ref: 1e8a9ebb0f76b0ebe8eb31d79c44324c1c1ed70f dir: /sys/src/libc/port/abs.c/
#include <u.h> #include <libc.h> int abs(int a) { if(a < 0) return -a; return a; } long labs(long a) { if(a < 0) return -a; return a; }