About abs() function

[Altera_Forum]

I want to invoke abs() function in NiosII. 

 But i find this function does not defined.  Which header file should I include? or I should implement it by myslef?

[Altera_Forum]

It should be there, as a part of newlib. Try including stdlib.h and see if that works. 

 Here's a brief description from a website I found:  Synopsis # include <stdlib.h> int abs(int i); Description abs returns the absolute value of i (also called the magnitude of i). That is, if i is negative, the result is the opposite of i, but if i is nonnegative the result is i. The similar function labs uses and returns long rather than int values. Returns The result is a nonnegative integer. Portability abs is ANSI. No supporting OS subroutines are required.  - slacker

[Altera_Forum]

That's OK. 

 abs() is working now when i add <stdlib.h> .  THX!