The origin patch for https://bugs.openjdk.org/browse/JDK-8324186 has 2 issue:
1 It show regression in some platform, like Apple silicon in mac os
2 Can not handle instruction sequence like "dmb.ishld; dmb.ishst; dmb.ishld; dmb.ishld"
It can be fixed by:
1 Enable AlwaysMergeDMB by default, only disable it in architecture we can see performance improvement (N1 or N2)
2 Check the special pattern and merge the subsequent dmb.
1 It show regression in some platform, like Apple silicon in mac os
2 Can not handle instruction sequence like "dmb.ishld; dmb.ishst; dmb.ishld; dmb.ishld"
It can be fixed by:
1 Enable AlwaysMergeDMB by default, only disable it in architecture we can see performance improvement (N1 or N2)
2 Check the special pattern and merge the subsequent dmb.
- duplicates
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JDK-8325821 [REDO] use "dmb.ishst+dmb.ishld" for release barrier
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- Resolved
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- relates to
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JDK-8325449 [BACKOUT] use "dmb.ishst+dmb.ishld" for release barrier
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- Resolved
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JDK-8324186 use "dmb.ishst+dmb.ishld" for release barrier
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- Closed
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