ref: 00f7f2ceb6a1818e2975baf6f5c55c1d2d4ecb6e 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; }