RFR: 8312332: C2: Refactor SWPointer out from SuperWord [v3]

[Pengfei Li]

On Thu, 10 Aug 2023 12:23:14 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> src/hotspot/share/opto/vectorization.cpp line 131:
>> 
>>> 129: bool VPointer::invariant(Node* n) const {
>>> 130:   NOT_PRODUCT(Tracer::Depth dd;)
>>> 131:   // TODO: Add more trace output for invariant check after later refactoring
>> 
>> We generally don't like `TODO`s in the code. Best is to just drop it in the code and file an RFE if you think it is really important.
>> 
>> When did this even trace anything?
>> `_slp->_lpt->is_member(_slp->_phase->get_loop(n_c)) != (int)_slp->in_bb(n)`
>> 
>> Do you think this tracing is relevant enough?
>
> If it should never happen: can we add an assert somewhere instead?

I don't know when this can happen. This was added in jdk9 without a test case. If this can happen, it should be in some real corner cases. But definitely, the trace message is not important and it's safe to drop that. `TODO` is removed in my latest commit.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15013#discussion_r1310121093