[11u] RFR: JDK-8222074: Enhance auto vectorization for x86

[Lemmond, Dan]

Hi,

I sent this review out previously but it was moderated. Moderators, feel free to discard the old one.

This backport is a prerequisite for backporting JDK-8230591<https://bugs.openjdk.java.net/browse/JDK-8230591>. I plan to backport JDK-8226721<https://bugs.openjdk.java.net/browse/JDK-8226721> and JDK-8231713<https://bugs.openjdk.java.net/browse/JDK-8231713> in the coming days before finally backporting JDK-8230591.

This review is part of a set and will need to be pushed with the backport for JDK-8224234<https://bugs.openjdk.java.net/browse/JDK-8224234> which I will be sending out shortly.

JBS: https://bugs.openjdk.java.net/browse/JDK-8222074
Webrev: http://cr.openjdk.java.net/~phh/8222074/webrev.11u.00/
Original review thread: https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-May/033561.html

Please review this backport for JDK-8222074 to 11u. The changeset applied cleanly for the most part, only requiring a manual fix for two hunks.

The two hunks that needed to be fixed were hunk 3 in assembler_x86.hpp and hunk 3 in x86.ad.

The backport compiled without issue and successfully passed the Tier1 Hotspot tests.

Please note that the change to CheckGraalIntrinsics.java was omitted from this backport as the check was “isJDK13OrHigher” which is not relevant for 11u.

Thank you,
Dan