ref: e03915a9f7d8c040c3b7f4e8de4f69f62aeefc99 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; }