2 * Copyright (C) 1995-2011 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
33 #include "irgraph_t.h"
35 #include "irmemory_t.h"
48 /** The debug handle. */
49 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
50 DEBUG_ONLY(static firm_dbg_module_t *dbgcall = NULL;)
52 /** The source language specific language disambiguator function. */
53 static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
55 /** The global memory disambiguator options. */
56 static unsigned global_mem_disamgig_opt = aa_opt_no_opt;
58 /* Returns a human readable name for an alias relation. */
59 const char *get_ir_alias_relation_name(ir_alias_relation rel)
61 #define X(a) case a: return #a
67 panic("UNKNOWN alias relation");
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;
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;
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;
93 /* Get the base storage class (ignore modifier) */
94 ir_storage_class_class_t get_base_sc(ir_storage_class_class_t x)
96 return x & ~ir_sc_modifiers;
100 * Find the base address and entity of an Sel node.
102 * @param sel the node
103 * @param pEnt after return points to the base entity.
105 * @return the base address.
107 static ir_node *find_base_adr(const ir_node *sel, ir_entity **pEnt)
109 ir_node *ptr = get_Sel_ptr(sel);
111 while (is_Sel(ptr)) {
113 ptr = get_Sel_ptr(sel);
115 *pEnt = get_Sel_entity(sel);
120 * Check if a given Const node is greater or equal a given size.
122 * @param cns a Const node
123 * @param size a integer size
125 * @return ir_no_alias if the Const is greater, ir_may_alias else
127 static ir_alias_relation check_const(const ir_node *cns, int size)
129 ir_tarval *tv = get_Const_tarval(cns);
133 return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
134 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
135 return tarval_cmp(tv_size, tv) & (ir_relation_less_equal) ? ir_no_alias : ir_may_alias;
139 * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
141 * @param idx1 a node representing the first index
142 * @param idx2 a node representing the second index
143 * @param size an integer size
145 * @return ir_sure_alias iff idx1 == idx2
146 * ir_no_alias iff they ALWAYS differ more than size
149 static ir_alias_relation different_index(const ir_node *idx1, const ir_node *idx2, int size)
152 return ir_sure_alias;
153 if (is_Const(idx1) && is_Const(idx2)) {
154 /* both are const, we can compare them */
155 ir_tarval *tv1 = get_Const_tarval(idx1);
156 ir_tarval *tv2 = get_Const_tarval(idx2);
157 ir_tarval *tv, *tv_size;
161 return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
163 /* arg, modes may be different */
164 m1 = get_tarval_mode(tv1);
165 m2 = get_tarval_mode(tv2);
167 int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
170 /* m1 is a small mode, cast up */
171 m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
173 /* should NOT happen, but if it does we give up here */
176 tv1 = tarval_convert_to(tv1, m1);
177 } else if (size > 0) {
178 /* m2 is a small mode, cast up */
179 m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
181 /* should NOT happen, but if it does we give up here */
184 tv2 = tarval_convert_to(tv2, m2);
186 /* here the size should be identical, check for signed */
187 if (get_mode_sign(m1) != get_mode_sign(m2)) {
188 /* find the signed */
189 if (mode_is_signed(m2)) {
196 /* m1 is now the signed one */
197 if (!tarval_is_negative(tv1)) {
198 /* tv1 is signed, but >= 0, simply cast into unsigned */
199 tv1 = tarval_convert_to(tv1, m2);
201 tv_size = new_tarval_from_long(size, m2);
203 if (tarval_cmp(tv2, tv_size) & (ir_relation_greater_equal)) {
204 /* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
207 /* tv_size > tv2, so we can subtract without overflow */
208 tv2 = tarval_sub(tv_size, tv2, NULL);
210 /* tv1 is < 0, so we can negate it */
211 tv1 = tarval_neg(tv1);
