RFR: 8367692: RISC-V: Align post call nop [v5]

[Robbin Ehn]

On Fri, 26 Sep 2025 11:13:27 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Robbin Ehn has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Use relocation spec as marker.
>
> src/hotspot/cpu/riscv/macroAssembler_riscv.cpp line 358:
> 
>> 356: 
>> 357: void MacroAssembler::post_call_nop() {
>> 358:   assert(!in_compressible_scope(), "Must be");
> 
> Maybe `do_compress` is better? All other places use `do_compress`.
> Similar suggestion as below.

There is a semantic difference: in_compressible_scope() only check if caller turned off c-instruction.
While do_compressed() also consider what ISA we are using in runtime.
Regardless of ISA : caller of post_call_nop() should have turned C off is what I want to assert.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27467#discussion_r2382284606