Re: [Patch, Fortran] PR fortran/36214: Wrong simplification of BOZ constants

[Daniel Kraft <d at domob dot eu>]

Hi Tobias,

thanks for your reply!

Tobias Burnus wrote:
> > > Regression testing on GNU/Linux-x86-32 at the moment. 
> > > Ok to commit if no failures?
> > All boz-tests are now passed, however; the rest is still running.
>
> OK when all tests have passed.

They have.  Thanks for the review!  I'm waiting with the commit, see below.

> > Should we test this on some other systems, too?
> > With REAL(KIND=10) vs. REAL(KIND=16)?
>
> I think a test for
>  { dg-require-effective-target fortran_large_real }
> which works with both kind=10 and kind=16 cannot harm. I don't think
> gfortrab will ever regress, but following Murphy's law and given
> that fortran_large_real is not so well tested ...

I was thinking about regression testing my patch on systems with 
REAL(KIND=16) instead of KIND=10, just in case some other tests might be 
affected there.

Do you mean adding a test for BOZ constants with KIND=10 / KIND=16?  If 
so, we should discriminate those two, shouldn't we, as the BOZ constants 
are surely quite different...  Can you explain in more detail what you 
had in mind for this?  Then I will try to add additional tests.

> > > Should I backport this to 4.3, too?
> > > (If the problem exists there, too, I've not yet tried.) 
>
> I think the
> +  gfc_set_model_kind (kind);
> is simple enough for GCC 4.3; it probably also affects
> TRANSFER(..., 0.0_kind).

Ok, then I'll try it out with 4.3 and backport in a few days.

> The vendor extension to allow BOZ everywhere is by the way quite
> surprising: Whether a boz is interpreted as int(BOZ) or real(BOZ)
> depends on the context - esp. on the type of variable on the LHS.
>   i = 4.4 + BOZ
>   r = 4 + BOZ
> Is the BOZ now a real or an integer bit pattern? (In gfortran:
> integer, cf.
> http://gcc.gnu.org/onlinedocs/gfortran/BOZ-literal-constants.html
> (Before the 4.3 patch  "i = BOZ" was also interpreted as integer,
> now it is a real(BOZ).)

Wow, that sounds like something nice :D  A bit like fixed-format where 
one need not insert spaces at certain places...

Daniel

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