http://svnweb.freebsd.org/base/stable/10/lib/libc/stdlib/qsort.c?revision=256281&view=markup
ʂ̃TCgɃWv悤ƂĂ܂BXΏL̃NNbNĂ
UPLIFTōLȂő̌܂傤IKȉ{Ct܂I