ref: 8e9d2434e97fe6cf4b0d3e7f43e3e35d7ae1033f 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; }