RFR: 8377658: G1: Cleanup g1ConcurrentMark.cpp for stricter warning flags [v2]

[Johan Sjölen]

On Fri, 13 Feb 2026 15:12:53 GMT, Leo Korinth <lkorinth at openjdk.org> wrote:

>> Cleanup `g1ConcurrentMark.cpp` and included header files to remove implicit narrowing conversions.
>> 
>> For gcc: `-Wconversion -Wno-float-conversion`
>> For clang: `-Wimplicit-int-conversion`
>
> Leo Korinth has updated the pull request incrementally with four additional commits since the last revision:
> 
>  - fix copyright
>  - split sizeof_auto to other enhancement
>  - change cast to checked type
>  - fix checked cast, fix field variable to uint

BSM changes seem correct to me. I'm fine with them being part of this PR.

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Marked as reviewed by jsjolen (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/29701#pullrequestreview-3808842737