[Bug tree-optimization/83241] [8 regression] ICE in verify_use after store-merging

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83241

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-12-01
                 CC|                            |jakub at gcc dot gnu.org
   Target Milestone|---                         |8.0
            Summary|[8 regression] segmentation |[8 regression] ICE in
                   |fault in dce                |verify_use after
                   |                            |store-merging
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
(gdb) p debug_tree (ssa_name)
 <ssa_name 0x7ffff689cb88 nothrow public visited var <var_decl 0x7ffff69e4000
.MEM>
    def_stmt 
    version:8 in-free-list>
$1 = void

some unlink_stmt_vdef () missing?

  <bb 2> [local count: 1073741825]:
  # .MEM_6 = VDEF <.MEM_5(D)>
  c = a;
  # VUSE <.MEM_8>
  _13 = MEM[(int *)&c + 4B];
  # VUSE <.MEM_6>
  _1 = c.md_tmplt_hdr_dma;
  _2 = (short int) _1;
  _3 = _1 >> 16;
  _4 = (short int) _3;
  # .MEM_10 = VDEF <.MEM_6>
  MEM[(short int *)&b + 12B] = _13;
...