Bug 142651 - Introduce SymbolType into SpeculativeTypes
Summary: Introduce SymbolType into SpeculativeTypes
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Yusuke Suzuki
URL:
Keywords:
Depends on: 140435
Blocks: 145000 145001
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Reported: 2015-03-12 21:38 PDT by Yusuke Suzuki
Modified: 2015-05-14 10:39 PDT (History)
5 users (show)

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Attachments
Patch (8.15 KB, patch)
2015-05-14 08:27 PDT, Yusuke Suzuki 		no flags Details | Formatted Diff | Diff
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Description Yusuke Suzuki 2015-03-12 21:38:22 PDT 
Currently, Symbol is classified as SpecCellOther.
But this is too conservative analysis and there's room to optimize it.

Introducing SpecSymbol and analyzing this type in DFG/FTL brings faster Symbol comparison and lookups with it.
It will encourage some applications that uses Symbol as an unique key, like React.js.
Comment 1 Yusuke Suzuki 2015-04-29 11:47:10 PDT 
CellOther is used for non-user-visible Cell objects.
So current status (categorizing Symbol into CellOther type) is not correct.
Comment 2 Yusuke Suzuki 2015-05-14 07:30:55 PDT 
Let's introduce SpecSymbol at first.
In the separated patch, I'll introduce SymbolUse.
Comment 3 Yusuke Suzuki 2015-05-14 08:27:06 PDT 
Created attachment 253121 [details]
Patch
Comment 4 Yusuke Suzuki 2015-05-14 09:02:49 PDT 
Comment on attachment 253121 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=253121&action=review

> Source/JavaScriptCore/dfg/DFGConstantFoldingPhase.cpp:454
> +                if (m_state.forNode(node->child1()).m_type & ~(SpecFullNumber | SpecBoolean | SpecString | SpecSymbol))

ToPrimitive is used in string concatnation. It is tested in tests/stress/dfg-to-primitive-pass-symbol.js
Comment 5 WebKit Commit Bot 2015-05-14 10:39:06 PDT 
Comment on attachment 253121 [details]
Patch

Clearing flags on attachment: 253121

Committed r184340: <http://trac.webkit.org/changeset/184340>
Comment 6 WebKit Commit Bot 2015-05-14 10:39:11 PDT 
All reviewed patches have been landed.  Closing bug.