re PR tree-optimization/40759 (segfault in useless_type_conversion_p)

	PR tree-optimization/40759
	* tree-ssa-dce.c (mark_virtual_phi_result_for_renaming): Mark all uses
	for renaming.

From-SVN: r150168

gcc/ChangeLog

+2009-07-28  Jan Hubicka  <jh@suse.cz>
+
+	PR tree-optimization/40759
+	* tree-ssa-dce.c (mark_virtual_phi_result_for_renaming): Mark all uses
+	for renaming.
+
 2009-07-27  DJ Delorie  <dj@redhat.com>
 
 	* config/mep/mep.c (mep_expand_builtin_saveregs): Make sure 64-bit

gcc/tree-ssa-dce.c

@@ -828,9 +828,6 @@ mark_virtual_phi_result_for_renaming (gimple phi)
     }
   FOR_EACH_IMM_USE_STMT (stmt, iter, gimple_phi_result (phi))
     {
-      if (gimple_code (stmt) != GIMPLE_PHI
-	  && !gimple_plf (stmt, STMT_NECESSARY))
-        continue;
       FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
         SET_USE (use_p, SSA_NAME_VAR (gimple_phi_result (phi)));
       update_stmt (stmt);