Re: single to double conversion

[Tim Prince <timothyprince at sbcglobal dot net>]

Brian Barnes wrote:

> However, in g77, the real*4 of the function was 'detected' and
> auto-promoted to real*8 in the subroutine.  There was loss of precision,
> but that was not important to us.  The g77 compiler seemed to have no
> problem at all in knowing that the precision of the subroutine and
> function differed, and handling the difference gracefully.
>
> gfortran, on the other hand, gives errant results for the real*8 variable,
> and there is no possible warning by the compiler.  This comes back to my
> original question:  if g77 handles this correctly, why does gfortan fail?

Sorry, but you persist in ignoring the fact that g77 works this way only 
when using the f2c compatibility option, where function results are 
passed as C double, because that is the way C worked when f2c was first 
developed.  g77 is not recognizing the source code error and correcting 
it; it just happens to work that way on the platforms and with the 
options you chose to use.
I suspect it would be unacceptable to make the gfortran f2c 
compatibility option a default, if that is the "feature" you are 
requesting.  The days of K&R C passed 15 years ago.  You could still use 
g77 for a while if you insist it is the only true Fortran.  Haven't I 
seen similar comments about several other compilers which have seen 
their day?