3 * File name: ir/ir/irgopt.c
4 * Purpose: Optimizations for a whole ir graph, i.e., a procedure.
5 * Author: Christian Schaefer, Goetz Lindenmaier
6 * Modified by: Sebastian Felis
9 * Copyright: (c) 1998-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
23 # include "irnode_t.h"
24 # include "irgraph_t.h"
32 # include "pdeq.h" /* Fuer code placement */
35 # include "irbackedge_t.h"
37 /* Defined in iropt.c */
38 pset *new_identities (void);
39 void del_identities (pset *value_table);
40 void add_identities (pset *value_table, ir_node *node);
42 /********************************************************************/
43 /* apply optimizations of iropt to all nodes. */
44 /********************************************************************/
46 static void init_link (ir_node *n, void *env) {
47 set_irn_link(n, NULL);
50 #if 0 /* Old version. Avoids Ids.
51 This is not necessary: we do a postwalk, and get_irn_n
52 removes ids anyways. So it's much cheaper to call the
53 optimization less often and use the exchange() algorithm. */
55 optimize_in_place_wrapper (ir_node *n, void *env) {
57 ir_node *optimized, *old;
59 irn_arity = get_irn_arity(n);
60 for (i = 0; i < irn_arity; i++) {
61 /* get_irn_n skips Id nodes, so comparison old != optimized does not
62 show all optimizations. Therefore always set new predecessor. */
63 old = get_irn_n(n, i);
64 optimized = optimize_in_place_2(old);
65 set_irn_n(n, i, optimized);
68 if (get_irn_op(n) == op_Block) {
69 optimized = optimize_in_place_2(n);
70 if (optimized != n) exchange (n, optimized);
75 optimize_in_place_wrapper (ir_node *n, void *env) {
76 ir_node *optimized = optimize_in_place_2(n);
77 if (optimized != n) exchange (n, optimized);
84 local_optimize_graph (ir_graph *irg) {
85 ir_graph *rem = current_ir_graph;
86 current_ir_graph = irg;
88 /* Handle graph state */
89 assert(get_irg_phase_state(irg) != phase_building);
90 if (get_opt_global_cse())
91 set_irg_pinned(current_ir_graph, floats);
92 if (get_irg_outs_state(current_ir_graph) == outs_consistent)
93 set_irg_outs_inconsistent(current_ir_graph);
94 if (get_irg_dom_state(current_ir_graph) == dom_consistent)
95 set_irg_dom_inconsistent(current_ir_graph);
97 /* Clean the value_table in irg for the cse. */
98 del_identities(irg->value_table);
99 irg->value_table = new_identities();
101 /* walk over the graph */
102 irg_walk(irg->end, init_link, optimize_in_place_wrapper, NULL);
104 current_ir_graph = rem;
107 /********************************************************************/
108 /* Routines for dead node elimination / copying garbage collection */
109 /* of the obstack. */
110 /********************************************************************/
112 /* Remeber the new node in the old node by using a field all nodes have. */
114 set_new_node (ir_node *old, ir_node *new)
119 /* Get this new node, before the old node is forgotton.*/
120 static INLINE ir_node *
121 get_new_node (ir_node * n)
126 /* We use the block_visited flag to mark that we have computed the
127 number of useful predecessors for this block.
128 Further we encode the new arity in this flag in the old blocks.
129 Remembering the arity is useful, as it saves a lot of pointer
130 accesses. This function is called for all Phi and Block nodes
133 compute_new_arity(ir_node *b) {
134 int i, res, irn_arity;
137 irg_v = get_irg_block_visited(current_ir_graph);
138 block_v = get_Block_block_visited(b);
139 if (block_v >= irg_v) {
140 /* we computed the number of preds for this block and saved it in the
142 return block_v - irg_v;
144 /* compute the number of good predecessors */
145 res = irn_arity = get_irn_arity(b);
146 for (i = 0; i < irn_arity; i++)
147 if (get_irn_opcode(get_irn_n(b, i)) == iro_Bad) res--;
148 /* save it in the flag. */
149 set_Block_block_visited(b, irg_v + res);
154 static INLINE void new_backedge_info(ir_node *n) {
155 switch(get_irn_opcode(n)) {
157 n->attr.block.cg_backedge = NULL;
158 n->attr.block.backedge = new_backedge_arr(current_ir_graph->obst, get_irn_arity(n));
161 n->attr.phi_backedge = new_backedge_arr(current_ir_graph->obst, get_irn_arity(n));
164 n->attr.filter.backedge = new_backedge_arr(current_ir_graph->obst, get_irn_arity(n));
170 /* Copies the node to the new obstack. The Ins of the new node point to
171 the predecessors on the old obstack. For block/phi nodes not all
172 predecessors might be copied. n->link points to the new node.
173 For Phi and Block nodes the function allocates in-arrays with an arity
174 only for useful predecessors. The arity is determined by counting
175 the non-bad predecessors of the block. */
177 copy_node (ir_node *n, void *env) {
181 /* The end node looses it's flexible in array. This doesn't matter,
182 as dead node elimination builds End by hand, inlineing doesn't use
184 //assert(n->op == op_End || ((_ARR_DESCR(n->in))->cookie != ARR_F_MAGIC));
186 if (get_irn_opcode(n) == iro_Block) {
188 new_arity = compute_new_arity(n);
189 n->attr.block.graph_arr = NULL;
191 block = get_nodes_Block(n);
192 if (get_irn_opcode(n) == iro_Phi) {
193 new_arity = compute_new_arity(block);
195 new_arity = get_irn_arity(n);
198 nn = new_ir_node(get_irn_dbg_info(n),
205 /* Copy the attributes. These might point to additional data. If this
206 was allocated on the old obstack the pointers now are dangling. This
207 frees e.g. the memory of the graph_arr allocated in new_immBlock. */
209 new_backedge_info(nn);
212 /* printf("\n old node: "); DDMSG2(n);
213 printf(" new node: "); DDMSG2(nn); */
217 /* Copies new predecessors of old node to new node remembered in link.
218 Spare the Bad predecessors of Phi and Block nodes. */
220 copy_preds (ir_node *n, void *env) {
224 nn = get_new_node(n);
226 /* printf("\n old node: "); DDMSG2(n);
227 printf(" new node: "); DDMSG2(nn);
228 printf(" arities: old: %d, new: %d\n", get_irn_arity(n), get_irn_arity(nn)); */
230 if (get_irn_opcode(n) == iro_Block) {
231 /* Don't copy Bad nodes. */
233 irn_arity = get_irn_arity(n);
234 for (i = 0; i < irn_arity; i++)
235 if (get_irn_opcode(get_irn_n(n, i)) != iro_Bad) {
236 set_irn_n (nn, j, get_new_node(get_irn_n(n, i)));
237 /*if (is_backedge(n, i)) set_backedge(nn, j);*/
240 /* repair the block visited flag from above misuse. Repair it in both
241 graphs so that the old one can still be used. */
242 set_Block_block_visited(nn, 0);
243 set_Block_block_visited(n, 0);
244 /* Local optimization could not merge two subsequent blocks if
245 in array contained Bads. Now it's possible.
246 We don't call optimize_in_place as it requires
247 that the fields in ir_graph are set properly. */
248 if ((get_opt_control_flow_straightening()) &&
249 (get_Block_n_cfgpreds(nn) == 1) &&
250 (get_irn_op(get_Block_cfgpred(nn, 0)) == op_Jmp))
251 exchange(nn, get_nodes_Block(get_Block_cfgpred(nn, 0)));
252 } else if (get_irn_opcode(n) == iro_Phi) {
253 /* Don't copy node if corresponding predecessor in block is Bad.
254 The Block itself should not be Bad. */
255 block = get_nodes_Block(n);
256 set_irn_n (nn, -1, get_new_node(block));
258 irn_arity = get_irn_arity(n);
259 for (i = 0; i < irn_arity; i++)
260 if (get_irn_opcode(get_irn_n(block, i)) != iro_Bad) {
261 set_irn_n (nn, j, get_new_node(get_irn_n(n, i)));
262 /*if (is_backedge(n, i)) set_backedge(nn, j);*/
265 /* If the pre walker reached this Phi after the post walker visited the
266 block block_visited is > 0. */
267 set_Block_block_visited(get_nodes_Block(n), 0);
268 /* Compacting the Phi's ins might generate Phis with only one
270 if (get_irn_arity(n) == 1)
271 exchange(n, get_irn_n(n, 0));
273 irn_arity = get_irn_arity(n);
274 for (i = -1; i < irn_arity; i++)
275 set_irn_n (nn, i, get_new_node(get_irn_n(n, i)));
277 /* Now the new node is complete. We can add it to the hash table for cse.
