ref: 1ef7217b96c4ef6ca86eb8d958d9a06c2d9f12b9 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; }