2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
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 Optimization of function calls.
23 * @author Michael Beck
30 #include <adt/raw_bitset.h>
32 #include "funccall_t.h"
35 #include "irgraph_t.h"
39 #include "dbginfo_t.h"
42 #include "iredges_t.h"
43 #include "analyze_irg_args.h"
47 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
50 * The walker environment for updating function calls.
52 typedef struct _env_t {
53 unsigned n_calls_SymConst;
55 ir_node *const_call_list; /**< The list of all const function calls that will be changed. */
56 ir_node *pure_call_list; /**< The list of all pure function calls that will be changed. */
57 ir_node *nothrow_call_list; /**< The list of all nothrow function calls that will be changed. */
58 ir_node *proj_list; /**< The list of all potential Proj nodes that must be fixed. */
61 /** If non-null, evaluates entities for being a heap alloc. */
62 static check_alloc_entity_func is_alloc_entity = NULL;
64 /** Ready IRG's are marked in the ready set. */
65 static unsigned *ready_set;
67 /** IRG's that are in progress are marked here. */
68 static unsigned *busy_set;
71 * We misuse the mtp_property_inherited flag as temporary here.
72 * The is ok, as we cannot set or get it anyway using the
73 * get_addtional_properties API.
75 #define mtp_temporary mtp_property_inherited
78 * Walker: Collect all calls to const and pure functions
79 * to lists. Collect all Proj(Call) nodes into a Proj list.
81 static void collect_const_and_pure_calls(ir_node *node, void *env) {
90 /* set the link to NULL for all non-const/pure calls */
91 set_irn_link(call, NULL);
92 ptr = get_Call_ptr(call);
94 ent = get_Global_entity(ptr);
96 prop = get_entity_additional_properties(ent);
97 if ((prop & (mtp_property_const|mtp_property_pure)) == 0)
99 ++ctx->n_calls_SymConst;
100 } else if (get_opt_closed_world() &&
102 get_irg_callee_info_state(current_ir_graph) == irg_callee_info_consistent) {
103 /* If all possible callees are const functions, we can remove the memory edge. */
104 int i, n_callees = get_Call_n_callees(call);
105 if (n_callees == 0) {
106 /* This is kind of strange: dying code or a Call that will raise an exception
107 when executed as there is no implementation to call. So better not
112 /* note that const function are a subset of pure ones */
113 prop = mtp_property_const | mtp_property_pure;
114 for (i = 0; i < n_callees; ++i) {
115 ent = get_Call_callee(call, i);
116 if (ent == unknown_entity) {
117 /* we don't know which entity is called here */
120 prop &= get_entity_additional_properties(ent);
121 if (prop == mtp_no_property)
128 /* ok, if we get here we found a call to a const or a pure function */
129 if (prop & mtp_property_pure) {
130 set_irn_link(call, ctx->pure_call_list);
131 ctx->pure_call_list = call;
133 set_irn_link(call, ctx->const_call_list);
134 ctx->const_call_list = call;
136 } else if (is_Proj(node)) {
138 * Collect all memory and exception Proj's from
141 call = get_Proj_pred(node);
145 /* collect the Proj's in the Proj list */
146 switch (get_Proj_proj(node)) {
147 case pn_Call_M_regular:
148 case pn_Call_X_except:
149 case pn_Call_X_regular:
150 case pn_Call_M_except:
151 set_irn_link(node, ctx->proj_list);
152 ctx->proj_list = node;
158 } /* collect_const_and_pure_calls */
161 * Fix the list of collected Calls.
163 * @param irg the graph that contained calls to pure functions
164 * @param call_list the list of all call sites of const functions
165 * @param proj_list the list of all memory/exception Proj's of this call sites
167 static void fix_const_call_list(ir_graph *irg, ir_node *call_list, ir_node *proj_list) {
168 ir_node *call, *next, *mem, *proj;
170 ir_graph *rem = current_ir_graph;
172 current_ir_graph = irg;
174 /* First step: fix all calls by removing their memory input.
175 * The original memory input is preserved in their link fields. */
176 for (call = call_list; call; call = next) {
177 next = get_irn_link(call);
178 mem = get_Call_mem(call);
180 set_irn_link(call, mem);
181 set_Call_mem(call, get_irg_no_mem(irg));
184 * Unfortunately we cannot simply set the node to 'float'.
