[Bug fortran/86837] [8/9 Regression] Optimization breaks an unformatted read with implicit loop

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86837

--- Comment #7 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Author: tkoenig
Date: Fri Aug 24 22:08:48 2018
New Revision: 263844

URL: https://gcc.gnu.org/viewcvs?rev=263844&root=gcc&view=rev
Log:
2018-08-24  Thomas Koenig  <tkoe...@gcc.gnu.org>

        Backport from trunk
        PR fortran/86837
        * frontend-passes.c (var_in_expr_callback): New function.
        (var_in_expr): New function.
        (traverse_io_block): Use var_in_expr instead of
        gfc_check_dependency for checking if the variable depends on the
        previous interators.

2018-08-24  Thomas Koenig  <tkoe...@gcc.gnu.org>

        Backport from trunk
        PR fortran/86837
        * gfortran.dg/implied_do_io_6.f90: New test.


Added:
    branches/gcc-8-branch/gcc/testsuite/gfortran.dg/implied_do_io_6.f90
Modified:
    branches/gcc-8-branch/gcc/fortran/ChangeLog
    branches/gcc-8-branch/gcc/fortran/frontend-passes.c
    branches/gcc-8-branch/gcc/testsuite/ChangeLog