I created a function called pad which performs exactly what str_repeat does (didn't realize str_repeat was there originally).

function pad($length,$padVar="-"){
 if($length<=0){return;}
 else{return pad($length-1,$padVar).$padVar;}
}

When passing a length > about 5000 the page will not load and I quickly get this error in the php.error log: 
[notice] child pid 15040 exit signal Segmentation fault (11)

I assume it is b/c the function stack is just not up to the task, but I thought I would let you know anyway. 
Of course I am using str_repeat now....

Thanks!
Jason