[Bug middle-end/81088] UBSAN: false positive as a result of reassosiation

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81088

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Jun 14 11:40:20 2017
New Revision: 249192

URL: https://gcc.gnu.org/viewcvs?rev=249192&root=gcc&view=rev
Log:
2017-06-14  Richard Biener  <rguent...@suse.de>

        PR middle-end/81088
        * fold-const.c (split_tree): Drop TREE_OVERFLOW flag from
        literal constants.
        (fold_binary_loc): When associating do not treat pre-existing
        TREE_OVERFLOW on literal constants as a reason to allow
        TREE_OVERFLOW on associated literal constants.

        * c-c++-common/ubsan/pr81088.c: New testcase.

Added:
    trunk/gcc/testsuite/c-c++-common/ubsan/pr81088.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/testsuite/ChangeLog