[Bug tree-optimization/45967] [4.5 Regression] gcc-4.5.x optimizes code with side-effects away

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45967

--- Comment #11 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-08 13:31:21 UTC ---
Author: rguenth
Date: Tue Mar  8 13:31:13 2011
New Revision: 170776

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170776
Log:
2011-03-08  Richard Guenther  <rguenther@suse.de>

    Backport from mainline
    2011-02-10  Richard Guenther  <rguenther@suse.de>

    * tree-ssa-structalias.c (bitpos_of_field): Use BITS_PER_UNIT, not 8.

    2010-10-18  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/45967
    * tree-ssa-structalias.c (type_could_have_pointers): Remove.
    (could_have_pointers): Likewise.
    (handle_rhs_call, handle_const_call, handle_pure_call,
    find_func_aliases, intra_create_variable_infos): Remove calls to them.
    (struct fieldoff): Add must_have_pointers field.
    (type_must_have_pointers): New function.
    (field_must_have_pointers): Likewise.
    (push_fields_onto_fieldstack): Remove must_have_pointers_p argument.
    Adjust field merging.
    (create_function_info_for): May-have-pointers of varinfo is
    almost always true.
    (create_variable_info_for_1): Likewise.

    * gcc.dg/torture/pr45967.c: New testcase.
    * gcc.dg/torture/pr45967-2.c: Likewise.
    * gcc.dg/torture/pr45967-3.c: Likewise.
    * gcc.dg/torture/pr39074-2.c: Adjust. 
    * gcc.dg/torture/pta-escape-1.c: Likewise
    * gcc.dg/torture/pta-ptrarith-1.c: Likewise
    * gcc.dg/tree-ssa/pta-callused.c: Likewise
    * gcc.dg/tree-ssa/pta-escape-1.c: Likewise
    * gcc.dg/tree-ssa/pta-escape-2.c: Likewise
    * gcc.dg/tree-ssa/pta-escape-3.c: Likewise
    * gcc.dg/tree-ssa/ssa-pre-21.c: Likewise

    2010-10-12  Richard Guenther  <rguenther@suse.de>

    * tree-ssa-structalias.c (get_constraint_for_1): Constants
    only point to nonlocal, not anything.

Added:
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/torture/pr45967-2.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/torture/pr45967-3.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/torture/pr45967.c
Modified:
    branches/gcc-4_5-branch/gcc/ChangeLog
    branches/gcc-4_5-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/torture/pr39074-2.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/torture/pta-escape-1.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/torture/pta-ptrarith-1.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/tree-ssa/pta-callused.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/tree-ssa/pta-escape-1.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/tree-ssa/pta-escape-2.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/tree-ssa/pta-escape-3.c
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-21.c
    branches/gcc-4_5-branch/gcc/tree-ssa-structalias.c