RFR: 8257483: C2: Split immediate vector rotate from RotateLeftV and RotateRightV nodes [v5]

[Dong Bo]

On Wed, 9 Dec 2020 12:55:37 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Dong Bo has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR.
>
> src/hotspot/cpu/x86/x86.ad line 1817:
> 
>> 1815: }
>> 1816: 
>> 1817: bool Matcher::supports_vector_variable_rotates(VectorNode *n) {
> 
> Please, turn it into a capability check (just `bool Matcher::supports_vector_variable_rotates(void)`, no argument).
> There's no need to wrap `Matcher::match_rule_supported_vector` since you already check it:
> (in(2)->is_Con() && !Matcher::supports_vector_variable_rotates(this)) ||
> !Matcher::match_rule_supported_vector(Op_RotateLeftV, vlen, bt)) {
> 
> Otherwise, looks good.

Done. Turned the capability check  into `bool Matcher::supports_vector_variable_rotates(void)`. On x86_64, it returns `true` directly now.

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PR: https://git.openjdk.java.net/jdk/pull/1532