[jdk17u-dev] RFR: 8292698: Improve performance of DataInputStream

[Aleksey Shipilev]

On Tue, 23 May 2023 12:57:56 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Clean backport to improve `DataInputStream` performance in JDK 17u.
> 
> Benchmark from the changeset:
> 
> 
> Benchmark                     Mode  Cnt   Score   Error  Units
> 
> #### x86_64
> 
> # Before
> DataInputStreamTest.readChar  avgt   20  19.939 ? 0.120  us/op
> DataInputStreamTest.readInt   avgt   20  20.538 ? 0.052  us/op
> 
> # After
> DataInputStreamTest.readChar  avgt   20  10.497 ? 0.079  us/op
> DataInputStreamTest.readInt   avgt   20   5.399 ? 0.073  us/op
> 
> ### AArch64
> 
> # Before
> DataInputStreamTest.readChar  avgt   20  21.600 ? 0.410  us/op
> DataInputStreamTest.readInt   avgt   20  21.425 ? 0.545  us/op
> 
> # After
> DataInputStreamTest.readChar  avgt   20  12.186 ? 0.366  us/op
> DataInputStreamTest.readInt   avgt   20   6.207 ? 0.174  us/op
> 
> 
> Additional testing:
>  - [x] Benchmark added by RFE
>  - [x] Linux x86_64 fastdebug, `tier1 tier2 tier3`
>  - [x] Linux AArch64 fastdebug, `tier1 tier2 tier3`

Testing is clean. Push approval is here.

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

PR Comment: https://git.openjdk.org/jdk17u-dev/pull/1390#issuecomment-1568910461