Integrated: 8354674: AArch64: Intrinsify Unsafe::setMemory

[Andrew Haley]

On Fri, 9 May 2025 14:11:27 GMT, Andrew Haley <aph at openjdk.org> wrote:

> This intrinsic is generally faster than the current implementation for Panama segment operations for all writes larger than about 8 bytes in size, increasing to more than 2* the performance on larger memory blocks on Graviton 2, between "panama" (C2 generated, what we use now) and "unsafe" (this intrinsic).
> 
> 
> Benchmark                       (aligned)  (size)  Mode  Cnt     Score    Error  Units
> MemorySegmentFillUnsafe.panama       true  262143  avgt   10  7295.638 ±  0.422  ns/op
> MemorySegmentFillUnsafe.panama      false  262143  avgt   10  8345.300 ± 80.161  ns/op
> MemorySegmentFillUnsafe.unsafe       true  262143  avgt   10  2930.594 ±  0.180  ns/op
> MemorySegmentFillUnsafe.unsafe      false  262143  avgt   10  3136.828 ±  0.232  ns/op

This pull request has now been integrated.

Changeset: a6ebcf61
Author:    Andrew Haley <aph at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/a6ebcf61eb522a1bcfc9f2169d42974af3883b00
Stats:     127 lines in 3 files changed: 122 ins; 0 del; 5 mod

8354674: AArch64: Intrinsify Unsafe::setMemory

Reviewed-by: adinn

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PR: https://git.openjdk.org/jdk/pull/25147