[webkit-changes] [WebKit/WebKit] 424d19: Use fixed-size deadCells vector in MarkedBlock::sweep

[Commit Queue]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 424d1996eedf829b94d9593ed1a4288994bf43f1
      https://github.com/WebKit/WebKit/commit/424d1996eedf829b94d9593ed1a4288994bf43f1
  Author: David Degazio <d_degazio at apple.com>
  Date:   2023-04-04 (Tue, 04 Apr 2023)

  Changed paths:
    M Source/JavaScriptCore/heap/MarkedBlock.h
    M Source/JavaScriptCore/heap/MarkedBlockInlines.h

  Log Message:
  -----------
  Use fixed-size deadCells vector in MarkedBlock::sweep
https://bugs.webkit.org/show_bug.cgi?id=254960
rdar://107585451

Reviewed by Justin Michaud and Yusuke Suzuki.

Allocates the deadCells vector in MarkedBlock::specializedSweep
entirely on the stack, and stores atom numbers using uint16_t instead
of uint64_t. Should reduce allocations and potentially improve locality.

* Source/JavaScriptCore/heap/MarkedBlockInlines.h:
(JSC::MarkedBlock::Handle::specializedSweep):

Canonical link: https://commits.webkit.org/262612@main