Re: pow_ functions in fortran.

[Tim Prince <timothyprince at sbcglobal dot net>]

Spundun Bhatt wrote:
> Andrew Pinski wrote:
> > > I am trying to compile this code and running into a problem with 
> > > functions pow_ci pow_cl pow_cc pow_zi pow_zl pow_zz .

> gfortran appends one underscore to a symbol, but then some code here 
> seems to expect a leading underscore (_foo instead of foo_) and 
> sometimes it seems to expect double underscores. Is there a known 
> discrepancy between versions of fortran or compiler vendors regarding 
> this underscore behavior?
gcc would be likely to prepend an underscore, without appending any. 
gfortran is somewhat consistent with f2c in that the usual default is to 
append a single underscore, making that the only thing to distinguish C 
and Fortran namespaces.  g77 had a different scheme, involving double 
appended underscores.  Consult the info or man pages for the 
compilers/translators you are involved with, if you really are willing 
to deal with the problems involved with the options most have to change 
their linkage conventions.
Many configure scripts have automatic schemes to discover the linkage 
scheme of the Fortran compiler in use.  Avoid second guessing this stuff 
yourself.  Ability to mix differing Fortran compilers is limited anyway.