185 * There is a reason for that:
187 * - The call might be inside a loop/if that is NOT entered
188 * and calls a endless function. Setting the call to float
189 * would allow to move it out from the loop/if causing this
190 * function be called even if the loop/if is not entered ...
192 * This could be fixed using post-dominators for calls and Pin nodes
193 * but need some more analyzes to ensure that a call that potential
194 * never returns is not executed before some code that generates
195 * observable states...
198 /* finally, this call can float */
199 set_irn_pinned(call, op_pin_state_floats);
200 hook_func_call(irg, call);
203 /* Second step: fix all Proj's */
204 for (proj = proj_list; proj; proj = next) {
205 next = get_irn_link(proj);
206 call = get_Proj_pred(proj);
207 mem = get_irn_link(call);
209 /* beware of calls in the pure call list */
210 if (!mem || is_Call(mem))
212 assert(get_irn_mode(mem) == mode_M);
214 switch (get_Proj_proj(proj)) {
215 case pn_Call_M_regular: {
216 /* in dead code there might be cycles where proj == mem */
221 case pn_Call_X_except:
222 case pn_Call_M_except:
224 exchange(proj, get_irg_bad(irg));
226 case pn_Call_X_regular: {
227 ir_node *block = get_nodes_block(call);
229 exchange(proj, new_r_Jmp(irg, block));
237 /* changes were done ... */
238 set_irg_outs_inconsistent(irg);
239 set_irg_loopinfo_state(irg, loopinfo_cf_inconsistent);
242 /* ... including exception edges */
243 set_irg_doms_inconsistent(irg);
245 current_ir_graph = rem;
246 } /* fix_const_call_list */
249 * Walker: Collect all calls to nothrow functions
250 * to lists. Collect all Proj(Call) nodes into a Proj list.
252 static void collect_nothrow_calls(ir_node *node, void *env) {
261 /* set the link to NULL for all non-const/pure calls */
262 set_irn_link(call, NULL);
263 ptr = get_Call_ptr(call);
264 if (is_Global(ptr)) {
265 ent = get_Global_entity(ptr);
267 prop = get_entity_additional_properties(ent);
268 if ((prop & mtp_property_nothrow) == 0)
270 ++ctx->n_calls_SymConst;
271 } else if (get_opt_closed_world() &&
273 get_irg_callee_info_state(current_ir_graph) == irg_callee_info_consistent) {
274 /* If all possible callees are nothrow functions, we can remove the exception edge. */
275 int i, n_callees = get_Call_n_callees(call);
276 if (n_callees == 0) {
277 /* This is kind of strange: dying code or a Call that will raise an exception
278 when executed as there is no implementation to call. So better not
283 /* note that const function are a subset of pure ones */
284 prop = mtp_property_nothrow;
285 for (i = 0; i < n_callees; ++i) {
286 ent = get_Call_callee(call, i);
287 if (ent == unknown_entity) {
288 /* we don't know which entity is called here */
291 prop &= get_entity_additional_properties(ent);
292 if (prop == mtp_no_property)
299 /* ok, if we get here we found a call to a nothrow function */
300 set_irn_link(call, ctx->nothrow_call_list);
301 ctx->nothrow_call_list = call;
302 } else if (is_Proj(node)) {
304 * Collect all memory and exception Proj's from
307 call = get_Proj_pred(node);
311 /* collect the Proj's in the Proj list */
312 switch (get_Proj_proj(node)) {
313 case pn_Call_M_regular:
314 case pn_Call_X_except:
315 case pn_Call_X_regular:
316 case pn_Call_M_except:
317 set_irn_link(node, ctx->proj_list);
318 ctx->proj_list = node;
324 } /* collect_nothrow_calls */
327 * Fix the list of collected nothrow Calls.
