or download this
S_sortcv(pTHX_ SV *a, SV *b)
S_sortcv_stacked(pTHX_ SV *a, SV *b)
...
S_amagic_i_ncmp(pTHX_ register SV *a, register SV *b)
S_amagic_cmp(pTHX_ register SV *str1, register SV *str2)
S_amagic_cmp_locale(pTHX_ register SV *str1, register SV *str2)