From 597a6996f14429d09a7c89b1f774d2490cca3dd6 Mon Sep 17 00:00:00 2001
From: win7-7 <win7-7@users.noreply.github.com>
Date: Mon, 3 Feb 2020 20:47:41 +0200
Subject: Issue #1386 - Devirtualize GetRowSpan/GetColSpan

It's at ~1.5% on the perf log for the Netflix use case, which seems a bit too much.
---
 dom/mathml/nsMathMLElement.cpp | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

(limited to 'dom/mathml/nsMathMLElement.cpp')

diff --git a/dom/mathml/nsMathMLElement.cpp b/dom/mathml/nsMathMLElement.cpp
index d6aef876c..2be931682 100644
--- a/dom/mathml/nsMathMLElement.cpp
+++ b/dom/mathml/nsMathMLElement.cpp
@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "mozilla/ArrayUtils.h"
 #include "nsGkAtoms.h"
+#include "nsITableCellLayout.h" // for MAX_COLSPAN / MAX_ROWSPAN
 #include "nsCRT.h"
 #include "nsLayoutStylesheetCache.h"
 #include "nsRuleData.h"
@@ -150,8 +151,9 @@ nsMathMLElement::ParseAttribute(int32_t aNamespaceID,
                                 const nsAString& aValue,
                                 nsAttrValue& aResult)
 {
+  MOZ_ASSERT(IsMathMLElement());
   if (aNamespaceID == kNameSpaceID_None) {
-    if (IsMathMLElement(nsGkAtoms::math) && aAttribute == nsGkAtoms::mode) {
+    if (mNodeInfo->Equals(nsGkAtoms::math) && aAttribute == nsGkAtoms::mode) {
       WarnDeprecated(nsGkAtoms::mode->GetUTF16String(),
                      nsGkAtoms::display->GetUTF16String(), OwnerDoc());
     }
@@ -165,6 +167,16 @@ nsMathMLElement::ParseAttribute(int32_t aNamespaceID,
         aAttribute == nsGkAtoms::mathbackground_) {
       return aResult.ParseColor(aValue);
     }
+    if (mNodeInfo->Equals(nsGkAtoms::mtd_)) {
+      if (aAttribute == nsGkAtoms::columnspan_) {
+        aResult.ParseClampedNonNegativeInt(aValue, 1, 1, MAX_COLSPAN);
+        return true;
+      }
+      if (aAttribute == nsGkAtoms::rowspan) {
+        aResult.ParseClampedNonNegativeInt(aValue, 1, 0, MAX_ROWSPAN);
+        return true;
+      }
+    }
   }
 
   return nsMathMLElementBase::ParseAttribute(aNamespaceID, aAttribute,
@@ -209,6 +221,8 @@ static Element::MappedAttributeEntry sDirStyles[] = {
 bool
 nsMathMLElement::IsAttributeMapped(const nsIAtom* aAttribute) const
 {
+  MOZ_ASSERT(IsMathMLElement());
+
   static const MappedAttributeEntry* const mtableMap[] = {
     sMtableStyles,
     sCommonPresStyles
@@ -240,10 +254,10 @@ nsMathMLElement::IsAttributeMapped(const nsIAtom* aAttribute) const
   if (IsAnyOfMathMLElements(nsGkAtoms::mstyle_, nsGkAtoms::math))
     return FindAttributeDependence(aAttribute, mstyleMap);
 
-  if (IsMathMLElement(nsGkAtoms::mtable_))
+  if (mNodeInfo->Equals(nsGkAtoms::mtable_))
     return FindAttributeDependence(aAttribute, mtableMap);
 
-  if (IsMathMLElement(nsGkAtoms::mrow_))
+  if (mNodeInfo->Equals(nsGkAtoms::mrow_))
     return FindAttributeDependence(aAttribute, mrowMap);
 
   if (IsAnyOfMathMLElements(nsGkAtoms::maction_,
-- 
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