[Bug middle-end/58941] [4.7 Regression] value modification on zero-length array optimized away

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58941

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Mar 18 10:58:22 2014
New Revision: 208640

URL: http://gcc.gnu.org/viewcvs?rev=208640&root=gcc&view=rev
Log:
2014-03-18  Richard Biener  <rguenther@suse.de>

    Backport from mainline
    2013-11-05  Richard Biener  <rguenther@suse.de>

    PR middle-end/58941
    * tree-dfa.c (get_ref_base_and_extent): Merge common code
    in MEM_REF and TARGET_MEM_REF handling.  Make sure to
    process trailing array detection before diving into the
    view-converted object (and possibly apply some extra offset).

    * gcc.dg/torture/pr58941.c: New testcase.

    2012-05-07  Eric Botcazou  <ebotcazou@adacore.com>

    * tree-dfa.c (get_ref_base_and_extent) <ARRAY_REF>: Do the offset
    computation using the precision of the index type.

    2012-05-31  Eric Botcazou  <ebotcazou@adacore.com>

    * tree-dfa.c (get_ref_base_and_extent): Compute the offset using
    double ints throughout.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/torture/pr58941.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_7-branch/gcc/tree-dfa.c