cs system call on RS/6000

[Tim Atchison]

I am looking for a test-and-set instruction (or something like it) on the
IBM RS/6000. I know that the assembly code is proprietary, but I found a 
compare-and-set (cs) system call that looks like it does the same thing.
Unfortunately, I can't find this command in my doc set. Could someone show
me how to use this call ?

The only information that I have is:

int cs (int *dest, int compare, int value)

It has the following logic:

if (compare == *dest) {*dest = value; return(0);}
else return(1);

--------------------------------------------------------------------------------
Timothy M. Atchison			UUCP: mit-eddie!progress!tma
Progress Software Corp.		    	Internet: tma at progress.com
5 Oak Park
Bedford, MA  01730