On Fri, 23 Apr 2021 03:50:54 GMT, Yi Yang <[email protected]> wrote:
>> The JDK codebase re-created many variants of checkIndex(`grep -I -r
>> 'cehckIndex' jdk/`). A notable variant is java.nio.Buffer.checkIndex, which
>> annotated with @IntrinsicCandidate and it only has a corresponding C1
>> intrinsic version.
>>
>> In fact, there is an utility method
>> `jdk.internal.util.Preconditions.checkIndex`(wrapped by
>> java.lang.Objects.checkIndex) that behaves the same as these variants of
>> checkIndex, we can replace these re-created variants of checkIndex by
>> Objects.checkIndex, it would significantly reduce duplicated code and enjoys
>> performance improvement because Preconditions.checkIndex is
>> @IntrinsicCandidate and it has a corresponding intrinsic method in HotSpot.
>>
>> But, the problem is currently HotSpot only implements the C2 version of
>> Preconditions.checkIndex. To reuse it global-widely in JDK code, I think we
>> can firstly implement its C1 counterpart. There are also a few kinds of
>> stuff we can do later:
>>
>> 1. Replace all variants of checkIndex by Objects.checkIndex in the whole JDK
>> codebase.
>> 2. Remove Buffer.checkIndex and obsolete/deprecate InlineNIOCheckIndex flag
>>
>> Testing: cds, compiler and jdk
>
> Yi Yang has updated the pull request incrementally with one additional commit
> since the last revision:
>
> remove java_nio_Buffer in javaClasses.hpp
src/java.base/share/classes/java/nio/Buffer.java line 740:
> 738: */
> 739: final int checkIndex(int i) { //
> package-private
> 740: return Objects.checkIndex(i, limit);
Changing Buffer.checkIndex to use Objects.checkIndex is okay.
-------------
PR: https://git.openjdk.java.net/jdk/pull/3615
