27 #include "iredges_t.h"
32 #include "besched_t.h"
39 #define DBG_MODULE "firm.be.irgmod"
40 #define DBG_LEVEL SET_LEVEL_0
44 | _ \ ___ _ __ ___ (_)_ __ __ _ _ __ ___ ___
45 | | | |/ _ \| '_ ` _ \| | '_ \ / _` | '_ \ / __/ _ \
46 | |_| | (_) | | | | | | | | | | (_| | | | | (_| __/
47 |____/ \___/|_| |_| |_|_|_| |_|\__,_|_| |_|\___\___|
48 | ___| __ ___ _ __ | |_(_) ___ _ __ ___
49 | |_ | '__/ _ \| '_ \| __| |/ _ \ '__/ __|
50 | _|| | | (_) | | | | |_| | __/ | \__ \
51 |_| |_| \___/|_| |_|\__|_|\___|_| |___/
56 struct _dom_front_info_t {
61 * A wrapper for get_Block_idom.
62 * This function returns the block itself, if the block is the start
63 * block. Returning NULL would make any != comparison true which
64 * suggests, that the start block is dominated by some other node.
65 * @param bl The block.
66 * @return The immediate dominator of the block.
68 static INLINE ir_node *get_idom(ir_node *bl)
70 ir_node *idom = get_Block_idom(bl);
71 return idom == NULL ? bl : idom;
74 static void compute_df(ir_node *n, pmap *df_map)
77 const ir_edge_t *edge;
78 pset *df = pset_new_ptr_default();
80 /* Add local dominance frontiers */
81 foreach_block_succ(n, edge) {
82 ir_node *y = edge->src;
85 pset_insert_ptr(df, y);
89 * Go recursively down the dominance tree and add all blocks
90 * int the dominance frontiers of the children, which are not
91 * dominated by the given block.
93 for(c = get_Block_dominated_first(n); c; c = get_Block_dominated_next(c)) {
97 compute_df(c, df_map);
98 df_c = pmap_get(df_map, c);
100 for(w = pset_first(df_c); w; w = pset_next(df_c)) {
102 pset_insert_ptr(df, w);
106 pmap_insert(df_map, n, df);
110 dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
112 dom_front_info_t *info = xmalloc(sizeof(*info));
115 info->df_map = pmap_create();
117 compute_df(get_irg_start_block(irg), info->df_map);
122 void be_free_dominance_frontiers(dom_front_info_t *info)
126 for(ent = pmap_first(info->df_map); ent; ent = pmap_next(info->df_map))
127 del_pset(ent->value);
129 pmap_destroy(info->df_map);
133 pset *be_get_dominance_frontier(dom_front_info_t *info, ir_node *block)
135 return pmap_get(info->df_map, block);
138 static void determine_phi_blocks(pset *copies, pset *copy_blocks, pset *phi_blocks, dom_front_info_t *df_info)
141 pdeq *worklist = new_pdeq();
142 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
145 * Fill the worklist queue and the rest of the orig blocks array.
147 for(bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
148 pdeq_putr(worklist, bl);
151 while (!pdeq_empty(worklist)) {
152 ir_node *bl = pdeq_getl(worklist);
153 pset *df = be_get_dominance_frontier(df_info, bl);
157 DBG((dbg, LEVEL_3, "dom front of %+F\n", bl));
159 for (y = pset_first(df); y; y = pset_next(df))
160 DBG((dbg, LEVEL_3, "\t%+F\n", y))
163 for(y = pset_first(df); y; y = pset_next(df)) {
164 if(!pset_find_ptr(phi_blocks, y)) {
165 pset_insert_ptr(phi_blocks, y);
168 * Clear the link field of a possible phi block, since
169 * the possibly created phi will be stored there. See,
172 set_irn_link(y, NULL);
174 if(!pset_find_ptr(copy_blocks, y))
175 pdeq_putr(worklist, y);
190 / ___|___ _ __ ___| |_ _ __ _ _ ___| |_(_) ___ _ __
191 | | / _ \| '_ \/ __| __| '__| | | |/ __| __| |/ _ \| '_ \
192 | |__| (_) | | | \__ \ |_| | | |_| | (__| |_| | (_) | | | |
193 \____\___/|_| |_|___/\__|_| \__,_|\___|\__|_|\___/|_| |_|
198 * Find the copy of the given original node whose value is 'active'
201 * The usage is given as a node and a position. Initially, the given operand
202 * points to a node for which copies were introduced. We have to find
203 * the valid copy for this usage. This is done by traversing the
204 * dominance tree upwards. If the usage is a phi function, we start
205 * traversing from the predecessor block which corresponds to the phi
208 * @param usage The node which uses the original node.
