Index: gcc/tree-ssa-tail-merge.c
===================================================================
--- gcc/tree-ssa-tail-merge.c (revision 179773)
+++ gcc/tree-ssa-tail-merge.c (working copy)
@@ -773,18 +773,53 @@ same_succ_flush_bbs (bitmap bbs)
     }
 }
 
+/* Release all vdefs in BB, either normal or phi results.  */
+
+static void
+release_vdefs (basic_block bb)
+{
+  gimple_stmt_iterator i;
+
+  for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i))
+    {
+      gimple phi = gsi_stmt (i);
+      tree res = gimple_phi_result (phi);
+      use_operand_p use_p;
+      imm_use_iterator iter;
+      gimple use_stmt;
+
+      if (is_gimple_reg (res))
+	continue;
+
+      FOR_EACH_IMM_USE_STMT (use_stmt, iter, res)
+	{
+	  FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+	    SET_USE (use_p, SSA_NAME_VAR (res));
+	}
+    }
+  
+  for (i = gsi_last_bb (bb); !gsi_end_p (i); gsi_prev_nondebug (&i))
+    unlink_stmt_vdef (gsi_stmt (i));
+}
+
 /* Delete all deleted_bbs.  */
 
 static void
-purge_bbs (void)
+purge_bbs (bool update_vops)
 {
   unsigned int i;
   bitmap_iterator bi;
+  basic_block bb;
 
   same_succ_flush_bbs (deleted_bbs);
 
   EXECUTE_IF_SET_IN_BITMAP (deleted_bbs, 0, i, bi)
-    delete_basic_block (BASIC_BLOCK (i));
+    {
+      bb = BASIC_BLOCK (i);
+      if (!update_vops)
+	release_vdefs (bb);
+      delete_basic_block (bb);
+    }
 
   bitmap_and_compl_into (deleted_bb_preds, deleted_bbs);
   bitmap_clear (deleted_bbs);
@@ -1665,7 +1700,7 @@ tail_merge_optimize (unsigned int todo)
 	break;
 
       free_dominance_info (CDI_DOMINATORS);
-      purge_bbs ();
+      purge_bbs (update_vops);
 
       if (iteration_nr == max_iterations)
 	break;