Go and generic programming on reddit, also touches on D

[Andrei Alexandrescu]

On 9/21/11 1:49 PM, Don wrote:
> On 19.09.2011 18:12, Andrei Alexandrescu wrote:
>> On 9/19/11 10:46 AM, Robert Jacques wrote:
>>> So, on balance, I'd say the two pointers representation is categorically
>>> worse than the fat pointer representation.
>>
>> Benchmark. A few of your assumptions don't hold.
>>
>> Andrei
>
> Note that high-performance libraries that use slices, like GMP and the
> many BLAS libraries, use the pointer+length representation, not
> pointer+pointer. They've done a lot of benchmarking on a huge range of
> architectures, with a large range of compilers.
>
> The underlying reason for this, is that almost all CISC instruction sets
> have built-in support for pointer+length. AFAIK nothing has builtin
> support for ptr+ptr.
>
> On x86, you have this wonderful [EAX+8*EBX] addressing mode, that can be
> used on almost every instruction, so that the calculation [addr +
> sz*index] takes ZERO clock cycles when sz is a power of 2.
> Generally, when you supply two pointers, the optimizer will try to
> convert it into ptr + offset (where offset isn't bytes, it corresponds
> to D's length).

To all who replied and tested - color me convinced we should keep the 
current state of affairs. Thanks!

Andrei