RFR: 8320725: C2: Add "is_associative" flag for floating-point add-reduction [v3]

[Bhavana Kilambi]

On Mon, 18 Mar 2024 12:35:50 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Bhavana Kilambi has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Naming changes: replace strict/non-strict with more technical terms
>
> src/hotspot/cpu/aarch64/aarch64_vector.ad line 2887:
> 
>> 2885: //    Such nodes can only be generated by Vector API.
>> 2886: // 2. Non-associative (or strictly ordered) AddReductionVF, which can only be generated by
>> 2887: //    auto-vectorization on SVE machine.
> 
> I'd be careful with such strong statements. You can name them as examples, but the "only" may not stay true forever. We may for example at some point add some way to have a `Float.addAssociative`, to allow "fast-math" reductions in plain java, which can then be auto-vectorized with a non-strict ordered implementation. I'm not sure if we will ever do that, but it is possible.

Agreed, will make the changes. Thanks

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/18034#discussion_r1531066198