213 /* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
214 tv1 = tarval_convert_to(tv1, m2);
216 /* now we can compare without overflow */
217 return tarval_cmp(tv1, tv2) & (ir_relation_greater_equal) ? ir_no_alias : ir_may_alias;
221 if (tarval_cmp(tv1, tv2) == ir_relation_greater) {
226 /* tv1 is now the "smaller" one */
227 tv = tarval_sub(tv2, tv1, NULL);
228 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
229 return tarval_cmp(tv_size, tv) & (ir_relation_less_equal) ? ir_no_alias : ir_may_alias;
232 /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
234 ir_node *l1 = get_Add_left(idx1);
235 ir_node *r1 = get_Add_right(idx1);
240 return check_const(r1, size);
243 /* both are Adds, check if they are of x + a == x + b kind */
244 ir_node *l2 = get_Add_left(idx2);
245 ir_node *r2 = get_Add_right(idx2);
248 return different_index(r1, r2, size);
250 return different_index(r1, l2, size);
252 return different_index(l1, l2, size);
254 return different_index(l1, r2, size);
258 ir_node *l2 = get_Add_left(idx2);
259 ir_node *r2 = get_Add_right(idx2);
264 return check_const(r2, size);
269 ir_node *l1 = get_Sub_left(idx1);
270 ir_node *r1 = get_Sub_right(idx1);
275 return check_const(r1, size);
279 /* both are Subs, check if they are of x - a == x - b kind */
280 ir_node *l2 = get_Sub_left(idx2);
283 ir_node *r2 = get_Sub_right(idx2);
284 return different_index(r1, r2, size);
289 ir_node *l2 = get_Sub_left(idx2);
290 ir_node *r2 = get_Sub_right(idx2);
295 return check_const(r2, size);
303 * Two Sel addresses have the same base address, check if there offsets are
306 * @param adr1 The first address.
307 * @param adr2 The second address.
309 static ir_alias_relation different_sel_offsets(const ir_node *sel1, const ir_node *sel2)
311 /* seems to be broken */
315 ir_entity *ent1 = get_Sel_entity(sel1);
316 ir_entity *ent2 = get_Sel_entity(sel2);
317 int i, check_arr = 0;
322 ir_type *tp1 = get_entity_type(ent1);
323 ir_type *tp2 = get_entity_type(ent2);
327 else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
328 get_type_size_bits(tp1) == get_type_size_bits(tp2))
332 /* we select an entity of same size, check for indexes */
333 int n = get_Sel_n_indexs(sel1);
336 if (n > 0 && n == get_Sel_n_indexs(sel2)) {
337 /* same non-zero number of indexes, an array access, check */
338 for (i = 0; i < n; ++i) {
339 ir_node *idx1 = get_Sel_index(sel1, i);
340 ir_node *idx2 = get_Sel_index(sel2, i);
341 ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
343 if (res == may_alias)
345 else if (res == no_alias)
348 /* if we have at least one no_alias, there is no alias relation, else we have sure */
349 return have_no > 0 ? no_alias : sure_alias;
353 (void) different_index;
359 * Determine the alias relation by checking if adr1 and adr2 are pointer
362 * @param adr1 The first address.
363 * @param adr2 The second address.
365 static ir_alias_relation different_types(const ir_node *adr1, const ir_node *adr2)
367 ir_entity *ent1 = NULL, *ent2 = NULL;
369 if (is_SymConst_addr_ent(adr1))
370 ent1 = get_SymConst_entity(adr1);
371 else if (is_Sel(adr1))
372 ent1 = get_Sel_entity(adr1);
374 if (is_SymConst_addr_ent(adr2))
375 ent2 = get_SymConst_entity(adr2);
376 else if (is_Sel(adr2))
377 ent2 = get_Sel_entity(adr2);
379 if (ent1 != NULL && ent2 != NULL) {
380 ir_type *tp1 = get_entity_type(ent1);
381 ir_type *tp2 = get_entity_type(ent2);
384 /* do deref until no pointer types are found */
385 while (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
386 tp1 = get_pointer_points_to_type(tp1);
387 tp2 = get_pointer_points_to_type(tp2);
390 if (get_type_tpop(tp1) != get_type_tpop(tp2)) {
391 /* different type structure */
394 if (is_Class_type(tp1)) {
395 /* check class hierarchy */
396 if (! is_SubClass_of(tp1, tp2) &&
397 ! is_SubClass_of(tp2, tp1))
400 /* different types */
409 * Returns non-zero if a node is a result on a malloc-like routine.