329 * @param irg the graph that contained calls to pure functions
330 * @param call_list the list of all call sites of const functions
331 * @param proj_list the list of all memory/exception Proj's of this call sites
333 static void fix_nothrow_call_list(ir_graph *irg, ir_node *call_list, ir_node *proj_list) {
334 ir_node *call, *next, *proj;
336 ir_graph *rem = current_ir_graph;
338 current_ir_graph = irg;
340 /* First step: go through the list of calls and mark them. */
341 for (call = call_list; call; call = next) {
342 next = get_irn_link(call);
344 /* current_ir_graph is in memory anyway, so it's a good marker */
345 set_irn_link(call, ¤t_ir_graph);
346 hook_func_call(irg, call);
349 /* Second step: Remove all exception Proj's */
350 for (proj = proj_list; proj; proj = next) {
351 next = get_irn_link(proj);
352 call = get_Proj_pred(proj);
354 /* handle only marked calls */
355 if (get_irn_link(call) != ¤t_ir_graph)
358 /* kill any exception flow */
359 switch (get_Proj_proj(proj)) {
360 case pn_Call_X_except:
361 case pn_Call_M_except:
363 exchange(proj, get_irg_bad(irg));
365 case pn_Call_X_regular: {
366 ir_node *block = get_nodes_block(call);
368 exchange(proj, new_r_Jmp(irg, block));
376 /* changes were done ... */
377 set_irg_outs_inconsistent(irg);
378 set_irg_loopinfo_state(irg, loopinfo_cf_inconsistent);
381 /* ... including exception edges */
382 set_irg_doms_inconsistent(irg);
384 current_ir_graph = rem;
385 } /* fix_nothrow_call_list */
388 #define SET_IRG_READY(irg) rbitset_set(ready_set, get_irg_idx(irg))
389 #define IS_IRG_READY(irg) rbitset_is_set(ready_set, get_irg_idx(irg))
390 #define SET_IRG_BUSY(irg) rbitset_set(busy_set, get_irg_idx(irg))
391 #define CLEAR_IRG_BUSY(irg) rbitset_clear(busy_set, get_irg_idx(irg))
392 #define IS_IRG_BUSY(irg) rbitset_is_set(busy_set, get_irg_idx(irg))
395 static unsigned check_const_or_pure_function(ir_graph *irg, int top);
396 static unsigned check_nothrow_or_malloc(ir_graph *irg, int top);
399 * Calculate the bigger property of two. Handle the temporary flag right.
401 static unsigned max_property(unsigned a, unsigned b) {
402 unsigned r, t = (a | b) & mtp_temporary;
406 if (a == mtp_no_property || b == mtp_no_property)
407 return mtp_no_property;
413 * Follow the memory chain starting at node and determine
416 * @return mtp_property_const if only calls of const functions are detected
417 * mtp_property_pure if only Loads and const/pure
419 * mtp_no_property else
421 static unsigned _follow_mem(ir_node *node) {
422 unsigned m, mode = mtp_property_const;
427 if (mode == mtp_no_property)
428 return mtp_no_property;
430 if (irn_visited(node))
433 mark_irn_visited(node);
435 switch (get_irn_opcode(node)) {
437 node = get_Proj_pred(node);
446 /* do a dfs search */
447 for (i = get_irn_arity(node) - 1; i >= 0; --i) {
448 m = _follow_mem(get_irn_n(node, i));
449 mode = max_property(mode, m);
450 if (mode == mtp_no_property)
451 return mtp_no_property;
456 /* Beware volatile Loads are NOT allowed in pure functions. */
457 if (get_Load_volatility(node) == volatility_is_volatile)
458 return mtp_no_property;
459 mode = max_property(mode, mtp_property_pure);
460 node = get_Load_mem(node);
464 /* A call is only tolerable if its either constant or pure. */
465 ptr = get_Call_ptr(node);
466 if (is_SymConst(ptr) && get_SymConst_kind(ptr) == symconst_addr_ent) {
467 ir_entity *ent = get_SymConst_entity(ptr);
468 ir_graph *irg = get_entity_irg(ent);
470 if (irg == current_ir_graph) {
471 /* A self-recursive call. The property did not depend on this call. */
472 } else if (irg == NULL) {
473 m = get_entity_additional_properties(ent) & (mtp_property_const|mtp_property_pure);
474 mode = max_property(mode, m);
475 } else if (irg != NULL) {
476 /* we have a graph, analyze it. */
477 m = check_const_or_pure_function(irg, /*top=*/0);
478 mode = max_property(mode, m);
481 return mtp_no_property;
482 node = get_Call_mem(node);
486 return mtp_no_property;
492 * Follow the memory chain starting at node and determine
495 * @return mtp_property_const if only calls of const functions are detected
496 * mtp_property_pure if only Loads and const/pure calls detected
497 * mtp_no_property else
499 static unsigned follow_mem(ir_node *node, unsigned mode) {
502 m = _follow_mem(node);
503 return max_property(mode, m);
507 * Check if a graph represents a const or a pure function.
