ref: 189b6dd7665a4b1fa35ff3052fb6c162e1c1c6f2 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; }