Hi Rajendra,Originally posted in cdnusers.org by jmueller
no, formal algorithms do not work that way. Leaving req_cntl unconstrained makes it to a "don't care", which is an easier to satisfy requirement for the tool than an explicit constraint on the same signal. And it does not do 2**5 operations, but only one which considers 2**5 values.
Having said that, constant pin constraints can lead to removal of logic, which can improve performance in some cases as well.