509 * @param irg the graph to check
510 * @param top if set, this is the top call
512 static unsigned check_const_or_pure_function(ir_graph *irg, int top) {
513 ir_node *end, *endbl;
515 unsigned prop = get_irg_additional_properties(irg);
516 ir_graph *rem = current_ir_graph;
518 if (prop & mtp_property_const) {
519 /* already marked as a const function */
520 return mtp_property_const;
522 if (prop & mtp_property_pure) {
523 /* already marked as a pure function */
524 return mtp_property_pure;
527 if (IS_IRG_READY(irg)) {
528 /* already checked */
529 return mtp_no_property;
531 if (IS_IRG_BUSY(irg)) {
532 /* we are still evaluate this method. Be optimistic,
533 return the best possible so far but mark the result as temporary. */
534 return mtp_temporary | mtp_property_const;
538 end = get_irg_end(irg);
539 endbl = get_nodes_block(end);
540 prop = mtp_property_const;
542 current_ir_graph = irg;
544 inc_irg_visited(irg);
545 /* mark the initial mem: recursion of follow_mem stops here */
546 mark_irn_visited(get_irg_initial_mem(irg));
548 /* visit every Return */
549 for (j = get_Block_n_cfgpreds(endbl) - 1; j >= 0; --j) {
550 ir_node *node = get_Block_cfgpred(endbl, j);
551 ir_opcode code = get_irn_opcode(node);
554 /* Bad nodes usually do NOT produce anything, so it's ok */
558 if (code == iro_Return) {
559 mem = get_Return_mem(node);
561 /* Bad nodes usually do NOT produce anything, so it's ok */
565 if (mem != get_irg_initial_mem(irg))
566 prop = max_property(prop, follow_mem(mem, prop));
568 /* Exception found. Cannot be const or pure. */
569 prop = mtp_no_property;
572 if (prop == mtp_no_property)
576 if (prop != mtp_no_property) {
577 /* check, if a keep-alive exists */
578 for (j = get_End_n_keepalives(end) - 1; j >= 0; --j) {
579 ir_node *kept = get_End_keepalive(end, j);
581 if (is_Block(kept)) {
582 prop = mtp_no_property;
586 if (mode_M != get_irn_mode(kept))
589 prop = max_property(prop, follow_mem(kept, prop));
590 if (prop == mtp_no_property)
595 if (prop != mtp_no_property) {
596 if (top || (prop & mtp_temporary) == 0) {
597 /* We use the temporary flag here to mark optimistic result.
598 Set the property only if we are sure that it does NOT base on
599 temporary results OR if we are at top-level. */
600 set_irg_additional_property(irg, prop & ~mtp_temporary);
607 current_ir_graph = rem;
609 } /* check_const_or_pure_function */
612 * Handle calls to const functions.
616 static void handle_const_Calls(env_t *ctx) {
619 ctx->n_calls_SymConst = 0;
620 ctx->n_calls_Sel = 0;
622 /* all calls of const functions can be transformed */
623 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
624 ir_graph *irg = get_irp_irg(i);
626 ctx->const_call_list = NULL;
627 ctx->pure_call_list = NULL;
628 ctx->proj_list = NULL;
629 irg_walk_graph(irg, NULL, collect_const_and_pure_calls, ctx);
631 if (ctx->const_call_list) {
632 fix_const_call_list(irg, ctx->const_call_list, ctx->proj_list);
634 /* this graph was changed, invalidate analysis info */
635 set_irg_outs_inconsistent(irg);
636 set_irg_doms_inconsistent(irg);
639 } /* handle_const_Calls */
642 * Handle calls to nothrow functions.