278 @@@ inlinening aborts if we identify End. Why? */
279 if(get_irn_op(nn) != op_End)
280 add_identities (current_ir_graph->value_table, nn);
283 /* Copies the graph recursively, compacts the keepalive of the end node. */
286 ir_node *oe, *ne; /* old end, new end */
287 ir_node *ka; /* keep alive */
290 oe = get_irg_end(current_ir_graph);
291 /* copy the end node by hand, allocate dynamic in array! */
292 ne = new_ir_node(get_irn_dbg_info(oe),
299 /* Copy the attributes. Well, there might be some in the future... */
301 set_new_node(oe, ne);
303 /* copy the live nodes */
304 irg_walk(get_nodes_Block(oe), copy_node, copy_preds, NULL);
305 /* copy_preds for the end node ... */
306 set_nodes_Block(ne, get_new_node(get_nodes_Block(oe)));
308 /** ... and now the keep alives. **/
309 /* First pick the not marked block nodes and walk them. We must pick these
310 first as else we will oversee blocks reachable from Phis. */
311 irn_arity = get_irn_arity(oe);
312 for (i = 0; i < irn_arity; i++) {
313 ka = get_irn_n(oe, i);
314 if ((get_irn_op(ka) == op_Block) &&
315 (get_irn_visited(ka) < get_irg_visited(current_ir_graph))) {
316 /* We must keep the block alive and copy everything reachable */
317 set_irg_visited(current_ir_graph, get_irg_visited(current_ir_graph)-1);
318 irg_walk(ka, copy_node, copy_preds, NULL);
319 add_End_keepalive(ne, get_new_node(ka));
323 /* Now pick the Phis. Here we will keep all! */
324 irn_arity = get_irn_arity(oe);
325 for (i = 0; i < irn_arity; i++) {
326 ka = get_irn_n(oe, i);
327 if ((get_irn_op(ka) == op_Phi)) {
328 if (get_irn_visited(ka) < get_irg_visited(current_ir_graph)) {
329 /* We didn't copy the Phi yet. */
330 set_irg_visited(current_ir_graph, get_irg_visited(current_ir_graph)-1);
331 irg_walk(ka, copy_node, copy_preds, NULL);
333 add_End_keepalive(ne, get_new_node(ka));
338 /* Copies the graph reachable from current_ir_graph->end to the obstack
339 in current_ir_graph and fixes the environment.
340 Then fixes the fields in current_ir_graph containing nodes of the
343 copy_graph_env (void) {
345 /* Not all nodes remembered in current_ir_graph might be reachable
346 from the end node. Assure their link is set to NULL, so that
347 we can test whether new nodes have been computed. */
348 set_irn_link(get_irg_frame (current_ir_graph), NULL);
349 set_irn_link(get_irg_globals(current_ir_graph), NULL);
350 set_irn_link(get_irg_args (current_ir_graph), NULL);
352 /* we use the block walk flag for removing Bads from Blocks ins. */
353 inc_irg_block_visited(current_ir_graph);
358 /* fix the fields in current_ir_graph */
359 old_end = get_irg_end(current_ir_graph);
360 set_irg_end (current_ir_graph, get_new_node(old_end));
362 set_irg_end_block (current_ir_graph, get_new_node(get_irg_end_block(current_ir_graph)));
363 if (get_irn_link(get_irg_frame(current_ir_graph)) == NULL) {
364 copy_node (get_irg_frame(current_ir_graph), NULL);
365 copy_preds(get_irg_frame(current_ir_graph), NULL);
367 if (get_irn_link(get_irg_globals(current_ir_graph)) == NULL) {
368 copy_node (get_irg_globals(current_ir_graph), NULL);
369 copy_preds(get_irg_globals(current_ir_graph), NULL);
371 if (get_irn_link(get_irg_args(current_ir_graph)) == NULL) {
372 copy_node (get_irg_args(current_ir_graph), NULL);
373 copy_preds(get_irg_args(current_ir_graph), NULL);
375 set_irg_start (current_ir_graph, get_new_node(get_irg_start(current_ir_graph)));
377 set_irg_start_block(current_ir_graph,
378 get_new_node(get_irg_start_block(current_ir_graph)));
379 set_irg_frame (current_ir_graph, get_new_node(get_irg_frame(current_ir_graph)));
380 set_irg_globals(current_ir_graph, get_new_node(get_irg_globals(current_ir_graph)));
381 set_irg_args (current_ir_graph, get_new_node(get_irg_args(current_ir_graph)));
382 if (get_irn_link(get_irg_bad(current_ir_graph)) == NULL) {
383 copy_node(get_irg_bad(current_ir_graph), NULL);
384 copy_preds(get_irg_bad(current_ir_graph), NULL);
386 set_irg_bad(current_ir_graph, get_new_node(get_irg_bad(current_ir_graph)));
387 /* GL removed: we need unknown with mode for analyses.
388 if (get_irn_link(get_irg_unknown(current_ir_graph)) == NULL) {
389 copy_node(get_irg_unknown(current_ir_graph), NULL);
390 copy_preds(get_irg_unknown(current_ir_graph), NULL);
392 set_irg_unknown(current_ir_graph, get_new_node(get_irg_unknown(current_ir_graph)));
396 /* Copies all reachable nodes to a new obstack. Removes bad inputs
397 from block nodes and the corresponding inputs from Phi nodes.
398 Merges single exit blocks with single entry blocks and removes
400 Adds all new nodes to a new hash table for cse. Does not
401 perform cse, so the hash table might contain common subexpressions. */
402 /* Amroq call this emigrate() */
404 dead_node_elimination(ir_graph *irg) {
406 struct obstack *graveyard_obst = NULL;
407 struct obstack *rebirth_obst = NULL;
409 /* Remember external state of current_ir_graph. */
410 rem = current_ir_graph;
411 current_ir_graph = irg;
413 /* Handle graph state */
414 assert(get_irg_phase_state(current_ir_graph) != phase_building);
415 assert(get_irg_callee_info_state(current_ir_graph) == irg_callee_info_none);
416 free_outs(current_ir_graph);
418 /* @@@ so far we loose loops when copying */
419 set_irg_loop(current_ir_graph, NULL);
421 if (get_optimize() && get_opt_dead_node_elimination()) {
423 /* A quiet place, where the old obstack can rest in peace,
424 until it will be cremated. */
425 graveyard_obst = irg->obst;
427 /* A new obstack, where the reachable nodes will be copied to. */
428 rebirth_obst = (struct obstack *) xmalloc (sizeof (struct obstack));
429 current_ir_graph->obst = rebirth_obst;
430 obstack_init (current_ir_graph->obst);
432 /* We also need a new hash table for cse */
433 del_identities (irg->value_table);
434 irg->value_table = new_identities ();
436 /* Copy the graph from the old to the new obstack */
439 /* Free memory from old unoptimized obstack */
440 obstack_free(graveyard_obst, 0); /* First empty the obstack ... */
441 xfree (graveyard_obst); /* ... then free it. */
444 current_ir_graph = rem;
447 /* Relink bad predeseccors of a block and store the old in array to the
448 link field. This function is called by relink_bad_predecessors().
