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 Memory disambiguator
23 * @author Michael Beck
34 #include "irgraph_t.h"
36 #include "irmemory_t.h"
49 /** The debug handle. */
50 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
51 DEBUG_ONLY(static firm_dbg_module_t *dbgcall = NULL;)
53 /** The source language specific language disambiguator function. */
54 static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
56 /** The global memory disambiguator options. */
57 static unsigned global_mem_disamgig_opt = aa_opt_no_opt;
59 /* Returns a human readable name for an alias relation. */
60 const char *get_ir_alias_relation_name(ir_alias_relation rel)
62 #define X(a) case a: return #a
67 default: assert(0); return "UNKNOWN";
72 /* Get the memory disambiguator options for a graph. */
73 unsigned get_irg_memory_disambiguator_options(const ir_graph *irg)
75 unsigned opt = irg->mem_disambig_opt;
76 if (opt & aa_opt_inherited)
77 return global_mem_disamgig_opt;
79 } /* get_irg_memory_disambiguator_options */
81 /* Set the memory disambiguator options for a graph. */
82 void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options)
84 irg->mem_disambig_opt = options & ~aa_opt_inherited;
85 } /* set_irg_memory_disambiguator_options */
87 /* Set the global disambiguator options for all graphs not having local options. */
88 void set_irp_memory_disambiguator_options(unsigned options)
90 global_mem_disamgig_opt = options;
91 } /* set_irp_memory_disambiguator_options */
94 * Find the base address and entity of an Sel node.
97 * @param pEnt after return points to the base entity.
99 * @return the base address.
101 static ir_node *find_base_adr(const ir_node *sel, ir_entity **pEnt)
103 ir_node *ptr = get_Sel_ptr(sel);
105 while (is_Sel(ptr)) {
107 ptr = get_Sel_ptr(sel);
109 *pEnt = get_Sel_entity(sel);
111 } /* find_base_adr */
114 * Check if a given Const node is greater or equal a given size.
116 * @param cns a Const node
117 * @param size a integer size
119 * @return ir_no_alias if the Const is greater, ir_may_alias else
121 static ir_alias_relation check_const(const ir_node *cns, int size)
123 tarval *tv = get_Const_tarval(cns);
127 return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
128 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
129 return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
133 * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
135 * @param idx1 a node representing the first index
136 * @param idx2 a node representing the second index
137 * @param size an integer size
139 * @return ir_sure_alias iff idx1 == idx2
140 * ir_no_alias iff they ALWAYS differ more than size
143 static ir_alias_relation different_index(const ir_node *idx1, const ir_node *idx2, int size)
146 return ir_sure_alias;
147 if (is_Const(idx1) && is_Const(idx2)) {
148 /* both are const, we can compare them */
149 tarval *tv1 = get_Const_tarval(idx1);
150 tarval *tv2 = get_Const_tarval(idx2);
151 tarval *tv, *tv_size;
155 return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
157 /* arg, modes may be different */
158 m1 = get_tarval_mode(tv1);
159 m2 = get_tarval_mode(tv2);
161 int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
164 /* m1 is a small mode, cast up */
165 m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
167 /* should NOT happen, but if it does we give up here */
170 tv1 = tarval_convert_to(tv1, m1);
171 } else if (size > 0) {
172 /* m2 is a small mode, cast up */
173 m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
175 /* should NOT happen, but if it does we give up here */
178 tv2 = tarval_convert_to(tv2, m2);
180 /* here the size should be identical, check for signed */
181 if (get_mode_sign(m1) != get_mode_sign(m2)) {
182 /* find the signed */
183 if (mode_is_signed(m2)) {
190 /* m1 is now the signed one */
191 if (tarval_cmp(tv1, get_tarval_null(m1)) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
192 /* tv1 is signed, but >= 0, simply cast into unsigned */
193 tv1 = tarval_convert_to(tv1, m2);
195 tv_size = new_tarval_from_long(size, m2);
197 if (tarval_cmp(tv2, tv_size) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
