;
     std::unique_ptr<RenderStyle> m_displayContentsStyle;
@@ -234,8 +239,6 @@ class ElementRareData : public NodeRareData {
     ExplicitlySetAttrElementsMap m_explicitlySetAttrElementsMap;
 
     std::unique_ptr<PopoverData> m_popoverData;
-
-    void releasePseudoElement(PseudoElement*);
 };
 
 inline ElementRareData::ElementRareData()

diff --git a/Source/WebCore/dom/NodeRareData.cpp b/Source/WebCore/dom/NodeRareData.cpp
@@ -36,10 +36,9 @@
 namespace WebCore {
 
 struct SameSizeAsNodeRareData {
-    uint32_t m_tabIndex;
-    uint32_t m_childIndexAndIsElementRareDataFlag;
     void* m_pointer[2];
     WeakPtr<Node, WeakPtrImplWithEventTargetData> m_weakPointer;
+    bool m_isElementRareData;
 };
 
 static_assert(sizeof(NodeRareData) == sizeof(SameSizeAsNodeRareData), "NodeRareData should stay small");

diff --git a/Source/WebCore/dom/NodeRareData.h b/Source/WebCore/dom/NodeRareData.h
@@ -263,7 +263,7 @@ class NodeRareData {
     {
     }
 
-    bool isElementRareData() { return m_isElementRareData; }
+    bool isElementRareData() const { return m_isElementRareData; }
 
     void clearNodeLists() { m_nodeLists = nullptr; }
     NodeListsNodeData* nodeLists() const { return m_nodeLists.get(); }
@@ -292,8 +292,6 @@ class NodeRareData {
         OptionSet<UseType> result;
         if (m_unusualTabIndex)
             result.add(UseType::TabIndex);
-        if (m_childIndex)
-            result.add(UseType::ChildIndex);
         if (m_nodeLists)
             result.add(UseType::NodeList);
         if (m_mutationObserverData)
@@ -306,17 +304,11 @@ class NodeRareData {
 
     void operator delete(NodeRareData*, std::destroying_delete_t);
 
-protected:
-    // Used by ElementRareData. Defined here for better packing in 64-bit.
-    int m_unusualTabIndex { 0 };
-    unsigned short m_childIndex { 0 };
-
 private:
-    bool m_isElementRareData;
-
     std::unique_ptr<NodeListsNodeData> m_nodeLists;
     std::unique_ptr<NodeMutationObserverData> m_mutationObserverData;
     WeakPtr<HTMLSlotElement, WeakPtrImplWithEventTargetData> m_manuallyAssignedSlot;
+    bool m_isElementRareData; // Keep last for better bit packing with ElementRareData.
 };
 
 template<> struct NodeListTypeIdentifier<NameNodeList> {