RFR (XS) 8060485: (str) contentEquals checks the String contents twice on mismatch

[Stanimir Simeonoff]

Hi,

This is an unrelated issue, yet is there any reason for the inner loop of
equals to be written in such a (confusing) way?

            if (n == anotherString.value.length) {
                char v1[] = value;
                char v2[] = anotherString.value;
                int i = 0;
                while (n-- != 0) {
                    if (v1[i] != v2[i])
                        return false;
                    i++;
                }
                return true;
            }

instead of just "for (int i=0;i<n;i++) if (v1[i]!=v2[i]) return false;"


Stanimir

On Tue, Oct 14, 2014 at 8:13 PM, Chris Hegarty <chris.hegarty at oracle.com>
wrote:

> On 14 Oct 2014, at 17:33, Martin Buchholz <martinrb at google.com> wrote:
>
> > Looks good to me!
>
> +1   'noreg-hard'
>
> -Chris.
>
> > On Tue, Oct 14, 2014 at 9:05 AM, Aleksey Shipilev <
> > aleksey.shipilev at oracle.com> wrote:
> >
> >> Hi,
> >>
> >> Please review a trivial change in String.contentEquals:
> >>  https://bugs.openjdk.java.net/browse/JDK-8060485
> >>  http://cr.openjdk.java.net/~shade/8060485/webrev.00/
> >>
> >> It improves the performance drastically:
> >>  http://cr.openjdk.java.net/~shade/8060485/perf.txt
> >>
> >> ...not to mention it improves the code readability, and protects us from
> >> rogue CharSequence-s.
> >>
> >> Testing: microbenchmarks, jdk/test/String* jtreg.
> >>
> >> Thanks,
> >> -Aleksey.
> >>
> >>
>
>