[Bug tree-optimization/79090] [7 regression] DSE wrongly removes store at variable offset

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79090

--- Comment #3 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Author: law
Date: Sun Jan 15 09:34:01 2017
New Revision: 244472

URL: https://gcc.gnu.org/viewcvs?rev=244472&root=gcc&view=rev
Log:
        PR tree-optimization/79090
        * tree-ssa-dse.c (valid_ao_ref_for_dse): Reject zero length and
        variable length stores.
        (compute_trims): Delete dead assignment to *trim_tail.
        (dse_dom_walker::dse_optimize_stmt): Optimize mem* calls with
        zero length.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-ssa-dse.c