RFR: 8302652: [SuperWord] Reduction should happen after loop, when possible [v2]

[Emanuel Peter]

On Mon, 8 May 2023 06:26:56 GMT, Pengfei Li <pli at openjdk.org> wrote:

>> Emanuel Peter has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   copy node notes with igvn registering
>
> src/hotspot/share/opto/loopopts.cpp line 4273:
> 
>> 4271:       VectorNode* vector_accumulator = current->make_normal_vector_op(last_vector_accumulator, vector_input, vec_t);
>> 4272:       _igvn.register_new_node_with_optimizer(vector_accumulator);
>> 4273:       C->copy_node_notes_to(vector_accumulator, current);
> 
> Copying node notes may be combined with registering new node by calling `_igvn.register_new_node_with_optimizer(vector_accumulator, current);`

@pfustc thanks for the hint, I did not know that!

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PR Review Comment: https://git.openjdk.org/jdk/pull/13056#discussion_r1187084497