+ case OP_NE:
+ if(stptr<1){
+ rrd_set_error("RPN stack underflow");
+ return -1;
+ }
+ if (isnan(rpnstack -> s[stptr-1]))
+ ;
+ else if (isnan(rpnstack -> s[stptr]))
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+ else
+ rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] == rpnstack -> s[stptr] ? 0.0 : 1.0;
+ stptr--;
+ break;