Re: [boost] Accelerating algorithms with SIMD - Segmented iterators and alternatives

Subject: Re: [boost] Accelerating algorithms with SIMD - Segmented iterators and alternatives
From: Thomas Klimpel (Thomas.Klimpel_at_[hidden])
Date: 2010-10-14 15:25:55

Mathias Gaunard wrote:
> On 13/10/10 18:50, David Abrahams wrote:
> 
> > I think you mean
> >
> >    1 2 | 3 4 5 6 | 7 8 9 10 | 11
> 
> What is that nonsense supposed to be?

Would it be easier to understand if written as

* * 1 2 | 3 4 5 6 | 7 8 9 10 | 11 * * *

or

X X 1 2 | 3 4 5 6 | 7 8 9 10 | 11 X X X

?
 

> All elements are of type pack<int, 4>, and therefore must have four
> values.

Yes, four values, and some value at the ends will be sort of "arbitrary". But "arbitrary" and "0" are not necessarily the same thing. I'm not expert enough in SIMD to know whether "0" has an advantage over "arbitrary" in that context.

Regards,
Thomas