[webkit-changes] [WebKit/WebKit] dd55ec: [JSC] Atomize 2-character substrings

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: dd55eccc28f8f388c83caf287b7bd2044319b6ab
      https://github.com/WebKit/WebKit/commit/dd55eccc28f8f388c83caf287b7bd2044319b6ab
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-08-01 (Tue, 01 Aug 2023)

  Changed paths:
    M Source/JavaScriptCore/heap/Heap.cpp
    M Source/JavaScriptCore/heap/Heap.h
    M Source/JavaScriptCore/heap/HeapInlines.h
    M Source/JavaScriptCore/runtime/JSString.h
    M Source/JavaScriptCore/runtime/JSStringInlines.h

  Log Message:
  -----------
  [JSC] Atomize 2-character substrings
https://bugs.webkit.org/show_bug.cgi?id=259675
rdar://113184158

Reviewed by Mark Lam.

This imports V8's heuristics: V8 atomize 2-character substrings because they are too
frequently used as a key of dictionary: because of code minifiers. This patch adopts
this change into our jsSubstringOfResolved.

* Source/JavaScriptCore/runtime/JSString.h:
(JSC::jsSubstringOfResolved):

Canonical link: https://commits.webkit.org/266466@main