usr.bin/perl/pp.c

1895         UV auv = 0;
1900             auv = 0;
1907                     auv = SvUVX(svl);
1911                         auv = aiv;
1914                         auv = (UV) (0 - (UV) aiv);
1948                 result = auv + buv;
1949                 if (result >= auv)
1953                 if (auv >= buv) {
1954                     result = auv - buv;
1956                     if (result <= auv)
1959                     result = buv - auv;
1961                         /* result really should be -(auv-buv). as its negation