RFR : 8007398 : (S) Performance improvements for Int/Long toString() at Radix 2, 8, 16

[Joseph Darcy]

Hi Mike,

Looks fine. Are you satisfied with the test coverage provided by the 
existing regression tests?

-Joe

On 5/15/2013 6:17 PM, Mike Duigou wrote:
> Hello all;
>
> This issue was originally part of JDK-8006627 (improve performance of UUID parsing/formatting) but was split out because it could be split out. I've been working incrementally on pieces of 8006627 as my time permits.
>
> http://cr.openjdk.java.net/~mduigou/JDK-8007398/1/webrev/
>
> I've done microbenchmarking of using digits table vs calculating digits, previously mentioned in <http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-April/016526.html>, and found that using the digits table was still faster.
>
> I've also benchmarked removing the offset param from formatUnsignedLong() and simplifying the loop termination logic but neither of these turned out to have little benefit.
>
> Since the last rev I have made a separate implementation Integer.formatUnsignedInteger for use by Integer rather than sharing the Long implementation because it's about 30% faster. I suspect the benefits would be even greater on a 32-bit VM or 32-bit native platform.
>
> We'll get back to 8006627 soon enough. (I have been tempted to split it again into parsing and formatting).
>
> Thanks,
>
> Mike