411 * @param node the Proj node to test
413 static int is_malloc_Result(const ir_node *node)
415 node = get_Proj_pred(node);
418 node = get_Proj_pred(node);
421 node = get_Call_ptr(node);
422 if (is_SymConst_addr_ent(node)) {
423 ir_entity *ent = get_SymConst_entity(node);
425 if (get_entity_additional_properties(ent) & mtp_property_malloc)
432 ir_storage_class_class_t classify_pointer(const ir_node *irn,
433 const ir_entity *ent)
435 ir_graph *irg = get_irn_irg(irn);
436 ir_storage_class_class_t res = ir_sc_pointer;
437 if (is_SymConst_addr_ent(irn)) {
438 ir_entity *entity = get_SymConst_entity(irn);
439 ir_type *owner = get_entity_owner(entity);
440 res = owner == get_tls_type() ? ir_sc_tls : ir_sc_globalvar;
441 if (! (get_entity_usage(entity) & ir_usage_address_taken))
442 res |= ir_sc_modifier_nottaken;
443 } else if (irn == get_irg_frame(irg)) {
444 res = ir_sc_localvar;
445 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
446 res |= ir_sc_modifier_nottaken;
447 } else if (is_Proj(irn) && is_malloc_Result(irn)) {
448 return ir_sc_malloced;
449 } else if (is_Const(irn)) {
450 return ir_sc_globaladdr;
451 } else if (is_arg_Proj(irn)) {
452 res |= ir_sc_modifier_argument;
459 * If adr represents a Bitfield Sel, skip it
461 static const ir_node *skip_Bitfield_Sels(const ir_node *adr)
464 ir_entity *ent = get_Sel_entity(adr);
465 ir_type *bf_type = get_entity_type(ent);
467 /* is it a bitfield type? */
468 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
469 adr = get_Sel_ptr(adr);
475 * Determine the alias relation between two addresses.
477 * @param addr1 pointer address of the first memory operation
478 * @param mode1 the mode of the accessed data through addr1
479 * @param addr2 pointer address of the second memory operation
480 * @param mode2 the mode of the accessed data through addr2
482 * @return found memory relation
484 static ir_alias_relation _get_alias_relation(
485 const ir_node *adr1, const ir_mode *mode1,
486 const ir_node *adr2, const ir_mode *mode2)
488 ir_entity *ent1, *ent2;
492 const ir_node *base1;
493 const ir_node *base2;
494 const ir_node *orig_adr1 = adr1;
495 const ir_node *orig_adr2 = adr2;
498 ir_storage_class_class_t class1, class2, mod1, mod2;
499 int have_const_offsets;
501 if (! get_opt_alias_analysis())
505 return ir_sure_alias;
507 irg = get_irn_irg(adr1);
508 options = get_irg_memory_disambiguator_options(irg);
510 /* The Armageddon switch */
511 if (options & aa_opt_no_alias)
514 /* do the addresses have constants offsets?
515 * Note: nodes are normalized to have constants at right inputs,
516 * sub X, C is normalized to add X, -C
518 have_const_offsets = 1;
519 while (is_Add(adr1)) {
520 ir_node *add_right = get_Add_right(adr1);
521 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
522 ir_tarval *tv = get_Const_tarval(add_right);
523 offset1 += get_tarval_long(tv);
524 adr1 = get_Add_left(adr1);
525 } else if (mode_is_reference(get_irn_mode(add_right))) {
527 have_const_offsets = 0;
529 adr1 = get_Add_left(adr1);
530 have_const_offsets = 0;
533 while (is_Add(adr2)) {
534 ir_node *add_right = get_Add_right(adr2);
535 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
536 ir_tarval *tv = get_Const_tarval(add_right);
537 offset2 += get_tarval_long(tv);
538 adr2 = get_Add_left(adr2);
539 } else if (mode_is_reference(get_irn_mode(add_right))) {
541 have_const_offsets = 0;
543 adr2 = get_Add_left(adr2);
544 have_const_offsets = 0;
548 mode_size = get_mode_size_bytes(mode1);
549 if (get_mode_size_bytes(mode2) > mode_size) {
550 mode_size = get_mode_size_bytes(mode2);
553 /* same base address -> compare offsets if possible.
554 * FIXME: type long is not sufficient for this task ...
