[patch, fortran] [4.6/4.7 Regression] Fix PR 48955

[Paul Richard Thomas]

Dear Thomas,

I am sorry for the long silence on this PR.  I have been up to my
eyeballs in daytime work.

I have posted a simpler alternative on the PR that uses your
suggestion that forward and backward dependences need to to be
recorded to get this right.

I believe that it's OK but have only now had the opportunity to put it
on to regtest.

Cheers

Paul

On Sun, May 22, 2011 at 5:32 PM, Thomas Koenig <tkoenig@netcologne.de> wrote:
> Hello world,
>
> the attached patch fixes PR 48955, a wrong-code regression for 4.6 and 4.7,
> including the test case from
> http://gcc.gnu.org/ml/fortran/2011-05/msg00093.html .  It follows the
> outline from http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48955#c7 .
>
> Regression-tested. OK for trunk?
>
>        Thomas
>
> 2011-05-22  Thomas Koenig  <tkoenig@gcc.gnu.org>
>
>        PR fortran/48955
>        * gfortran.h (gfc_reverse):  Change to struct with two boolean
>        variables, forward_ok and backward_ok.
>        * trans-expr.c (gfc_trans_assignment_1):  Initialize using
>        new gfc_reverse struct.
>        * trans-array.c (gfc_init_loopinfo):  Likewise.
>        (gfc_trans_scalarized_loop):  Use new gfc_reverse.
>        * dependency.c (gfc_dep_resovler):  Use new gfc_reverse.
>        If a forward dependency is found, a backward dependency is
>        no longer possible and vice versa.
>
> 2011-05-22  Thomas Koenig  <tkoenig@gcc.gnu.org>
>
>        PR fortran/48955
>        * gfortran.dg/dependency_40.f90:  New test.
>
>



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