Changeset 132995 in webkit

Timestamp:

Oct 31, 2012, 1:14:00 AM (13 years ago)

Author:

[email protected]

Message:

Add non-virtual firstChild/lastChild overrides to RenderBlock and RenderTableCol for a > 30% speedup on table from bug 100304
​https://bugs.webkit.org/show_bug.cgi?id=100306

Reviewed by Abhishek Arya.

Presumably this is a speedup for other rendering tests as well. We use firstChild() all over
the rendering code w/o considering that it makes a virtual function call.
Originally I just fixed the one callsite which was showing up on the sample to
use children()->firstChild() directly. However after further thought, this
broader solution seemed the better way to go. The first patch was a 15% win for
this large table, this broader solution was a 30%!? win.

The elephant in the room for this table is that we're walking the whole table
for many nextColumn calls. But that I will solve in a later bug.

• rendering/RenderBlock.h:

(WebCore::RenderBlock::firstChild):
(WebCore::RenderBlock::lastChild):
(RenderBlock):

• rendering/RenderObject.h:

(RenderObject):

• rendering/RenderTableCol.h:

(WebCore::RenderTableCol::firstChild):
(WebCore::RenderTableCol::lastChild):
(RenderTableCol):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderBlock.h (modified) (1 diff)
• rendering/RenderFrameSet.h (modified) (1 diff)
• rendering/RenderInline.h (modified) (1 diff)
• rendering/RenderMedia.h (modified) (1 diff)
• rendering/RenderObject.h (modified) (1 diff)
• rendering/RenderTableCol.h (modified) (1 diff)
• rendering/RenderTableRow.h (modified) (1 diff)
• rendering/RenderTableSection.h (modified) (1 diff)
• rendering/svg/RenderSVGContainer.h (modified) (1 diff)
• rendering/svg/RenderSVGRoot.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2012-10-31  Eric Seidel  <[email protected]>
+
+        Add non-virtual firstChild/lastChild overrides to RenderBlock and RenderTableCol for a > 30% speedup on table from bug 100304
+        https://bugs.webkit.org/show_bug.cgi?id=100306
+
+        Reviewed by Abhishek Arya.
+
+        Presumably this is a speedup for other rendering tests as well.  We use firstChild() all over
+        the rendering code w/o considering that it makes a virtual function call.
+        Originally I just fixed the one callsite which was showing up on the sample to
+        use children()->firstChild() directly.  However after further thought, this
+        broader solution seemed the better way to go.  The first patch was a 15% win for
+        this large table, this broader solution was a 30%!? win.
+
+        The elephant in the room for this table is that we're walking the whole table
+        for many nextColumn calls.  But that I will solve in a later bug.
+
+        * rendering/RenderBlock.h:
+        (WebCore::RenderBlock::firstChild):
+        (WebCore::RenderBlock::lastChild):
+        (RenderBlock):
+        * rendering/RenderObject.h:
+        (RenderObject):
+        * rendering/RenderTableCol.h:
+        (WebCore::RenderTableCol::firstChild):
+        (WebCore::RenderTableCol::lastChild):
+        (RenderTableCol):
+
 2012-10-31  Philippe Normand  <[email protected]>
 

trunk/Source/WebCore/rendering/RenderBlock.h

@@ -87 +87 @@
     virtual ~RenderBlock();
 
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
+
     const RenderObjectChildList* children() const { return &m_children; }
     RenderObjectChildList* children() { return &m_children; }

trunk/Source/WebCore/rendering/RenderFrameSet.h

@@ -58 +58 @@
     RenderFrameSet(HTMLFrameSetElement*);
     virtual ~RenderFrameSet();
+
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
 
     const RenderObjectChildList* children() const { return &m_children; }

trunk/Source/WebCore/rendering/RenderInline.h

@@ -35 +35 @@
 public:
     explicit RenderInline(Node*);
+
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
 
     virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0);

trunk/Source/WebCore/rendering/RenderMedia.h

@@ -41 +41 @@
     virtual ~RenderMedia();
 
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
+
     const RenderObjectChildList* children() const { return &m_children; }
     RenderObjectChildList* children() { return &m_children; }

trunk/Source/WebCore/rendering/RenderObject.h

@@ -179 +179 @@
     RenderObject* nextSibling() const { return m_next; }
 
+    // FIXME: These should be renamed slowFirstChild, slowLastChild, etc.
+    // to discourage their use. The virtualChildren() call inside these
+    // can be slow for hot code paths.
+    // Currently, some subclasses like RenderBlock, override these NON-virtual
+    // functions to make these fast when we already have a more specific pointer type.
     RenderObject* firstChild() const
     {

trunk/Source/WebCore/rendering/RenderTableCol.h

@@ -37 +37 @@
 public:
     explicit RenderTableCol(Node*);
+
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
 
     const RenderObjectChildList* children() const { return &m_children; }

trunk/Source/WebCore/rendering/RenderTableRow.h

@@ -36 +36 @@
 public:
     explicit RenderTableRow(Node*);
+
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
 
     const RenderObjectChildList* children() const { return &m_children; }

trunk/Source/WebCore/rendering/RenderTableSection.h

@@ -66 +66 @@
     virtual ~RenderTableSection();
 
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
+
     const RenderObjectChildList* children() const { return &m_children; }
     RenderObjectChildList* children() { return &m_children; }

trunk/Source/WebCore/rendering/svg/RenderSVGContainer.h

@@ -36 +36 @@
     explicit RenderSVGContainer(SVGStyledElement*);
     virtual ~RenderSVGContainer();
+
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
 
     const RenderObjectChildList* children() const { return &m_children; }

trunk/Source/WebCore/rendering/svg/RenderSVGRoot.h

@@ -44 +44 @@
 
     virtual void computeIntrinsicRatioInformation(FloatSize& intrinsicSize, double& intrinsicRatio, bool& isPercentageIntrinsicSize) const;
+
+    RenderObject* firstChild() const { ASSERT(children() == virtualChildren()); return children()->firstChild(); }
+    RenderObject* lastChild() const { ASSERT(children() == virtualChildren()); return children()->lastChild(); }
+
     const RenderObjectChildList* children() const { return &m_children; }
     RenderObjectChildList* children() { return &m_children; }