ref: 2c8f291db2f04b4f87c01fcd3344c8d2fb1f8e89 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; }