[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

--- Comment #4 from janus at gcc dot gnu.org 2011-01-05 12:16:33 UTC ---
(In reply to comment #2)
> For SAME_TYPE_AS and EXTENDS_TYPE_OF one should add a
> compile-time simplification to simplify.c.
> Currently, only the run-time version is implemented.

Well, currently the translation of SAME_TYPE_AS is done by
gfc_conv_same_type_as (trans-intrinsic.c), for both TYPE- and CLASS-valued
arguments.

Note: If both arguments are TYPE-valued, the result will be a compile-time
constant, otherwise it has to be evaluated at runtime, according to the _hash
values in the vtabs.

In which situations would we actually gain something by treating the TYPE-TYPE
case in simplify.c?

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-01-05 17:19:45 UTC ---
Created attachment 22907
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22907
Draft patch - not fully working

(In reply to comment #4)
> Note: If both arguments are TYPE-valued, the result will be a compile-time
> constant, otherwise it has to be evaluated at runtime, according to the _hash
> values in the vtabs.

Well, extends_type_of can also be (sometimes) be evaluated at compile time for
CLASS.

> In which situations would we actually gain something

I assume that in practice it only matters for automatically generated code -
but there it might reduce the code size and improve the performance.

By the way: I think that's a 4.7 item.

 * * *

I attached a draft patch. Note, however, that it does not work (cf. bottom of
patch/test case). For

   if (extends_type_of(a11,b11) .neqv. .true.) call abort()

one enters gfc_simplify_extends_type_of twice: Once the second argument (mold)
is BT_CLASS (which give the correct result: NULL, i.e. not compile-time
simplifiable). But then again with mold being BT_DERIVED - which is then
compile-time simplified to .TRUE. as "a11" and "b11" are the same type.

I have not dug into this, but it seems to occur in two steps - first a normal
simplification happens, then a specific interface is used via
gfc_intrinsic_func_interface, which is then again simplified - but with
BT_DERIVED argument (base type). I think all gfc_simplify_* functions could be
affected.

TODO:
- Fix the double-simplification problem
- Add more test cases - I think the double-simplification also affects
same_type, but it is currently not tested for.

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #22907|0                           |1
        is obsolete|                            |

--- Comment #6 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-01-06 17:40:26 UTC ---
Created attachment 22914
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22914
Draft patch - should be OK

Updated patch, fixed the issue (but did not add more tests). On the way, I
encountered PR 47194.

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

--- Comment #7 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-01-07 12:59:06 UTC ---
Submitted patch: http://gcc.gnu.org/ml/fortran/2011-01/msg00051.html

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

--- Comment #8 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-01-07 16:19:34 UTC ---
Author: burnus
Date: Fri Jan  7 16:19:29 2011
New Revision: 168579

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=168579
Log:
2011-01-07  Tobias Burnus  <burnus@net-b.de>

        PR fortran/41580
        * class.c (gfc_build_class_symbol): Mark __vtab as attr.vtab.
        * intrinsic.c (add_functions): Use simplify functions for
        EXTENDS_TYPE_OF and SAME_TYPE_AS.
        * intrinsic.h (gfc_simplify_extends_type_of,
        gfc_simplify_same_type_as): New prototypes.
        * simplify.c (is_last_ref_vtab, gfc_simplify_extends_type_of,
        gfc_simplify_same_type_as): New functions.

2011-01-07  Tobias Burnus  <burnus@net-b.de>

        PR fortran/41580
        * gfortran.dg/extends_type_of_3.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/extends_type_of_3.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/intrinsic.c
    trunk/gcc/fortran/intrinsic.h
    trunk/gcc/fortran/simplify.c
    trunk/gcc/testsuite/ChangeLog

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED

--- Comment #9 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-01-07 16:20:14 UTC ---
... and FIXED (on the 4.6 trunk).

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[dominiq at lps dot ens dot fr]

------- Comment #3 from dominiq at lps dot ens dot fr  2010-04-18 16:47 -------
> Currently, only the run-time version is implemented.

So could the pr marked as NEW?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2010-04-18 16:21 -------
> Could this PR be more explicit about the problem?

No it cannot; as written: For SAME_TYPE_AS and EXTENDS_TYPE_OF one should add a
compile-time simplification to simplify.c.
Currently, only the run-time version is implemented.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580

[Bug fortran/41580] [OOP] SAME_TYPE_AS and EXTENDS_TYPE_OF - add compile-time simplifcation

[dominiq at lps dot ens dot fr]

------- Comment #1 from dominiq at lps dot ens dot fr  2010-04-18 15:56 -------
I cannot reproduce the error at
http://gcc.gnu.org/ml/fortran/2009-09/msg00298.html neither with trunk nor with
fortran-dev. Could this PR be more explicit about the problem?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41580