review (M) for 4809552: Optimize Arrays.fill(...)

[Ulf Zibis]

Couldn't we intrinsify loops like? :
         for (int i = fromIndex; i < toIndex; i++)
             a[i] = val;
         for (int i = 0, len = a.length; i < len; i++)
             a[i] = val;

So all similar Java-coded loops would benefit from the performance gain 
of using REP STOS operation, especially in case of client compiler and 
maybe interpreter too.

-Ulf


Am 20.08.2010 00:11, schrieb Tom Rodriguez:
> 4809552: Optimize Arrays.fill(...)
> Reviewed-by:
>
> This adds new logic to recognize fill idioms and convert them into a
> call to an optimized fill routine.  Loop predication creates easily
> matched loops that are simply replaced with calls to the new assembly
> stubs.  Currently only 1,2 and 4 byte primitive types are supported.
> Objects and longs/double will be supported in a later putback.  Tested
> with runthese, nsk and ctw plus jbb2005.
>
> http://cr.openjdk.java.net/~never/4809552
>
>
>