I got warnings as follow(Qu@rtus), I would like to know if and how these warnings will affect my design, and how to correct them? or maybe I can ignore them?
1. Warning: Ignored 13 CARRY_SUM primitives
2. Warning: Ignored 2 CARRY_SUM primitives -- cannot place fan-in logic in single logic cell
3. Warning: Can't place logic feeding CARRY_SUM primitive 74163:2|f74163:sub|140~0 in single logic cell
4. Warning: Ignored 2 CARRY_SUM primitives -- logic cell requires more inputs than it can contain
Thanks in advance.