Fix typos in comments of JSCJSValue.h

[witch-factory]

b2b0e19

Fix typos in comments of JSCJSValue.h
https://bugs.webkit.org/show_bug.cgi?id=270775

Reviewed by Keith Miller.

It is the second bit which is set for non-numeric immediates and the second bit is bit 1.

* Source/JavaScriptCore/runtime/JSCJSValue.h:

Canonical link: https://commits.webkit.org/275951@main

9dc1c21

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[kmiller68]

I think this comment is meant to be interpreted as zero indexed. Documenting that seems reasonable though. Maybe "All non-numeric (bool, null, undefined) immediates have bit 1 (zero indexed) set."?

[witch-factory]

Thank you for the review. However, there are sections in other comments as well where the bit ordering is represented as 0-indexed. So how about making a similar documenting to those part? This would help clarify that the bits are 0-indexed in the content of the subsequent comments as well.

Line 454~458:

     * These values have the following properties:
     * - Bit 1 (0-indexed) is set (OtherTag) for all four values, allowing real pointers to be
     *   quickly distinguished from all immediate values, including these invalid pointers.
     * - With bit 3 (0-indexed) masked out (UndefinedTag), Undefined and Null share the
     *   same value, allowing null & undefined to be quickly detected.

Line 485 as reviewed.

// All non-numeric (bool, null, undefined) immediates have bit 1 (0-indexed) set.

The expression 0-indexed are being used in Source/JavaScriptCore/runtime/JSBigInt.cpp

[kmiller68]

I think your commit comment is duplicated.

[witch-factory]

I apologize for the mistake in handling Git. I have now combined the commit messages into one. Could you please take a look?

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 6904fa5)

Details

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
🧪 style	🛠 ios	🛠 mac	🛠 wpe	🛠 wincairo
	🛠 ios-sim	🛠 mac-AS-debug	🧪 wpe-wk2
🧪 webkitperl	🧪 ios-wk2	🧪 api-mac	🧪 api-wpe
	🧪 ios-wk2-wpt	🧪 mac-wk1	🛠 wpe-skia
🛠 🧪 jsc	🧪 api-ios	🧪 mac-wk2	🛠 gtk
🛠 🧪 jsc-arm64	🛠 tv	🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	🛠 tv-sim	🧪 mac-wk2-stress	🧪 api-gtk
	🛠 watch		🛠 jsc-armv7
	🛠 watch-sim		🧪 jsc-armv7-tests

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 45e390d)

Details

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
🧪 style	🛠 ios	🛠 mac	🛠 wpe	🛠 wincairo
	🛠 ios-sim	🛠 mac-AS-debug	🧪 wpe-wk2
🧪 webkitperl	🧪 ios-wk2	🧪 api-mac	🧪 api-wpe
	🧪 ios-wk2-wpt	🧪 mac-wk1	🛠 wpe-skia
🛠 🧪 jsc	🧪 api-ios	🧪 mac-wk2	🛠 gtk
🛠 🧪 jsc-arm64	🛠 tv	🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	🛠 tv-sim	🧪 mac-wk2-stress	🧪 api-gtk
	🛠 watch		🛠 jsc-armv7
	🛠 watch-sim		🧪 jsc-armv7-tests

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 223b739)

Details

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
🧪 style	🛠 ios	🛠 mac	🛠 wpe	🛠 wincairo
	🛠 ios-sim	🛠 mac-AS-debug	🧪 wpe-wk2
🧪 webkitperl	🧪 ios-wk2	🧪 api-mac	🧪 api-wpe
	🧪 ios-wk2-wpt	🧪 mac-wk1	🛠 wpe-skia
🛠 🧪 jsc	🧪 api-ios	🧪 mac-wk2	🛠 gtk
🛠 🧪 jsc-arm64	🛠 tv	🧪 mac-AS-debug-wk2	🧪 gtk-wk2
	🛠 tv-sim	🧪 mac-wk2-stress	🧪 api-gtk
	🛠 watch		🛠 jsc-armv7
	🛠 watch-sim		🧪 jsc-armv7-tests

[webkit-early-warning-system]

EWS run on current version of this PR (hash 9dc1c21)

Details

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-skia
✅ 🛠 🧪 jsc	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 tv-sim		✅ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🛠 watch		✅ 🛠 jsc-armv7
	✅ 🛠 watch-sim		✅ 🧪 jsc-armv7-tests

[kmiller68]

r=me.

[webkit-ews-buildbot]

Safe-Merge-Queue: Build #14672.

[webkit-commit-queue]

Committed 275951@main (b2b0e19): https://commits.webkit.org/275951@main

Reviewed commits have been landed. Closing PR #25696 and removing active labels.