[jdk11u-dev] RFR: 8271567: AArch64: AES Galois CounterMode (GCM) interleaved implementation using vector instructions [v4]

[Aleksey Shipilev]

On Tue, 2 Nov 2021 12:19:49 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> This is a backport of the big AES/GCM patch from JDK head. It's a
>> major change and it's had very little time (almost a day) to mature in
>> head, so perhaps it shouldn't be backported to 11 for some time; I
>> wouldn't be at all surprised if some reviewers' reaction was "What
>> have you been smoking?" However, there is a good reason for a
>> backport: OpenJDK on x86 has a major advantage. AES/GCM is an
>> important cipher, the current AArch64 implementation is much slower
>> than x86, and some workloads are severely impacted.
>> 
>> I'm open to all arguments about why this should or shouldn't be pushed,
>> and I'm quite happy to wait for another release cycle or two if people
>> think that's the best course of action.
>
> Andrew Haley has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Backport 4f3b626a36319cbbbbdcb1c02a84486a3d4eddb6

Looks fine to me.

src/hotspot/cpu/aarch64/vm_version_aarch64.cpp line 313:

> 311:     if (FLAG_IS_DEFAULT(UseAESCTRIntrinsics)) {
> 312:       FLAG_SET_DEFAULT(UseAESCTRIntrinsics, false);
> 313:     }

`UseAESCTRIntrinsics` is already `false` by default, so this seems to be excessive. No harm doing this anyway.

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Marked as reviewed by shade (Reviewer).

PR: https://git.openjdk.java.net/jdk11u-dev/pull/410