ref: 8f44d1f6e8a47395c2ebd9b6899f1b8dc94a9b3f 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; }