RFR: 8367325: [s390x] build failure due to JDK-8361376

[Dean Long]

On Thu, 11 Sep 2025 22:13:25 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> src/hotspot/cpu/s390/gc/shared/barrierSetAssembler_s390.cpp line 174:
>> 
>>> 172: void BarrierSetAssembler::nmethod_entry_barrier(MacroAssembler* masm) {
>>> 173:   BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
>>> 174:   __ align(8); // must align the following block which requires atomic updates
>> 
>> Thanks for fixing this.  Rather than aligning at the start, wouldn't it be more maintainable to do
>> `__ align(4, offset() + 2);`
>> before the z_cfi?
>
> That would require much more changes. The barrier sequence is expected to have a fixed size.

OK, then how about we align the beginning using
` __ align(4, offset() + 3*6 + 2);`
to make it more self-documenting?

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PR Review Comment: https://git.openjdk.org/jdk/pull/27213#discussion_r2342632201