Coreutils 7.4, Sort

[mecej4]

This is a suggestion to speed up Sort, rather than a bug report.

This addition at the entry to function mergelines() of GNU Sort will exploit of 
the special relation between the arguments (HI - NHI = T - (NLO + NHI)) to 
replace the merge operation with a less expensive copy operation if it so 
happens that the last element of LO and the first element of HI are in order 
with respect to each other. Since the two subarrays are already sorted, the 
merging can be accomplished with a simple memory copy.

    if(compare (lo - nlo, hi - 1) <= 0){
                     /* Skip merge */
        if (t - lo) do *--t = *--lo; while  (--nlo);
        return;
        }

Sincerely,

N. Shamsundar
Assoc. Professor (Retd.)
University of Houston