ref: 6ef7d2b79c9dbc015fb8c7caf95960bfb4a8ee53 dir: /sys/src/ape/lib/ap/gen/abs.c/
#include <stdlib.h> int abs(int a) { if(a < 0) return -a; return a; } long labs(long a) { if(a < 0) return -a; return a; }