ALTFP_MATRIX_MULT problem in Quartus 10.0

The altfpc_lib should have been generated by the megawizard alongside the altfp_matrix_mult file. If you don't see it try re-generating the altfp_matrix_mult (open megawizard, select edit an exisitng, find your existing altfp_matrix_mult file, keep clicking next until its finished, click ok to replace the files). Then have a look in the output directory and see if it created the altfpc_lib. If it is make sure it's included in your project (probably already included in the .qip). Now try compiling again.