RFR: 8257882: Implement linkToNative intrinsic on AArch64 [v2]

[Andrew Haley]

On Thu, 10 Dec 2020 13:55:25 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

> Thanks for the amazing work!
> 
> FWIW, on x86 RBP was being passed as debug info (see last line in MachCallNode::in_RegMask), so the solution Vlad I proposed would be to override MachCallNativeNode::in_RegMask to not include it IIRC. I haven't had time to look into it yet though.
> 
> The situation on AArch64 seems to be different though? The RFP is not passed as debug info but as part of the normal calling convention maybe?

On AArch64 JIT-compiled code, RFP is a callee-saved register that's free for any use. It's very useful for a spilled value across calls.

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

PR: https://git.openjdk.java.net/jdk/pull/1711