SIMD support...

[Vladimir Panteleev]

On Friday, 6 January 2012 at 20:26:37 UTC, Walter Bright wrote:
> On 1/6/2012 11:16 AM, Brad Roberts wrote:
>> However, a counter example, it'd be a lot easier to write a 
>> memcpy routine that uses them
>> without having to resort to asm code under this theoretical 
>> model.
>
> I would seriously argue that individuals not attempt to write 
> their own memcpy.

Agner Fog states in his optimization manuals that the glibc 
routines are fairly unoptimized. He provides his own versions, 
however they are GPL.

> Why? Because the C one has had probably thousands of 
> programmers looking at it for the last 30 years. You're not 
> going to spend 5 minutes, or even 5 days, and make it faster.

This assumes that hardware never changes. New memcpy 
implementations can take advantage of large registers in newer 
CPUs for higher speeds.