Converting mpz_t to different integer representations

[Steve Kargl]

On Fri, Jan 12, 2007 at 08:08:59PM +0100, Paul Thomas wrote:
> In making a patch for PR29786, I have met a problem with converting 
> mpz_t variables into a C type of known length len.  One way of doing 
> this is given in the patch attached to the PR; another is:

(snip code)

> This works fine on the platforms that I am using but I suppose that 
> there will be some for which, for example, long long does not exist?  
> How do I check for this?

I read PR29786 and must admit I'm confused at what you're trying
to do.  AFAIK, trans-type.c defines info for storage:

trans-types.c:  gfc_numeric_storage_size = 4 * 8;
trans-types.c:  gfc_character_storage_size = gfc_default_character_kind * 8;

You should be able to do

  switch (e->ts.type) {
    BT_INTEGER:
    BT_REAL:
    BT_LOGICAL:
       switch (e->ts.kind)
       {
         case 1:  len = 8;  break;
         case 2:  len = 16; break;
         case 4:  len = 32; break;
         case 8:  len = 64; break;
         case 10:
         case 16: len = 128; break;
       }
    }  

Of course, you would also need BT_CHARACTER and BT_COMPLEX.  For
BT_DERIVED, a recursive function could build up the storage size.

Note to avoid hardcoded numbers here, you can use information 
from gfc_real_info, gfc_logical_info, and gfc_integer_info.

-- 
Steve