ref: f31c5b3b3b9bc06b2ccbb1db17a731ff1b80fcbf 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; }