646 static void handle_nothrow_Calls(env_t *ctx) {
649 ctx->n_calls_SymConst = 0;
650 ctx->n_calls_Sel = 0;
652 /* all calls of const functions can be transformed */
653 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
654 ir_graph *irg = get_irp_irg(i);
656 ctx->nothrow_call_list = NULL;
657 ctx->proj_list = NULL;
658 irg_walk_graph(irg, NULL, collect_nothrow_calls, ctx);
660 if (ctx->nothrow_call_list) {
661 fix_nothrow_call_list(irg, ctx->nothrow_call_list, ctx->proj_list);
663 /* this graph was changed, invalidate analysis info */
664 set_irg_outs_inconsistent(irg);
665 set_irg_doms_inconsistent(irg);
671 * Check, whether a given node represents a return value of
672 * a malloc like function (ie, new heap allocated memory).
674 * @param node the node to check
676 static int is_malloc_call_result(const ir_node *node) {
677 if (is_Alloc(node) && get_Alloc_where(node) == heap_alloc) {
678 /* Firm style high-level allocation */
681 if (is_alloc_entity != NULL && is_Call(node)) {
682 ir_node *ptr = get_Call_ptr(node);
684 if (is_Global(ptr)) {
685 ir_entity *ent = get_Global_entity(ptr);
686 return is_alloc_entity(ent);
690 } /* is_malloc_call_result */
693 * Update a property depending on a call property.
695 static unsigned update_property(unsigned orig_prop, unsigned call_prop) {
696 unsigned t = (orig_prop | call_prop) & mtp_temporary;
697 unsigned r = orig_prop & call_prop;
699 } /** update_property */
702 * Check if a node is stored.
704 static int is_stored(const ir_node *n) {
705 const ir_edge_t *edge;
708 foreach_out_edge(n, edge) {
709 const ir_node *succ = get_edge_src_irn(edge);
711 switch (get_irn_opcode(succ)) {
718 if (get_Store_value(succ) == n)
720 /* ok if its only the address input */
729 ptr = get_Call_ptr(succ);
730 if (is_Global(ptr)) {
731 ir_entity *ent = get_Global_entity(ptr);
734 /* we know the called entity */
735 for (i = get_Call_n_params(succ) - 1; i >= 0; --i) {
736 if (get_Call_param(succ, i) == n) {
737 /* n is the i'th param of the call */
738 if (get_method_param_access(ent, i) & ptr_access_store) {
739 /* n is store in ent */
745 /* unknown call address */
750 /* bad, potential alias */
758 * Check that the return value of an irg is not stored anywhere.
760 * return ~mtp_property_malloc if return values are stored, ~0 else
762 static unsigned check_stored_result(ir_graph *irg) {
763 ir_node *end_blk = get_irg_end_block(irg);
766 int old_edges = edges_assure_kind(irg, EDGE_KIND_NORMAL);
768 for (i = get_Block_n_cfgpreds(end_blk) - 1; i >= 0; --i) {
769 ir_node *pred = get_Block_cfgpred(end_blk, i);
771 if (! is_Return(pred))
773 for (j = get_Return_n_ress(pred) - 1; j >= 0; --j) {
774 const ir_node *irn = get_Return_res(pred, j);
776 if (is_stored(irn)) {
777 /* bad, might create an alias */
778 res = ~mtp_property_malloc;
785 edges_deactivate_kind(irg, EDGE_KIND_NORMAL);
787 } /* check_stored_result */
790 * Check if a graph represents a nothrow or a malloc function.