198 /* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
201 /* tv_size > tv2, so we can subtract without overflow */
202 tv2 = tarval_sub(tv_size, tv2, NULL);
204 /* tv1 is < 0, so we can negate it */
205 tv1 = tarval_neg(tv1);
207 /* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
208 tv1 = tarval_convert_to(tv1, m2);
210 /* now we can compare without overflow */
211 return tarval_cmp(tv1, tv2) & (pn_Cmp_Eq|pn_Cmp_Gt) ? ir_no_alias : ir_may_alias;
215 if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) {
220 /* tv1 is now the "smaller" one */
221 tv = tarval_sub(tv2, tv1, NULL);
222 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
223 return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
226 /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
228 ir_node *l1 = get_Add_left(idx1);
229 ir_node *r1 = get_Add_right(idx1);
234 return check_const(r1, size);
237 /* both are Adds, check if they are of x + a == x + b kind */
238 ir_node *l2 = get_Add_left(idx2);
239 ir_node *r2 = get_Add_right(idx2);
242 return different_index(r1, r2, size);
244 return different_index(r1, l2, size);
246 return different_index(l1, l2, size);
248 return different_index(l1, r2, size);
252 ir_node *l2 = get_Add_left(idx2);
253 ir_node *r2 = get_Add_right(idx2);
258 return check_const(r2, size);
263 ir_node *l1 = get_Sub_left(idx1);
264 ir_node *r1 = get_Sub_right(idx1);
269 return check_const(r1, size);
273 /* both are Subs, check if they are of x - a == x - b kind */
274 ir_node *l2 = get_Sub_left(idx2);
277 ir_node *r2 = get_Sub_right(idx2);
278 return different_index(r1, r2, size);
283 ir_node *l2 = get_Sub_left(idx2);
284 ir_node *r2 = get_Sub_right(idx2);
289 return check_const(r2, size);
294 } /* different_index */
297 * Two Sel addresses have the same base address, check if there offsets are
300 * @param adr1 The first address.
301 * @param adr2 The second address.
303 static ir_alias_relation different_sel_offsets(const ir_node *sel1, const ir_node *sel2)
305 /* seems to be broken */
309 ir_entity *ent1 = get_Sel_entity(sel1);
310 ir_entity *ent2 = get_Sel_entity(sel2);
311 int i, check_arr = 0;
316 ir_type *tp1 = get_entity_type(ent1);
317 ir_type *tp2 = get_entity_type(ent2);
321 else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
322 get_type_size_bits(tp1) == get_type_size_bits(tp2))
326 /* we select an entity of same size, check for indexes */
327 int n = get_Sel_n_indexs(sel1);
330 if (n > 0 && n == get_Sel_n_indexs(sel2)) {
331 /* same non-zero number of indexes, an array access, check */
332 for (i = 0; i < n; ++i) {
333 ir_node *idx1 = get_Sel_index(sel1, i);
334 ir_node *idx2 = get_Sel_index(sel2, i);
335 ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
337 if (res == may_alias)
339 else if (res == no_alias)
342 /* if we have at least one no_alias, there is no alias relation, else we have sure */
343 return have_no > 0 ? no_alias : sure_alias;
347 (void) different_index;
350 } /* different_sel_offsets */
353 * Determine the alias relation by checking if adr1 and adr2 are pointer
356 * @param adr1 The first address.
357 * @param adr2 The second address.
359 static ir_alias_relation different_types(const ir_node *adr1, const ir_node *adr2)
361 ir_entity *ent1 = NULL, *ent2 = NULL;
364 ent1 = get_Global_entity(adr1);
365 else if (is_Sel(adr1))
366 ent1 = get_Sel_entity(adr1);
369 ent2 = get_Global_entity(adr2);
370 else if (is_Sel(adr2))
371 ent2 = get_Sel_entity(adr2);
373 if (ent1 != NULL && ent2 != NULL) {
374 ir_type *tp1 = get_entity_type(ent1);
375 ir_type *tp2 = get_entity_type(ent2);
378 /* do deref until no pointer types are found */
379 while (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
380 tp1 = get_pointer_points_to_type(tp1);
381 tp2 = get_pointer_points_to_type(tp2);
384 if (get_type_tpop(tp1) != get_type_tpop(tp2)) {
385 /* different type structure */
388 if (is_Class_type(tp1)) {
389 /* check class hierarchy */
390 if (! is_SubClass_of(tp1, tp2) &&
391 ! is_SubClass_of(tp2, tp1))
394 /* different types */
400 } /* different_types */
403 * Returns non-zero if a node is a result on a malloc-like routine.
