[Bug fortran/51338] [4.6/4.7 Regression] seg fault in gfc_dep_compare_expr with -O2

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51338

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-11-28
                 CC|                            |tkoenig at gcc dot gnu.org
            Summary|seg fault in                |[4.6/4.7 Regression] seg
                   |gfc_dep_compare_expr with   |fault in
                   |-O2                         |gfc_dep_compare_expr with
                   |                            |-O2
     Ever Confirmed|0                           |1

--- Comment #4 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-11-28 22:22:59 UTC ---
Workaround -fno-frontend-optimize.

Revision 164728 (20100929) is OK
revision 165415 (20101013) gives the segmentation fault.

Likely

Revision 165248

Author:    tkoenig
Date:    Sun Oct 10 09:52:46 2010 UTC (13 months, 2 weeks ago)
Changed paths:    7
Log Message:    
2010-10-09  Thomas Koenig  <tkoenig@gcc.gnu.org>

    * frontend-passes.c:  Include opts.h.
    (optimize_comparison):  Renamed from optimize_equality.
    Change second argument to operation to be compared.
    Use flag_finite_math_only to avoid comparing REAL and
    COMPLEX only when NANs are honored.  Simplify comparing
    of string concatenations where left or right operands are
    equal.  Simplify all comparison operations, based on the result
    of gfc_dep_compare_expr.
    * dependency.c:  Include arith.h.
    (gfc_are_identical_variables):  Volatile variables should not
    compare equal to themselves.
    (gfc_dep_compare_expr):  Handle string constants and string
    concatenations.