8368724: RISC-V: Remove AvoidUnalignedAccesses Flag

[Anjian-Wen]

According to the discuss in #27445, we can use UseUnalignedAccesses and !UseUnalignedAccesses to cover the AvoidUnalignedAccesses Flag, so I Remove the AvoidUnalignedAccesses Flag in this patch

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
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• Commit message must refer to an issue

Issue

• JDK-8368724: RISC-V: Remove AvoidUnalignedAccesses Flag (Enhancement - P4)

Reviewers

• Fei Yang (@RealFYang - Reviewer) 🔄 Re-review required (review applies to 3f657e0a)

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/27510/head:pull/27510
$ git checkout pull/27510

Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk.git pull/27510/head

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$ git pr checkout 27510

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[bridgekeeper]

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[openjdk]

@Anjian-Wen This change is no longer ready for integration - check the PR body for details.

[openjdk]

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[Anjian-Wen]

/issue JDK-8368724

[openjdk]

@Anjian-Wen The primary solved issue for a PR is set through the PR title. Since the current title does not contain an issue reference, it will now be updated.

[mlbridge]

Webrevs

• 05: Full - Incremental (6eb1dd95)
• 04: Full - Incremental (be963cdc)
• 03: Full - Incremental (c1b209fe)
• 02: Full (910840da)
• 01: Full - Incremental (42f1db93)
• 00: Full (3f657e0a)

[RealFYang]

Looks reasonable. Thanks.

[Hamlin-Li]

I think we're going to remove the AvoidUnalignedAccesses? And if unaligned_access is not enabled, then its value can not be MISALIGNED_FAST?
If both above are true, then seems this check is not necessary?

[Anjian-Wen]

I think we're going to remove the AvoidUnalignedAccesses? And if unaligned_access is not enabled, then its value can not be MISALIGNED_FAST? If both above are true, then seems this check is not necessary?

@Hamlin-Li Thanks for your review.
According to the current use of unaligned_access.value, if it is not enabled, then using value will depend on the default value -1. This change is to try to make the use of unaligned_access.value more reasonable.
Maybe we can keep this judgment and consider removing the Avoid flag latter？

[Hamlin-Li]

@Hamlin-Li Thanks for your review. According to the current use of unaligned_access.value, if it is not enabled, then using value will depend on the default value -1. This change is to try to make the use of unaligned_access.value more reasonable. Maybe we can keep this judgment and consider removing the Avoid flag latter？

If the default value is -1, then unaligned_access.value() == MISALIGNED_FAST can only be true when it's enabled, so that makes the extra check added in this pr unnecessary for UseUnalignedAccesses.
As for AvoidUnalignedAccesses, there is a discussion here to remove AvoidUnalignedAccesses: #27445 (review).
So my suggestion is to just remove AvoidUnalignedAccesses in riscv, how do you think about it?

[Hamlin-Li]

So my suggestion is to just remove AvoidUnalignedAccesses in riscv, how do you think about it?

I guess no one's already working it? Maybe you could take it if you are available. :)

[Anjian-Wen]

@Hamlin-Li Thanks for your review. According to the current use of unaligned_access.value, if it is not enabled, then using value will depend on the default value -1. This change is to try to make the use of unaligned_access.value more reasonable. Maybe we can keep this judgment and consider removing the Avoid flag latter？

If the default value is -1, then unaligned_access.value() == MISALIGNED_FAST can only be true when it's enabled, so that makes the extra check added in this pr unnecessary for UseUnalignedAccesses. As for AvoidUnalignedAccesses, there is a discussion here to remove AvoidUnalignedAccesses: #27445 (review). So my suggestion is to just remove AvoidUnalignedAccesses in riscv, how do you think about it?

@Hamlin-Li Oh, Thanks! I get it, I think it makes sence. I will try to figure out how to modify the code and remove AvoidUnalignedAccesses together

[openjdk]

@Anjian-Wen this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout add_unaligned_access_check
git fetch https://git.openjdk.org/jdk.git master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[Hamlin-Li]

Not sure what's the rule to remove this riscv specific options. Can we just simply delete it in this pr?

[Anjian-Wen]

Ok I understand, I have deleted the change

[Hamlin-Li]

Sorry, I did not mean you should delete the AvoidUnalignedAccesses. I just don't know the exact rule about how to delete it.
Please hold on for a while to get a comment on this part of change from others.

[Anjian-Wen]

Oh, I misunderstood, I will try to check the rule and test tier1