[Webkit-unassigned] [Bug 181953] New: Split objects that have indexed properties from normal objects.

bugzilla-daemon at webkit.org bugzilla-daemon at webkit.org
Mon Jan 22 14:36:20 PST 2018


https://bugs.webkit.org/show_bug.cgi?id=181953

            Bug ID: 181953
           Summary: Split objects that have indexed properties from normal
                    objects.
           Product: WebKit
           Version: WebKit Nightly Build
          Hardware: Unspecified
                OS: Unspecified
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: JavaScriptCore
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: keith_miller at apple.com

The current approach we have for handling indexed properties, index masking, works pretty well but it has a large perf cost. We think a large part of this cost is the extra allocation size for JSFinalObjects. Almost all JSFinalObjects don't have indexed properties. Thus, if we split the butterfly into two buffers where every object has named property storage (replacing butterfly) and all indexed objects have a second pointer containing indexed properties, we will save space on most objects. If a non-JSArray gets an indexed property later we can allocate an buffer object and put it in the named property storage.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20180122/b83855d8/attachment-0001.html>


More information about the webkit-unassigned mailing list