[Bug c++/61982] Optimizer does not eliminate stores to destroyed objects

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61982

--- Comment #18 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Mon Apr 30 15:21:01 2018
New Revision: 259772

URL: https://gcc.gnu.org/viewcvs?rev=259772&root=gcc&view=rev
Log:
        PR c++/61982 - dead stores to destroyed objects.

gcc/cp/
        * call.c (build_trivial_dtor_call): New, assigns a clobber.
        (build_over_call, build_special_member_call): Use it.
        * cp-tree.h: Declare it.
        * init.c (build_delete): Remove trivial path.
gcc/
        * gimplify.c (gimplify_modify_expr): Simplify complex lvalue on LHS
        of clobber.

Added:
    trunk/gcc/testsuite/g++.dg/tree-ssa/lifetime-dse1.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/call.c
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/init.c
    trunk/gcc/gimplify.c