ref: 8c1c1acfdb9670ccf47d7acd0c0c9e29097c64cd 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; }