PR c++/24686

[pf3gnuchains/gcc-fork.git] / gcc / tree-cfg.c

diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index df97058..13868e9 100644 (file)
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -1237,8 +1237,7 @@ replace_uses_by (tree name, tree val)
   FOR_EACH_IMM_USE_SAFE (use, imm_iter, name)
     {
       stmt = USE_STMT (use);
-
-      SET_USE (use, val);
+      replace_exp (use, val);
 
       if (TREE_CODE (stmt) == PHI_NODE)
        {
@@ -1315,8 +1314,17 @@ tree_merge_blocks (basic_block a, basic_block b)
     {
       tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0);
       tree copy;
-      
-      if (!may_propagate_copy (def, use))
+      bool may_replace_uses = may_propagate_copy (def, use);
+
+      /* In case we have loops to care about, do not propagate arguments of
+        loop closed ssa phi nodes.  */
+      if (current_loops
+         && is_gimple_reg (def)
+         && TREE_CODE (use) == SSA_NAME
+         && a->loop_father != b->loop_father)
+       may_replace_uses = false;
+
+      if (!may_replace_uses)
        {
          gcc_assert (is_gimple_reg (def));
 
@@ -1979,6 +1987,12 @@ remove_bb (basic_block bb)
        {
          loop->latch = NULL;
          loop->header = NULL;
+
+         /* Also clean up the information associated with the loop.  Updating
+            it would waste time. More importantly, it may refer to ssa
+            names that were defined in other removed basic block -- these
+            ssa names are now removed and invalid.  */
+         free_numbers_of_iterations_estimates_loop (loop);
        }
     }
 
@@ -2923,7 +2937,7 @@ tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi,
       if (TREE_CODE (tmp) == RETURN_EXPR)
         {
          tree op = TREE_OPERAND (tmp, 0);
-         if (!is_gimple_val (op))
+         if (op && !is_gimple_val (op))
            {
              gcc_assert (TREE_CODE (op) == MODIFY_EXPR);
              bsi_insert_before (bsi, op, BSI_NEW_STMT);
@@ -5125,7 +5139,8 @@ execute_warn_function_return (void)
        {
          tree last = last_stmt (e->src);
          if (TREE_CODE (last) == RETURN_EXPR
-             && TREE_OPERAND (last, 0) == NULL)
+             && TREE_OPERAND (last, 0) == NULL
+             && !TREE_NO_WARNING (last))
            {
 #ifdef USE_MAPPED_LOCATION
              location = EXPR_LOCATION (last);