209 * @param pos The position of the argument which corresponds to the original node.
210 * @param copies A set containing all node which are copies from the original node.
211 * @param copy_blocks A set containing all basic block in which copies of the original node are located.
212 * @param phis A set where all created phis are recorded.
213 * @param phi_blocks A set of all blocks where Phis shall be inserted (iterated dominance frontier).
214 * @param mode The mode for the Phi if one has to be created.
215 * @return The valid copy for usage.
217 static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks, pset *phis, pset *phi_blocks, ir_mode *mode)
221 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
223 curr_bl = get_nodes_block(usage);
225 DBG((dbg, LEVEL_1, "Searching valid def for use %+F at pos %d\n", usage, pos));
227 * If the usage is in a phi node, search the copy in the
228 * predecessor denoted by pos.
231 curr_bl = get_Block_cfgpred_block(curr_bl, pos);
232 start_irn = sched_last(curr_bl);
234 start_irn = sched_prev(usage);
238 * Traverse the dominance tree upwards from the
239 * predecessor block of the usage.
241 while(curr_bl != NULL) {
244 * If this block contains a copy, search the block
245 * instruction by instruction.
247 if(pset_find_ptr(copy_blocks, curr_bl)) {
250 /* Look at each instruction from last to first. */
251 sched_foreach_reverse_from(start_irn, irn) {
253 /* Take the first copy we find. */
254 if(pset_find_ptr(copies, irn))
259 if(pset_find_ptr(phi_blocks, curr_bl)) {
260 ir_node *phi = get_irn_link(curr_bl);
263 int i, n_preds = get_irn_arity(curr_bl);
264 ir_graph *irg = get_irn_irg(curr_bl);
265 ir_node **ins = xmalloc(n_preds * sizeof(ins[0]));
267 for(i = 0; i < n_preds; ++i)
268 ins[i] = new_r_Bad(irg);
270 phi = new_r_Phi(irg, curr_bl, n_preds, ins, mode);
271 DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, curr_bl));
273 set_irn_link(curr_bl, phi);
274 sched_add_after(curr_bl, phi);
277 for(i = 0; i < n_preds; ++i) {
278 ir_node *arg = search_def(phi, i, copies, copy_blocks, phis, phi_blocks, mode);
279 DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
280 set_irn_n(phi, i, arg);
284 pset_insert_ptr(phis, phi);
290 /* If were not done yet, look in the immediate dominator */
291 curr_bl = get_Block_idom(curr_bl);
293 start_irn = sched_last(curr_bl);
299 static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *phis, pset *ignore_uses)
310 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
315 * Put all outs into an array.
316 * This is necessary, since the outs would be modified while
317 * iterating on them what could bring the outs module in trouble.
319 for (irn = pset_first(copies); irn; irn = pset_next(copies)) {
320 const ir_edge_t *edge;
321 foreach_out_edge(irn, edge) {
322 if (!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
324 tmp.irn = get_edge_src_irn(edge);
325 tmp.pos = get_edge_src_pos(edge);
326 obstack_grow(&obst, &tmp, sizeof(tmp));
331 outs = obstack_finish(&obst);
334 * Search the valid def for each out and set it.
336 for(i = 0; i < n_outs; ++i) {
337 ir_node *irn = outs[i].irn;
338 int pos = outs[i].pos;
339 ir_mode *mode = get_irn_mode(get_irn_n(irn, pos));
343 def = search_def(irn, pos, copies, copy_blocks, phis, phi_blocks, mode);
344 DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
347 set_irn_n(irn, pos, def);
350 obstack_free(&obst, NULL);
354 * Remove phis which are not necessary.
355 * During place_phi_functions() phi functions are put on the dominance
356 * frontiers blindly. However some of them will never be used (these
357 * have at least one predecessor which is NULL, see search_def() for
358 * this case). Since place_phi_functions() enters them into the
359 * schedule, we have to remove them from there.
361 * @param copies The set of all copies made (including the phi functions).
