ref: dfa90ed5c09a923e19d6d1f1e2ccb4f61fca5d43 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; }