Two questions about mpz_addmul() and mpz_submul()

[Roberto Bagnara]

Hi there,

I have just come across these functions and I have
two questions:

1) Can I assume that mpz_addmul and mpz_submul
    are not less efficient than what a user could write
    using other GMP mpz_* functions?  I am especially
    concerned about the cost of allocation and deallocation
    of space to hold the result of the multiplication.

2) Is there some fundamental reason why these functions
    are not available for rationals?

All the best,

     Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it