RFR: 8303040: linux PPC64le: Implementation of Foreign Function & Memory API (Preview) [v24]

[Martin Doerr]

On Thu, 27 Apr 2023 16:19:46 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

>> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Revert unintended formatting changes. Fix comment.
>
> src/hotspot/cpu/ppc/upcallLinker_ppc.cpp line 202:
> 
>> 200: 
>> 201:   MacroAssembler* _masm = new MacroAssembler(&buffer);
>> 202:   address start = __ function_entry(); // called by C
> 
> If `!defined(ABI_ELFv2)` a function descriptor will be emitted here. It will be initialized with `friend_toc` and `friend_env`. But that's not correct for external callers, is it? If so, wouldn't an `Unimplemented()` be better than obscure crashes?

No, this code is correct and tested (I have a partially working Big Endian patch). `toc` and `env` are loaded by the external caller (C code), but not used by the stub. So, we don't need to initialize them to any specific values.

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PR Review Comment: https://git.openjdk.org/jdk/pull/12708#discussion_r1189755698