[lworld+vector] RFR: 8319945: [lworld+vector] Fix vector api jtreg crash with "-XX:-EnableVectorSupport"

Xiaohong Gong xgong at openjdk.org
Wed Nov 15 07:40:22 UTC 2023


Several vector api jtreg tests crash with `"-XX:-EnableVectorSupport"` when running on machines that the operations of vector payload can be vectorized.

Here is the log:


 Internal Error (valhalla/src/hotspot/share/opto/library_call.cpp:2465), pid=467482, tid=467499
 assert(bt == alias_type->basic_type() || bt == T_PRIMITIVE_OBJECT) failed: should match

 JRE version: OpenJDK Runtime Environment (22.0) (fastdebug build 22-internal-git-5b2fa0aab)
 Java VM: OpenJDK 64-Bit Server VM (fastdebug 22-internal-git-5b2fa0aab, mixed mode, sharing, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
 Problematic frame:
 V [[libjvm.so](http://libjvm.so/)+0x11b1738] LibraryCallKit::inline_unsafe_access(bool, BasicType, LibraryCallKit::AccessKind, bool)+0x13e8


The reason is the matched field of the given offset in the vector payload is not found when using Usafe's access methods. And the root cause is when the operations of the multifields are vectorizable in C2, only the multifield base is added into the holder klass's non-static fields list in ci stage. Hence when accessing other multifields by Unsafe's get/put methods (which is the fall-back java implementation of current vector operations), the fields cannot be found with the given field offset.

This issue is involved by [JDK-8314980](https://bugs.openjdk.java.net/browse/JDK-8314980) (see [1]), which refactors the multifields parsing in ci stage. The special handling for multifields in `ciInstanceKlass::get_field_by_offset` is removed. Adding it back can fix this issue.

This patch also reverted the special consideration for multifields when printing out the JVM state in a safepoint. It is not needed anymore, because the fields of an `InlineTypeNode` in C2 is always consistent with the holder klass's non-static fields after [JDK-8314980](https://bugs.openjdk.java.net/browse/JDK-8314980).

[1] https://github.com/openjdk/valhalla/pull/918

Verified with Vector API jtreg tests with `-XX:-EnableVectorSupport`, and all tests clean.

-------------

Commit messages:
 - 8319945: [lworld+vector] Fix vector api jtreg crash with "-XX:-EnableVectorSupport"

Changes: https://git.openjdk.org/valhalla/pull/953/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=953&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8319945
  Stats: 45 lines in 2 files changed: 19 ins; 19 del; 7 mod
  Patch: https://git.openjdk.org/valhalla/pull/953.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/953/head:pull/953

PR: https://git.openjdk.org/valhalla/pull/953



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