Remove algo logic duplication Round 3

[Paolo Carlini]

On 9/30/13 9:33 PM, François Dumont wrote:
>     Regarding number of comparisons in sort algo I don't think that it 
> is a regression of this patch right ? I only remove duplication of 
> code, didn't change number of invocation of functors.
Certainly. Of course, however, any sort of help in this area too is more 
than welcome, eg figure out if we regressed recently or the HP / SGI 
code already performed redundant comparisons in some striking special 
cases of small vectors (granted that the O complexity was of course fine).

Paolo.