[Bug tree-optimization/84486] [7 Regression] code hoisting removes alignment assumption

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84486

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Mar  6 10:01:52 2018
New Revision: 258274

URL: https://gcc.gnu.org/viewcvs?rev=258274&root=gcc&view=rev
Log:
2018-03-06  Richard Biener  <rguenther@suse.de>

        Backport from mainline
        2018-03-05  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/84486
        * tree-ssa-pre.c (create_expression_by_pieces): Remove dead code.
        When inserting a __builtin_assume_aligned call set the LHS
        SSA name alignment info accordingly.

        2018-02-28  Richard Biener  <rguenther@suse.de>

        PR middle-end/84607
        * genmatch.c (capture_info::walk_match): Do not mark
        captured expressions without operands as expr_p given
        they act more like predicates and should be subject to
        "lost tail" side-effect preserving.

        * gcc.dg/pr84607.c: New testcase.

Added:
    branches/gcc-7-branch/gcc/testsuite/gcc.dg/pr84607.c
Modified:
    branches/gcc-7-branch/gcc/ChangeLog
    branches/gcc-7-branch/gcc/genmatch.c
    branches/gcc-7-branch/gcc/testsuite/ChangeLog
    branches/gcc-7-branch/gcc/tree-ssa-pre.c