449 The array of link field starts with the block operand at position 0.
450 If block has bad predecessors, create a new in array without bad preds.
451 Otherwise let in array untouched. */
452 static void relink_bad_block_predecessors(ir_node *n, void *env) {
453 ir_node **new_in, *irn;
454 int i, new_irn_n, old_irn_arity, new_irn_arity = 0;
456 /* if link field of block is NULL, look for bad predecessors otherwise
457 this is allready done */
458 if (get_irn_op(n) == op_Block &&
459 get_irn_link(n) == NULL) {
461 /* save old predecessors in link field (position 0 is the block operand)*/
462 set_irn_link(n, (void *)get_irn_in(n));
464 /* count predecessors without bad nodes */
465 old_irn_arity = get_irn_arity(n);
466 for (i = 0; i < old_irn_arity; i++)
467 if (!is_Bad(get_irn_n(n, i))) new_irn_arity++;
469 /* arity changing: set new predecessors without bad nodes */
470 if (new_irn_arity < old_irn_arity) {
471 /* get new predecessor array without Block predecessor */
472 new_in = NEW_ARR_D (ir_node *, current_ir_graph->obst, (new_irn_arity+1));
474 /* set new predeseccors in array */
477 for (i = 1; i < old_irn_arity; i++) {
478 irn = get_irn_n(n, i);
479 if (!is_Bad(irn)) new_in[new_irn_n++] = irn;
482 } /* ir node has bad predecessors */
484 } /* Block is not relinked */
487 /* Relinks Bad predecesors from Bocks and Phis called by walker
488 remove_bad_predecesors(). If n is a Block, call
489 relink_bad_block_redecessors(). If n is a Phinode, call also the relinking
490 function of Phi's Block. If this block has bad predecessors, relink preds
492 static void relink_bad_predecessors(ir_node *n, void *env) {
493 ir_node *block, **old_in;
494 int i, old_irn_arity, new_irn_arity;
496 /* relink bad predeseccors of a block */
497 if (get_irn_op(n) == op_Block)
498 relink_bad_block_predecessors(n, env);
500 /* If Phi node relink its block and its predecessors */
501 if (get_irn_op(n) == op_Phi) {
503 /* Relink predeseccors of phi's block */
504 block = get_nodes_Block(n);
505 if (get_irn_link(block) == NULL)
506 relink_bad_block_predecessors(block, env);
508 old_in = (ir_node **)get_irn_link(block); /* Of Phi's Block */
509 old_irn_arity = ARR_LEN(old_in);
511 /* Relink Phi predeseccors if count of predeseccors changed */
512 if (old_irn_arity != ARR_LEN(get_irn_in(block))) {
513 /* set new predeseccors in array
514 n->in[0] remains the same block */
516 for(i = 1; i < old_irn_arity; i++)
517 if (!is_Bad((ir_node *)old_in[i])) n->in[new_irn_arity++] = n->in[i];
519 ARR_SETLEN(ir_node *, n->in, new_irn_arity);
522 } /* n is a Phi node */
525 /* Removes Bad Bad predecesors from Blocks and the corresponding
526 inputs to Phi nodes as in dead_node_elimination but without
528 On walking up set the link field to NULL, on walking down call
529 relink_bad_predecessors() (This function stores the old in array
530 to the link field and sets a new in array if arity of predecessors
532 void remove_bad_predecessors(ir_graph *irg) {
533 irg_walk_graph(irg, init_link, relink_bad_predecessors, NULL);
537 /**********************************************************************/
538 /* Funcionality for inlining */
539 /**********************************************************************/
541 /* Copy node for inlineing. Updates attributes that change when
542 * inlineing but not for dead node elimination.
544 * Copies the node by calling copy_node and then updates the entity if
545 * it's a local one. env must be a pointer of the frame type of the
546 * inlined procedure. The new entities must be in the link field of
549 copy_node_inline (ir_node *n, void *env) {
551 type *frame_tp = (type *)env;
554 if (get_irn_op(n) == op_Sel) {
555 new = get_new_node (n);
556 assert(get_irn_op(new) == op_Sel);
557 if (get_entity_owner(get_Sel_entity(n)) == frame_tp) {
558 set_Sel_entity(new, get_entity_link(get_Sel_entity(n)));
560 } else if (get_irn_op(n) == op_Block) {
561 new = get_new_node (n);
562 new->attr.block.irg = current_ir_graph;
567 void inline_method(ir_node *call, ir_graph *called_graph) {
569 ir_node *post_call, *post_bl;
571 ir_node *end, *end_bl;
575 int arity, n_ret, n_exc, n_res, i, j, rem_opt, irn_arity;
576 int exc_handling; ir_node *proj;
579 if (!get_optimize() || !get_opt_inline()) return;
580 /* -- Turn off optimizations, this can cause problems when allocating new nodes. -- */
581 rem_opt = get_optimize();
584 /* Handle graph state */
585 assert(get_irg_phase_state(current_ir_graph) != phase_building);
586 assert(get_irg_pinned(current_ir_graph) == pinned);
587 assert(get_irg_pinned(called_graph) == pinned);
588 if (get_irg_outs_state(current_ir_graph) == outs_consistent)
589 set_irg_outs_inconsistent(current_ir_graph);
591 /* -- Check preconditions -- */
592 assert(get_irn_op(call) == op_Call);
593 /* @@@ does not work for InterfaceIII.java after cgana
594 assert(get_Call_type(call) == get_entity_type(get_irg_ent(called_graph)));
595 assert(smaller_type(get_entity_type(get_irg_ent(called_graph)),
596 get_Call_type(call)));
598 assert(get_type_tpop(get_Call_type(call)) == type_method);
599 if (called_graph == current_ir_graph) {
600 set_optimize(rem_opt);
604 /* -- Decide how to handle exception control flow: Is there a handler
605 for the Call node, or do we branch directly to End on an exception?
606 exc_handling: 0 There is a handler.
608 2 Exception handling not represented in Firm. -- */
610 for (proj = (ir_node *)get_irn_link(call); proj; proj = (ir_node *)get_irn_link(proj)) {
611 assert(get_irn_op(proj) == op_Proj);
612 if (get_Proj_proj(proj) == pn_Call_M_except) { exc_handling = 0; break;}
613 if (get_Proj_proj(proj) == pn_Call_X_except) { exc_handling = 1; }
617 ir_node *proj, *Mproj = NULL, *Xproj = NULL;
618 for (proj = (ir_node *)get_irn_link(call); proj; proj = (ir_node *)get_irn_link(proj)) {
619 assert(get_irn_op(proj) == op_Proj);
620 if (get_Proj_proj(proj) == pn_Call_X_except) Xproj = proj;
621 if (get_Proj_proj(proj) == pn_Call_M_except) Mproj = proj;
623 if (Mproj) { assert(Xproj); exc_handling = 0; }
624 else if (Xproj) { exc_handling = 1; }
625 else { exc_handling = 2; }
630 the procedure and later replaces the Start node of the called graph.
631 Post_call is the old Call node and collects the results of the called
632 graph. Both will end up being a tuple. -- */
633 post_bl = get_nodes_Block(call);
634 set_irg_current_block(current_ir_graph, post_bl);
635 /* XxMxPxP of Start + parameter of Call */
637 in[1] = get_Call_mem(call);
638 in[2] = get_irg_frame(current_ir_graph);
639 in[3] = get_irg_globals(current_ir_graph);
640 in[4] = new_Tuple (get_Call_n_params(call), get_Call_param_arr(call));
641 pre_call = new_Tuple(5, in);
645 The new block gets the ins of the old block, pre_call and all its
646 predecessors and all Phi nodes. -- */
647 part_block(pre_call);
649 /* -- Prepare state for dead node elimination -- */
650 /* Visited flags in calling irg must be >= flag in called irg.
651 Else walker and arity computation will not work. */
652 if (get_irg_visited(current_ir_graph) <= get_irg_visited(called_graph))
653 set_irg_visited(current_ir_graph, get_irg_visited(called_graph)+1);
654 if (get_irg_block_visited(current_ir_graph)< get_irg_block_visited(called_graph))
655 set_irg_block_visited(current_ir_graph, get_irg_block_visited(called_graph));
656 /* Set pre_call as new Start node in link field of the start node of
657 calling graph and pre_calls block as new block for the start block
659 Further mark these nodes so that they are not visited by the
661 set_irn_link(get_irg_start(called_graph), pre_call);
662 set_irn_visited(get_irg_start(called_graph),
663 get_irg_visited(current_ir_graph));
664 set_irn_link(get_irg_start_block(called_graph),
665 get_nodes_Block(pre_call));
666 set_irn_visited(get_irg_start_block(called_graph),
667 get_irg_visited(current_ir_graph));
669 /* Initialize for compaction of in arrays */
670 inc_irg_block_visited(current_ir_graph);
672 /* -- Replicate local entities of the called_graph -- */
673 /* copy the entities. */
674 called_frame = get_irg_frame_type(called_graph);
675 for (i = 0; i < get_class_n_members(called_frame); i++) {
676 entity *new_ent, *old_ent;
677 old_ent = get_class_member(called_frame, i);
678 new_ent = copy_entity_own(old_ent, get_cur_frame_type());
679 set_entity_link(old_ent, new_ent);
682 /* visited is > than that of called graph. With this trick visited will
683 remain unchanged so that an outer walker, e.g., searching the call nodes
684 to inline, calling this inline will not visit the inlined nodes. */
685 set_irg_visited(current_ir_graph, get_irg_visited(current_ir_graph)-1);
687 /* -- Performing dead node elimination inlines the graph -- */
688 /* Copies the nodes to the obstack of current_ir_graph. Updates links to new
690 /* @@@ endless loops are not copied!! -- they should be, I think... */
691 irg_walk(get_irg_end(called_graph), copy_node_inline, copy_preds,
692 get_irg_frame_type(called_graph));
694 /* Repair called_graph */
695 set_irg_visited(called_graph, get_irg_visited(current_ir_graph));
696 set_irg_block_visited(called_graph, get_irg_block_visited(current_ir_graph));
697 set_Block_block_visited(get_irg_start_block(called_graph), 0);
699 /* -- Merge the end of the inlined procedure with the call site -- */
700 /* We will turn the old Call node into a Tuple with the following
703 0: Phi of all Memories of Return statements.
