-/* Copyright (C) 2002 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors: Goetz Lindenmaier
-**
-** irdom.h: This file contains routines to construct and access dominator
-** information.
-** The dominator information is stored in three fields of block nodes:
-** idom: a reference to the block that is the immediate dominator of
-** this block.
-** dom_depth: a number giving the depth of the block in the dominator
-** tree.
-** pre_num: Number in preorder traversal.
+/*
+ * Project: libFIRM
+ * File name: ir/ana/irdom.h
+ * Purpose: Construct and access dominator tree.
+ * Author: Goetz Lindenmaier
+ * Modified by:
+ * Created: 2.2002
+ * CVS-ID: $Id$
+ * Copyright: (c) 2002-2003 Universität Karlsruhe
+ * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ */
+
+/**
+* @file irdom.h
+*
+* This file contains routines to construct and access dominator information.
+*
+* The dominator information is stored in three fields of block nodes:
+* - idom: a reference to the block that is the immediate dominator of
+* this block.
+* - dom_depth: a number giving the depth of the block in the dominator
+* tree.
+* - pre_num: Number in preorder traversal.
+*
+* @author Goetz Lindenmaier
*/
-/* $Id$ */
# ifndef _IRDOM_H_
# define _IRDOM_H_
# include "irgraph.h"
+# include "irgwalk.h"
# include "irnode.h"
-/**********************************************************************/
-/** Accessing the dopminator datastructure. **/
-/** These routines only work properly if the ir_graph is in state **/
-/** dom_consistent or dom_inconsistent. **/
-/**********************************************************************/
-
-ir_node *get_Block_idom(ir_node *bl);
+/** Accessing the dominator data structure.
+ *
+ * These routines only work properly if the ir_graph is in state
+ * dom_consistent or dom_inconsistent.
+ *
+ * If the block is not reachable from Start, returns a Bad node.
+ */
+ir_node *get_Block_idom(const ir_node *bl);
void set_Block_idom(ir_node *bl, ir_node *n);
-int get_Block_dom_depth(ir_node *bl);
+int get_Block_dom_depth(const ir_node *bl);
void set_Block_dom_depth(ir_node *bl, int depth);
-int get_Block_pre_num(ir_node *bl);
+int get_Block_pre_num(const ir_node *bl);
void set_Block_pre_num(ir_node *bl, int num);
+/**
+ * Get the pre-order number of a block resulting from a
+ * Depth-First-Search walkover the dominator tree.
+ *
+ * @param bl The block.
+ * @return The pre-order number.
+ */
+unsigned get_Block_dom_tree_pre_num(const ir_node *bl);
+
+/**
+ * Get the largest pre-order number found in the subtree of the
+ * dominator tree rooted at a given block.
+ * @param bl The block.
+ * @return The largest pre-order number of block's dominator subtree.
+ */
+unsigned get_Block_dom_max_subtree_pre_num(const ir_node *bl);
+
+/**
+ * Get the first node in the list of nodes dominated by a given block.
+ *
+ * Each node keeps a list of nodes which it immediately dominates. The
+ * nodes are queued using the @c next pointer in the @c dom_info struct.
+ * Each node keeps a head of this list using the pointer @c first in the
+ * same structure.
+ *
+ * @param bl The block for which to get the first node dominated by @c bl.
+ * @return The first node dominated by @p bl.
+ */
+ir_node *get_Block_dominated_first(const ir_node *bl);
+
+/**
+ * Get the next node in a list of nodes which are dominated by some
+ * other node.
+ * @see get_Block_dominated_first().
+ * @param dom The previous node.
+ * @return The next node in this list or NULL if it was the last.
+ */
+ir_node *get_Block_dominated_next(const ir_node *dom);
+
+/**
+ * Iterate over all nodes which are immediately dominated by a given
+ * node.
+ * @param bl The block whose dominated blocks shall be iterated on.
+ * @param curr An iterator variable of type ir_node*
+ */
+#define dominates_for_each(bl,curr) \
+ for(curr = get_Block_dominated_first(bl); curr; \
+ curr = get_Block_dominated_next(curr))
+
+/**
+ * Check, if a block dominates another block.
+ * @param a The first block.
+ * @param b The second block.
+ * @return 1, if @p a dominates @p b, else 0.
+ */
+int block_dominates(const ir_node *a, const ir_node *b);
+
+/**
+ * Visit all nodes in the dominator subtree of a given node.
+ * Call a pre-visitor before descending to the children and call a
+ * post-visitor after returning from them.
+ * @param n The node to start walking from.
+ * @param pre The pre-visitor callback.
+ * @param post The post-visitor callback.
+ * @param env Some custom data passed to the visitors.
+ */
+void dom_tree_walk(ir_node *n, irg_walk_func *pre,
+ irg_walk_func *post, void *env);
+
+
+/**
+ * Walk over the dominator tree of an irg starting at the root.
+ * @param irg The graph.
+ * @param pre A pre-visitor to call.
+ * @param post A post-visitor to call.
+ * @param env Some private data to give to the visitors.
+ */
+void dom_tree_walk_irg(ir_graph *irg, irg_walk_func *pre,
+ irg_walk_func *post, void *env);
-/**********************************************************************/
-/* Building and Removing the dominator datasturcture **/
-/**********************************************************************/
+/* ------------ Building and Removing the dominator data structure ----------- */
-/* Computes the dominator trees. Sets a flag in irg to "dom_consistent".
- If the control flow of the graph is changed this flag must be set to
- "dom_inconsistent".
- Does not compute dominator information for control dead code. Blocks
- not reachable from Start contain the following information:
- idom = NULL;
- dom_depth = -1;
- pre_num = -1; */
+/** Computes the dominator trees.
+ *
+ * Sets a flag in irg to "dom_consistent".
+ * If the control flow of the graph is changed this flag must be set to
+ * "dom_inconsistent".
+ * Does not compute dominator information for control dead code. Blocks
+ * not reachable from Start contain the following information:
+ * @code
+ * idom = NULL;
+ * dom_depth = -1;
+ * pre_num = -1;
+ * @endcode
+ * Also constructs outs information. As this information is correct after
+ * the run does not free the outs information.
+ */
void compute_doms(ir_graph *irg);
-/* Frees the dominator datastructures. Sets the flag in irg to "no_dom". */
+/** Frees the dominator data structures. Sets the flag in irg to "dom_none". */
void free_dom_and_peace(ir_graph *irg);
#endif /* _IRDOM_H_ */
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