Thank you all!
I have tried to include the GTECH library into my GTECH netlish for gate-level simulation ( I do not have other technology libraries available in Modelsim), and the warnings are gone.
But for big designs, this method seem to be tedious. So I'd like to try to include the library to the simulation environment (ModelSim), like dcreddy said. But I have 2 questions:
1. How to import the umc library to Modelsim?
2. if the library is imported, how can i set it to simulation environment?
Thanks a lot !