405 * @param node the Proj node to test
407 static int is_malloc_Result(const ir_node *node)
409 node = get_Proj_pred(node);
412 node = get_Proj_pred(node);
415 node = get_Call_ptr(node);
416 if (is_Global(node)) {
417 ir_entity *ent = get_Global_entity(node);
419 if (get_entity_additional_properties(ent) & mtp_property_malloc)
424 } /* is_malloc_Result */
427 * Classify a base pointer.
429 * @param irg the graph of the pointer
430 * @param irn the node representing the base address
431 * @param ent the base entity of the base address iff any
433 ir_storage_class_class_t classify_pointer(const ir_graph *irg, const ir_node *irn, const ir_entity *ent)
435 ir_storage_class_class_t res = ir_sc_pointer;
436 if (is_Global(irn)) {
437 ir_entity *entity = get_Global_entity(irn);
438 res = ir_sc_globalvar;
439 if (! (get_entity_usage(entity) & ir_usage_address_taken))
440 res |= ir_sc_modifier_nottaken;
441 } else if (irn == get_irg_frame(irg)) {
442 res = ir_sc_localvar;
443 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
444 res |= ir_sc_modifier_nottaken;
445 } else if (irn == get_irg_tls(irg)) {
447 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
448 res |= ir_sc_modifier_nottaken;
449 } else if (is_Proj(irn) && is_malloc_Result(irn)) {
450 return ir_sc_malloced;
451 } else if (is_Const(irn)) {
452 return ir_sc_globaladdr;
453 } else if (is_arg_Proj(irn)) {
454 res |= ir_sc_modifier_argument;
461 * If adr represents a Bitfield Sel, skip it
463 static const ir_node *skip_Bitfield_Sels(const ir_node *adr)
466 ir_entity *ent = get_Sel_entity(adr);
467 ir_type *bf_type = get_entity_type(ent);
469 /* is it a bitfield type? */
470 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
471 adr = get_Sel_ptr(adr);
477 * Determine the alias relation between two addresses.
479 * @param irg the graph of both memory operations
480 * @param addr1 pointer address of the first memory operation
481 * @param mode1 the mode of the accessed data through addr1
482 * @param addr2 pointer address of the second memory operation
483 * @param mode2 the mode of the accessed data through addr2
485 * @return found memory relation
487 static ir_alias_relation _get_alias_relation(
489 const ir_node *adr1, const ir_mode *mode1,
490 const ir_node *adr2, const ir_mode *mode2)
492 ir_entity *ent1, *ent2;
496 const ir_node *base1;
497 const ir_node *base2;
498 const ir_node *orig_adr1 = adr1;
499 const ir_node *orig_adr2 = adr2;
501 ir_storage_class_class_t class1, class2, mod1, mod2;
502 int have_const_offsets;
504 if (! get_opt_alias_analysis())
508 return ir_sure_alias;
510 options = get_irg_memory_disambiguator_options(irg);
512 /* The Armageddon switch */
513 if (options & aa_opt_no_alias)
516 /* do the addresses have constants offsets?
