faster splitter

[qznc via Digitalmars-d]

On Tuesday, 31 May 2016 at 22:50:37 UTC, David Nadlinger wrote:
> Another thing that might be interesting to do (now that you 
> have a "clever" baseline) is to start counting cycles and make 
> some comparisons against manual asm/intrinsics implementations. 
> For short(-ish) needles, PCMPESTRI is probably the most 
> promising candidate, although I suspect that for \r\n scanning 
> in long strings in particular, an optimised AVX2 solution might 
> have higher throughput.
>
> Of course these observations are not very valuable without 
> backing them up with measurements, but it seems like before 
> optimising a generic search algorithm for short-needle test 
> cases, having one's eyes on a solid SIMD baseline would be a 
> prudent thing to do.

The current algorithm is generic with respect to the predicate. 
Once we use SSE/AVX tricks, it is a special case for equality.

As a next step in Phobos, this is probably worth it for strings. 
We could probably steal some well-optimized strcmp from somewhere.