https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70239
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- And indeed --- tree-ssa-sccvn.c.jj 2016-02-16 16:14:43.000000000 +0100 +++ tree-ssa-sccvn.c 2016-03-15 13:02:40.876997092 +0100 @@ -407,7 +407,7 @@ VN_INFO_GET (tree name) newinfo = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux); memset (newinfo, 0, sizeof (struct vn_ssa_aux)); if (SSA_NAME_VERSION (name) >= vn_ssa_aux_table.length ()) - vn_ssa_aux_table.safe_grow (SSA_NAME_VERSION (name) + 1); + vn_ssa_aux_table.safe_grow_cleared (SSA_NAME_VERSION (name) + 1); vn_ssa_aux_table[SSA_NAME_VERSION (name)] = newinfo; return newinfo; } fixes the ICE.