[webkit-changes] [WebKit/WebKit] d60baf: [JSC] Refine Object.create modeling in DFG after m...

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: d60bafb0be1bf24b79a858f9208e5047c58f0d06
      https://github.com/WebKit/WebKit/commit/d60bafb0be1bf24b79a858f9208e5047c58f0d06
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-05-09 (Tue, 09 May 2023)

  Changed paths:
    A JSTests/stress/object-create-will-do-transition.js
    M Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h
    M Source/JavaScriptCore/dfg/DFGClobberize.h

  Log Message:
  -----------
  [JSC] Refine Object.create modeling in DFG after mayBePrototype bit is mored to Structure
https://bugs.webkit.org/show_bug.cgi?id=256551
rdar://109045428

Reviewed by Justin Michaud.

To adopt megamorphic IC, we moved mayBePrototype to Structure. As a result, DFG ObjectCreate should
claim that it can clobber JSCell_structureID since prototype object can be transitioned. This fixes it appropriately.

* JSTests/stress/object-create-will-do-transition.js: Added.
(q):
* Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
* Source/JavaScriptCore/dfg/DFGClobberize.h:
(JSC::DFG::clobberize):

Canonical link: https://commits.webkit.org/263889@main