172685 2017-05-28 04:27:30 -0700 [JSC] Move WebCore jsDynamicDowncast mechanism to JSC 2018-04-01 12:26:12 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Nightly Build Unspecified Unspecified RESOLVED DUPLICATE 183449 P2 Normal --- 1 ysuzuki ysuzuki oldest_to_newest 1313474 0 ysuzuki 2017-05-28 04:27:30 -0700 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. 1410969 1 ysuzuki 2018-04-01 12:26:12 -0700 We already did it. *** This bug has been marked as a duplicate of bug 183449 ***