RFR: 8264173: [s390] Improve Hardware Feature Detection And Reporting [v2]

[Martin Doerr]

On Fri, 26 Mar 2021 14:07:52 GMT, Lutz Schmidt <lucy at openjdk.org> wrote:

>> This enhancement is intended to improve the hardware feature detection and reporting, in particular for more recently introduced hardware. The enhancement is a prerequisite for possible future feature exploitation. 
>> 
>> Reviews are highly welcome and appreciated.
>
> Lutz Schmidt has updated the pull request incrementally with one additional commit since the last revision:
> 
>   update copyright headers

I didn't expect the change to become that large. But it looks good to me. The lengthy output only gets generated with -XX:+Verbose. That's fine.

src/hotspot/cpu/s390/vm_version_s390.cpp line 87:

> 85:                                    "system-z, g8-z14, ldisp_fast, extimm, pcrel_load/store, cmpb, cond_load/store, interlocked_update, txm, vectorinstr, instrext2, venh1)",
> 86:                                    "system-z, g9-z15, ldisp_fast, extimm, pcrel_load/store, cmpb, cond_load/store, interlocked_update, txm, vectorinstr, instrext2, venh1, instrext3, VEnh2 )"
> 87:                                   };

Would be nice to generate the feature string from a table it instead of having so many copies. But I'm ok with it for now.

src/hotspot/cpu/s390/vm_version_s390.cpp line 94:

> 92: 
> 93:   if (Verbose || PrintAssembly || PrintStubCode) {
> 94:     print_features_internal("CPU Version as detected internally:  ", PrintAssembly || PrintStubCode);

2 spaces while other usages have no spaces?

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

Marked as reviewed by mdoerr (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/3196