[Bug c++/82084] [5/6 Regression] ICE: constructing wstring with -O3

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82084

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Mon Sep 18 11:07:50 2017
New Revision: 252919

URL: https://gcc.gnu.org/viewcvs?rev=252919&root=gcc&view=rev
Log:
2017-09-18  Richard Biener  <rguenther@suse.de>

        Backport from mainline
        2017-08-28  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/81977
        * tree-ssa-sccvn.c (vn_reference_lookup_3): Fix look through
        memcpy.

        * g++.dg/torture/pr81977.C: New testcase.

        2017-09-04  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/82084
        * fold-const.h (can_native_encode_string_p): Declare.
        * fold-const.c (can_native_encode_string_p): Factor out from ...
        (native_encode_string): ... here.
        * tree-vect-stmts.c (vectorizable_store): Call it to avoid
        vectorizing stores from constants we later cannot handle.

        * g++.dg/torture/pr82084.C: New testcase.

        2017-07-25  Richard Biener  <rguenther@suse.de>

        PR middle-end/81505
        * fold-const.c (fold_negate_const): TREE_OVERFLOW should be
        sticky.

        * gcc.dg/ubsan/pr81505.c: New testcase.

Added:
    branches/gcc-6-branch/gcc/testsuite/g++.dg/torture/pr81977.C
    branches/gcc-6-branch/gcc/testsuite/g++.dg/torture/pr82084.C
    branches/gcc-6-branch/gcc/testsuite/gcc.dg/ubsan/pr81505.c
Modified:
    branches/gcc-6-branch/gcc/ChangeLog
    branches/gcc-6-branch/gcc/fold-const.c
    branches/gcc-6-branch/gcc/fold-const.h
    branches/gcc-6-branch/gcc/testsuite/ChangeLog
    branches/gcc-6-branch/gcc/tree-ssa-sccvn.c
    branches/gcc-6-branch/gcc/tree-vect-stmts.c