792 * @param irg the graph to check
793 * @param top if set, this is the top call
795 static unsigned check_nothrow_or_malloc(ir_graph *irg, int top) {
796 ir_node *end_blk = get_irg_end_block(irg);
800 unsigned curr_prop = mtp_property_malloc | mtp_property_nothrow;
802 if (IS_IRG_READY(irg)) {
803 /* already checked */
804 return get_irg_additional_properties(irg);
806 if (IS_IRG_BUSY(irg)) {
807 /* we are still evaluate this method. Be optimistic,
808 return the best possible so far but mark the result as temporary. */
809 return mtp_temporary | mtp_property_malloc | mtp_property_nothrow;
813 ent = get_irg_entity(irg);
814 mtp = get_entity_type(ent);
816 if (get_method_n_ress(mtp) <= 0)
817 curr_prop &= ~mtp_property_malloc;
819 for (i = get_Block_n_cfgpreds(end_blk) - 1; i >= 0; --i) {
820 ir_node *pred = get_Block_cfgpred(end_blk, i);
822 if (is_Return(pred)) {
823 if (curr_prop & mtp_property_malloc) {
824 /* check, if malloc is called here */
825 for (j = get_Return_n_ress(pred) - 1; j >= 0; --j) {
826 ir_node *res = get_Return_res(pred, j);
828 /* skip Confirms and Casts */
829 res = skip_HighLevel_ops(res);
832 res = get_Proj_pred(res);
833 if (is_malloc_call_result(res)) {
834 /* ok, this is a malloc */
835 } else if (is_Call(res)) {
836 ir_node *ptr = get_Call_ptr(res);
838 if (is_Global(ptr)) {
840 ir_entity *ent = get_Global_entity(ptr);
841 ir_graph *callee = get_entity_irg(ent);
844 /* A self-recursive call. The property did not depend on this call. */
845 } else if (callee != NULL) {
846 unsigned prop = check_nothrow_or_malloc(callee, /*top=*/0);
847 curr_prop = update_property(curr_prop, prop);
849 curr_prop = update_property(curr_prop, get_entity_additional_properties(ent));
851 } else if (get_opt_closed_world() &&
853 get_irg_callee_info_state(irg) == irg_callee_info_consistent) {
854 /* check if all possible callees are malloc functions. */
855 int i, n_callees = get_Call_n_callees(res);
856 if (n_callees == 0) {
857 /* This is kind of strange: dying code or a Call that will raise an exception
858 when executed as there is no implementation to call. So better not
860 curr_prop &= ~mtp_property_malloc;
864 for (i = 0; i < n_callees; ++i) {
865 ir_entity *ent = get_Call_callee(res, i);
866 if (ent == unknown_entity) {
867 /* we don't know which entity is called here */
868 curr_prop &= ~mtp_property_malloc;
871 if ((get_entity_additional_properties(ent) & mtp_property_malloc) == 0) {
872 curr_prop &= ~mtp_property_malloc;
876 /* if we pass the for cycle, malloc is still ok */
879 curr_prop &= ~mtp_property_malloc;
882 /* unknown return value */
883 curr_prop &= ~mtp_property_malloc;
887 } else if (curr_prop & mtp_property_nothrow) {
888 /* exception flow detected */
889 pred = skip_Proj(pred);
892 ir_node *ptr = get_Call_ptr(pred);
894 if (is_Global(ptr)) {
896 ir_entity *ent = get_Global_entity(ptr);
897 ir_graph *callee = get_entity_irg(ent);
900 /* A self-recursive call. The property did not depend on this call. */
901 } else if (callee != NULL) {
902 /* Note: we check here for nothrow only, so do NOT reset the malloc property */
903 unsigned prop = check_nothrow_or_malloc(callee, /*top=*/0) | mtp_property_malloc;
904 curr_prop = update_property(curr_prop, prop);
906 if ((get_entity_additional_properties(ent) & mtp_property_nothrow) == 0)
907 curr_prop &= ~mtp_property_nothrow;
909 } else if (get_opt_closed_world() &&
911 get_irg_callee_info_state(irg) == irg_callee_info_consistent) {
912 /* check if all possible callees are nothrow functions. */
913 int i, n_callees = get_Call_n_callees(pred);
914 if (n_callees == 0) {
915 /* This is kind of strange: dying code or a Call that will raise an exception
916 when executed as there is no implementation to call. So better not
918 curr_prop &= ~mtp_property_nothrow;
922 for (i = 0; i < n_callees; ++i) {
923 ir_entity *ent = get_Call_callee(pred, i);
924 if (ent == unknown_entity) {
925 /* we don't know which entity is called here */
926 curr_prop &= ~mtp_property_nothrow;
929 if ((get_entity_additional_properties(ent) & mtp_property_nothrow) == 0) {
930 curr_prop &= ~mtp_property_nothrow;
934 /* if we pass the for cycle, nothrow is still ok */
937 curr_prop &= ~mtp_property_nothrow;
940 /* real exception flow possible. */
941 curr_prop &= ~mtp_property_nothrow;
944 if ((curr_prop & ~mtp_temporary) == mtp_no_property) {
945 /* no need to search further */
950 if (curr_prop & mtp_property_malloc) {
952 * Note that the malloc property means not only return newly allocated
953 * memory, but also that this memory is ALIAS FREE.
