GC.calloc with random bits causes slowdown, also seen in built in AA

[Steven Schveighoffer]

On Fri, 12 Mar 2010 07:46:50 -0500, Michael Rynn  
<michaelrynn at optusnet.com.au> wrote:

>
>> When there is such a drop in replacement, it will be easier for others
>> to try it out in existing code and uncover quirks and limitations.  Then
>> there might be benefits.
>
> Committed a struct AA wrapper and a modified PyDict class in  
> hash\pydict.d
> as builtin AA behave-alike, to the DSource - aa project.
>
> Actually the builtin is initially about 10% bit faster in uint[uint] than
> the PyDict.  Based on the first few runs that is,  before progressive
> slowdown of builtin takes affect.   Perhaps some crafty optimization
> could narrow the gap a bit.
>
> There appears to be no significant performance effect of wrapping the
> modified PyDict class as an implementation reference inside the struct.
>
>
> Tried with dmd2 2.041, but the built-in AA crashed sometime during a what
> looked like a rehash, probably triggered by a big resize.  This happened
> in both debug and release versions.  This is strange, because a winmerge
> comparison of the D-runtime source aaA.d, showed no significant
> difference apart from the removal of a AA_equals function.
>
> Back next week

Oops, sorry about that.  The array allocation and appending went through a  
major overhaul, and I introduced a nasty bug that causes this.  Please  
apply the fix identified here:  
http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.announce&article_id=17841

Sorry again.  I hope this can be fixed soon.

-Steve