517 * Note: nodes are normalized to have constants at right inputs,
518 * sub X, C is normalized to add X, -C
520 have_const_offsets = 1;
521 while (is_Add(adr1)) {
522 ir_node *add_right = get_Add_right(adr1);
523 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
524 tarval *tv = get_Const_tarval(add_right);
525 offset1 += get_tarval_long(tv);
526 adr1 = get_Add_left(adr1);
527 } else if (mode_is_reference(get_irn_mode(add_right))) {
529 have_const_offsets = 0;
531 adr1 = get_Add_left(adr1);
532 have_const_offsets = 0;
535 while (is_Add(adr2)) {
536 ir_node *add_right = get_Add_right(adr2);
537 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
538 tarval *tv = get_Const_tarval(add_right);
539 offset2 += get_tarval_long(tv);
540 adr2 = get_Add_left(adr2);
541 } else if (mode_is_reference(get_irn_mode(add_right))) {
543 have_const_offsets = 0;
545 adr2 = get_Add_left(adr2);
546 have_const_offsets = 0;
550 mode_size = get_mode_size_bytes(mode1);
551 if (get_mode_size_bytes(mode2) > mode_size) {
552 mode_size = get_mode_size_bytes(mode2);
555 /* same base address -> compare offsets if possible.
556 * FIXME: type long is not sufficient for this task ...
558 if (adr1 == adr2 && have_const_offsets) {
559 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
562 return ir_sure_alias;
566 * Bitfields can be constructed as Sels from its base address.
567 * As they have different entities, the disambiguator would find that they are
568 * alias free. While this is true for it's values, it is false for the addresses
569 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
570 * So, skip those bitfield selecting Sel's.
572 adr1 = skip_Bitfield_Sels(adr1);
573 adr2 = skip_Bitfield_Sels(adr2);
581 base1 = find_base_adr(adr1, &ent1);
584 base2 = find_base_adr(adr2, &ent2);
587 /* same base address -> compare Sel entities */
588 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
591 else if (have_const_offsets)
592 return different_sel_offsets(adr1, adr2);
595 mod1 = classify_pointer(irg, base1, ent1);
596 mod2 = classify_pointer(irg, base2, ent2);
598 class1 = GET_BASE_SC(mod1);
599 class2 = GET_BASE_SC(mod2);
601 if (class1 == ir_sc_pointer || class2 == ir_sc_pointer) {
602 /* swap pointer class to class1 */
603 if (class2 == ir_sc_pointer) {
604 ir_storage_class_class_t temp = mod1;
607 class1 = GET_BASE_SC(mod1);
608 class2 = GET_BASE_SC(mod2);
610 /* a pointer and an object whose address was never taken */
611 if (mod2 & ir_sc_modifier_nottaken) {
614 if (mod1 & ir_sc_modifier_argument) {
615 if ( (options & aa_opt_no_alias_args)
616 && (mod2 & ir_sc_modifier_argument))
618 if ( (options & aa_opt_no_alias_args_global)
619 && (class2 == ir_sc_globalvar
620 || class2 == ir_sc_tls
621 || class2 == ir_sc_globaladdr))
624 } else if (class1 != class2) {
625 /* two objects from different memory spaces */
628 /* both classes are equal */
629 if (class1 == ir_sc_globalvar) {
630 ir_entity *entity1 = get_SymConst_entity(base1);
631 ir_entity *entity2 = get_SymConst_entity(base2);
632 if (entity1 != entity2)
635 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
637 } else if (class1 == ir_sc_globaladdr) {
638 tarval *tv = get_Const_tarval(base1);
639 offset1 += get_tarval_long(tv);
640 tv = get_Const_tarval(base2);
641 offset2 += get_tarval_long(tv);
643 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
646 return ir_sure_alias;
650 /* Type based alias analysis */
651 if (options & aa_opt_type_based) {
652 ir_alias_relation rel;
654 if (options & aa_opt_byte_type_may_alias) {
655 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
656 /* One of the modes address a byte. Assume a ir_may_alias and leave
657 the type based check. */
658 goto leave_type_based_alias;
661 /* cheap check: If the mode sizes did not match, the types MUST be different */
662 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
665 /* cheap test: if only one is a reference mode, no alias */
666 if (mode_is_reference(mode1) != mode_is_reference(mode2))
669 /* cheap test: if arithmetic is different, no alias */
670 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
674 rel = different_types(orig_adr1, orig_adr2);
675 if (rel != ir_may_alias)
677 leave_type_based_alias:;
680 /* do we have a language specific memory disambiguator? */
681 if (language_disambuigator != NULL) {
682 ir_alias_relation rel = language_disambuigator(irg, orig_adr1, mode1, orig_adr2, mode2);
683 if (rel != ir_may_alias)
687 /* access points-to information here */
689 } /* _get_alias_relation */
692 * Determine the alias relation between two addresses.