363 static void remove_odd_phis(pset *copies, pset *unused_copies)
367 for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
372 assert(sched_is_scheduled(irn) && "phi must be scheduled");
373 for(i = 0, n = get_irn_arity(irn); i < n && !illegal; ++i)
374 illegal = get_irn_n(irn, i) == NULL;
381 for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
386 void be_ssa_constr_phis_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *phis, pset *ignore_uses)
388 pset *irns = pset_new_ptr(n);
391 for(i = 0; i < n; ++i)
392 pset_insert_ptr(irns, nodes[i]);
393 be_ssa_constr_set_phis_ignore(info, irns, phis, ignore_uses);
397 void be_ssa_constr_ignore(dom_front_info_t *info, int n, ir_node *nodes[], pset *ignore_uses)
399 be_ssa_constr_phis_ignore(info, n, nodes, NULL, ignore_uses);
402 void be_ssa_constr(dom_front_info_t *info, int n, ir_node *nodes[])
404 pset *empty_set = be_empty_set();
405 be_ssa_constr_ignore(info, n, nodes, empty_set);
408 void be_ssa_constr_set_phis_ignore(dom_front_info_t *df, pset *nodes, pset *phis, pset *ignore_uses)
410 int n = pset_count(nodes);
411 pset *blocks = pset_new_ptr(n);
412 pset *phi_blocks = pset_new_ptr(n);
413 int save_optimize = get_optimize();
414 int save_normalize = get_opt_normalize();
415 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
419 DBG((dbg, LEVEL_1, "Introducing following copies for:\n"));
422 for(irn = pset_first(nodes); irn; irn = pset_next(nodes)) {
423 ir_node *bl = get_nodes_block(irn);
424 pset_insert_ptr(blocks, bl);
425 DBG((dbg, LEVEL_1, "\t%+F in %+F\n", irn, bl));
429 * Disable optimization so that the phi functions do not
433 set_opt_normalize(0);
436 * Place the phi functions and reroute the usages.
438 determine_phi_blocks(nodes, blocks, phi_blocks, df);
439 fix_usages(nodes, blocks, phi_blocks, phis, ignore_uses);
441 /* reset the optimizations */
442 set_optimize(save_optimize);
443 set_opt_normalize(save_normalize);
445 del_pset(phi_blocks);
450 void be_ssa_constr_set_phis(dom_front_info_t *df, pset *nodes, pset *phis)
452 pset *empty_set = be_empty_set();
453 be_ssa_constr_set_phis_ignore(df, nodes, phis, empty_set);
456 void be_ssa_constr_set_ignore(dom_front_info_t *df, pset *nodes, pset *ignore_uses)
458 be_ssa_constr_set_phis_ignore(df, nodes, NULL, ignore_uses);
461 void be_ssa_constr_set(dom_front_info_t *info, pset *nodes)
463 pset *empty_set = be_empty_set();
464 be_ssa_constr_set_ignore(info, nodes, empty_set);
469 |_ _|_ __ ___ ___ _ __| |_ | _ \ ___ _ __ _ __ ___
470 | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ '__| '_ ` _ \
471 | || | | \__ \ __/ | | |_ | __/ __/ | | | | | | |
472 |___|_| |_|___/\___|_| \__| |_| \___|_| |_| |_| |_|
476 ir_node *insert_Perm_after(const arch_env_t *arch_env,
477 const arch_register_class_t *cls,
478 dom_front_info_t *dom_front,
481 ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
482 ir_graph *irg = get_irn_irg(bl);
483 pset *live = pset_new_ptr_default();
484 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, "be.node");
486 ir_node *curr, *irn, *perm, **nodes;
489 DBG((dbg, LEVEL_1, "Insert Perm after: %+F\n", pos));
491 be_liveness_nodes_live_at(arch_env, cls, pos, live);
493 n = pset_count(live);
500 nodes = xmalloc(n * sizeof(nodes[0]));
502 DBG((dbg, LEVEL_1, "live:\n"));
503 for(irn = pset_first(live), i = 0; irn; irn = pset_next(live), i++) {
504 DBG((dbg, LEVEL_1, "\t%+F\n", irn));
509 perm = be_new_Perm(cls, irg, bl, n, nodes);
510 sched_add_after(pos, perm);
514 for(i = 0; i < n; ++i) {
516 ir_node *perm_op = get_irn_n(perm, i);
517 const arch_register_t *reg = arch_get_irn_register(arch_env, perm_op);
519 ir_mode *mode = get_irn_mode(perm_op);
520 ir_node *proj = new_r_Proj(irg, bl, perm, mode, i);
521 arch_set_irn_register(arch_env, proj, reg);
523 sched_add_after(curr, proj);
528 be_ssa_constr(dom_front, 2, copies);