[Bug tree-optimization/91108] [8 Regression] Fails to pun through unions

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91108

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Aug 30 16:33:05 2019
New Revision: 275206

URL: https://gcc.gnu.org/viewcvs?rev=275206&root=gcc&view=rev
Log:
2019-08-30  Richard Biener  <rguenther@suse.de>

        Backport from mainline
        2019-07-08  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/91108
        * tree-ssa-sccvn.c: Include builtins.h.
        (vn_reference_lookup_3): Use only alignment constraints to
        verify same-valued store disambiguation.

        * gcc.dg/tree-ssa/pr91091-1.c: New testcase.
        * gcc.dg/tree-ssa/ssa-fre-78.c: Likewise.

Added:
    branches/gcc-8-branch/gcc/testsuite/gcc.dg/tree-ssa/pr91091-1.c
    branches/gcc-8-branch/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-78.c
Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/testsuite/ChangeLog
    branches/gcc-8-branch/gcc/tree-ssa-sccvn.c