sum_ns           2273 maint/gnulib/lib/parse-datetime.y         intmax_t sum_ns = orig_ns + pc.rel.ns;
sum_ns           2274 maint/gnulib/lib/parse-datetime.y         int normalized_ns = (sum_ns % BILLION + BILLION) % BILLION;
sum_ns           2275 maint/gnulib/lib/parse-datetime.y         int d4 = (sum_ns - normalized_ns) / BILLION;