704 1: Jmp from new Block that merges the control flow from all exception
705 predecessors of the old end block.
706 2: Tuple of all arguments.
707 3: Phi of Exception memories.
708 In case the old Call directly branches to End on an exception we don't
709 need the block merging all exceptions nor the Phi of the exception
713 /* -- Precompute some values -- */
714 end_bl = get_new_node(get_irg_end_block(called_graph));
715 end = get_new_node(get_irg_end(called_graph));
716 arity = get_irn_arity(end_bl); /* arity = n_exc + n_ret */
717 n_res = get_method_n_ress(get_Call_type(call));
719 res_pred = (ir_node **) malloc (n_res * sizeof (ir_node *));
720 cf_pred = (ir_node **) malloc (arity * sizeof (ir_node *));
722 set_irg_current_block(current_ir_graph, post_bl); /* just to make sure */
724 /* -- archive keepalives -- */
725 irn_arity = get_irn_arity(end);
726 for (i = 0; i < irn_arity; i++)
727 add_End_keepalive(get_irg_end(current_ir_graph), get_irn_n(end, i));
729 /* The new end node will die. We need not free as the in array is on the obstack:
730 copy_node only generated 'D' arrays. */
732 /* -- Replace Return nodes by Jump nodes. -- */
734 for (i = 0; i < arity; i++) {
736 ret = get_irn_n(end_bl, i);
737 if (get_irn_op(ret) == op_Return) {
738 cf_pred[n_ret] = new_r_Jmp(current_ir_graph, get_nodes_Block(ret));
742 set_irn_in(post_bl, n_ret, cf_pred);
744 /* -- Build a Tuple for all results of the method.
745 Add Phi node if there was more than one Return. -- */
746 turn_into_tuple(post_call, 4);
747 /* First the Memory-Phi */
749 for (i = 0; i < arity; i++) {
750 ret = get_irn_n(end_bl, i);
751 if (get_irn_op(ret) == op_Return) {
752 cf_pred[n_ret] = get_Return_mem(ret);
756 phi = new_Phi(n_ret, cf_pred, mode_M);
757 set_Tuple_pred(call, 0, phi);
758 /* Conserve Phi-list for further inlinings -- but might be optimized */
759 if (get_nodes_Block(phi) == post_bl) {
760 set_irn_link(phi, get_irn_link(post_bl));
761 set_irn_link(post_bl, phi);
763 /* Now the real results */
765 for (j = 0; j < n_res; j++) {
767 for (i = 0; i < arity; i++) {
768 ret = get_irn_n(end_bl, i);
769 if (get_irn_op(ret) == op_Return) {
770 cf_pred[n_ret] = get_Return_res(ret, j);
774 phi = new_Phi(n_ret, cf_pred, get_irn_mode(cf_pred[0]));
776 /* Conserve Phi-list for further inlinings -- but might be optimized */
777 if (get_nodes_Block(phi) == post_bl) {
778 set_irn_link(phi, get_irn_link(post_bl));
779 set_irn_link(post_bl, phi);
782 set_Tuple_pred(call, 2, new_Tuple(n_res, res_pred));
784 set_Tuple_pred(call, 2, new_Bad());
786 /* Finally the exception control flow.
787 We have two (three) possible situations:
788 First if the Call branches to an exception handler: We need to add a Phi node to
789 collect the memory containing the exception objects. Further we need
790 to add another block to get a correct representation of this Phi. To
791 this block we add a Jmp that resolves into the X output of the Call
792 when the Call is turned into a tuple.
793 Second the Call branches to End, the exception is not handled. Just
794 add all inlined exception branches to the End node.
795 Third: there is no Exception edge at all. Handle as case two. */
796 if (exc_handler == 0) {
798 for (i = 0; i < arity; i++) {
800 ret = get_irn_n(end_bl, i);
801 if (is_fragile_op(skip_Proj(ret)) || (get_irn_op(skip_Proj(ret)) == op_Raise)) {
802 cf_pred[n_exc] = ret;
807 new_Block(n_exc, cf_pred); /* watch it: current_block is changed! */
808 set_Tuple_pred(call, 1, new_Jmp());
809 /* The Phi for the memories with the exception objects */
811 for (i = 0; i < arity; i++) {
813 ret = skip_Proj(get_irn_n(end_bl, i));
814 if (get_irn_op(ret) == op_Call) {
815 cf_pred[n_exc] = new_r_Proj(current_ir_graph, get_nodes_Block(ret), ret, mode_M, 3);
817 } else if (is_fragile_op(ret)) {
818 /* We rely that all cfops have the memory output at the same position. */
819 cf_pred[n_exc] = new_r_Proj(current_ir_graph, get_nodes_Block(ret), ret, mode_M, 0);
821 } else if (get_irn_op(ret) == op_Raise) {
822 cf_pred[n_exc] = new_r_Proj(current_ir_graph, get_nodes_Block(ret), ret, mode_M, 1);
826 set_Tuple_pred(call, 3, new_Phi(n_exc, cf_pred, mode_M));
828 set_Tuple_pred(call, 1, new_Bad());
829 set_Tuple_pred(call, 3, new_Bad());
832 /* assert(exc_handler == 1 || no exceptions. ) */
834 for (i = 0; i < arity; i++) {
836 ret = get_irn_n(end_bl, i);
837 if (is_fragile_op(skip_Proj(ret)) || (get_irn_op(skip_Proj(ret)) == op_Raise)) {
838 cf_pred[n_exc] = ret;
842 ir_node *main_end_bl = get_irg_end_block(current_ir_graph);
843 int main_end_bl_arity = get_irn_arity(main_end_bl);
844 ir_node **end_preds = (ir_node **) malloc ((n_exc + main_end_bl_arity) * sizeof (ir_node *));
845 for (i = 0; i < main_end_bl_arity; ++i)
846 end_preds[i] = get_irn_n(main_end_bl, i);
847 for (i = 0; i < n_exc; ++i)
848 end_preds[main_end_bl_arity + i] = cf_pred[i];
849 set_irn_in(main_end_bl, n_exc + main_end_bl_arity, end_preds);
850 set_Tuple_pred(call, 1, new_Bad());
851 set_Tuple_pred(call, 3, new_Bad());
857 #if 0 /* old. now better, correcter, faster implementation. */
859 /* -- If the exception control flow from the inlined Call directly
860 branched to the end block we now have the following control
861 flow predecessor pattern: ProjX -> Tuple -> Jmp. We must
862 remove the Jmp along with it's empty block and add Jmp's
863 predecessors as predecessors of this end block. No problem if
864 there is no exception, because then branches Bad to End which
866 @@@ can't we know this beforehand: by getting the Proj(1) from
867 the Call link list and checking whether it goes to Proj. */
868 /* find the problematic predecessor of the end block. */
869 end_bl = get_irg_end_block(current_ir_graph);
870 for (i = 0; i < get_Block_n_cfgpreds(end_bl); i++) {
871 cf_op = get_Block_cfgpred(end_bl, i);
872 if (get_irn_op(cf_op) == op_Proj) {
873 cf_op = get_Proj_pred(cf_op);
874 if ((get_irn_op(cf_op) == op_Tuple) && (cf_op == call)) {
875 // There are unoptimized tuples from inlineing before when no exc
876 assert(get_Proj_proj(get_Block_cfgpred(end_bl, i)) == pn_Call_X_except);
877 cf_op = get_Tuple_pred(cf_op, pn_Call_X_except);
878 assert(get_irn_op(cf_op) == op_Jmp);
884 if (i < get_Block_n_cfgpreds(end_bl)) {
885 bl = get_nodes_Block(cf_op);
886 arity = get_Block_n_cfgpreds(end_bl) + get_Block_n_cfgpreds(bl) - 1;
887 cf_pred = (ir_node **) malloc (arity * sizeof (ir_node *));
888 for (j = 0; j < i; j++)
889 cf_pred[j] = get_Block_cfgpred(end_bl, j);
890 for (j = j; j < i + get_Block_n_cfgpreds(bl); j++)
891 cf_pred[j] = get_Block_cfgpred(bl, j-i);
892 for (j = j; j < arity; j++)
893 cf_pred[j] = get_Block_cfgpred(end_bl, j-get_Block_n_cfgpreds(bl) +1);
894 set_irn_in(end_bl, arity, cf_pred);
896 // Remove the exception pred from post-call Tuple.
