1 /*
2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
3  *
4  * This file is part of libFirm.
5  *
6  * This file may be distributed and/or modified under the terms of the
7  * GNU General Public License version 2 as published by the Free Software
8  * Foundation and appearing in the file LICENSE.GPL included in the
9  * packaging of this file.
10  *
11  * Licensees holding valid libFirm Professional Edition licenses may use
12  * this file in accordance with the libFirm Commercial License.
13  * Agreement provided with the Software.
14  *
15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE.
18  */
19 
20 /**
21  * @file
22  * @brief    Loop datastructure and access functions -- private stuff.
23  * @author   Goetz Lindenmaier
24  * @date     7.2002
25  */
26 #ifndef FIRM_ANA_IRLOOP_T_H
27 #define FIRM_ANA_IRLOOP_T_H
28 
29 #include "firm_common.h"
30 #include "irgraph_t.h"
31 #include "irnode_t.h"
32 #include "irloop.h"
33 
34 /**
35  * Possible loop flags, can be or'ed.
36  */
37 typedef enum loop_flags {
38 	loop_is_count_loop = 0x00000001,  /**< if set it's a counting loop */
39 	loop_downto_loop   = 0x00000002,  /**< if set, it's a downto loop, else an upto loop */
40 	loop_is_endless    = 0x00000004,  /**< if set, this is an endless loop */
41 	loop_is_dead       = 0x00000008,  /**< if set, it's a dead loop ie will never be entered */
42 	loop_wrap_around   = 0x00000010,  /**< this loop is NOT endless, because of wrap around */
43 	loop_end_false     = 0x00000020,  /**< this loop end can't be computed "from compute_loop_info.c" */
44 	do_loop            = 0x00000040,  /**< this is a do loop */
45 	once               = 0x00000080,  /**< this is a do loop, with a false condition. It iterate exactly once. */
46 	loop_outer_loop    = 0x00000100   /**< if set, this loop has child loops (is a no leaf). */
47 } loop_flags_t;
48 
49 /**
50  * The loops data structure.
51  *
52  * The loops data structure represents circles in the intermediate
53  * representation.  It does not represent loops in the terms of a
54  * source program.
55  * Each ir_graph can contain one outermost loop data structure.
56  * loop is the entry point to the nested loops.
57  * The loop data structure contains a field indicating the depth of
58  * the loop within the nesting.  Further it contains a list of the
59  * loops with nesting depth -1.  Finally it contains a list of all
60  * nodes in the loop.
61  */
62 struct ir_loop {
63 	firm_kind       kind;             /**< A type tag, set to k_ir_loop. */
64 	unsigned        depth;            /**< Nesting depth */
65 	unsigned        flags;            /**< a set of loop_flags_t */
66 	struct ir_loop *outer_loop;       /**< The outer loop */
67 	loop_element   *children;         /**< Mixed flexible array: Contains sons and loop_nodes */
68 	ir_tarval      *loop_iter_start;  /**< counting loop: the start value */
69 	ir_tarval      *loop_iter_end;    /**< counting loop: the last value reached */
70 	ir_tarval      *loop_iter_increment; /**< counting loop: the increment */
71 	ir_node        *loop_iter_variable;  /**< The iteration variable of counting loop.*/
72 
73 	void *link;                       /**< link field. */
74 #ifdef DEBUG_libfirm
75 	long loop_nr;                     /**< A unique node number for each loop node to make output
76 	                                       readable. */
77 #endif
78 };
79 
80 /**
81  * Allocates a new loop as son of father on the given obstack.
82  * If father is equal NULL, a new root loop is created.
83  */
84 ir_loop *alloc_loop(ir_loop *father, struct obstack *obst);
85 
86 /** Add a son loop to a father loop. */
87 void add_loop_son(ir_loop *loop, ir_loop *son);
88 
89 /** Add a node to a loop. */
90 void add_loop_node(ir_loop *loop, ir_node *n);
91 
92 /** Add an IR graph to a loop. */
93 void add_loop_irg(ir_loop *loop, ir_graph *irg);
94 
95 /** Sets the loop a node belonging to. */
96 void set_irn_loop(ir_node *n, ir_loop *loop);
97 
98 /**
99  * Mature all loops by removing the flexible arrays of a loop tree
100  * and putting them on the given obstack.
101  */
102 void mature_loops(ir_loop *loop, struct obstack *obst);
103 
104 /* -------- inline functions -------- */
105 
_is_ir_loop(const void * thing)106 static inline int _is_ir_loop(const void *thing)
107 {
108 	return get_kind(thing) == k_ir_loop;
109 }
110 
_set_irg_loop(ir_graph * irg,ir_loop * loop)111 static inline void _set_irg_loop(ir_graph *irg, ir_loop *loop)
112 {
113 	assert(irg);
114 	irg->loop = loop;
115 }
116 
_get_irg_loop(const ir_graph * irg)117 static inline ir_loop *_get_irg_loop(const ir_graph *irg)
118 {
119 	assert(irg);
120 	return irg->loop;
121 }
122 
_get_loop_outer_loop(const ir_loop * loop)123 static inline ir_loop *_get_loop_outer_loop(const ir_loop *loop)
124 {
125 	assert(_is_ir_loop(loop));
126 	return loop->outer_loop;
127 }
128 
_get_loop_depth(const ir_loop * loop)129 static inline unsigned _get_loop_depth(const ir_loop *loop)
130 {
131 	assert(_is_ir_loop(loop));
132 	return loop->depth;
133 }
134 
135 /* Uses temporary information to get the loop */
_get_irn_loop(const ir_node * n)136 static inline ir_loop *_get_irn_loop(const ir_node *n)
137 {
138 	return n->loop;
139 }
140 
141 #define is_ir_loop(thing)         _is_ir_loop(thing)
142 #define set_irg_loop(irg, loop)   _set_irg_loop(irg, loop)
143 #define get_irg_loop(irg)         _get_irg_loop(irg)
144 #define get_loop_outer_loop(loop) _get_loop_outer_loop(loop)
145 #define get_loop_depth(loop)      _get_loop_depth(loop)
146 #define get_irn_loop(n)           _get_irn_loop(n)
147 
148 #endif
149