Null references redux + Cyclone

[Christopher Wright]

bearophile wrote:
> Jeremie Pelletier:
>> Again, that's a lazy view on programming. High level constructs are 
>> useful to isolate small and simple algorithms which are implemented at 
>> low level.
> 
> Software is inherently multi-scale. Probably in 90-95% of the code of a program micro-optimizations aren't that necessary because those operations are done only once in a while. But then it often happens that certain loops are done an enormous amount of times, so even small inefficiencies inside them lead to low performance. That's why profiling helps.
> 
> This can be seen by how HotSpot (and modern dynamic language JITters work): usually virtual calls like you can find in a D program are quick, they don't slow down code. Yet if a dynamic call prevents the compile to perform a critical inlining or such dynamic call is left in the middle of a critical code, it may lead to a slower program. That's why I have Java code go 10-30% faster than D code compiled with LDC, not because of the GC and memory allocations, but just because LDC isn't smart enough to inline certain virtual methods.

Certainly agreed on virtual calls: on my machine, I timed a simple 
example as executing 65 interface calls per microsecond, 85 virtual 
calls per microsecond, and 210 non-member function calls per 
microsecond. So you should almost never worry about the cost of 
interface calls since they're so cheap, but they are 3.5 times slower 
than non-member functions.

In most cases, the body of a method is a lot more expensive than the 
method call, so even when optimizing, it won't often benefit you to use 
free functions rather than class or interface methods.