ref: f0ea8a3f6019b4fe7d37f33b0a5a3a88fd1fcdc7 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; }