RFR: JDK-8331732 : [PPC64] Unify and optimize code which converts != 0 to 1 [v7]

[Martin Doerr]

On Fri, 28 Jun 2024 10:47:32 GMT, Suchismith Roy <sroy at openjdk.org> wrote:

>> [JDK-8331732](https://bugs.openjdk.org/browse/JDK-8331732)
>> The template interpreter contains branch-free conversion code for T_BOOLEAN (TemplateInterpreterGenerator::generate_result_handler_for).
>> 
>> SharedRuntime::generate_native_wrapper uses unoptimized code to "Unpack the native result" for T_BOOLEAN.
>> Power10 has the "setbc" / "setbcr" instruction.
>> 
>> A new function has been created for the conversion and use "setbcr" on Power10 (determined by VM_Version::has_brw()) and otherwise the branch-free implementation. We should have a function for 32 and one for 64 bit operations (or one with supports both).
>> 
>> The new code for MacroAssembler::verify_secondary_supers_table  also uses the new function.
>
> Suchismith Roy has updated the pull request incrementally with one additional commit since the last revision:
> 
>   register name and indendt

src/hotspot/cpu/ppc/macroAssembler_ppc.cpp line 365:

> 363:     }
> 364:   }
> 365: }

Please find a better place to insert this function! It doesn't fit between the 2 functions which are related.

src/hotspot/cpu/ppc/macroAssembler_ppc.hpp line 298:

> 296: 
> 297:   // Branch-free implementation to convert !=0 to 1.
> 298:   void normalize_bool(Register dst, Register temp, bool use_64bit);

Same here.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/19886#discussion_r1658654116
PR Review Comment: https://git.openjdk.org/jdk/pull/19886#discussion_r1658654282