ref: 65bd53b9b89b0a84d0f16db4adc3f53fa6ab3a3a 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; }