Bug 72546 – De-virtualize ScriptExecutable::unlinkCalls

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Mark Hahnenberg]

We'll add some extra type info to JSType to include the subclasses of ScriptExecutable and test them to determine which function to call.

[Mark Hahnenberg]

Created attachment 115447 [details]
Patch

[Geoffrey Garen]

Comment on attachment 115447 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=115447&action=review

r=me

> Source/JavaScriptCore/runtime/Executable.h:692
> +        switch (structure()->typeInfo().type()) {

i'd like to understand better when we use ClassInfo and when we use a JSType. Do you have a rule for that?

> Source/JavaScriptCore/runtime/JSType.h:56
> +    StaticScopeObjectType = 22,

Yeah, I really think you want to remove the explicit numeric values for these enumerated constants.

[Mark Hahnenberg]

> i'd like to understand better when we use ClassInfo and when we use a JSType. Do you have a rule for that?

I don't have a specific rule.  I figured it might be easier for the compiler to optimize a switch with JSType since the values we're testing are clustered together.  This patch does actually seem to be a small perf win according to bencher.

[Mark Hahnenberg]

Committed r100537: <http://trac.webkit.org/changeset/100537>