PR c++/41109

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

diff --git a/gcc/tree-nrv.c b/gcc/tree-nrv.c
index 7e811cf..c1e9d60 100644 (file)
--- a/gcc/tree-nrv.c
+++ b/gcc/tree-nrv.c
@@ -1,5 +1,5 @@
 /* Language independent return value optimizations
-   Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -56,6 +56,7 @@ struct nrv_data
   /* This is the function's RESULT_DECL.  We will replace all occurrences
      of VAR with RESULT_DECL when we apply this optimization.  */
   tree result;
+  int modified;
 };
 
 static tree finalize_nrv_r (tree *, int *, void *);
@@ -83,7 +84,10 @@ finalize_nrv_r (tree *tp, int *walk_subtrees, void *data)
 
   /* Otherwise replace all occurrences of VAR with RESULT.  */
   else if (*tp == dp->var)
-    *tp = dp->result;
+    {
+      *tp = dp->result;
+      dp->modified = 1;
+    }
 
   /* Keep iterating.  */
   return NULL_TREE;
@@ -229,13 +233,19 @@ tree_nrv (void)
          if (gimple_assign_copy_p (stmt)
              && gimple_assign_lhs (stmt) == result
              && gimple_assign_rhs1 (stmt) == found)
-           gsi_remove (&gsi, true);
+           {
+             unlink_stmt_vdef (stmt);
+             gsi_remove (&gsi, true);
+           }
          else
            {
              struct walk_stmt_info wi;
              memset (&wi, 0, sizeof (wi));
              wi.info = &data;
+             data.modified = 0;
              walk_gimple_op (stmt, finalize_nrv_r, &wi);
+             if (data.modified)
+               update_stmt (stmt);
              gsi_next (&gsi);
            }
        }
@@ -263,7 +273,7 @@ struct gimple_opt_pass pass_nrv =
   NULL,                                        /* next */
   0,                                   /* static_pass_number */
   TV_TREE_NRV,                         /* tv_id */
-  PROP_cfg,                            /* properties_required */
+  PROP_ssa | PROP_cfg,                         /* properties_required */
   0,                                   /* properties_provided */
   0,                                   /* properties_destroyed */
   0,                                   /* todo_flags_start */
@@ -349,8 +359,8 @@ struct gimple_opt_pass pass_return_slot =
   NULL,                                        /* sub */
   NULL,                                        /* next */
   0,                                   /* static_pass_number */
-  0,                                   /* tv_id */
-  PROP_ssa | PROP_alias,               /* properties_required */
+  TV_NONE,                             /* tv_id */
+  PROP_ssa,                            /* properties_required */
   0,                                   /* properties_provided */
   0,                                   /* properties_destroyed */
   0,                                   /* todo_flags_start */