On Fri, 2 Feb 2024 13:54:46 GMT, Claes Redestad <redes...@openjdk.org> wrote:
> This patch streamlines and specializes various `String::indexOf` methods.
> Mainly avoids the need for clamping and doing checks that are redundant in
> almost all cases, moving the checks to the API boundary where they are
> needed.
>
> This improves performance both at peak and during startup/warmup. Since
> indexOf is heavily used in bootstrapping code it makes sense to slightly dial
> back abstraction and delegation, which in this case also brought some benefit
> to peak performance.
>
> Testing: tier1-3
src/java.base/share/classes/java/lang/String.java line 2506:
> 2504: fromIndex = Math.max(0, fromIndex);
> 2505: return isLatin1() ? StringLatin1.indexOf(value, ch, fromIndex,
> value.length)
> 2506: : StringUTF16.indexOf(value, ch, fromIndex,
> value.length >> 1);
This needs to include the check for `fromIndex >= this.length()`:
Suggestion:
fromIndex = Math.max(0, fromIndex);
int toIndex = length();
if (fromIndex >= toIndex) {
return -1;
}
return isLatin1()
? StringLatin1.indexOf(value, ch, fromIndex, toIndex)
: StringUTF16.indexOf(value, ch, fromIndex, toIndex);
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/17685#discussion_r1476268336
