/* Copyright (C) 2002 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors: Goetz Lindenmaier
-**
-** irloops.h: Computes backedges in the control and data flow.
-** Only Block and Phi/Filter nodes can have incoming backedges.
-** Constructs loops data structure: indicates loop nesting.
+* All rights reserved.
+*/
+
+/**
+* @file irloop.h
+*
+* Computes backedges in the control and data flow.
+*
+* @author Goetz Lindenmaier
+*
+* Only Block and Phi/Filter nodes can have incoming backedges.
+* Constructs loops data structure: indicates loop nesting.
*/
/* $Id$ */
# include "irnode.h"
-/** @@@ Interprocedural backedges ... ???? **/
+/* @@@ Interprocedural backedges ... ???? */
-/**********************************************************************/
-/** Backedge information. **/
-/** **/
-/** Predecessors of Block, Phi and interprocedural Filter nodes can **/
-/** have backedges. If loop information is computed, this **/
-/** information is computed, too. **/
-/** The backedge information can only be used if the graph is not in **/
-/** phase phase_building. **/
-/**********************************************************************/
+/*
+ * Backedge information.
+ *
+ * Predecessors of Block, Phi and interprocedural Filter nodes can
+ * have backedges. If loop information is computed, this
+ * information is computed, too.
+ * The backedge information can only be used if the graph is not in
+ * phase phase_building.
+ */
-/* Returns true if the predesessor pos is a backedge. */
+/** Returns true if the predesessor pos is a backedge. */
bool is_backedge (ir_node *n, int pos);
-/* Remarks that edge pos is a backedge. */
+/** Remarks that edge pos is a backedge. */
void set_backedge (ir_node *n, int pos);
-/* Remarks that edge pos is not a backedge. */
+/** Remarks that edge pos is not a backedge. */
void set_not_backedge (ir_node *n, int pos);
-/* Returns true if n has backedges. */
+/** Returns true if n has backedges. */
bool has_backedges (ir_node *n);
-/* Sets backedge information to zero. */
+/** Sets backedge information to zero. */
void clear_backedges (ir_node *n);
-/**********************************************************************/
-/** The loops datastructure **/
-/** **/
-/** The loops datastructure represents circles in the intermediate **/
-/** representation. It does not represent loops in the terms of a **/
-/** source program. **/
-/** Each ir_graph can contain one outermost loop datastructure. **/
-/** loop is the entry point to the nested loops. **/
-/** The loop datastructure contains a field indicating the depth of **/
-/** the loop within the nesting. Further it contains a list of the **/
-/** loops with nesting depth -1. Finally it contains a list of all **/
-/** nodes in the loop. **/
-/* @@@ We could add a field pointing from a node to the containing loop,
- this would cost a lot of memory, though. */
-/**********************************************************************/
-
+/**
+ * The loops datastructure.
+ *
+ * The loops datastructure represents circles in the intermediate
+ * representation. It does not represent loops in the terms of a
+ * source program.
+ * Each ir_graph can contain one outermost loop datastructure.
+ * loop is the entry point to the nested loops.
+ * The loop datastructure contains a field indicating the depth of
+ * the loop within the nesting. Further it contains a list of the
+ * loops with nesting depth -1. Finally it contains a list of all
+ * nodes in the loop.
+ *
+ * @todo We could add a field pointing from a node to the containing loop,
+ * this would cost a lot of memory, though.
+ */
typedef struct ir_loop ir_loop;
+/* Loop elements are loop nodes and ir nodes */
+typedef union {
+ firm_kind *kind; /**< is either k_ir_node or k_ir_loop */
+ ir_node *node; /**< Pointer to an ir_node element */
+ ir_loop *son; /**< Pointer to an ir_loop element */
+} loop_element;
+
void set_irg_loop(ir_graph *irg, ir_loop *l);
ir_loop *get_irg_loop(ir_graph *irg);
-/* Returns the loop n is contained in.
+/** Returns the loop n is contained in.
assumes current_ir_graph set properly. */
ir_loop *get_irn_loop(ir_node *n);
-/* Returns outer loop, itself if outermost. */
+/** Returns outer loop, itself if outermost. */
ir_loop *get_loop_outer_loop (ir_loop *loop);
-/* Returns nesting depth of this loop */
+/** Returns nesting depth of this loop */
int get_loop_depth (ir_loop *loop);
/* Sons are the inner loops contained in this loop. */
-/* Returns the number of inner loops */
+/** Returns the number of inner loops */
int get_loop_n_sons (ir_loop *loop);
ir_loop *get_loop_son (ir_loop *loop, int pos);
-/* Returns the number of nodes contained in loop. */
+/** Returns the number of nodes contained in loop. */
int get_loop_n_nodes (ir_loop *loop);
ir_node *get_loop_node (ir_loop *loop, int pos);
+/** Returns the number of elements contained in loop. */
+int get_loop_n_elements (ir_loop *loop);
+/** Returns a loop element. A loop element can be interpreted as a
+ kind poitner, an ir_node* or an ir_loop*. */
+loop_element get_loop_element (ir_loop *loop, int pos);
-/**********************************************************************/
-/* Constructing and destructing the loop/backedge information. **/
-/**********************************************************************/
+/*
+ * Constructing and destructing the loop/backedge information.
+ */
-/* Constructs backedge information for irg. In interprocedural view constructs
- backedges for all methods called by irg, too.
- @@@ I'm not sure what happens if irg is within a recursion in iterproc_view.
- @@@ Interprocedural backedge construction is not yet functioning!!!
-*/
+/** Constructs backedge information for irg in intraprocedural view. */
void construct_backedges(ir_graph *irg);
+/** Constructs backedges for all irgs in interprocedural view. All
+ loops in the graph will be marked as such, not only realizeable
+ loops and recursions in the program. E.g., if the same funcion is
+ called twice, there is a loop between the first funcion return and
+ the second call. */
+void construct_ip_backedges(void);
+
#endif /* _IRLOOP_H_ */