[webkit-changes] [WebKit/WebKit] b0b694: Strength reduction analyzes RegEx.exec incorrectly...

[Michael Saboff]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: b0b694fd099f5692c3d73f7d66abaca58c4f9b4e
      https://github.com/WebKit/WebKit/commit/b0b694fd099f5692c3d73f7d66abaca58c4f9b4e
  Author: Michael Saboff <msaboff at apple.com>
  Date:   2022-11-02 (Wed, 02 Nov 2022)

  Changed paths:
    A JSTests/stress/regexp-strengthreduce-results-noholes.js
    M Source/JavaScriptCore/dfg/DFGStrengthReductionPhase.cpp

  Log Message:
  -----------
  Strength reduction analyzes RegEx.exec incorrectly and generate a hole for the result array
https://bugs.webkit.org/show_bug.cgi?id=245464
rdar://100494428

Reviewed by Mark Lam.

When employing RegExp.exec strength reductions, we need to create "undefined" entries in the result array
instead of null entries per the EcmaScript spec for RegExp.match.

* JSTests/stress/regexp-strengthreduce-results-noholes.js: Added.
(runRegExp):
(assertSameAsFirstResult):
* Source/JavaScriptCore/dfg/DFGStrengthReductionPhase.cpp:
(JSC::DFG::StrengthReductionPhase::handleNode):

Canonical link: https://commits.webkit.org/256241@main