RFR: 8051725: Improve expansion of Conv2B nodes in the middle-end [v6]

[Jasmine Karthikeyan]

On Wed, 10 May 2023 00:54:08 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> Jasmine Karthikeyan has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 11 commits:
>> 
>>  - Merge branch 'master' into conv2b-x86-lowering
>>  - Whitespace tweak
>>  - Make transform conditional
>>  - Remove Conv2B from backend as it's macro expanded now
>>  - Re-work transform to happen in macro expansion
>>  - Fix whitespace and add bug tag to IR test
>>  - Merge branch 'master' into conv2b-x86-lowering
>>  - Merge branch 'master' into conv2b-x86-lowering
>>  - Merge branch 'master' into conv2b-x86-lowering
>>  - Merge branch 'master' into conv2b-x86-lowering
>>  - ... and 1 more: https://git.openjdk.org/jdk/compare/bad6aa68...295b9a67
>
> src/hotspot/share/opto/cfgnode.cpp line 1530:
> 
>> 1528:   if (phase->C->post_loop_opts_phase()) {
>> 1529:     return nullptr;
>> 1530:   }
> 
> Should this only be done if (!Matcher::match_rule_supported(Op_Conv2B))?

Yes, I think adding that would help in not accidentally removing optimization opportunities here, for other platforms. Thanks for this!

> src/hotspot/share/opto/convertnode.hpp line 36:
> 
>> 34: class Conv2BNode : public Node {
>> 35:   public:
>> 36:   Conv2BNode(Node* i) : Node(nullptr, i) {}
> 
> Need to also update the copyright year to 2023 for convertnode.hpp.

Thanks for the catch!

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

PR Review Comment: https://git.openjdk.org/jdk/pull/13345#discussion_r1197338729
PR Review Comment: https://git.openjdk.org/jdk/pull/13345#discussion_r1197338854