ref: 1f15f469f9a659fe26f2ad3f8c1f9db3d49d79c5 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; }