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4 * This file is part of libFirm.
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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
22 * @brief Procedure cloning.
23 * @author Beyhan Veliev, Michael Beck
27 * The purpose is first to find and analyze functions, that are called
28 * with constant parameter(s).
29 * The second step is to optimize the function that are found from our
30 * analyze. Optimize mean to make a new function with parameters, that
31 * aren't be constant. The constant parameters of the function are placed
32 * in the function graph. They aren't be passed as parameters.
38 #include "iroptimize.h"
44 #include "analyze_irg_args.h"
55 * This struct contains the information quadruple for a Call, which we need to
56 * decide if this function must be cloned.
58 typedef struct quadruple {
59 ir_entity *ent; /**< The entity of our Call. */
60 int pos; /**< Position of a constant argument of our Call. */
61 tarval *tv; /**< The tarval of this argument if Const node. */
62 ir_node **calls; /**< The list of all calls with the same characteristics */
66 * The quadruplets are hold in a sorted list
68 typedef struct entry {
69 quadruple_t q; /**< the quadruple */
70 float weight; /**< its weight */
71 struct entry *next; /**< link to the next one */
74 typedef struct q_set {
75 struct obstack obst; /**< an obstack containing all entries */
76 pset *map; /**< a hash map containing the quadruples */
77 entry_t *heavy_uses; /**< the ordered list of heavy uses */
81 * Compare two quadruplets.
83 * @return zero if they are identically, non-zero else
85 static int entry_cmp(const void *elt, const void *key)
87 const entry_t *e1 = elt;
88 const entry_t *e2 = key;
90 return (e1->q.ent != e2->q.ent) || (e1->q.pos != e2->q.pos) || (e1->q.tv != e2->q.tv);
94 * Hash an element of type entry_t.
96 * @param entry The element to be hashed.
98 static int hash_entry(const entry_t *entry)
100 return HASH_PTR(entry->q.ent) ^ HASH_PTR(entry->q.tv) ^ (entry->q.pos * 9);
104 * Free memory associated with a quadruplet.
106 static void kill_entry(entry_t *entry)
108 if (entry->q.calls) {
109 DEL_ARR_F(entry->q.calls);
110 entry->q.calls = NULL;
115 * Process a call node.
117 * @param call A ir_node to be checked.
118 * @param callee The entity of the callee
119 * @param hmap The quadruple-set containing the calls with constant parameters
121 static void process_call(ir_node *call, ir_entity *callee, q_set *hmap)
124 entry_t *key, *entry;
128 n_params = get_Call_n_params(call);
130 /* Beware: we cannot clone variadic parameters as well as the
131 * last non-variadic one, which might be needed for the va_start()
134 mtp = get_Call_type(call);
135 if (get_method_variadicity(mtp) != variadicity_non_variadic) {
136 n_params = get_method_first_variadic_param_index(mtp) - 1;
139 /* In this for loop we collect the calls, that have
140 an constant parameter. */
141 for (i = n_params - 1; i >= 0; --i) {
142 call_param = get_Call_param(call, i);
143 if (is_Const(call_param)) {
144 /* we have found a Call to collect and we save the informations,
147 hmap->map = new_pset(entry_cmp, 8);
149 key = OALLOC(&hmap->obst, entry_t);
153 key->q.tv = get_Const_tarval(call_param);
158 /* We insert our information in the set, where we collect the calls.*/
159 entry = pset_insert(hmap->map, key, hash_entry(key));
162 obstack_free(&hmap->obst, key);
164 /* add the call to the list */
165 if (! entry->q.calls) {
166 entry->q.calls = NEW_ARR_F(ir_node *, 1);
167 entry->q.calls[0] = call;
169 ARR_APP1(ir_node *, entry->q.calls, call);
175 * Collect all calls in a ir_graph to a set.
177 * @param call A ir_node to be checked.
178 * @param env The quadruple-set containing the calls with constant parameters
180 static void collect_irg_calls(ir_node *call, void *env)
186 /* We collect just "Call" nodes */
188 call_ptr = get_Call_ptr(call);
190 if (! is_Global(call_ptr))
193 callee = get_Global_entity(call_ptr);
195 /* we don't know which function gets finally bound to a weak symbol */
196 if (get_entity_linkage(callee) & IR_LINKAGE_WEAK)
199 /* we can only clone calls to existing entities */
200 if (get_entity_irg(callee) == NULL)
203 process_call(call, callee, hmap);
208 * Make a name for a clone. The clone name is
209 * the name of the original method suffixed with "_cl_pos_nr".
210 * pos is the pos from our quadruplet and nr is a counter.
212 * @param id The ident of the cloned function.
213 * @param pos The "pos" from our quadruplet.
