On Fri, 31 Mar 2023 18:30:19 GMT, Xin Liu <x...@openjdk.org> wrote:
>> Cesar Soares Lucas has updated the pull request incrementally with one
>> additional commit since the last revision:
>>
>> Address PR feeedback 1: make ObjectMergeValue subclass of ObjectValue &
>> create new IR class to represent scalarized merges.
>
> src/hotspot/share/opto/escape.cpp line 457:
>
>> 455: found_sr_allocate = true;
>> 456: } else {
>> 457: ptn->set_scalar_replaceable(false);
>
> This member function is const. Do we really need to change ptn's property
> here?
>
> My reading is ophi is profitable as long as we spot any input object which
> can be eliminated. how about you just return at line 455?
This is actually necessary here. By setting the input to NSR I don't need to
later, when performing reduction, check that I can eliminate the node. I can
just check that I can scalar replace the input. If I removed this line I'd hit
a problem if the merge had an input that is SR but that ME can't eliminate.
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PR Review Comment: https://git.openjdk.org/jdk/pull/12897#discussion_r1167263888
