On Sun, 6 Oct 2024 15:07:02 GMT, Claes Redestad <redes...@openjdk.org> wrote:
>> src/java.base/share/classes/java/util/zip/ZipUtils.java line 175:
>>
>>> 173: public static final int get16(byte[] b, int off) {
>>> 174: Preconditions.checkIndex(off, b.length,
>>> Preconditions.AIOOBE_FORMATTER);
>>> 175: Preconditions.checkIndex(off + 1, b.length,
>>> Preconditions.AIOOBE_FORMATTER);
>>
>> Please use `Preconditions.checkFromIndexSize`, which should be less overhead:
>> Suggestion:
>>
>> Preconditions.checkFromIndexSize(off, 2, b.length,
>> Preconditions.AIOOBE_FORMATTER);
>>
>> Similarly for other methods.
>
> It's actually not less overhead in my tests, since `checkIndex` is intrinsic
> and mostly disappears, while with `checkFromIndexSize` performance gets
> significantly worse (on par with baseline). It's on my todo to investigate
> this in-depth but I think `checkFromIndexSize` needs to be given similar
> intrinsification treatment as `checkIndex`.
Actually if we trust the input index to be nonnegative, we can just check our
end index for out of bounds too.
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PR Review Comment: https://git.openjdk.org/jdk/pull/21377#discussion_r1789127887
