[lworld+vector] RFR: 8314980: [lworld+vector] consider scalarization conditions during ciMultiField creation. [v5]

[Xiaohong Gong]

On Mon, 28 Aug 2023 06:12:20 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> src/hotspot/share/ci/ciEnv.cpp line 1782:
>> 
>>> 1780:   return InlineTypeNode::is_multifield_scalarized(bt, vec_length);
>>> 1781: #else
>>> 1782:   return false;
>> 
>> 1. I think it's better to implement `is_multifield_scalarized()` here, and reference it in C2 compiler. It's opposite here.
>> 2. By default, it should return `true` instead of `false` if `COMPILER2` is not supported.
>
> Agree with 2, thanks, will correct it! Idea here is that ci should leverage compiler exposed interfaces to determine scalarizability.

What is the expected return value of `is_multifield_scalarized()` for C1 compiler?

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PR Review Comment: https://git.openjdk.org/valhalla/pull/918#discussion_r1314473670