954 * To ensure that, we do NOT allow that the returned memory is somewhere
957 curr_prop &= check_stored_result(irg);
960 if (curr_prop != mtp_no_property) {
961 if (top || (curr_prop & mtp_temporary) == 0) {
962 /* We use the temporary flag here to mark an optimistic result.
963 Set the property only if we are sure that it does NOT base on
964 temporary results OR if we are at top-level. */
965 set_irg_additional_property(irg, curr_prop & ~mtp_temporary);
973 } /* check_nothrow_or_malloc */
976 * optimize function calls by handling const functions
978 void optimize_funccalls(int force_run, check_alloc_entity_func callback)
981 unsigned num_const = 0;
982 unsigned num_pure = 0;
983 unsigned num_nothrow = 0;
984 unsigned num_malloc = 0;
986 is_alloc_entity = callback;
988 /* prepare: mark all graphs as not analyzed */
989 last_idx = get_irp_last_idx();
990 ready_set = rbitset_malloc(last_idx);
991 busy_set = rbitset_malloc(last_idx);
993 /* first step: detect, which functions are nothrow or malloc */
994 DB((dbg, LEVEL_2, "Detecting nothrow and malloc properties ...\n"));
995 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
996 ir_graph *irg = get_irp_irg(i);
997 unsigned prop = check_nothrow_or_malloc(irg, /*top=*/1);
999 if (prop & mtp_property_nothrow) {
1001 DB((dbg, LEVEL_2, "%+F has the nothrow property\n", irg));
1002 } else if (prop & mtp_property_malloc) {
1004 DB((dbg, LEVEL_2, "%+F has the malloc property\n", irg));
1008 /* second step: remove exception edges: this must be done before the
1009 detection of const and pure functions take place. */
1010 if (force_run || num_nothrow > 0) {
1013 handle_nothrow_Calls(&ctx);
1014 DB((dbg, LEVEL_1, "Detected %u nothrow graphs, %u malloc graphs.\n", num_nothrow, num_malloc));
1015 DB((dbg, LEVEL_1, "Optimizes %u(SymConst) + %u(Sel) calls to nothrow functions.\n",
1016 ctx.n_calls_SymConst, ctx.n_calls_Sel));
1018 DB((dbg, LEVEL_1, "No graphs without side effects detected\n"));
1021 rbitset_clear_all(ready_set, last_idx);
1022 rbitset_clear_all(busy_set, last_idx);
1024 /* third step: detect, which functions are const or pure */
1025 DB((dbg, LEVEL_2, "Detecting const and pure properties ...\n"));
1026 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1027 ir_graph *irg = get_irp_irg(i);
1028 unsigned prop = check_const_or_pure_function(irg, /*top=*/1);
1030 if (prop & mtp_property_const) {
1032 DB((dbg, LEVEL_2, "%+F has the const property\n", irg));
1033 } else if (prop & mtp_property_pure) {
1035 DB((dbg, LEVEL_2, "%+F has the pure property\n", irg));
1039 if (force_run || num_const > 0) {
1042 handle_const_Calls(&ctx);
1043 DB((dbg, LEVEL_1, "Detected %u const graphs, %u pure graphs.\n", num_const, num_pure));
1044 DB((dbg, LEVEL_1, "Optimizes %u(SymConst) + %u(Sel) calls to const functions.\n",
1045 ctx.n_calls_SymConst, ctx.n_calls_Sel));
1047 DB((dbg, LEVEL_1, "No graphs without side effects detected\n"));
1051 } /* optimize_funccalls */
1053 /* initialize the funccall optimization */
1054 void firm_init_funccalls(void) {
1055 FIRM_DBG_REGISTER(dbg, "firm.opt.funccalls");
1056 // firm_dbg_set_mask(dbg, -1);
1057 } /* firm_init_funccalls */