Integrated: 8289908: Skip bounds check for cases when String is constructed from entirely used byte[]

Сергей Цыпанов duke at openjdk.org
Mon Jul 18 17:20:08 UTC 2022


On Thu, 7 Jul 2022 10:21:06 GMT, Сергей Цыпанов <duke at openjdk.org> wrote:

> We can skip bounds check and null check for Charset in case we use the array entirely and the Charset is either default one or proven to be non-null.
> 
> Benchmark results:
> 
> before
> 
> Benchmark                                                  Mode  Cnt  Score   Error  Units
> StringConstructor.newStringFromArray                       avgt   50  4,815 ± 0,154  ns/op
> StringConstructor.newStringFromArrayWithCharset            avgt   50  4,462 ± 0,068  ns/op
> StringConstructor.newStringFromArrayWithCharsetName        avgt   50  8,653 ± 0,040  ns/op
> StringConstructor.newStringFromRangedArray                 avgt   50  5,090 ± 0,066  ns/op
> StringConstructor.newStringFromRangedArrayWithCharset      avgt   50  4,550 ± 0,041  ns/op
> StringConstructor.newStringFromRangedArrayWithCharsetName  avgt   50  8,080 ± 0,055  ns/op
> 
> after
> 
> Benchmark                                                  Mode  Cnt  Score   Error  Units
> StringConstructor.newStringFromArray                       avgt   50  4,595 ± 0,053  ns/op
> StringConstructor.newStringFromArrayWithCharset            avgt   50  4,038 ± 0,062  ns/op
> StringConstructor.newStringFromArrayWithCharsetName        avgt   50  8,035 ± 0,031  ns/op
> StringConstructor.newStringFromRangedArray                 avgt   50  4,084 ± 0,007  ns/op
> StringConstructor.newStringFromRangedArrayWithCharset      avgt   50  4,014 ± 0,008  ns/op
> StringConstructor.newStringFromRangedArrayWithCharsetName  avgt   50  7,466 ± 0,071  ns/op

This pull request has now been integrated.

Changeset: efed7a7f
Author:    Sergey Tsypanov <sergei.tsypanov at yandex.ru>
Committer: Phil Race <prr at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/efed7a7f65c0fa4b757ac6b448d11d7ddebdcc9a
Stats:     97 lines in 5 files changed: 84 ins; 1 del; 12 mod

8289908: Skip bounds check for cases when String is constructed from entirely used byte[]

Reviewed-by: prr, rriggs, aturbanov

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

PR: https://git.openjdk.org/jdk/pull/9407


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