🚀 go-pugleaf

I need to calculate Confluent Hypergeometric functions of 
the form:
           M( (m+1), (m+n+2), -x)
           M( (n+1), (m+n+2), x)
   where
           (0 < Abs[x])
           n = 0, 1, 2, 3, ...
           m = 0, 1, 2, 3, ...

I picked up a package last night off of Netlib that claims
to be able to calculate these for most cases using a log-
orithmic method ("dchu.f").  Has anyone used this code from 
Netlib? I am looking for a double precision, fast code 
that preforms these calculations which I can use in a 
Fortran 77 code.  Should I really be looking at IMSL? What
about MATLAB?  Portablility is major concern, that is why 
I would prefer to stick with a straight Fortran 77 code. 
Any help here would be greatly appreciated!  
Thanks! -> Bryan Minor