memset and related things

[Don]

language_fan wrote:
> Sun, 20 Sep 2009 18:16:37 -0400, bearophile thusly wrote:
> 
>> My benchmarks aren't chosen randomly, I naturally focus on things that
>> are slower in D, so sometimes you can see Java to "win". I usually
>> discard the code where Java results slower :-)
> 
> I have seen people many times mention that Java is in general orders of 
> magnitude slower than D, no matter what kind of algorithms you run on 
> both environments.

I think you're creating a straw man. I don't recall anyone saying that. 
Certainly not "orders of magnitude" in general.
In general, when D is faster, it'll be because more coding techniques 
are available. For example, because you're not forced to used OOP all 
the time.

> This is because of the VM - nothing on a VM can run 
> faster than native code, they say.  If you decide to hide the bad results
> (for D), it will only reinforce the misinformation. I personally use a 
> lot of heap memory allocation in my work, and so far Java has not only 
> been safer (and provides decent stack traces and no compiler bugs), but 
> also faster - each time.

On this ng, it seems to be universally acknowledged that Java's GC is 
much better than D's; and that Java's tool chain is orders of magnitude 
more mature than D.
But, in the cases where Java beats D, it will almost always be because 
of the GC. LDC probably only gets beaten on the GC.
Having looked at the DMD optimiser, I'm a bit surprised that it's 
competitive at all (especially in floating point). There is so much 
low-hanging fruit, it's practically an orchard <g>. It's hardly been 
touched since the mid-90's, while Java's had 15 years of massive 
commercial development during that time.