RFR: 8343685: C2 SuperWord: refactor VPointer with MemPointer [v6]

[Emanuel Peter]

On Wed, 15 Jan 2025 12:43:15 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> Emanuel Peter has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   More fixes for vnkozlov
>
> src/hotspot/share/opto/vectorization.hpp line 949:
> 
>> 947: 
>> 948: // Vector element size statistics for loop vectorization with vector masks
>> 949: class VectorElementSizeStats {
> 
> Just noticed this when scrolling through the class in my IDE: All methods of this class could be made `const`. You could probably squeeze this in here as well as part of this bigger refactoring - probably not worth a separate RFE.

Turns out it is dead code!

emanuel at emanuel-oracle:/oracle-work/jdk-fork5/open$ grep VectorElementSizeStats src/hotspot/share/ -r
src/hotspot/share/opto/vectorization.hpp:class VectorElementSizeStats {
src/hotspot/share/opto/vectorization.hpp:  VectorElementSizeStats(Arena* a) : _stats(NEW_ARENA_ARRAY(a, int, 4)) {
Binary file src/hotspot/share/opto/.vectorization.hpp.swp matches
emanuel at emanuel-oracle:/oracle-work/jdk-fork5/open$ git log -S VectorElementSizeStats
commit 96781ba33d4717c8df2b9ba4cd5d66858cf5c2d1
Author: Pengfei Li <pli at openjdk.org>
Date:   Fri Sep 15 01:02:44 2023 +0000

    8312332: C2: Refactor SWPointer out from SuperWord
    
    Reviewed-by: epeter, kvn

commit a38582e941c0234e76d1dbea60c731c83d2c9977
Author: Pengfei Li <pli at openjdk.org>
Date:   Thu Jul 13 01:45:52 2023 +0000

    8311691: C2: Remove legacy code related to PostLoopMultiversioning
    
    Reviewed-by: kvn, sviswanathan

commit 741be46138c4a02f1d9661b3acffb533f50ba9cf
Author: Pengfei Li <pli at openjdk.org>
Date:   Tue Apr 5 23:50:13 2022 +0000

    8183390: Fix and re-enable post loop vectorization
    
    Reviewed-by: roland, thartmann, kvn

The last occurance was removed with https://github.com/openjdk/jdk/pull/14824

I'll just rip it out now.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21926#discussion_r1917811724