RFR: 8352972: PPC64: Intrinsify Unsafe::setMemory [v3]

[David Linus Briemann]

On Wed, 26 Mar 2025 16:36:10 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> Similar to the x86 implementation. The non-product feature for counting things like `SharedRuntime::_unsafe_set_memory_ctr` is currently not supported on PPC64. I've left it commented out.
>> 
>> Before this patch (measured on Power10):
>> 
>> Benchmark                       (aligned)  (size)  Mode  Cnt   Score   Error  Units
>> MemorySegmentZeroUnsafe.panama       true       1  avgt   30  15.048 ± 0.095  ns/op
>> MemorySegmentZeroUnsafe.panama       true       2  avgt   30  15.054 ± 0.089  ns/op
>> MemorySegmentZeroUnsafe.panama       true       3  avgt   30  15.161 ± 0.089  ns/op
>> MemorySegmentZeroUnsafe.panama       true       4  avgt   30  15.147 ± 0.082  ns/op
>> MemorySegmentZeroUnsafe.panama       true       5  avgt   30  15.198 ± 0.089  ns/op
>> MemorySegmentZeroUnsafe.panama       true       6  avgt   30  15.128 ± 0.099  ns/op
>> MemorySegmentZeroUnsafe.panama       true       7  avgt   30  19.234 ± 0.148  ns/op
>> MemorySegmentZeroUnsafe.panama       true       8  avgt   30  15.060 ± 0.090  ns/op
>> MemorySegmentZeroUnsafe.panama       true      15  avgt   30  19.229 ± 0.171  ns/op
>> MemorySegmentZeroUnsafe.panama       true      16  avgt   30  15.030 ± 0.082  ns/op
>> MemorySegmentZeroUnsafe.panama       true      63  avgt   30  85.290 ± 0.431  ns/op
>> MemorySegmentZeroUnsafe.panama       true      64  avgt   30  84.273 ± 0.843  ns/op
>> MemorySegmentZeroUnsafe.panama       true     255  avgt   30  89.551 ± 0.706  ns/op
>> MemorySegmentZeroUnsafe.panama       true     256  avgt   30  87.736 ± 0.679  ns/op
>> MemorySegmentZeroUnsafe.panama      false       1  avgt   30  15.044 ± 0.073  ns/op
>> MemorySegmentZeroUnsafe.panama      false       2  avgt   30  14.980 ± 0.058  ns/op
>> MemorySegmentZeroUnsafe.panama      false       3  avgt   30  15.138 ± 0.126  ns/op
>> MemorySegmentZeroUnsafe.panama      false       4  avgt   30  15.025 ± 0.049  ns/op
>> MemorySegmentZeroUnsafe.panama      false       5  avgt   30  15.192 ± 0.118  ns/op
>> MemorySegmentZeroUnsafe.panama      false       6  avgt   30  15.464 ± 0.667  ns/op
>> MemorySegmentZeroUnsafe.panama      false       7  avgt   30  19.179 ± 0.143  ns/op
>> MemorySegmentZeroUnsafe.panama      false       8  avgt   30  15.278 ± 0.130  ns/op
>> MemorySegmentZeroUnsafe.panama      false      15  avgt   30  19.428 ± 0.146  ns/op
>> MemorySegmentZeroUnsafe.panama      false      16  avgt   30  18.011 ± 1.233  ns/op
>> MemorySegmentZeroUnsafe.panama      false      63  avgt   30  87.090 ± 0.989  ns/op
>> MemorySegmentZeroUnsaf...
>
> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Simplify usage of UnsafeMemoryAccessMark.

LGTM

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

Marked as reviewed by dbriemann at github.com (no known OpenJDK username).

PR Review: https://git.openjdk.org/jdk/pull/24254#pullrequestreview-2739162483