RFR: 8256986: [PPC64] C2 crashes when accessing nonexisting jvms of CallLeafDirectNode [v2]

[Ziviani]

On Fri, 27 Nov 2020 10:35:08 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> observe_safepoint() is called with jvms == NULL from fill_buffer with mach = CallLeafDirectNode.
>> That node represents a leaf call and does not safepoint.
>> "_guaranteed_safepoint" needs to get set correctly for all MachCallNodes after JDK-8254231. 
>> 
>> In addition MachCallRuntimeNode::ret_addr_offset() need update for the new assertion in output.cpp.
>> This was already fixed on some other platforms.
>
> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Also fix CallDynamicJavaDirectSchedNode. Add assertion.

Looks good to me

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Marked as reviewed by jrziviani at github.com (no known OpenJDK username).

PR: https://git.openjdk.java.net/jdk/pull/1418