I ran with a smaller byte[] initially and saw about a 10% improvement from
removing the branch, which is why I felt the superfluous bytes were motivated.
/Claes
Paul Sandoz <paul.san...@oracle.com> skrev: (29 januari 2018 19:14:44 CET)
>
>
>> On Jan 29, 2018, at 9:44 AM, Martin Buchholz <marti...@google.com>
>wrote:
>>
>> Thanks. I might try to shrink the size of the static array, by only
>> storing values between '0' and 'z', at the cost of slightly greater
>lookup
>> costs for each char.
>>
>
>I was wondering the same, or just clip the end of the array to’z'
>
>if (ch <= ‘z’ && radix …) { // Might even fold the upper bounds check
>for DIGITS
> value = DIGITS[ch];
> ...
>}
>
>Paul.
>
>> On Mon, Jan 29, 2018 at 3:15 AM, Claes Redestad
><claes.redes...@oracle.com>
>> wrote:
>>
>>> Hi,
>>>
>>> for the latin1 block of CharacterData we can improve the
>>> digit(int, int) implementation by providing an optimized lookup
>>> table. This improves microbenchmarks exercising Integer.parseInt,
>>> Long.parseLong and UUID.fromString etc by around 50%for typical
>>> inputs.
>>>
>>> Webrev: http://cr.openjdk.java.net/~redestad/8196331/open.00/
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8196331
>>>
>>> The lookup array is pre-calculated to minimize startup impact
>>> (adds 1,027 bytecodes executed during initialization)
>>>
>>> /Claes
>>>
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