306383 2026-01-27 17:03:00 -0800 [appearance: base] Shrink ComputedStyleBase to free some bits for form controls pseudo elements 2026-01-28 09:32:24 -0800 1 1 1 Unclassified WebKit Forms WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=306081 InRadar P2 Normal --- 305601 1 sabouhallawa sabouhallawa cdumez webkit-bug-importer wenson_hsieh oldest_to_newest 2175604 0 sabouhallawa 2026-01-27 17:03:00 -0800 ComputedStyleBase has m_nonInheritedData, which is DataRef, as its first member. m_nonInheritedData has to be aligned at 8 bytes boundary. Because the CheckedPtr uses a 4-bytes counter which comes the first thing, there are 4-bytes padding between this counter and m_inheritedRareData. Similarly there are 2-bytes padding between m_nonInheritedFlags and m_inheritedRareData. To shrink this class by using the padding bytes, m_nonInheritedFlags and m_inheritedFlags should be the first members of ComputedStyleBase. If we reserve 22 unused bits for pseudo elements in m_nonInheritedFlags, moving the m_nonInheritedFlags and m_inheritedFlags the current padding will be reduced from Total byte size: 64 Total pad bytes: 6 Padding percentage: 10.16% To be Total byte size: 64 Total pad bytes: 0 Padding percentage: 0.78 % 2175605 1 webkit-bug-importer 2026-01-27 17:03:25 -0800 <rdar://problem/169048994> 2175611 2 sabouhallawa 2026-01-27 17:14:00 -0800 Pull request: https://github.com/WebKit/WebKit/pull/57374 2175831 3 ews-feeder 2026-01-28 09:32:21 -0800 Committed 306352@main (653d8d23600e): <https://commits.webkit.org/306352@main> Reviewed commits have been landed. Closing PR #57374 and removing active labels.