[Bug tree-optimization/92751] VN partial def support confused about clobbers

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92751

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Dec  3 10:46:52 2019
New Revision: 278931

URL: https://gcc.gnu.org/viewcvs?rev=278931&root=gcc&view=rev
Log:
2019-12-03  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/92751
        * tree-ssa-sccvn.c (vn_walk_cb_data::push_partial_def): Fail
        when a clobber ends up in the partial-def vector.
        (vn_reference_lookup_3): Let clobbers be handled by the
        assignment from CTOR handling.

        * g++.dg/tree-ssa/pr92751.C: New testcase.

Added:
    trunk/gcc/testsuite/g++.dg/tree-ssa/pr92751.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c