897 set_Tuple_pred(call, pn_Call_X_except, new_Bad());
902 /* -- Turn cse back on. -- */
903 set_optimize(rem_opt);
906 /********************************************************************/
907 /* Apply inlineing to small methods. */
908 /********************************************************************/
912 /* It makes no sense to inline too many calls in one procedure. Anyways,
913 I didn't get a version with NEW_ARR_F to run. */
914 #define MAX_INLINE 1024
916 /* given an Call node, returns the irg called. NULL if not
918 static ir_graph *get_call_called_irg(ir_node *call) {
921 ir_graph *called_irg = NULL;
923 assert(get_irn_op(call) == op_Call);
925 addr = get_Call_ptr(call);
926 if (get_irn_op(addr) == op_Const) {
927 /* Check whether the constant is the pointer to a compiled entity. */
928 tv = get_Const_tarval(addr);
929 if (tarval_to_entity(tv))
930 called_irg = get_entity_irg(tarval_to_entity(tv));
935 static void collect_calls(ir_node *call, void *env) {
937 if (get_irn_op(call) != op_Call) return;
939 ir_node **calls = (ir_node **)env;
942 ir_graph *called_irg;
944 addr = get_Call_ptr(call);
945 if (get_irn_op(addr) == op_Const) {
946 /* Check whether the constant is the pointer to a compiled entity. */
947 tv = get_Const_tarval(addr);
948 if (tarval_to_entity(tv)) {
949 called_irg = get_entity_irg(tarval_to_entity(tv));
950 if (called_irg && pos < MAX_INLINE) {
951 /* The Call node calls a locally defined method. Remember to inline. */
959 /* Inlines all small methods at call sites where the called address comes
960 from a Const node that references the entity representing the called
962 The size argument is a rough measure for the code size of the method:
963 Methods where the obstack containing the firm graph is smaller than
965 void inline_small_irgs(ir_graph *irg, int size) {
967 ir_node *calls[MAX_INLINE];
968 ir_graph *rem = current_ir_graph;
970 if (!(get_optimize() && get_opt_inline())) return;
972 current_ir_graph = irg;
973 /* Handle graph state */
974 assert(get_irg_phase_state(current_ir_graph) != phase_building);
975 assert(get_irg_callee_info_state(current_ir_graph) == irg_callee_info_none);
977 /* Find Call nodes to inline.
978 (We can not inline during a walk of the graph, as inlineing the same
979 method several times changes the visited flag of the walked graph:
980 after the first inlineing visited of the callee equals visited of
981 the caller. With the next inlineing both are increased.) */
983 irg_walk(get_irg_end(irg), NULL, collect_calls, (void *) calls);
985 if ((pos > 0) && (pos < MAX_INLINE)) {
986 /* There are calls to inline */
987 collect_phiprojs(irg);
988 for (i = 0; i < pos; i++) {
991 tv = get_Const_tarval(get_Call_ptr(calls[i]));
992 callee = get_entity_irg(tarval_to_entity(tv));
993 if ((_obstack_memory_used(callee->obst) - obstack_room(callee->obst)) < size) {
994 inline_method(calls[i], callee);
999 current_ir_graph = rem;
1003 int n_nodes; /* Nodes in graph except Id, Tuple, Proj, Start, End */
1004 int n_nodes_orig; /* for statistics */
1005 eset *call_nodes; /* All call nodes in this graph */
1007 int n_call_nodes_orig; /* for statistics */
1008 int n_callers; /* Number of known graphs that call this graphs. */
1009 int n_callers_orig; /* for statistics */
1012 static inline_irg_env *new_inline_irg_env(void) {
1013 inline_irg_env *env = malloc(sizeof(inline_irg_env));
1014 env->n_nodes = -2; /* uncount Start, End */
1015 env->n_nodes_orig = -2; /* uncount Start, End */
1016 env->call_nodes = eset_create();
1017 env->n_call_nodes = 0;
1018 env->n_call_nodes_orig = 0;
1020 env->n_callers_orig = 0;
1024 static void free_inline_irg_env(inline_irg_env *env) {
1025 eset_destroy(env->call_nodes);
1029 static void collect_calls2(ir_node *call, void *env) {
1030 inline_irg_env *x = (inline_irg_env *)env;
1031 ir_op *op = get_irn_op(call);
1033 /* count nodes in irg */
1034 if (op != op_Proj && op != op_Tuple && op != op_Sync) {
1039 if (op != op_Call) return;
1041 /* collect all call nodes */
1042 eset_insert(x->call_nodes, (void *)call);
1044 x->n_call_nodes_orig++;
1046 /* count all static callers */
1047 ir_graph *callee = get_call_called_irg(call);
1049 ((inline_irg_env *)get_irg_link(callee))->n_callers++;
1050 ((inline_irg_env *)get_irg_link(callee))->n_callers_orig++;
1054 INLINE static int is_leave(ir_graph *irg) {
1055 return (((inline_irg_env *)get_irg_link(irg))->n_call_nodes == 0);
1058 INLINE static int is_smaller(ir_graph *callee, int size) {
1059 return (((inline_irg_env *)get_irg_link(callee))->n_nodes < size);
1063 /* Inlines small leave methods at call sites where the called address comes
1064 from a Const node that references the entity representing the called
1066 The size argument is a rough measure for the code size of the method:
1067 Methods where the obstack containing the firm graph is smaller than
1068 size are inlined. */
1069 void inline_leave_functions(int maxsize, int leavesize, int size) {
1070 inline_irg_env *env;
1071 int i, n_irgs = get_irp_n_irgs();
1072 ir_graph *rem = current_ir_graph;
1075 if (!(get_optimize() && get_opt_inline())) return;
1077 /* extend all irgs by a temporary datastructure for inlineing. */
1078 for (i = 0; i < n_irgs; ++i)
1079 set_irg_link(get_irp_irg(i), new_inline_irg_env());
1081 /* Precompute information in temporary datastructure. */
1082 for (i = 0; i < n_irgs; ++i) {
1083 current_ir_graph = get_irp_irg(i);
1084 assert(get_irg_phase_state(current_ir_graph) != phase_building);
1085 assert(get_irg_callee_info_state(current_ir_graph) == irg_callee_info_none);
1087 irg_walk(get_irg_end(current_ir_graph), NULL, collect_calls2,
1088 get_irg_link(current_ir_graph));
1089 env = (inline_irg_env *)get_irg_link(current_ir_graph);
1093 Inline leaves recursively -- we might construct new leaves. */
1095 while (did_inline) {
1096 //printf("iteration %d\n", itercnt++);
1098 for (i = 0; i < n_irgs; ++i) {
1101 int phiproj_computed = 0;
1103 current_ir_graph = get_irp_irg(i);
1104 env = (inline_irg_env *)get_irg_link(current_ir_graph);
1106 /* we can not walk and change a set, nor remove from it.
1108 walkset = env->call_nodes;
1109 env->call_nodes = eset_create();
1110 for (call = eset_first(walkset); call; call = eset_next(walkset)) {
1111 ir_graph *callee = get_call_called_irg(call);
1112 if (env->n_nodes > maxsize) break;
1113 if (callee && is_leave(callee) && is_smaller(callee, leavesize)) {
1114 if (!phiproj_computed) {
1115 phiproj_computed = 1;
1116 collect_phiprojs(current_ir_graph);
1118 inline_irg_env *callee_env = (inline_irg_env *)get_irg_link(callee);
1119 // printf(" %s: Inlineing %s.\n", get_entity_name(get_irg_entity(current_ir_graph)),
1120 // get_entity_name(get_irg_entity(callee)));
1121 inline_method(call, callee);
1123 env->n_call_nodes--;
1124 eset_insert_all(env->call_nodes, callee_env->call_nodes);
1125 env->n_call_nodes += callee_env->n_call_nodes;
1126 env->n_nodes += callee_env->n_nodes;
1127 callee_env->n_callers--;
1129 eset_insert(env->call_nodes, call);
1132 eset_destroy(walkset);
1136 //printf("Non leaves\n");
1137 /* inline other small functions. */
1138 for (i = 0; i < n_irgs; ++i) {
1141 int phiproj_computed = 0;
1143 current_ir_graph = get_irp_irg(i);
1144 env = (inline_irg_env *)get_irg_link(current_ir_graph);
1146 /* we can not walk and change a set, nor remove from it.
