RFR: 8341006: Optimize StackMapGenerator detect frames [v2]

[Chen Liang]

On Fri, 27 Sep 2024 01:34:18 GMT, Shaojin Wen <swen at openjdk.org> wrote:

>> 1. Construct Frames directly without BitSet
>> 2. Use Frame[] instead of ArrayList
>> 3. Use EMPTY_FRAME_ARRAY for initialization. No need to allocate objects when there is no frame.
>
> Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:
> 
>   copyright

The removal of bitset makes this frame detection significantly slower for startup. A heap sort or manual unrolling of bitset may be better.

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Changes requested by liach (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21183#pullrequestreview-2344464999