[lworld] RFR: 8371993: [lworld] Aarch64: save bad values instead of rfp and lr above the extension space [v2]

[Marc Chevalier]

On Fri, 28 Nov 2025 12:20:14 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

> Do we even need the && C->needs_stack_repair()?

In my version, we do. With `sp_inc != 0`, I think we don't. And yes, I think it should just work. Will do.

> src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp line 192:
> 
>> 190: 
>> 191:   // Frame creation and destruction shared between JITs.
>> 192:   void build_frame(int framesize DEBUG_ONLY(COMMA bool save_fake_rfp_lr));
> 
> Suggestion:
> 
>   void build_frame(int framesize DEBUG_ONLY(COMMA bool save_fake_rfp_lr = false));
> 
> 
> So you can leave the C1 code untouched.

I'm not fan of optional arguments, they make maintenance difficult when changing the arity of such a function, with new parameters of compatible types. What about an overload that would just call `build_frame(framesize, false)`?

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PR Review Comment: https://git.openjdk.org/valhalla/pull/1764#discussion_r2571566138
PR Review Comment: https://git.openjdk.org/valhalla/pull/1764#discussion_r2571572326