I'm wondering if it's the build flags associated with armf....
I ran the glib submission, and it is truly smoking in 64 bit:
riveraa@dpi:~/Projects/glib$ timex ./mil64
r LEN: 999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back: ZYXWVUTSRQPONMLKJIHGFEDCBA
UBVal: 1000000
0.02user 0.01system 0:00.04elapsed 100%CPU (0avgtext+0avgdata 6512maxresident)k
0inputs+0outputs (0major+1332minor)pagefaults 0swaps
AIR.