PR 135718 enhance qsort(3) to properly handle 32-bit aligned data on 64-bit systems

[pfg]

Summary

See
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=135718

[pfg]

This appears to be only a prototype. The code is not ready for public consumption yet. It will be worked through bugzilla first.

[pfg]

Updated version by ache@

Updating D1752: PR 135718 enhance qsort(3) to properly handle 32-bit aligned data on

64-bit systems

[pfg]

Here is some testing I did not long ago:
...
I updated the testing utility with 4096 23 bit datapoints of random data.
...

$ time ./test-heapsort
1..1
ok 1 - heapsort

27.83 real        27.61 user         0.00 sys

$ time ./test-mergesort
1..1
ok 1 - mergesort

27.02 real        26.83 user         0.00 sys

$ time ./test-qsort (old)
1..1
ok 1 - qsort

27.07 real        26.94 user         0.00 sys

...
$ time ./test-qsort (new)
1..1
ok 1 - qsort

26.94 real        26.81 user         0.00 sys

...

IMHO. the performance improvements are measurable, and even when they may not seem huge, they are significant enough to make qsort preferable over heapsort and mergesort (at least for my particular dataset).

---

I will commit the updated version sometime this week, before I forget about it ;).

[pfg]

Committed as revision 279663.