3 * File name: ir/ana/irextbb.c
4 * Purpose: Extended basis block support.
9 * Copyright: (c) 2002-2005 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
16 * Computes extended basic blocks.
18 * @author Michael Beck
20 #include "irextbb_t.h"
27 struct obstack *obst; /**< the obstack where allocations took place */
28 ir_extblk *head; /**< head of the list of all extended blocks */
32 * allocate a new extended block header.
34 static void allocate_extblk(ir_node *block, env_t *env)
36 ir_extblk *extblk = obstack_alloc(env->obst, sizeof(*extblk));
38 extblk->kind = k_ir_extblk;
40 extblk->blks = (ir_node **)env->head;
44 set_Block_extbb(block, extblk);
45 set_irn_link(block, NULL);
49 * add a block to an extended block
51 static void addto_extblk(ir_extblk *extblk, ir_node *block)
53 /* link all blocks belonging to this extended block */
54 set_irn_link(block, extblk->link);
59 set_Block_extbb(block, extblk);
64 * Pre block-walker. Calculates the extended block info.
66 static void pre_walk_calc_extbb(ir_node *block, void *ctx)
68 int n = get_Block_n_cfgpreds(block);
71 if (n <= 0 || n > 1 || block == get_irg_start_block(current_ir_graph)) {
73 * block is a JOIN-node ie he control flow from
74 * many other blocks joins here. block is a leader.
75 * Note that we handle unreachable blocks (n <= 0) here too.
77 allocate_extblk(block, env);
80 ir_node *add_to = get_Block_cfgpred(block, 0);
83 add_to = get_nodes_block(add_to);
85 /* blocks with only one BAD predecessors are leaders too */
87 allocate_extblk(block, env);
91 * Only one control flow predecessor. This block belongs
92 * to the same extended basic block as its predecessor.
94 set_Block_extbb(block, NULL);
100 * Post block-walker. Calculates the extended block info.
101 * During construction, we use the (free) block input of all basic blocks
102 * to point to there previous block.
104 static void post_walk_calc_extbb(ir_node *block, void *env)
106 ir_extblk *extbb = get_Block_extbb(block);
109 ir_node *prev = block;
111 /* search the leader */
113 prev = get_nodes_block(get_Block_cfgpred(prev, 0));
114 extbb = get_Block_extbb(prev);
117 addto_extblk(extbb, block);
122 * Compute the extended basic blocks for a graph
124 void compute_extbb(ir_graph *irg) {
126 ir_extblk *extbb, *next;
129 obstack_free(irg->extbb_obst, NULL);
131 irg->extbb_obst = xmalloc(sizeof(*irg->extbb_obst));
133 obstack_init(irg->extbb_obst);
135 env.obst = irg->extbb_obst;
138 irg_block_walk_graph(irg, pre_walk_calc_extbb, post_walk_calc_extbb, &env);
141 * Ok, we have now the list of all extended blocks starting with env.head
142 * every extended block "knowns" the number of blocks in visited and
143 * the blocks are linked in link.
144 * Now we can create arrays that hold the blocks, some kind of "out" edges
145 * for the extended block
147 for (extbb = env.head; extbb; extbb = next) {
148 int i, len = (int)extbb->visited;
151 next = (ir_extblk *)extbb->blks;
153 extbb->blks = NEW_ARR_D(ir_node *, env.obst, len);
155 for (block = extbb->link, i = 0; i < len; ++i) {
156 ir_node *nblock = get_irn_link(block);
158 extbb->blks[i] = block;
159 set_irn_link(block, NULL);
167 irg->extblk_state = ir_extblk_info_valid;
170 /* free all extended block info. */
171 void free_extbb(ir_graph *irg) {
172 if (irg->extbb_obst) {
173 obstack_free(irg->extbb_obst, NULL);
174 xfree(irg->extbb_obst);
175 irg->extbb_obst = NULL;
177 irg->extblk_state = ir_extblk_info_none;
180 /* Return the extended block of a node. */
181 ir_extblk *get_nodes_extbb(ir_node *node) {
182 ir_node *block = is_Block(node) ? node : get_nodes_block(node);
183 return get_Block_extbb(block);
186 /* Gets the visited counter of an extended block. */
187 unsigned long (get_extbb_visited)(const ir_extblk *blk) {
188 return _get_extbb_visited(blk);
191 /* Sets the visited counter of an extended block. */
192 void (set_extbb_visited)(ir_extblk *blk, unsigned long visited) {
193 _set_extbb_visited(blk, visited);
196 /* Mark an extended block as visited in a graph. */
197 void (mark_extbb_visited)(ir_extblk *blk) {
198 _mark_extbb_visited(blk);
201 /* Returns non-zero if an extended was visited. */
202 int (extbb_visited)(const ir_extblk *blk) {
203 return _extbb_visited(blk);
206 /* Returns non-zero if an extended block was NOT visited. */
207 int (extbb_not_visited)(const ir_extblk *blk) {
208 return _extbb_not_visited(blk);
211 /* Returns the link field of an extended block. */
212 void *(get_extbb_link)(const ir_extblk *blk) {
213 return _get_extbb_link(blk);
216 /* Sets the link field of an extended block. */
217 void (set_extbb_link)(ir_extblk *blk, void *link) {
218 _set_extbb_link(blk, link);
221 /* Return the number of basic blocks of an extended block */
222 int (get_extbb_n_blocks)(const ir_extblk *blk) {
223 return _get_extbb_n_blocks(blk);
226 /* Return the i'th basic block of an extended block */
227 ir_node *(get_extbb_block)(ir_extblk *blk, int pos) {
228 return _get_extbb_block(blk, pos);
231 /* Return the leader basis block of an extended block. */
232 ir_node *(get_extbb_leader)(ir_extblk *blk) {
233 return _get_extbb_leader(blk);
236 /* Return the node number of an extended block. */
237 long get_extbb_node_nr(ir_extblk *blk) {
238 return get_irn_node_nr(get_extbb_leader(blk));