+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
/**
* @file
- * @brief Introduce several copies for one node.
- * @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
- * @date 30.03.2007
- * @version $Id$
- * Copyright: (c) Universitaet Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
-
+ * @brief SSA construction for a set of nodes
+ * @author Sebastian Hack, Daniel Grund, Matthias Braun, Christian Wuerdig
+ * @date 30.03.2007
+ *
+ * The problem: Given a value and a set of "copies" that are known to
+ * represent the same abstract value, rewire all usages of the original value
+ * to their closest copy while introducing phis as necessary.
+ *
+ * Algorithm: Mark all blocks in the iterated dominance frontiers of the value
+ * and its copies. Link the copies ordered by dominance to the blocks. Then
+ * we search for each use all definitions in the current block, if none is
+ * found, then we search one in the immediate dominator. If we are in a block
+ * of the dominance frontier, create a phi and do the same search for all
+ * phi arguments.
+ *
* A copy in this context means, that you want to introduce several new
* abstract values (in Firm: nodes) for which you know, that they
* represent the same concrete value. This is the case if you
* This function reroutes all uses of the original value to the copies in the
* corresponding dominance subtrees and creates Phi functions where necessary.
*/
-#ifndef FIRM_BE_SSACONSTR_H
-#define FIRM_BE_SSACONSTR_H
+#ifndef FIRM_BE_BESSACONSTR_H
+#define FIRM_BE_BESSACONSTR_H
-#include <stdlib.h>
-#include "bedomfront.h"
-#include "irnode.h"
+#include <stdbool.h>
+#include "firm_types.h"
#include "irnodeset.h"
#include "belive.h"
+#include "bitset.h"
#include "beirg.h"
#include "pdeq.h"
+#include "irnodemap.h"
+#include "obst.h"
typedef struct be_ssa_construction_env_t {
- ir_graph *irg;
- const be_dom_front_info_t *domfronts;
- ir_mode *mode;
- waitq *worklist;
- const ir_nodeset_t *ignore_uses;
- ir_node **new_phis;
- int iterated_domfront_calculated;
+ ir_graph *irg;
+ ir_mode *mode;
+ const arch_register_req_t *phi_req;
+ waitq *worklist;
+ const ir_nodeset_t *ignore_uses;
+ ir_node **new_phis;
+ bool iterated_domfront_calculated;
+ ir_nodemap infos;
+ struct obstack obst;
} be_ssa_construction_env_t;
/**
- * Initializes an ssa construction environment.
+ * Initializes an SSA construction environment.
+ *
+ * @param env an empty SSA construction environment
+ * @param irg the graph
*/
-void be_ssa_construction_init(be_ssa_construction_env_t *env, be_irg_t *birg);
+void be_ssa_construction_init(be_ssa_construction_env_t *env, ir_graph *irg);
void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
ir_node *value);
const ir_nodeset_t *ignore_uses);
/**
- * Reconstructs the ssa form for all users of node @p node
+ * Reconstructs the SSA form for all users of node @p node
*/
void be_ssa_construction_fix_users(be_ssa_construction_env_t *env,
ir_node *node);
ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env);
/**
- * Destroys an ssa construction environment.
+ * Destroys an SSA construction environment.
*/
void be_ssa_construction_destroy(be_ssa_construction_env_t *env);
-#endif
+#endif /* FIRM_BE_BESSACONSTR_H */