[aarch64-port-dev ] RFR: 8135231: add support for vectorizing double precision sqrt

[Edward Nevill]

Hi,

Please review the following webrev

http://cr.openjdk.java.net/~enevill/8135231/webrev/

JIRA issue: https://bugs.openjdk.java.net/browse/JDK-8135231

This adds support for vector double sqrt for aarch64.

I have tested this with JTreg hotspot+langtools with no regressions.

There is a trivial change to
test/compiler/loopopts/superword/SumRedSqrt_Double.java

-* @requires os.arch=="x86" | os.arch=="amd64" | os.arch=="x86_64"
+* @requires os.arch=="x86" | os.arch=="amd64" | os.arch=="x86_64" |
os.arch=="aarch64"

I am not clear whether this change means that the change requires
sponsoring and pushing through JPRT, but if so could someone do this.

Thanks for your help,
Ed.