694 ir_alias_relation get_alias_relation(
696 const ir_node *adr1, const ir_mode *mode1,
697 const ir_node *adr2, const ir_mode *mode2)
699 ir_alias_relation rel = _get_alias_relation(irg, adr1, mode1, adr2, mode2);
700 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
702 } /* get_alias_relation */
704 /* Set a source language specific memory disambiguator function. */
705 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func)
707 language_disambuigator = func;
708 } /* set_language_memory_disambiguator */
710 /** The result cache for the memory disambiguator. */
711 static set *result_cache = NULL;
713 /** An entry in the relation cache. */
714 typedef struct mem_disambig_entry {
715 const ir_node *adr1; /**< The first address. */
716 const ir_mode *mode1; /**< The first address mode. */
717 const ir_node *adr2; /**< The second address. */
718 const ir_mode *mode2; /**< The second address mode. */
719 ir_alias_relation result; /**< The alias relation result. */
720 } mem_disambig_entry;
722 #define HASH_ENTRY(adr1, adr2) (HASH_PTR(adr1) ^ HASH_PTR(adr2))
725 * Compare two relation cache entries.
727 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size)
729 const mem_disambig_entry *p1 = elt;
730 const mem_disambig_entry *p2 = key;
733 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2 &&
734 p1->mode1 == p2->mode1 && p1->mode2 == p2->mode2;
735 } /* cmp_mem_disambig_entry */
738 * Initialize the relation cache.
740 void mem_disambig_init(void)
742 result_cache = new_set(cmp_mem_disambig_entry, 8);
743 } /* mem_disambig_init */
746 * Determine the alias relation between two addresses.
748 ir_alias_relation get_alias_relation_ex(
750 const ir_node *adr1, const ir_mode *mode1,
751 const ir_node *adr2, const ir_mode *mode2)
753 mem_disambig_entry key, *entry;
755 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
757 if (! get_opt_alias_analysis())
760 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
761 const ir_node *t = adr1;
770 entry = set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
772 return entry->result;
774 key.result = get_alias_relation(irg, adr1, mode1, adr2, mode2);
776 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
778 } /* get_alias_relation_ex */
780 /* Free the relation cache. */
781 void mem_disambig_term(void)
783 if (result_cache != NULL) {
784 del_set(result_cache);
787 } /* mem_disambig_term */
790 * Check the mode of a Load/Store with the mode of the entity
792 * If the mode of the entity and the Load/Store mode do not match, we
793 * have the bad reinterpret case:
796 * char b = *(char *)&i;
798 * We do NOT count this as one value and return address_taken
800 * However, we support an often used case. If the mode is two-complement
801 * we allow casts between signed/unsigned.
803 * @param mode the mode of the Load/Store
804 * @param ent_mode the mode of the accessed entity
806 * @return non-zero if the Load/Store is a hidden cast, zero else
808 static int is_hidden_cast(const ir_mode *mode, const ir_mode *ent_mode)
810 if (ent_mode == NULL)
813 if (ent_mode != mode) {
814 if (ent_mode == NULL ||
815 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
816 get_mode_sort(ent_mode) != get_mode_sort(mode) ||
817 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
818 get_mode_arithmetic(mode) != irma_twos_complement)
822 } /* is_hidden_cast */
825 * Determine the usage state of a node (or its successor Sels).
