ref: 47682ee42a1f686dbd3aa9de7375c16f7d3d95e8 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; }