RFR: 8319799: Recursive lightweight locking: x86 implementation [v13]

[Roman Kennke]

On Thu, 25 Jan 2024 13:46:36 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

>> src/hotspot/cpu/x86/x86_32.ad line 13807:
>> 
>>> 13805:   predicate(LockingMode == LM_LIGHTWEIGHT);
>>> 13806:   match(Set cr (FastLock object box));
>>> 13807:   effect(TEMP eax_reg, TEMP tmp, USE_KILL box, TEMP thread);
>> 
>> Consider changing USE_KILL box to TEMP box. Same overall considerations (long-term, in a follow-up) as in aarch64.
>
> An input cannot be `TEMP` so must change the required input nodes for FastLockNode and FastUnlockNode.
> 
> Planned this as a followup RFE, would also change the `eBXRegP` / `rbx_RegP ` constraint to `eRegP` and `rRegP`.

Ok, good then. (What a mess. Looking forward to see this cleaned-up)

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PR Review Comment: https://git.openjdk.org/jdk/pull/16607#discussion_r1466408270