827 * @param irn the node
829 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity)
832 ir_mode *emode, *mode;
835 ir_entity_usage res = 0;
837 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
838 ir_node *succ = get_irn_out(irn, i);
840 switch (get_irn_opcode(succ)) {
842 /* beware: irn might be a Id node here, so irn might be not
843 equal to get_Load_ptr(succ) */
844 res |= ir_usage_read;
846 /* check if this load is not a hidden conversion */
847 mode = get_Load_mode(succ);
848 emode = get_type_mode(get_entity_type(entity));
849 if (is_hidden_cast(mode, emode))
850 res |= ir_usage_reinterpret_cast;
854 /* check that the node is not the Store's value */
855 if (irn == get_Store_value(succ)) {
856 res |= ir_usage_unknown;
858 if (irn == get_Store_ptr(succ)) {
859 res |= ir_usage_write;
861 /* check if this Store is not a hidden conversion */
862 value = get_Store_value(succ);
863 mode = get_irn_mode(value);
864 emode = get_type_mode(get_entity_type(entity));
865 if (is_hidden_cast(mode, emode))
866 res |= ir_usage_reinterpret_cast;
868 assert(irn != get_Store_mem(succ));
872 /* CopyB are like Loads/Stores */
873 tp = get_entity_type(entity);
874 if (tp != get_CopyB_type(succ)) {
875 /* bad, different types, might be a hidden conversion */
876 res |= ir_usage_reinterpret_cast;
878 if (irn == get_CopyB_dst(succ)) {
879 res |= ir_usage_write;
881 assert(irn == get_CopyB_src(succ));
882 res |= ir_usage_read;
888 /* Check the successor of irn. */
889 res |= determine_entity_usage(succ, entity);
892 ir_entity *entity = get_Sel_entity(succ);
893 /* this analysis can't handle unions correctly */
894 if (is_Union_type(get_entity_owner(entity))) {
895 res |= ir_usage_unknown;
898 /* Check the successor of irn. */
899 res |= determine_entity_usage(succ, entity);
904 if (irn == get_Call_ptr(succ)) {
905 /* TODO: we could check for reinterpret casts here...
906 * But I doubt anyone is interested in that bit for
907 * function entities and I'm too lazy to write the code now.
909 res |= ir_usage_read;
911 assert(irn != get_Call_mem(succ));
912 res |= ir_usage_unknown;
916 /* skip identities */
918 res |= determine_entity_usage(succ, entity);
924 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
926 ir_node *pred = get_Tuple_pred(succ, input_nr);
929 /* we found one input */
930 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
931 ir_node *proj = get_irn_out(succ, k);
933 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
934 res |= determine_entity_usage(proj, entity);
944 /* another op, we don't know anything (we could do more advanced
945 * things like a dataflow analysis here) */
946 res |= ir_usage_unknown;
955 * Update the usage flags of all frame entities.
957 static void analyse_irg_entity_usage(ir_graph *irg)
959 ir_type *ft = get_irg_frame_type(irg);
961 int i, j, k, static_link_arg;
963 /* set initial state to not_taken, as this is the "smallest" state */
964 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
965 ir_entity *ent = get_class_member(ft, i);
967 /* methods can only be analyzed globally */
968 if (! is_method_entity(ent)) {
969 ir_entity_usage flags = 0;
970 if (get_entity_linkage(ent) & IR_LINKAGE_HIDDEN_USER)
971 flags = ir_usage_unknown;
972 set_entity_usage(ent, flags);
976 assure_irg_outs(irg);
978 irg_frame = get_irg_frame(irg);
980 for (i = get_irn_n_outs(irg_frame) - 1; i >= 0; --i) {
981 ir_node *succ = get_irn_out(irg_frame, i);
983 ir_entity_usage flags;
988 entity = get_Sel_entity(succ);
989 flags = get_entity_usage(entity);
990 flags |= determine_entity_usage(succ, entity);
991 set_entity_usage(entity, flags);
994 /* check inner functions accessing outer frame */
996 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
997 ir_entity *ent = get_class_member(ft, i);
1001 if (! is_method_entity(ent))
1004 inner_irg = get_entity_irg(ent);
1005 if (inner_irg == NULL)
1008 assure_irg_outs(inner_irg);
1009 args = get_irg_args(inner_irg);
1010 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
1011 ir_node *arg = get_irn_out(args, j);
1013 if (get_Proj_proj(arg) == static_link_arg) {
1014 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
1015 ir_node *succ = get_irn_out(arg, k);
1018 ir_entity *entity = get_Sel_entity(succ);
1020 if (get_entity_owner(entity) == ft) {
1021 /* found an access to the outer frame */
1022 ir_entity_usage flags;
1024 flags = get_entity_usage(entity);
1025 flags |= determine_entity_usage(succ, entity);
1026 set_entity_usage(entity, flags);
1036 irg->entity_usage_state = ir_entity_usage_computed;
1039 ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg)
1041 return irg->entity_usage_state;
1044 void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state)
1046 irg->entity_usage_state = state;
1049 void assure_irg_entity_usage_computed(ir_graph *irg)
1051 if (irg->entity_usage_state != ir_entity_usage_not_computed)
1054 analyse_irg_entity_usage(irg);
1059 * Initialize the entity_usage flag for a global type like type.
