RFR: 8258243: C2: assert failed ("Bad derived pointer") with -XX:+VerifyRegisterAllocator

[Vladimir Kozlov]

On Fri, 8 Jan 2021 14:05:32 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> The base pointer verification code in the register allocator checks that a base for a derived constant node is always `NULL`. However, this is not the case if the offset is zero (returns on L1744):
> https://github.com/openjdk/jdk/blob/b549cbd39250c5b22c6e863172d18cf247022894/src/hotspot/share/opto/chaitin.cpp#L1740-L1754
> 
> This case is added to the verification code which fixes the reported failing testcases.
> 
> I additionally added a hello world test to sanity check the `-XX:+VerifyRegisterAllocator` flag.
> 
> Thanks,
> Christian

Good. Make sense.

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Marked as reviewed by kvn (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2005