ref: 78e2f69c0d7e4c17227e1ec0545cbb2a0ae1e96e 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; }