On Wed, 25 Jan 2023 16:39:04 GMT, Per Minborg <pminb...@openjdk.org> wrote:
> This PR suggests improving performance by using the newly introduced class
> `jdk.internal.util.ByteArray` to improve packing/unpacking operations.
>
> The PR also proposes adding a `ByteArrayLittleEndian` class for support for
> little endian packing/unpacking.
Here are some performance figures (TLDR: about 2% performance increase):
Baseline (J21 master)
[java] All test results:
[java] Test(imageio.input.stream.tests.readFully(int[])) averaged
2.0089243986475606E9 bytes/sec
[java] with 250x250, photo, byteArray, !useCache
[java] Test(imageio.input.stream.tests.readLong) averaged
6.087925258517034E8 bytes/sec
[java] with 250x250, photo, byteArray, !useCache
Patch
[java] All test results:
[java] Test(imageio.input.stream.tests.readFully(int[]) averaged
2.0537614726652384E9 bytes/sec
[java] with 250x250, photo, byteArray, !useCache
[java] Test(imageio.input.stream.tests.readLong) averaged
6.227265050569915E8 bytes/sec
[java] with 250x250, photo, byteArray, !useCache
the `readFully(int[])` is a custom benchmark:
iis.mark();
int[] array = new int[8];
do {
if (pos + 4*8 > length) {
iis.reset();
iis.mark();
pos = 0;
}
iis.readFully(array, 0, 8);
pos += 4*8;
} while (--numReps >= 0);
Tests were run on a Mac M1 aarch64 machine.
-------------
PR: https://git.openjdk.org/jdk/pull/12204
