ref: 204a96f163641de8ebca76a0b0873412b3b333aa 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; }