[Bug middle-end/71002] [6 Regression] -fstrict-aliasing breaks Boost's short string optimization implementation

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71002

--- Comment #16 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Jun 29 07:30:31 2016
New Revision: 237839

URL: https://gcc.gnu.org/viewcvs?rev=237839&root=gcc&view=rev
Log:
2016-06-29  Richard Biener  <rguenther@suse.de>

        PR middle-end/71002
        * alias.c (component_uses_parent_alias_set_from): Handle
        type punning through union accesses by using the union alias set.
        * gimple.c (gimple_get_alias_set): Remove union type punning case.

        c-family/
        * c-common.c (c_common_get_alias_set): Remove union type punning case.

        fortran/
        * f95-lang.c (LANG_HOOKS_GET_ALIAS_SET): Remove (un-)define.
        (gfc_get_alias_set): Remove.

        * g++.dg/torture/pr71002.C: Adjust testcase.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/alias.c
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c-common.c
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/f95-lang.c
    trunk/gcc/gimple.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/torture/pr71002.C