[Bug fortran/22629] Would like to access "long double" equivalent type as real*16

["fxcoudert at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #7 from fxcoudert at gcc dot gnu dot org  2006-06-21 16:46 -------
(In reply to comment #5)
>         else if (mode == TYPE_MODE(float_long_double))
>                 kind = sizeof(long double);

sizeof(long double) is the size of a long double for the host, not on the
target.

> Sorry.  With "outlandish" I did not mean to imply that someone should  
> implement that; I would never request that.  I meant whether the  
> gfortran developers would accept such a patch, which I didn't want to  
> prepare before I know whether there is a chance that it would be  
> accepted.

To have the answer to that question, you'd need to ask on the mailing-list,
detailing the implications of such a change (pros and cons).

> I had somehow assumed that it would be only a matter of changing the  
> kind numbers that are assigned to the real types that gfortran  
> already supports.  I assumed that a patch similar to the lines I  
> suggest above would be sufficient.  Is there something big that I  
> overlooked?

I think the whole library interaction would change, requiring a multilib
libgfortran. Plus, you'd probably need good interaction with the target's libm.

> When I last looked at  
> real*16, there were big problems with the I/O library in gfortran,  
> and I also don't know whether these have been solved in the mean  
> time.  I think it just mapped long double to double, which would kind  
> of defeat the purpose of using long double in the first place.

No, the library should be completely working. Although I'm not sure many people
use real(kind>8), so the testing may not be very wide.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
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                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22629