ChangeLog:

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-pre.c

diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 49dff65..816aeb6 100644 (file)
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -4347,10 +4347,15 @@ eliminate (void)
 
          remove_phi_node (&gsi, false);
 
+         if (!bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res))
+             && TREE_CODE (sprime) == SSA_NAME)
+           gimple_set_plf (SSA_NAME_DEF_STMT (sprime), NECESSARY, true);
+
          if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
            sprime = fold_convert (TREE_TYPE (res), sprime);
          stmt = gimple_build_assign (res, sprime);
          SSA_NAME_DEF_STMT (res) = stmt;
+         gimple_set_plf (stmt, NECESSARY, gimple_plf (phi, NECESSARY));
 
          gsi2 = gsi_after_labels (b);
          gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
@@ -4381,8 +4386,11 @@ eliminate (void)
          && single_imm_use (lhs, &use_p, &use_stmt)
          && may_propagate_copy (USE_FROM_PTR (use_p), rhs))
        {
-         SET_USE (use_p, gimple_assign_rhs1 (stmt));
+         SET_USE (use_p, rhs);
          update_stmt (use_stmt);
+         if (bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (lhs))
+             && TREE_CODE (rhs) == SSA_NAME)
+           gimple_set_plf (SSA_NAME_DEF_STMT (rhs), NECESSARY, true);
        }
 
       /* If this is a store or a now unused copy, remove it.  */
@@ -4710,17 +4718,14 @@ execute_pre (bool do_fre)
   if (!run_scc_vn (do_fre))
     {
       if (!do_fre)
-       {
-         remove_dead_inserted_code ();
-         loop_optimizer_finalize ();
-       }
+       loop_optimizer_finalize ();
 
       return 0;
     }
+
   init_pre (do_fre);
   scev_initialize ();
 
-
   /* Collect and value number expressions computed in each basic block.  */
   compute_avail ();