RFR: JDK-8330795 : C2: assert((uint)type <= T_CONFLICT && _zero_type[type] != nullptr) failed: bad type with -XX:-UseCompressedClassPointers [v3]

Mon May 13 22:09:23 UTC 2024

> The `assert((uint)type <= T_CONFLICT && _zero_type[type] != nullptr) failed: bad type` failure was caused by the fact that we didn't have a "zero value" for the type T_METADATA. The RAM patch uses that data when it creates a Phi node merging Klass loads and UseCompressedClassPointers is disabled.
> 
> Tested with JTREG tier1-4 on Linux x86_64 & ARM64.

Cesar Soares Lucas has updated the pull request incrementally with one additional commit since the last revision:

  Addressing feedback: more tests. Reverting previous change.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/19148/files
  - new: https://git.openjdk.org/jdk/pull/19148/files/91fc61de..bb632c27

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19148&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19148&range=01-02

  Stats: 79 lines in 4 files changed: 54 ins; 3 del; 22 mod
  Patch: https://git.openjdk.org/jdk/pull/19148.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19148/head:pull/19148

PR: https://git.openjdk.org/jdk/pull/19148