1061 static void init_entity_usage(ir_type *tp)
1065 /* We have to be conservative: All external visible entities are unknown */
1066 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1067 ir_entity *ent = get_compound_member(tp, i);
1068 ir_entity_usage flags = ir_usage_none;
1070 if (entity_is_externally_visible(ent)) {
1071 flags |= ir_usage_unknown;
1073 set_entity_usage(ent, flags);
1078 * Mark all entities used in the initializer as unknown usage.
1080 * @param initializer the initializer to check
1082 static void check_initializer_nodes(ir_initializer_t *initializer)
1087 switch (initializer->kind) {
1088 case IR_INITIALIZER_CONST:
1089 /* let's check if it's an address */
1090 n = initializer->consti.value;
1092 ir_entity *ent = get_Global_entity(n);
1093 set_entity_usage(ent, ir_usage_unknown);
1096 case IR_INITIALIZER_TARVAL:
1097 case IR_INITIALIZER_NULL:
1099 case IR_INITIALIZER_COMPOUND:
1100 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1101 ir_initializer_t *sub_initializer
1102 = initializer->compound.initializers[i];
1103 check_initializer_nodes(sub_initializer);
1107 panic("invalid initializer found");
1108 } /* check_initializer_nodes */
1111 * Mark all entities used in the initializer for the given entity as unknown
1114 * @param ent the entity
1116 static void check_initializer(ir_entity *ent)
1121 /* Beware: Methods are always initialized with "themself". This does not
1122 * count as a taken address.
1123 * TODO: this initialisation with "themself" is wrong and should be removed
1125 if (is_Method_type(get_entity_type(ent)))
1128 if (ent->initializer != NULL) {
1129 check_initializer_nodes(ent->initializer);
1130 } else if (entity_has_compound_ent_values(ent)) {
1131 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
1132 n = get_compound_ent_value(ent, i);
1134 /* let's check if it's an address */
1136 ir_entity *ent = get_Global_entity(n);
1137 set_entity_usage(ent, ir_usage_unknown);
1145 * Mark all entities used in initializers as unknown usage.
1147 * @param tp a compound type
1149 static void check_initializers(ir_type *tp)
1153 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1154 ir_entity *ent = get_compound_member(tp, i);
1156 check_initializer(ent);
1158 } /* check_initializers */
1160 #ifdef DEBUG_libfirm
1162 * Print the entity usage flags of all entities of a given type for debugging.
1164 * @param tp a compound type
1166 static void print_entity_usage_flags(ir_type *tp)
1169 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1170 ir_entity *ent = get_compound_member(tp, i);
1171 ir_entity_usage flags = get_entity_usage(ent);
1175 ir_printf("%+F:", ent);
1176 if (flags & ir_usage_address_taken)
1177 printf(" address_taken");
1178 if (flags & ir_usage_read)
1180 if (flags & ir_usage_write)
1182 if (flags & ir_usage_reinterpret_cast)
1183 printf(" reinterp_cast");
1187 #endif /* DEBUG_libfirm */
1190 * Post-walker: check for global entity address
1192 static void check_global_address(ir_node *irn, void *env)
1196 ir_entity_usage flags;
1198 if (is_Global(irn)) {
1200 ent = get_Global_entity(irn);
1201 } else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
1202 /* A TLS variable. */
1203 ent = get_Sel_entity(irn);
1207 flags = get_entity_usage(ent);
1208 flags |= determine_entity_usage(irn, ent);
1209 set_entity_usage(ent, flags);
1210 } /* check_global_address */
1213 * Update the entity usage flags of all global entities.
