ref: 3bc4e5a6d568889eeeb2d0b7d443c0a3e02fb499 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; }