1148 walkset = env->call_nodes;
1149 env->call_nodes = eset_create();
1150 for (call = eset_first(walkset); call; call = eset_next(walkset)) {
1151 ir_graph *callee = get_call_called_irg(call);
1152 if (env->n_nodes > maxsize) break;
1153 if (callee && is_smaller(callee, size)) {
1154 if (!phiproj_computed) {
1155 phiproj_computed = 1;
1156 collect_phiprojs(current_ir_graph);
1158 inline_irg_env *callee_env = (inline_irg_env *)get_irg_link(callee);
1159 //printf(" %s: Inlineing %s.\n", get_entity_name(get_irg_entity(current_ir_graph)),
1160 // get_entity_name(get_irg_entity(callee)));
1161 inline_method(call, callee);
1163 env->n_call_nodes--;
1164 eset_insert_all(env->call_nodes, callee_env->call_nodes);
1165 env->n_call_nodes += callee_env->n_call_nodes;
1166 env->n_nodes += callee_env->n_nodes;
1167 callee_env->n_callers--;
1169 eset_insert(env->call_nodes, call);
1172 eset_destroy(walkset);
1175 for (i = 0; i < n_irgs; ++i) {
1176 current_ir_graph = get_irp_irg(i);
1178 env = (inline_irg_env *)get_irg_link(current_ir_graph);
1179 if ((env->n_call_nodes_orig != env->n_call_nodes) ||
1180 (env->n_callers_orig != env->n_callers))
1181 printf("Nodes:%3d ->%3d, calls:%3d ->%3d, callers:%3d ->%3d, -- %s\n",
1182 env->n_nodes_orig, env->n_nodes, env->n_call_nodes_orig, env->n_call_nodes,
1183 env->n_callers_orig, env->n_callers,
1184 get_entity_name(get_irg_entity(current_ir_graph)));
1186 free_inline_irg_env((inline_irg_env *)get_irg_link(current_ir_graph));
1189 current_ir_graph = rem;
1192 /********************************************************************/
1193 /* Code Placement. Pinns all floating nodes to a block where they */
1194 /* will be executed only if needed. */
1195 /********************************************************************/
1197 static pdeq *worklist; /* worklist of ir_node*s */
1199 /* Find the earliest correct block for N. --- Place N into the
1200 same Block as its dominance-deepest Input. */
1202 place_floats_early (ir_node *n)
1204 int i, start, irn_arity;
1206 /* we must not run into an infinite loop */
1207 assert (irn_not_visited(n));
1208 mark_irn_visited(n);
1210 /* Place floating nodes. */
1211 if (get_op_pinned(get_irn_op(n)) == floats) {
1213 ir_node *b = new_Bad(); /* The block to place this node in */
1215 assert(get_irn_op(n) != op_Block);
1217 if ((get_irn_op(n) == op_Const) ||
1218 (get_irn_op(n) == op_SymConst) ||
1220 (get_irn_op(n) == op_Unknown)) {
1221 /* These nodes will not be placed by the loop below. */
1222 b = get_irg_start_block(current_ir_graph);
1226 /* find the block for this node. */
1227 irn_arity = get_irn_arity(n);
1228 for (i = 0; i < irn_arity; i++) {
1229 ir_node *dep = get_irn_n(n, i);
1231 if ((irn_not_visited(dep)) &&
1232 (get_op_pinned(get_irn_op(dep)) == floats)) {
1233 place_floats_early (dep);
1235 /* Because all loops contain at least one pinned node, now all
1236 our inputs are either pinned or place_early has already
1237 been finished on them. We do not have any unfinished inputs! */
1238 dep_block = get_nodes_Block(dep);
1239 if ((!is_Bad(dep_block)) &&
1240 (get_Block_dom_depth(dep_block) > depth)) {
1242 depth = get_Block_dom_depth(dep_block);
1244 /* Avoid that the node is placed in the Start block */
1245 if ((depth == 1) && (get_Block_dom_depth(get_nodes_Block(n)) > 1)) {
1246 b = get_Block_cfg_out(get_irg_start_block(current_ir_graph), 0);
1247 assert(b != get_irg_start_block(current_ir_graph));
1251 set_nodes_Block(n, b);
1254 /* Add predecessors of non floating nodes on worklist. */
1255 start = (get_irn_op(n) == op_Block) ? 0 : -1;
1256 irn_arity = get_irn_arity(n);
1257 for (i = start; i < irn_arity; i++) {
1258 ir_node *pred = get_irn_n(n, i);
1259 if (irn_not_visited(pred)) {
1260 pdeq_putr (worklist, pred);
1265 /* Floating nodes form subgraphs that begin at nodes as Const, Load,
1266 Start, Call and end at pinned nodes as Store, Call. Place_early
1267 places all floating nodes reachable from its argument through floating
1268 nodes and adds all beginnings at pinned nodes to the worklist. */
1269 static INLINE void place_early (void) {
1271 inc_irg_visited(current_ir_graph);
1273 /* this inits the worklist */
1274 place_floats_early (get_irg_end(current_ir_graph));
1276 /* Work the content of the worklist. */
1277 while (!pdeq_empty (worklist)) {
1278 ir_node *n = pdeq_getl (worklist);
1279 if (irn_not_visited(n)) place_floats_early (n);
1282 set_irg_outs_inconsistent(current_ir_graph);
1283 current_ir_graph->pinned = pinned;
1287 /* deepest common dominance ancestor of DCA and CONSUMER of PRODUCER */
1289 consumer_dom_dca (ir_node *dca, ir_node *consumer, ir_node *producer)
1291 ir_node *block = NULL;
1293 /* Compute the latest block into which we can place a node so that it is
1295 if (get_irn_op(consumer) == op_Phi) {
1296 /* our comsumer is a Phi-node, the effective use is in all those
1297 blocks through which the Phi-node reaches producer */
1299 ir_node *phi_block = get_nodes_Block(consumer);
1300 irn_arity = get_irn_arity(consumer);
1301 for (i = 0; i < irn_arity; i++) {
1302 if (get_irn_n(consumer, i) == producer) {
1303 block = get_nodes_Block(get_Block_cfgpred(phi_block, i));
1307 assert(is_no_Block(consumer));
1308 block = get_nodes_Block(consumer);
1311 /* Compute the deepest common ancestor of block and dca. */
1313 if (!dca) return block;
1314 while (get_Block_dom_depth(block) > get_Block_dom_depth(dca))
1315 block = get_Block_idom(block);
1316 while (get_Block_dom_depth(dca) > get_Block_dom_depth(block))
1317 dca = get_Block_idom(dca);
1318 while (block != dca)
1319 { block = get_Block_idom(block); dca = get_Block_idom(dca); }
1324 static INLINE int get_irn_loop_depth(ir_node *n) {
1325 return get_loop_depth(get_irn_loop(n));
1328 /* Move n to a block with less loop depth than it's current block. The
1329 new block must be dominated by early. */
1331 move_out_of_loops (ir_node *n, ir_node *early)
1333 ir_node *best, *dca;
1337 /* Find the region deepest in the dominator tree dominating
1338 dca with the least loop nesting depth, but still dominated
1339 by our early placement. */
1340 dca = get_nodes_Block(n);
1342 while (dca != early) {
1343 dca = get_Block_idom(dca);
1344 if (!dca) break; /* should we put assert(dca)? */
1345 if (get_irn_loop_depth(dca) < get_irn_loop_depth(best)) {
1349 if (best != get_nodes_Block(n)) {
1351 printf("Moving out of loop: "); DDMN(n);
1352 printf(" Outermost block: "); DDMN(early);
1353 printf(" Best block: "); DDMN(best);
1354 printf(" Innermost block: "); DDMN(get_nodes_Block(n));
1356 set_nodes_Block(n, best);
1360 /* Find the latest legal block for N and place N into the
1361 `optimal' Block between the latest and earliest legal block.
1362 The `optimal' block is the dominance-deepest block of those
1363 with the least loop-nesting-depth. This places N out of as many
1364 loops as possible and then makes it as controldependant as
1367 place_floats_late (ir_node *n)
1372 assert (irn_not_visited(n)); /* no multiple placement */
1374 /* no need to place block nodes, control nodes are already placed. */
1375 if ((get_irn_op(n) != op_Block) &&
1377 (get_irn_mode(n) != mode_X)) {
1378 /* Remember the early palacement of this block to move it
1379 out of loop no further than the early placement. */
1380 early = get_nodes_Block(n);
1381 /* Assure that our users are all placed, except the Phi-nodes.
