RFR: Increase card offset mask [v2]

[Y. Srinivas Ramakrishna]

On Wed, 10 May 2023 20:58:28 GMT, Y. Srinivas Ramakrishna <ysr at openjdk.org> wrote:

>> William Kemper has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:
>> 
>>  - Merge branch 'openjdk:master' into increase-card-offset-mask
>>  - Re-problem-list failing pipeline tests
>>  - Re-problem-list failing GHA tests
>>  - Increase card offset mask to cover 32-bit words and/or 1k cards
>
> src/hotspot/share/gc/shenandoah/shenandoahScanRemembered.hpp line 401:
> 
>> 399:   // If we're setting first_start, assume the card has an object.
>> 400:   inline void set_first_start(size_t card_index, uint8_t value) {
>> 401:     assert(value < FirstStartBits, "Offset into card would be truncated");
> 
> `value <= FirstStartBits` ?
> 
> Can/should replace (or augment, if you prefer) with a static assert using the maximum possible offset computed using card size and heap word size?

(dynamic) may be also in `set_last_start`?

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PR Review Comment: https://git.openjdk.org/shenandoah/pull/275#discussion_r1190394955