[webkit-changes] [WebKit/WebKit] 34a1f6: [JSC] Use or64 since it can encode startOfStructur...

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 34a1f637714c4b88cb27cde64e9c1298a29276d2
      https://github.com/WebKit/WebKit/commit/34a1f637714c4b88cb27cde64e9c1298a29276d2
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-04-17 (Mon, 17 Apr 2023)

  Changed paths:
    M Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
    M Source/JavaScriptCore/jit/AssemblyHelpers.cpp

  Log Message:
  -----------
  [JSC] Use or64 since it can encode startOfStructureHeap in imm
https://bugs.webkit.org/show_bug.cgi?id=255570
rdar://108171748

Reviewed by Justin Michaud.

StructureAlignedMemoryAllocator ensures that we can compose Structure* with StructureID with BitOr operation.
This patch changes add64 to or64 since or64 can encode bits more nicely in imm field, removing one unnecessary `mov`.

* Source/JavaScriptCore/jit/AssemblyHelpers.cpp:
(JSC::AssemblyHelpers::emitNonNullDecodeZeroExtendedStructureID):

Canonical link: https://commits.webkit.org/263057@main