ref: 99ed32c9f5a5aaf6b32ebb49ce5c7045ffe7d0b0 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; }