214 * @param nr A counter for the clones.
216 static ident *get_clone_ident(ident *id, int pos, unsigned nr)
218 char clone_postfix[32];
220 snprintf(clone_postfix, sizeof(clone_postfix), "_cl_%d_%u", pos, nr);
222 return id_mangle(id, new_id_from_str(clone_postfix));
226 * Pre-Walker: Copies blocks and nodes from the original method graph
227 * to the cloned graph. Fixes the argument projection numbers for
228 * all arguments behind the removed one.
230 * @param irn A node from the original method graph.
231 * @param env The clone graph.
233 static void copy_nodes(ir_node *irn, void *env)
235 ir_node *arg, *irg_args, *irn_copy;
237 ir_graph *clone_irg = env;
239 arg = get_irg_link(clone_irg);
240 irg_args = get_Proj_pred(arg);
242 /* Copy all nodes except the arg. */
244 copy_irn_to_irg(irn, clone_irg);
246 irn_copy = get_irn_link(irn);
248 /* Fix argument numbers */
249 if (is_Proj(irn) && get_Proj_pred(irn) == irg_args) {
250 proj_nr = get_Proj_proj(irn);
251 if (get_Proj_proj(arg) < proj_nr)
252 set_Proj_proj(irn_copy, proj_nr - 1);
257 * Post-walker: Set the predecessors of the copied nodes.
258 * The copied nodes are set as link of their original nodes. The links of
259 * "irn" predecessors are the predecessors of copied node.
261 static void set_preds(ir_node *irn, void *env)
264 ir_node *irn_copy, *pred, *arg;
265 ir_graph *clone_irg = env;
267 arg = get_irg_link(clone_irg);
268 /* Arg is the method argument, that we have replaced by a constant.*/
272 irn_copy = get_irn_link(irn);
275 set_Block_MacroBlock(irn_copy, get_irn_link(get_Block_MacroBlock(irn)));
276 for (i = get_Block_n_cfgpreds(irn) - 1; i >= 0; i--) {
277 pred = get_Block_cfgpred(irn, i);
278 /* "End" block must be handled extra, because it is not matured.*/
279 if (get_irg_end_block(current_ir_graph) == irn)
280 add_immBlock_pred(get_irg_end_block(clone_irg), get_irn_link(pred));
282 set_Block_cfgpred(irn_copy, i, get_irn_link(pred));
285 /* First we set the block our copy if it is not a block.*/
286 set_nodes_block(irn_copy, get_irn_link(get_nodes_block(irn)));
288 /* Handle the keep-alives. This must be done separately, because
289 the End node was NOT copied */
290 for (i = 0; i < get_End_n_keepalives(irn); ++i)
291 add_End_keepalive(irn_copy, get_irn_link(get_End_keepalive(irn, i)));
293 for (i = get_irn_arity(irn) - 1; i >= 0; i--) {
294 pred = get_irn_n(irn, i);
295 set_irn_n(irn_copy, i, get_irn_link(pred));
302 * Get the method argument at the position "pos".
304 * @param irg irg that must be cloned.
305 * @param pos The position of the argument.
307 static ir_node *get_irg_arg(ir_graph *irg, int pos)
309 ir_node *irg_args = get_irg_args(irg), *arg = NULL;
312 /* Call algorithm that computes the out edges */
313 assure_irg_outs(irg);
315 /* Search the argument with the number pos.*/
316 for (i = get_irn_n_outs(irg_args) - 1; i >= 0; --i) {
317 ir_node *proj = get_irn_out(irg_args, i);
318 if (pos == get_Proj_proj(proj)) {
321 * More than one arg node found:
322 * We rely on the fact the only one arg exists, so do
323 * a cheap CSE in this case.
325 set_irn_out(irg_args, i, arg, 0);
331 assert(arg && "Argument not found");
336 * Create a new graph for the clone of the method,
337 * that we want to clone.
339 * @param ent The entity of the method that must be cloned.
340 * @param q Our quadruplet.
342 static void create_clone_proc_irg(ir_entity *ent, quadruple_t *q)
344 ir_graph *method_irg, *clone_irg;
345 ir_node *arg, *const_arg;
347 method_irg = get_entity_irg(ent);
349 /* We create the skeleton of the clone irg.*/
350 clone_irg = new_ir_graph(ent, 0);
352 arg = get_irg_arg(get_entity_irg(q->ent), q->pos);
353 /* we will replace the argument in position "q->pos" by this constant. */
354 const_arg = new_r_Const_type(
356 get_method_param_type(get_entity_type(q->ent), q->pos));
358 /* args copy in the cloned graph will be the const. */
359 set_irn_link(arg, const_arg);
361 /* Store the arg that will be replaced here, so we can easily detect it. */
362 set_irg_link(clone_irg, arg);
364 /* We copy the blocks and nodes, that must be in
365 the clone graph and set their predecessors. */
366 irg_walk_graph(method_irg, copy_nodes, set_preds, clone_irg);
368 /* The "cloned" graph must be matured. */
369 mature_immBlock(get_irg_end_block(clone_irg));
370 irg_finalize_cons(clone_irg);
374 * The function create a new entity type
375 * for our clone and set it to clone entity.
