ref: 1b44caa0c40d7b722a7d9edd0a6eaefe1616c4b0 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; }