RFR(S): 8007986: GrowableArray should implement binary search

[Vitaly Davidovich]

Also, if you decide to take my suggestion on calculating mid, probably best
to use shift instead of div - I don't think compiler will do that for you
unless it proves the signed ints can't be negative.

sent from my phone
On Apr 15, 2015 10:52 AM, "Vitaly Davidovich" <vitalyd at gmail.com> wrote:

> Hi Roland,
>
> int mid = (int)((uint)max + min) / 2;
>
> I'd write this as:
> int mid = min + (max - min) / 2;
>
> I'd change these:
>
> assert(min >= 0 && (max+1) >= min, "bad bounds");assert((uint)min <= length() && (uint)(max+1) <= length(), "incorrect bounds");
>
> to:
>
> assert(min >= 0 && (max - min) >= 0, "bad bounds");
> assert(min <= length() && (length() - max) > 0, "incorrect bounds");
>
> This is pedantic so please feel free to ignore if you think it's not
> worthwhile.
>
> Thanks
>
>
> On Wed, Apr 15, 2015 at 6:25 AM, Roland Westrelin <
> roland.westrelin at oracle.com> wrote:
>
>> Hi Vitaly,
>>
>> > Just a couple of notes in passing.
>> >
>> > 1) may be worthwhile to compute mid in a way that avoids possible
>> signed overflow? I'm guessing this class is not used with sizes that large,
>> but just a precaution.
>> >
>> > 2) perhaps store the result of calling f() in a local to avoid calling
>> it twice?
>>
>> Thanks for the suggestions. Here is a new webrev that take them into
>> account:
>>
>> http://cr.openjdk.java.net/~roland/8007986/webrev.01/
>>
>> Roland.
>>
>> >
>> > $.02
>> >
>> > sent from my phone
>> >
>> > On Mar 26, 2015 9:34 AM, "Roland Westrelin" <
>> roland.westrelin at oracle.com> wrote:
>> > http://cr.openjdk.java.net/~roland/8007986/webrev.00/
>> >
>> > The same binary search code on GrowableArray is used in 3 places (in
>> the compilers). This moves that code in GrowableArray.
>> >
>> > Roland.
>>
>>
>