1382 --- Each dataflow cycle contains at least one Phi-node. We
1383 have to break the `user has to be placed before the
1384 producer' dependance cycle and the Phi-nodes are the
1385 place to do so, because we need to base our placement on the
1386 final region of our users, which is OK with Phi-nodes, as they
1387 are pinned, and they never have to be placed after a
1388 producer of one of their inputs in the same block anyway. */
1389 for (i = 0; i < get_irn_n_outs(n); i++) {
1390 ir_node *succ = get_irn_out(n, i);
1391 if (irn_not_visited(succ) && (get_irn_op(succ) != op_Phi))
1392 place_floats_late (succ);
1395 /* We have to determine the final block of this node... except for
1397 if ((get_op_pinned(get_irn_op(n)) == floats) &&
1398 (get_irn_op(n) != op_Const) &&
1399 (get_irn_op(n) != op_SymConst)) {
1400 ir_node *dca = NULL; /* deepest common ancestor in the
1401 dominator tree of all nodes'
1402 blocks depending on us; our final
1403 placement has to dominate DCA. */
1404 for (i = 0; i < get_irn_n_outs(n); i++) {
1405 dca = consumer_dom_dca (dca, get_irn_out(n, i), n);
1407 set_nodes_Block(n, dca);
1409 move_out_of_loops (n, early);
1413 mark_irn_visited(n);
1415 /* Add predecessors of all non-floating nodes on list. (Those of floating
1416 nodes are placeded already and therefore are marked.) */
1417 for (i = 0; i < get_irn_n_outs(n); i++) {
1418 if (irn_not_visited(get_irn_out(n, i))) {
1419 pdeq_putr (worklist, get_irn_out(n, i));
1424 static INLINE void place_late(void) {
1426 inc_irg_visited(current_ir_graph);
1428 /* This fills the worklist initially. */
1429 place_floats_late(get_irg_start_block(current_ir_graph));
1430 /* And now empty the worklist again... */
1431 while (!pdeq_empty (worklist)) {
1432 ir_node *n = pdeq_getl (worklist);
1433 if (irn_not_visited(n)) place_floats_late(n);
1437 void place_code(ir_graph *irg) {
1438 ir_graph *rem = current_ir_graph;
1439 current_ir_graph = irg;
1441 if (!(get_optimize() && get_opt_global_cse())) return;
1443 /* Handle graph state */
1444 assert(get_irg_phase_state(irg) != phase_building);
1445 if (get_irg_dom_state(irg) != dom_consistent)
1448 construct_backedges(irg);
1450 /* Place all floating nodes as early as possible. This guarantees
1451 a legal code placement. */
1452 worklist = new_pdeq ();
1455 /* place_early invalidates the outs, place_late needs them. */
1457 /* Now move the nodes down in the dominator tree. This reduces the
1458 unnecessary executions of the node. */
1461 set_irg_outs_inconsistent(current_ir_graph);
1462 del_pdeq (worklist);
1463 current_ir_graph = rem;
1468 /********************************************************************/
1469 /* Control flow optimization. */
1470 /* Removes Bad control flow predecessors and empty blocks. A block */
1471 /* is empty if it contains only a Jmp node. */
1472 /* Blocks can only be removed if they are not needed for the */
1473 /* semantics of Phi nodes. */
1474 /********************************************************************/
1476 /* Removes Tuples from Block control flow predecessors.
1477 Optimizes blocks with equivalent_node().
1478 Replaces n by Bad if n is unreachable control flow. */
1479 static void merge_blocks(ir_node *n, void *env) {
1481 set_irn_link(n, NULL);
1483 if (get_irn_op(n) == op_Block) {
1485 for (i = 0; i < get_Block_n_cfgpreds(n); i++)
1486 /* GL @@@ : is this possible? if (get_opt_normalize()) -- added, all tests go throug.
1487 A different order of optimizations might cause problems. */
1488 if (get_opt_normalize())
1489 set_Block_cfgpred(n, i, skip_Tuple(get_Block_cfgpred(n, i)));
1490 } else if (get_optimize() && (get_irn_mode(n) == mode_X)) {
1491 /* We will soon visit a block. Optimize it before visiting! */
1492 ir_node *b = get_nodes_Block(n);
1493 ir_node *new = equivalent_node(b);
1494 while (irn_not_visited(b) && (!is_Bad(new)) && (new != b)) {
1495 /* We would have to run gigo if new is bad, so we
1496 promote it directly below. */
1497 assert(((b == new) ||
1498 get_opt_control_flow_straightening() ||
1499 get_opt_control_flow_weak_simplification()) &&
1500 ("strange flag setting"));
1503 new = equivalent_node(b);
1505 /* GL @@@ get_opt_normalize hinzugefuegt, 5.5.2003 */
1506 if (is_Bad(new) && get_opt_normalize()) exchange (n, new_Bad());
1510 /* Collects all Phi nodes in link list of Block.
1511 Marks all blocks "block_visited" if they contain a node other
1513 static void collect_nodes(ir_node *n, void *env) {
1514 if (is_no_Block(n)) {
1515 ir_node *b = get_nodes_Block(n);
1517 if ((get_irn_op(n) == op_Phi)) {
1518 /* Collect Phi nodes to compact ins along with block's ins. */
1519 set_irn_link(n, get_irn_link(b));
1521 } else if (get_irn_op(n) != op_Jmp) { /* Check for non empty block. */
1522 mark_Block_block_visited(b);
1527 /* Returns true if pred is pred of block */
1528 static int is_pred_of(ir_node *pred, ir_node *b) {
1530 for (i = 0; i < get_Block_n_cfgpreds(b); i++) {
1531 ir_node *b_pred = get_nodes_Block(get_Block_cfgpred(b, i));
1532 if (b_pred == pred) return 1;
1537 static int test_whether_dispensable(ir_node *b, int pos) {
1538 int i, j, n_preds = 1;
1539 int dispensable = 1;
1540 ir_node *cfop = get_Block_cfgpred(b, pos);
1541 ir_node *pred = get_nodes_Block(cfop);
1543 if (get_Block_block_visited(pred) + 1
1544 < get_irg_block_visited(current_ir_graph)) {
1545 if (!get_optimize() || !get_opt_control_flow_strong_simplification()) {
1546 /* Mark block so that is will not be removed. */
1547 set_Block_block_visited(pred, get_irg_block_visited(current_ir_graph)-1);
1550 /* Seems to be empty. */
1551 if (!get_irn_link(b)) {
1552 /* There are no Phi nodes ==> dispensable. */
1553 n_preds = get_Block_n_cfgpreds(pred);
1555 /* b's pred blocks and pred's pred blocks must be pairwise disjunct.
1556 Work preds < pos as if they were already removed. */
1557 for (i = 0; i < pos; i++) {
1558 ir_node *b_pred = get_nodes_Block(get_Block_cfgpred(b, i));
1559 if (get_Block_block_visited(b_pred) + 1
1560 < get_irg_block_visited(current_ir_graph)) {
1561 for (j = 0; j < get_Block_n_cfgpreds(b_pred); j++) {
1562 ir_node *b_pred_pred = get_nodes_Block(get_Block_cfgpred(b_pred, j));
1563 if (is_pred_of(b_pred_pred, pred)) dispensable = 0;
1566 if (is_pred_of(b_pred, pred)) dispensable = 0;
1569 for (i = pos +1; i < get_Block_n_cfgpreds(b); i++) {
1570 ir_node *b_pred = get_nodes_Block(get_Block_cfgpred(b, i));
1571 if (is_pred_of(b_pred, pred)) dispensable = 0;
1574 set_Block_block_visited(pred, get_irg_block_visited(current_ir_graph)-1);
1577 n_preds = get_Block_n_cfgpreds(pred);
1585 static void optimize_blocks(ir_node *b, void *env) {
1586 int i, j, k, max_preds, n_preds;
1587 ir_node *pred, *phi;
1590 /* Count the number of predecessor if this block is merged with pred blocks
1593 for (i = 0; i < get_Block_n_cfgpreds(b); i++) {
1594 max_preds += test_whether_dispensable(b, i);
1596 in = (ir_node **) malloc(max_preds * sizeof(ir_node *));
1599 printf(" working on "); DDMN(b);
1600 for (i = 0; i < get_Block_n_cfgpreds(b); i++) {
1601 pred = get_nodes_Block(get_Block_cfgpred(b, i));
1602 if (is_Bad(get_Block_cfgpred(b, i))) {
1603 printf(" removing Bad %i\n ", i);
1604 } else if (get_Block_block_visited(pred) +1
1605 < get_irg_block_visited(current_ir_graph)) {
1606 printf(" removing pred %i ", i); DDMN(pred);
1607 } else { printf(" Nothing to do for "); DDMN(pred); }
1609 * end Debug output **/
1611 /** Fix the Phi nodes **/
1612 phi = get_irn_link(b);
1614 assert(get_irn_op(phi) == op_Phi);
1615 /* Find the new predecessors for the Phi */
1617 for (i = 0; i < get_Block_n_cfgpreds(b); i++) {
1618 pred = get_nodes_Block(get_Block_cfgpred(b, i));
1619 if (is_Bad(get_Block_cfgpred(b, i))) {
1621 } else if (get_Block_block_visited(pred) +1
1622 < get_irg_block_visited(current_ir_graph)) {
1623 /* It's an empty block and not yet visited. */
1624 ir_node *phi_pred = get_Phi_pred(phi, i);
1625 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
1626 if (get_nodes_Block(phi_pred) == pred) {
1627 assert(get_irn_op(phi_pred) == op_Phi); /* Block is empty!! */
1628 in[n_preds] = get_Phi_pred(phi_pred, j);
1630 in[n_preds] = phi_pred;
1634 /* The Phi_pred node is replaced now if it is a Phi.
