Bug 172685 - [JSC] Move WebCore jsDynamicDowncast mechanism to JSC
Summary: [JSC] Move WebCore jsDynamicDowncast mechanism to JSC
Status: RESOLVED DUPLICATE of bug 183449
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Yusuke Suzuki
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-05-28 04:27 PDT by Yusuke Suzuki
Modified: 2018-04-01 12:26 PDT (History)
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Description Yusuke Suzuki 2017-05-28 04:27:30 PDT 
We have bunch of adhoc functions, like, isSymbol, asSymbol, isJSMap etc.
We may easily miss the chance to use optimized casting.

For example,

jsDynamicCast<JSMap*>(vm, iterable)

If we do not have a fast overloading function (checking type() == JSMapType), it falls back to the usual slow inherits() code.
Comment 1 Yusuke Suzuki 2018-04-01 12:26:12 PDT 
We already did it.

*** This bug has been marked as a duplicate of bug 183449 ***