[lworld+vector] RFR: 8307715: Integrate VectorMask/Shuffle with value/primitive classes [v5]

[Xiaohong Gong]

On Wed, 24 May 2023 06:50:44 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> Xiaohong Gong has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix jtreg failures
>
> src/hotspot/share/opto/inlinetypenode.cpp line 448:
> 
>> 446:           Matcher::match_rule_supported_vector(VectorNode::replicate_opcode(bt), vec_len, bt)) {
>> 447:           value = kit->gvn().transform(VectorNode::scalar2vector(value, vec_len, Type::get_const_type(field->type()), false));
>> 448:         }
> 
> It may be needed for constant oops (gvn.zerocon(T_PRIMITIVE_OBJECT)) as created on following line.
> Otherwise it may result into semantically incorrect IR which tries to load a vector from a constant.

The reason that I change this here is I met another issue when the constant oops is `IOTA` which saves the index values. For such cases, the `scalar2vector` will result into wrong result. Besides, for subtype vectors, the basic type from line-443 (i.e. `BasicType bt = con_type->basic_type();`) is promoted to `int`. I cannot see the issue if loading a vector from a constant oop.  Could you please give an example? Alternatively, I was thinking about generating different IRs for the `ZERO` and `IOTA` constants. But we need to do more check about the actual values, which I think is not so urgent now.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/845#discussion_r1204919614