RFR JDK-7143928 : (coll) Optimize for Empty ArrayList and HashMap
martinrb at google.com
Tue Apr 2 18:33:41 UTC 2013
On Tue, Apr 2, 2013 at 11:24 AM, Mike Duigou <mike.duigou at oracle.com> wrote:
> On Apr 2 2013, at 10:55 , Martin Buchholz wrote:
> > Thanks for the research.
> > It seems like hotspot is recognizing and optimizing fill loops, rather
> > intrinsifying calls to Arrays.fill itself (good!).
> Why wouldn't doing both be better?
If hotspot recognizes and optimizes fill loops, Arrays.fill is optimized
> > Anyways, I'd still like the "simple" fill loops in ArrayList to stay
> > unchanged. Using Arrays.fill is only slightly more readable.
> Part of the goal of the change was to make the intent clearer. I'll
> improve the comments instead.
ArrayList is one of those classes that are important for educational
reasons. Studying it will be part of many peoples' university education.
So I applaud efforts to improve clarity. But I think the fill loops are
sufficiently clear as they stand.
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