1215 static void analyse_irp_globals_entity_usage(void)
1220 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1221 ir_type *type = get_segment_type(s);
1222 init_entity_usage(type);
1225 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1226 ir_type *type = get_segment_type(s);
1227 check_initializers(type);
1230 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1231 ir_graph *irg = get_irp_irg(i);
1233 assure_irg_outs(irg);
1234 irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
1237 #ifdef DEBUG_libfirm
1238 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1240 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1241 print_entity_usage_flags(get_segment_type(s));
1244 #endif /* DEBUG_libfirm */
1247 irp->globals_entity_usage_state = ir_entity_usage_computed;
1250 /* Returns the current address taken state of the globals. */
1251 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void)
1253 return irp->globals_entity_usage_state;
1256 /* Sets the current address taken state of the graph. */
1257 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state)
1259 irp->globals_entity_usage_state = state;
1262 /* Assure that the address taken flag is computed for the globals. */
1263 void assure_irp_globals_entity_usage_computed(void)
1265 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1268 analyse_irp_globals_entity_usage();
1271 void firm_init_memory_disambiguator(void)
1273 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1274 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1278 /** Maps method types to cloned method types. */
1279 static pmap *mtp_map;
1282 * Clone a method type if not already cloned.
1284 * @param tp the type to clone
1286 static ir_type *clone_type_and_cache(ir_type *tp)
1289 pmap_entry *e = pmap_find(mtp_map, tp);
1294 res = clone_type_method(tp);
1295 pmap_insert(mtp_map, tp, res);
1298 } /* clone_type_and_cache */
1301 * Walker: clone all call types of Calls to methods having the
1302 * mtp_property_private property set.
1304 static void update_calls_to_private(ir_node *call, void *env)
1307 if (is_Call(call)) {
1308 ir_node *ptr = get_Call_ptr(call);
1310 if (is_SymConst(ptr)) {
1311 ir_entity *ent = get_SymConst_entity(ptr);
1312 ir_type *ctp = get_Call_type(call);
1314 if (get_entity_additional_properties(ent) & mtp_property_private) {
1315 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1316 ctp = clone_type_and_cache(ctp);
1317 set_method_additional_property(ctp, mtp_property_private);
1318 set_Call_type(call, ctp);
1319 DB((dbgcall, LEVEL_1, "changed call to private method %+F using cloned type %+F\n", ent, ctp));
1324 } /* update_calls_to_private */
1326 /* Mark all private methods, i.e. those of which all call sites are known. */
1327 void mark_private_methods(void)
1332 assure_irp_globals_entity_usage_computed();
1334 mtp_map = pmap_create();
1336 /* first step: change the calling conventions of the local non-escaped entities */
1337 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1338 ir_graph *irg = get_irp_irg(i);
1339 ir_entity *ent = get_irg_entity(irg);
1340 ir_entity_usage flags = get_entity_usage(ent);
1342 if (!entity_is_externally_visible(ent) &&
1343 !(flags & ir_usage_address_taken)) {
1344 ir_type *mtp = get_entity_type(ent);
1346 set_entity_additional_property(ent, mtp_property_private);
1347 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1348 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1349 /* need a new type */
1350 mtp = clone_type_and_cache(mtp);
1351 set_method_additional_property(mtp, mtp_property_private);
1352 set_entity_type(ent, mtp);
1353 DB((dbgcall, LEVEL_2, "changed entity type of %+F to %+F\n", ent, mtp));
1360 all_irg_walk(NULL, update_calls_to_private, NULL);
1362 pmap_destroy(mtp_map);
1363 } /* mark_private_methods */
1365 /* create a pass for mark_private_methods() */
1366 ir_prog_pass_t *mark_private_methods_pass(const char *name)
1368 return def_prog_pass(name ? name : "mark_private_methods", mark_private_methods);
1369 } /* mark_private_methods_pass */