Bug 170881 – REGRESSION(215272): microbenchmark/seal-and-do-work and microbenchmark/freeze-and-do-work are 27x slower

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Caio Lima]

Comparing r215126 with r215394 I've found the following performance regression into microbenchmarks. Need to investigate the reason.

                             baseline                  changes                                      

freeze-and-do-work       17.8163+-1.1731     !    481.5174+-10.8908       ! definitely 27.0268x slower
seal-and-do-work         18.0572+-1.2018     !    491.9421+-18.0567       ! definitely 27.2436x slower

<geometric>              17.9014+-0.9676     !    486.4490+-11.4703       ! definitely 27.1737x slower

[Michael Saboff]

This is like change set r215272 <https://trac.webkit.org/changeset/215272>.  I'll take a look at it.

[Radar WebKit Bug Importer]

<rdar://problem/31649374>

[Michael Saboff]

Created attachment 307319 [details]
Patch

[Saam Barati]

Comment on attachment 307319 [details]
Patch

r=me

[Mark Lam]

Comment on attachment 307319 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=307319&action=review

> Source/JavaScriptCore/runtime/ObjectConstructor.cpp:614
> +    if (isJSFinalObject(object) && !hasIndexedProperties(object->indexingType())) {
> +        object->seal(vm);
> +        return JSValue::encode(obj);
> +    }

In r215272 <https://trac.webkit.org/changeset/215272>, you also eliminated the fast paths for objectConstructorIsSealed() and objectConstructorIsFrozen().  Should those be restored as well with the additional !hasIndexedProperties() check?

[Michael Saboff]

(In reply to Mark Lam from comment #5)
> Comment on attachment 307319 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=307319&action=review
> 
> > Source/JavaScriptCore/runtime/ObjectConstructor.cpp:614
> > +    if (isJSFinalObject(object) && !hasIndexedProperties(object->indexingType())) {
> > +        object->seal(vm);
> > +        return JSValue::encode(obj);
> > +    }
> 
> In r215272 <https://trac.webkit.org/changeset/215272>, you also eliminated
> the fast paths for objectConstructorIsSealed() and
> objectConstructorIsFrozen().  Should those be restored as well with the
> additional !hasIndexedProperties() check?

Yes.  I added those checks back in.

[Michael Saboff]

Committed r215471: <http://trac.webkit.org/changeset/215471>