ref: 1a5dafcc3d8c455b0e7b36dd9bd45c13dd4d91eb 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; }