Bug 207438 – Optimize Style::determineChange()

• Component: CSS
• Status: RESOLVED FIXED

[Simon Fraser (smfr)]

Optimize Style::determineChange()

[Simon Fraser (smfr)]

Created attachment 390194 [details]
Patch

[Antti Koivisto]

Comment on attachment 390194 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=390194&action=review

> Source/WebCore/rendering/style/RenderStyle.cpp:451
> +bool RenderStyle::alignItemsEqual(const RenderStyle& other) const
> +{
> +    return m_rareNonInheritedData.ptr() == other.m_rareNonInheritedData.ptr()
> +        || m_rareNonInheritedData->alignItems == other.m_rareNonInheritedData->alignItems;
> +}
> +
> +bool RenderStyle::justifyItemsEqual(const RenderStyle& other) const
> +{
> +    return m_rareNonInheritedData.ptr() == other.m_rareNonInheritedData.ptr()
> +        || m_rareNonInheritedData->justifyItems == other.m_rareNonInheritedData->justifyItems;
> +}

Combining these ("alignAndJustifyItemsEqual") would eliminate one m_rareNonInheritedData comparison.

[Simon Fraser (smfr)]

(In reply to Antti Koivisto from comment #2)
> Comment on attachment 390194 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=390194&action=review
> 
> > Source/WebCore/rendering/style/RenderStyle.cpp:451
> > +bool RenderStyle::alignItemsEqual(const RenderStyle& other) const
> > +{
> > +    return m_rareNonInheritedData.ptr() == other.m_rareNonInheritedData.ptr()
> > +        || m_rareNonInheritedData->alignItems == other.m_rareNonInheritedData->alignItems;
> > +}
> > +
> > +bool RenderStyle::justifyItemsEqual(const RenderStyle& other) const
> > +{
> > +    return m_rareNonInheritedData.ptr() == other.m_rareNonInheritedData.ptr()
> > +        || m_rareNonInheritedData->justifyItems == other.m_rareNonInheritedData->justifyItems;
> > +}
> 
> Combining these ("alignAndJustifyItemsEqual") would eliminate one
> m_rareNonInheritedData comparison.

I thought about that. Wasn't sure what to name the function.

[Simon Fraser (smfr)]

Created attachment 390204 [details]
Patch

[Antti Koivisto]

Comment on attachment 390204 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=390204&action=review

> Source/WebCore/style/StyleChange.cpp:56
> +    if (!s1.childAffectingFlexPropertiesEqual(s2))
> +        return Inherit;

Seems like this also affects grid.

Could also be something more generic like descendantStyleAffectingNonInheritedPropertiesEqual

[Simon Fraser (smfr)]

https://trac.webkit.org/changeset/256102/webkit

[Radar WebKit Bug Importer]

<rdar://problem/59300384>