RFR: 8349686: [s390x] C1: Improve Class.isInstance intrinsic [v9]

[Andrew Haley]

On Thu, 20 Feb 2025 11:43:08 GMT, Amit Kumar <amitkumar at openjdk.org> wrote:

>> s390x implementation for Class.isInstance intrinsic. 
>> 
>> Tier1 test on release & fastdebug vm are clean with flag: `-XX:-UseSecondarySupersCache -XX:+UseSecondarySupersTable -XX:+VerifySecondarySupers -XX:+StressSecondarySupers`. 
>> 
>> Benchmark results will be updated soon.
>
> Amit Kumar has updated the pull request incrementally with one additional commit since the last revision:
> 
>   no need of Z_R0_scratch

src/hotspot/cpu/s390/c1_Runtime1_s390.cpp line 635:

> 633:       __ z_bcr(Assembler::bcondEqual, Z_R14);
> 634: 
> 635:       // Z_R10 and Z_R11 are caller saved, so we must need to preserve them before any use

Suggestion:

      // Z_R10 and Z_R11 are callee saved, so we must need to preserve them before any use


We are the callee!

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PR Review Comment: https://git.openjdk.org/jdk/pull/23535#discussion_r1965554704