Bug 262498

Summary:	Use StringView in CSSParserToken and simplify its code
Product:	WebKit	Reporter:	Chris Dumez <cdumez>
Component:	CSS	Assignee:	Chris Dumez <cdumez>
Status:	REOPENED ---
Severity:	Normal	CC:	commit-queue, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
Bug Depends on:	263153
Bug Blocks:

Description Chris Dumez 2023-10-02 12:50:43 PDT

Use StringView in CSSParserToken and simplify its code.

Previously, CSSParserToken wasn't using StringView internally for better bit packing, as the size of this object matters a lot.
Instead, do better bit packing in StringView so that CSSParserToken can use it without increasing its size (24 bits on my macBookPro M1).

To better bit-pack StringView, we rely on PackedPtr to fit the is8Bit flag in the same word as the character pointer.

This is performance neutral on Speedometer.

Comment 1 Chris Dumez 2023-10-02 12:53:51 PDT

Pull request: https://github.com/WebKit/WebKit/pull/18508

Comment 2 EWS 2023-10-02 20:09:40 PDT

Committed 268760@main (855b9cf6ef5a): <https://commits.webkit.org/268760@main>

Reviewed commits have been landed. Closing PR #18508 and removing active labels.

Comment 3 Radar WebKit Bug Importer 2023-10-02 20:10:15 PDT

<rdar://problem/116381450>

Comment 4 WebKit Commit Bot 2023-10-13 19:22:07 PDT

Re-opened since this is blocked by bug 263153