377 * @param q Contains information for the method to clone.
378 * @param ent The entity of the clone.
379 * @param nr A pointer to the counter of clones.
381 static void change_entity_type(quadruple_t *q, ir_entity *ent)
383 ir_type *mtp, *new_mtp, *tp;
384 int i, j, n_params, n_ress;
386 mtp = get_entity_type(q->ent);
387 n_params = get_method_n_params(mtp);
388 n_ress = get_method_n_ress(mtp);
390 /* Create the new type for our clone. It must have one parameter
391 less then the original.*/
392 new_mtp = new_type_method(n_params - 1, n_ress);
394 /* We must set the type of the methods parameters.*/
395 for (i = j = 0; i < n_params; ++i) {
397 /* This is the position of the argument, that we have
401 tp = get_method_param_type(mtp, i);
402 set_method_param_type(new_mtp, j++, tp);
404 /* Copy the methods result types. */
405 for (i = 0; i < n_ress; ++i) {
406 tp = get_method_res_type(mtp, i);
407 set_method_res_type(new_mtp, i, tp);
409 set_entity_type(ent, new_mtp);
413 * Make a clone of a method.
415 * @param q Contains information for the method to clone.
417 static ir_entity *clone_method(quadruple_t *q)
419 ir_entity *new_entity;
422 /* A counter for the clones.*/
423 static unsigned nr = 0;
425 /* We get a new ident for our clone method.*/
426 clone_ident = get_clone_ident(get_entity_ident(q->ent), q->pos, nr);
427 /* We get our entity for the clone method. */
428 new_entity = copy_entity_name(q->ent, clone_ident);
430 /* a cloned entity is always local */
431 set_entity_visibility(new_entity, ir_visibility_local);
433 /* set a ld name here: Should we mangle this ? */
434 set_entity_ld_ident(new_entity, get_entity_ident(new_entity));
436 /* set a new type here. */
437 change_entity_type(q, new_entity);
439 /* We need now a new ir_graph for our clone method. */
440 create_clone_proc_irg(new_entity, q);
442 /* We must set the atomic value of our "new_entity". */
443 sym.entity_p = new_entity;
445 /* The "new_entity" don't have this information. */
446 new_entity->attr.mtd_attr.param_access = NULL;
447 new_entity->attr.mtd_attr.param_weight = NULL;
453 * Creates a new "cloned" Call node and return it.
455 * @param call The call that must be cloned.
456 * @param new_entity The entity of the cloned function.
457 * @param pos The position of the replaced parameter of this call.
459 static ir_node *new_cl_Call(ir_node *call, ir_entity *new_entity, int pos)
462 int i, n_params, new_params = 0;
465 ir_graph *irg = get_irn_irg(call);
466 ir_node *bl = get_nodes_block(call);
468 sym.entity_p = new_entity;
469 callee = new_r_SymConst(irg, mode_P_code, sym, symconst_addr_ent);
471 n_params = get_Call_n_params(call);
472 NEW_ARR_A(ir_node *, in, n_params - 1);
474 /* we save the parameters of the new call in the array "in" without the
475 * parameter in position "pos", that is replaced with a constant.*/
476 for (i = 0; i < n_params; i++){
478 in[new_params++] = get_Call_param(call, i);
480 /* Create and return the new Call. */
481 return new_r_Call(bl, get_Call_mem(call),
482 callee, n_params - 1, in, get_entity_type(new_entity));
486 * Exchange all Calls stored in the quadruplet to Calls of the cloned entity.
488 * @param q The quadruple
489 * @param cloned_ent The entity of the new function that must be called
492 static void exchange_calls(quadruple_t *q, ir_entity *cloned_ent)
495 ir_node *new_call, *call;
498 /* We iterate the list of the "call".*/
499 for (i = 0; i < ARR_LEN(q->calls); ++i) {
502 /* A clone exist and the copy of "call" in this
503 * clone graph must be exchanged with new one.*/
504 new_call = new_cl_Call(call, cloned_ent, pos);
505 exchange(call, new_call);
510 * The weight formula:
511 * We save one instruction in every caller and param_weight instructions
514 static float calculate_weight(const entry_t *entry)
516 return ARR_LEN(entry->q.calls) *
517 (float)(get_method_param_weight(entry->q.ent, entry->q.pos) + 1);
521 * After we exchanged all calls, some entries on the list for
522 * the next cloned entity may get invalid, so we have to check
523 * them and may even update the list of heavy uses.
