Title: [183879] trunk/Source/WebCore
- Revision
- 183879
- Author
- hy...@apple.com
- Date
- 2015-05-06 11:37:51 -0700 (Wed, 06 May 2015)
Log Message
Optimize relativePositionOffset() to avoid doing unnecessary work
https://bugs.webkit.org/show_bug.cgi?id=144698
Reviewed by Simon Fraser.
* rendering/RenderBoxModelObject.cpp:
(WebCore::RenderBoxModelObject::relativePositionOffset):
Patch relativePositionOffset to avoid doing unnecessary work in the common case where
all values of top/left/right/bottom are either auto or fixed. We no longer fetch
containingBlock() into a local always, but instead just invoke the function only
when necessary.
Also avoid computing the percentage-relative maximum for the top/right/bottom/left lengths
when they are fixed values, since that maximum won't be examined at all.
Modified Paths
Diff
Modified: trunk/Source/WebCore/ChangeLog (183878 => 183879)
--- trunk/Source/WebCore/ChangeLog 2015-05-06 17:52:43 UTC (rev 183878)
+++ trunk/Source/WebCore/ChangeLog 2015-05-06 18:37:51 UTC (rev 183879)
@@ -1,3 +1,21 @@
+2015-05-06 David Hyatt <hy...@apple.com>
+
+ Optimize relativePositionOffset() to avoid doing unnecessary work
+ https://bugs.webkit.org/show_bug.cgi?id=144698
+
+ Reviewed by Simon Fraser.
+
+ * rendering/RenderBoxModelObject.cpp:
+ (WebCore::RenderBoxModelObject::relativePositionOffset):
+
+ Patch relativePositionOffset to avoid doing unnecessary work in the common case where
+ all values of top/left/right/bottom are either auto or fixed. We no longer fetch
+ containingBlock() into a local always, but instead just invoke the function only
+ when necessary.
+
+ Also avoid computing the percentage-relative maximum for the top/right/bottom/left lengths
+ when they are fixed values, since that maximum won't be examined at all.
+
2015-05-06 Martin Robinson <mrobin...@igalia.com>
[FreeType] Vertical CJK glyphs should not be rendered with synthetic oblique
Modified: trunk/Source/WebCore/rendering/RenderBoxModelObject.cpp (183878 => 183879)
--- trunk/Source/WebCore/rendering/RenderBoxModelObject.cpp 2015-05-06 17:52:43 UTC (rev 183878)
+++ trunk/Source/WebCore/rendering/RenderBoxModelObject.cpp 2015-05-06 18:37:51 UTC (rev 183879)
@@ -274,21 +274,22 @@
LayoutSize RenderBoxModelObject::relativePositionOffset() const
{
+ // This function has been optimized to avoid calls to containingBlock() in the common case
+ // where all values are either auto or fixed.
+
LayoutSize offset = accumulateInFlowPositionOffsets(this);
- RenderBlock* containingBlock = this->containingBlock();
-
// Objects that shrink to avoid floats normally use available line width when computing containing block width. However
// in the case of relative positioning using percentages, we can't do this. The offset should always be resolved using the
// available width of the containing block. Therefore we don't use containingBlockLogicalWidthForContent() here, but instead explicitly
// call availableWidth on our containing block.
if (!style().left().isAuto()) {
- if (!style().right().isAuto() && !containingBlock->style().isLeftToRightDirection())
- offset.setWidth(-valueForLength(style().right(), containingBlock->availableWidth()));
+ if (!style().right().isAuto() && !containingBlock()->style().isLeftToRightDirection())
+ offset.setWidth(-valueForLength(style().right(), !style().right().isFixed() ? containingBlock()->availableWidth() : LayoutUnit()));
else
- offset.expand(valueForLength(style().left(), containingBlock->availableWidth()), 0);
+ offset.expand(valueForLength(style().left(), !style().left().isFixed() ? containingBlock()->availableWidth() : LayoutUnit()), 0);
} else if (!style().right().isAuto()) {
- offset.expand(-valueForLength(style().right(), containingBlock->availableWidth()), 0);
+ offset.expand(-valueForLength(style().right(), !style().right().isFixed() ? containingBlock()->availableWidth() : LayoutUnit()), 0);
}
// If the containing block of a relatively positioned element does not
@@ -298,16 +299,16 @@
// calculate the percent offset based on this height.
// See <https://bugs.webkit.org/show_bug.cgi?id=26396>.
if (!style().top().isAuto()
- && (!containingBlock->hasAutoHeightOrContainingBlockWithAutoHeight()
- || !style().top().isPercent()
- || containingBlock->stretchesToViewport()))
- offset.expand(0, valueForLength(style().top(), containingBlock->availableHeight()));
+ && (!style().top().isPercent()
+ || !containingBlock()->hasAutoHeightOrContainingBlockWithAutoHeight()
+ || containingBlock()->stretchesToViewport()))
+ offset.expand(0, valueForLength(style().top(), !style().top().isFixed() ? containingBlock()->availableHeight() : LayoutUnit()));
else if (!style().bottom().isAuto()
- && (!containingBlock->hasAutoHeightOrContainingBlockWithAutoHeight()
- || !style().bottom().isPercent()
- || containingBlock->stretchesToViewport()))
- offset.expand(0, -valueForLength(style().bottom(), containingBlock->availableHeight()));
+ && (!style().bottom().isPercent()
+ || !containingBlock()->hasAutoHeightOrContainingBlockWithAutoHeight()
+ || containingBlock()->stretchesToViewport()))
+ offset.expand(0, -valueForLength(style().bottom(), !style().bottom().isFixed() ? containingBlock()->availableHeight() : LayoutUnit()));
return offset;
}
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