Array append performance

[Fawzi Mohamed]

On 2008-08-27 17:20:55 +0200, bearophile <bearophileHUGS at lycos.com> said:

> Sean Kelly:
>> Why not just change that to this instead:
>> 
>> switch(i) {
>> case 8: a[7] = b[7];
>> case 7: a[6] = b[6];
>> case 6: a[5] = b[5];
>> case 5: a[4] = b[4];
>> case 4: a[3] = b[3];
>> case 3: a[2] = b[2];
>> case 1: a[0] = b[0];
>> case 0: break;
>> default: memcpy( a.ptr, b.ptr, a.length * DataType.sizeof );
>> }
>> 
>> The Range stuff is cool and all, but not really necessary :-)
> 
> I have benchmarked many alternative versions, your one too, but mine is 
> significantly faster than your one on the DMD I am using. Don't ask me 
> why.

memory ordering probably, looping from 0 to 7 is faster than 7 to 0...

> 
> You can find the Range!([start,] stop[, step]) in my libs, of course ;-)
> 
> Bye,
> bearophile