525 static void reorder_weights(q_set *hmap, float threshold)
527 entry_t **adr, *p, *entry;
532 entry = hmap->heavy_uses;
536 len = ARR_LEN(entry->q.calls);
537 for (i = 0; i < len; ++i) {
538 ir_node *ptr, *call = entry->q.calls[i];
540 /* might be exchanged, so skip Id nodes here. */
541 call = skip_Id(call);
543 /* we know, that a SymConst is here */
544 ptr = get_Call_ptr(call);
545 assert(is_SymConst(ptr));
547 callee = get_SymConst_entity(ptr);
548 if (callee != entry->q.ent) {
550 * This call is already changed because of a previous
551 * optimization. Remove it from the list.
554 entry->q.calls[i] = entry->q.calls[len];
555 entry->q.calls[len] = NULL;
557 /* the new call should be processed */
558 process_call(call, callee, hmap);
563 /* the length might be changed */
564 ARR_SHRINKLEN(entry->q.calls, len);
566 /* recalculate the weight and resort the heavy uses map */
567 entry->weight = calculate_weight(entry);
569 if (len <= 0 || entry->weight < threshold) {
570 hmap->heavy_uses = entry->next;
573 /* we have changed the list, check the next one */
578 for (p = entry->next; p && entry->weight < p->weight; p = p->next) {
583 hmap->heavy_uses = entry->next;
586 entry = hmap->heavy_uses;
588 /* we have changed the list, check the next one */
594 * Do the procedure cloning. Evaluate a heuristic weight for every
595 * call(..., Const, ...). If the weight is bigger than threshold,
596 * clone the entity and fix the calls.
598 void proc_cloning(float threshold)
600 entry_t *entry = NULL, *p;
605 obstack_init(&hmap.obst);
607 hmap.heavy_uses = NULL;
609 /* initially fill our map by visiting all irgs */
610 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
611 irg = get_irp_irg(i);
612 irg_walk_graph(irg, collect_irg_calls, NULL, &hmap);
615 /* We have the "Call" nodes to optimize in set "set_entries". Our algorithm
616 replace one constant parameter and make a new "Call" node for all found "Calls". It exchange the
617 old one with the new one and the algorithm is called with the new "Call".
619 while (hmap.map || hmap.heavy_uses) {
620 /* We iterate the set and arrange the element of the set in a list.
621 The elements are arranged dependent of their value descending.*/
623 foreach_pset(hmap.map, entry) {
624 entry->weight = calculate_weight(entry);
627 * Do not put entry with a weight < threshold in the list
629 if (entry->weight < threshold) {
634 /* put entry in the heavy uses list */
636 if (! hmap.heavy_uses)
637 hmap.heavy_uses = entry;
639 if (entry->weight >= hmap.heavy_uses->weight) {
640 entry->next = hmap.heavy_uses;
641 hmap.heavy_uses = entry;
643 for (p = hmap.heavy_uses; p->next; p = p->next) {
644 if (entry->weight >= p->next->weight) {
645 entry->next = p->next;
659 /* Print some information about the list. */
660 printf("-----------------\n");
661 for (entry = hmap.heavy_uses; entry; entry = entry->next) {
662 printf("\nweight: is %f\n", entry->weight);
663 ir_printf("Call for Method %E\n", entry->q.ent);
664 printf("Position %i\n", entry->q.pos);
665 ir_printf("Value %T\n", entry->q.tv);
668 entry = hmap.heavy_uses;
670 ir_entity *ent = clone_method(&entry->q);
672 hmap.heavy_uses = entry->next;
674 /* We must exchange the copies of this call in all clones too.*/
675 exchange_calls(&entry->q, ent);
679 * after we exchanged all calls, some entries on the list for
680 * the next cloned entity may get invalid, so we have to check
681 * them and may even update the list of heavy uses.
683 reorder_weights(&hmap, threshold);
686 obstack_free(&hmap.obst, NULL);
695 * Wrapper to run proc_cloning() as an ir_prog pass.
697 static int proc_cloning_wrapper(ir_prog *irp, void *context)
699 struct pass_t *pass = context;
702 proc_cloning(pass->threshold);
706 /* create a ir_prog pass */
707 ir_prog_pass_t *proc_cloning_pass(const char *name, float threshold)
709 struct pass_t *pass = XMALLOCZ(struct pass_t);
711 pass->threshold = threshold;
712 return def_prog_pass_constructor(
713 &pass->pass, name ? name : "cloning", proc_cloning_wrapper);