1635 In Schleifen kann offenbar der entfernte Phi Knoten legal verwendet werden.
1636 Daher muss der Phiknoten durch den neuen ersetzt werden.
1637 Weiter muss der alte Phiknoten entfernt werden (durch ersetzen oder
1638 durch einen Bad) damit er aus den keep_alive verschwinden kann.
1639 Man sollte also, falls keine Schleife vorliegt, exchange mit new_Bad
1641 if (get_nodes_Block(phi_pred) == pred) {
1642 /* remove the Phi as it might be kept alive. Further there
1643 might be other users. */
1644 exchange(phi_pred, phi); /* geht, ist aber doch semantisch falsch! Warum?? */
1647 in[n_preds] = get_Phi_pred(phi, i);
1652 set_irn_in(phi, n_preds, in);
1654 phi = get_irn_link(phi);
1658 This happens only if merge between loop backedge and single loop entry. **/
1659 for (k = 0; k < get_Block_n_cfgpreds(b); k++) {
1660 pred = get_nodes_Block(get_Block_cfgpred(b, k));
1661 if (get_Block_block_visited(pred) +1
1662 < get_irg_block_visited(current_ir_graph)) {
1663 phi = get_irn_link(pred);
1665 if (get_irn_op(phi) == op_Phi) {
1666 set_nodes_Block(phi, b);
1669 for (i = 0; i < k; i++) {
1670 pred = get_nodes_Block(get_Block_cfgpred(b, i));
1671 if (is_Bad(get_Block_cfgpred(b, i))) {
1673 } else if (get_Block_block_visited(pred) +1
1674 < get_irg_block_visited(current_ir_graph)) {
1675 /* It's an empty block and not yet visited. */
1676 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
1677 /* @@@ Hier brauche ich Schleifeninformation!!! Kontrollflusskante
1678 muss Rueckwaertskante sein! (An allen vier in[n_preds] = phi
1679 Anweisungen.) Trotzdem tuts bisher!! */
1688 for (i = 0; i < get_Phi_n_preds(phi); i++) {
1689 in[n_preds] = get_Phi_pred(phi, i);
1692 for (i = k+1; i < get_Block_n_cfgpreds(b); i++) {
1693 pred = get_nodes_Block(get_Block_cfgpred(b, i));
1694 if (is_Bad(get_Block_cfgpred(b, i))) {
1696 } else if (get_Block_block_visited(pred) +1
1697 < get_irg_block_visited(current_ir_graph)) {
1698 /* It's an empty block and not yet visited. */
1699 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
1708 set_irn_in(phi, n_preds, in);
1710 phi = get_irn_link(phi);
1715 /** Fix the block **/
1717 for (i = 0; i < get_Block_n_cfgpreds(b); i++) {
1718 pred = get_nodes_Block(get_Block_cfgpred(b, i));
1719 if (is_Bad(get_Block_cfgpred(b, i))) {
1721 } else if (get_Block_block_visited(pred) +1
1722 < get_irg_block_visited(current_ir_graph)) {
1723 /* It's an empty block and not yet visited. */
1724 assert(get_Block_n_cfgpreds(b) > 1);
1725 /* Else it should be optimized by equivalent_node. */
1726 for (j = 0; j < get_Block_n_cfgpreds(pred); j++) {
1727 in[n_preds] = get_Block_cfgpred(pred, j);
1730 /* Remove block as it might be kept alive. */
1731 exchange(pred, b/*new_Bad()*/);
1733 in[n_preds] = get_Block_cfgpred(b, i);
1737 set_irn_in(b, n_preds, in);
1741 void optimize_cf(ir_graph *irg) {
1744 ir_node *end = get_irg_end(irg);
1745 ir_graph *rem = current_ir_graph;
1746 current_ir_graph = irg;
1748 /* Handle graph state */
1749 assert(get_irg_phase_state(irg) != phase_building);
1750 if (get_irg_outs_state(current_ir_graph) == outs_consistent)
1751 set_irg_outs_inconsistent(current_ir_graph);
1752 if (get_irg_dom_state(current_ir_graph) == dom_consistent)
1753 set_irg_dom_inconsistent(current_ir_graph);
1755 /* Use block visited flag to mark non-empty blocks. */
1756 inc_irg_block_visited(irg);
1757 irg_walk(end, merge_blocks, collect_nodes, NULL);
1759 /* Optimize the standard code. */
1760 irg_block_walk(get_irg_end_block(irg), optimize_blocks, NULL, NULL);
1762 /* Walk all keep alives, optimize them if block, add to new in-array
1763 for end if useful. */
1764 in = NEW_ARR_F (ir_node *, 1);
1765 in[0] = get_nodes_Block(end);
1766 inc_irg_visited(current_ir_graph);
1767 for(i = 0; i < get_End_n_keepalives(end); i++) {
1768 ir_node *ka = get_End_keepalive(end, i);
1769 if (irn_not_visited(ka)) {
1770 if ((get_irn_op(ka) == op_Block) && Block_not_block_visited(ka)) {
1771 set_irg_block_visited(current_ir_graph, /* Don't walk all the way to Start. */
1772 get_irg_block_visited(current_ir_graph)-1);
1773 irg_block_walk(ka, optimize_blocks, NULL, NULL);
1774 mark_irn_visited(ka);
1775 ARR_APP1 (ir_node *, in, ka);
1776 } else if (get_irn_op(ka) == op_Phi) {
1777 mark_irn_visited(ka);
1778 ARR_APP1 (ir_node *, in, ka);
1782 /* DEL_ARR_F(end->in); GL @@@ tut nicht ! */
1785 current_ir_graph = rem;
1790 * Called by walker of remove_critical_cf_edges.
1792 * Place an empty block to an edge between a blocks of multiple
1793 * predecessors and a block of multiple sucessors.
1796 * @param env Envirnment of walker. This field is unused and has
1799 static void walk_critical_cf_edges(ir_node *n, void *env) {
1801 ir_node *pre, *block, **in, *jmp;
1803 /* Block has multiple predecessors */
1804 if ((op_Block == get_irn_op(n)) &&
1805 (get_irn_arity(n) > 1)) {
1806 arity = get_irn_arity(n);
1808 if (n == get_irg_end_block(current_ir_graph))
1809 return; // No use to add a block here.
1811 for (i=0; i<arity; i++) {
1812 pre = get_irn_n(n, i);
1813 /* Predecessor has multiple sucessors. Insert new flow edge */
1814 if ((NULL != pre) &&
1815 (op_Proj == get_irn_op(pre)) &&
1816 op_Raise != get_irn_op(skip_Proj(pre))) {
1818 /* set predecessor array for new block */
1819 in = NEW_ARR_D (ir_node *, current_ir_graph->obst, 1);
1820 /* set predecessor of new block */
1822 block = new_Block(1, in);
1823 /* insert new jmp node to new block */
1824 switch_block(block);
1827 /* set sucessor of new block */
1828 set_irn_n(n, i, jmp);
1830 } /* predecessor has multiple sucessors */
1831 } /* for all predecessors */
1832 } /* n is a block */
1835 void remove_critical_cf_edges(ir_graph *irg) {
1836 if (get_opt_critical_edges())
1837 irg_walk_graph(irg, NULL, walk_critical_cf_edges, NULL);