RFR: 8336489: Track scoped accesses in JVMCI compiled code [v5]

Carlo Refice duke at openjdk.org
Fri Jul 26 17:16:02 UTC 2024


> This PR adds JVMCI support to scoped access tracking introduced in #20158.
> 
> In this PR:
> * The `Method::is_scoped` flag is now exposed in JVMCI as `HotSpotResolvedJavaMethod.isScoped()`, and serialized to / deserialized from the JVMCI compiled code stream as a boolean flag.
> * To determine whether a compiled method has a scoped access, we simply check `HotSpotResolvedJavaMethod.isScoped()` returns `true` for the root method or any of the methods that were inlined in the compilation.
> * The above check is implemented as the method `HotSpotCompiledNMethod.hasScopedAccess()`, instead of as an explicit flag set in a the constructor of `HotSpotCompiledNMethod`. This keeps the change isolated to JVMCI, without requiring coordinated changes to the Graal compiler. No other changes in the compiler are necessary to benefit from the optimization.

Carlo Refice has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:

 - Add test for ResolvedJavaMethod#isScoped()
 - Pull HotSpotResolvedJavaMethod#isScoped() to ResolvedJavaMethod
 - Fix truncation of Method and ConstMethod flags in HotSpotResolvedJavaMethodImpl
 - Clarify HotSpotResolvedJavaMethod#isScoped javadoc
 - Track scoped accesses in JVMCI compiled code

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

Changes: https://git.openjdk.org/jdk/pull/20256/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20256&range=04
  Stats: 69 lines in 12 files changed: 61 ins; 0 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/20256.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20256/head:pull/20256

PR: https://git.openjdk.org/jdk/pull/20256


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