556 if (adr1 == adr2 && have_const_offsets) {
557 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
560 return ir_sure_alias;
564 * Bitfields can be constructed as Sels from its base address.
565 * As they have different entities, the disambiguator would find that they are
566 * alias free. While this is true for its values, it is false for the addresses
567 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
568 * So, skip those bitfield selecting Sel's.
570 adr1 = skip_Bitfield_Sels(adr1);
571 adr2 = skip_Bitfield_Sels(adr2);
579 base1 = find_base_adr(adr1, &ent1);
582 base2 = find_base_adr(adr2, &ent2);
585 /* same base address -> compare Sel entities */
586 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
589 else if (have_const_offsets)
590 return different_sel_offsets(adr1, adr2);
593 mod1 = classify_pointer(base1, ent1);
594 mod2 = classify_pointer(base2, ent2);
596 class1 = get_base_sc(mod1);
597 class2 = get_base_sc(mod2);
599 /* struct-access cannot alias with variables */
600 if (ent1 == NULL && ent2 != NULL && is_compound_type(get_entity_owner(ent2))
601 && (class1 == ir_sc_globalvar || class1 == ir_sc_localvar || class1 == ir_sc_tls || class1 == ir_sc_globaladdr)) {
604 if (ent2 == NULL && ent1 != NULL && is_compound_type(get_entity_owner(ent1))
605 && (class2 == ir_sc_globalvar || class2 == ir_sc_localvar || class2 == ir_sc_tls || class2 == ir_sc_globaladdr)) {
609 if (class1 == ir_sc_pointer || class2 == ir_sc_pointer) {
610 /* swap pointer class to class1 */
611 if (class2 == ir_sc_pointer) {
612 ir_storage_class_class_t temp = mod1;
615 class1 = get_base_sc(mod1);
616 class2 = get_base_sc(mod2);
618 /* a pointer and an object whose address was never taken */
619 if (mod2 & ir_sc_modifier_nottaken) {
622 if (mod1 & ir_sc_modifier_argument) {
623 if ( (options & aa_opt_no_alias_args)
624 && (mod2 & ir_sc_modifier_argument))
626 if ( (options & aa_opt_no_alias_args_global)
627 && (class2 == ir_sc_globalvar
628 || class2 == ir_sc_tls
629 || class2 == ir_sc_globaladdr))
632 } else if (class1 != class2) {
633 /* two objects from different memory spaces */
636 /* both classes are equal */
637 if (class1 == ir_sc_globalvar) {
638 ir_entity *entity1 = get_SymConst_entity(base1);
639 ir_entity *entity2 = get_SymConst_entity(base2);
640 if (entity1 != entity2)
643 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
645 } else if (class1 == ir_sc_globaladdr) {
646 ir_tarval *tv = get_Const_tarval(base1);
647 offset1 += get_tarval_long(tv);
648 tv = get_Const_tarval(base2);
649 offset2 += get_tarval_long(tv);
651 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
654 return ir_sure_alias;
658 /* Type based alias analysis */
659 if (options & aa_opt_type_based) {
660 ir_alias_relation rel;
662 if (options & aa_opt_byte_type_may_alias) {
663 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
664 /* One of the modes address a byte. Assume a ir_may_alias and leave
665 the type based check. */
666 goto leave_type_based_alias;
669 /* cheap check: If the mode sizes did not match, the types MUST be different */
670 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
673 /* cheap test: if only one is a reference mode, no alias */
674 if (mode_is_reference(mode1) != mode_is_reference(mode2))
677 /* cheap test: if arithmetic is different, no alias */
678 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
682 rel = different_types(orig_adr1, orig_adr2);
683 if (rel != ir_may_alias)
685 leave_type_based_alias:;
688 /* do we have a language specific memory disambiguator? */
689 if (language_disambuigator != NULL) {
690 ir_alias_relation rel = language_disambuigator(orig_adr1, mode1, orig_adr2, mode2);
691 if (rel != ir_may_alias)
695 /* access points-to information here */
700 * Determine the alias relation between two addresses.
702 ir_alias_relation get_alias_relation(
703 const ir_node *adr1, const ir_mode *mode1,
704 const ir_node *adr2, const ir_mode *mode2)
706 ir_alias_relation rel = _get_alias_relation(adr1, mode1, adr2, mode2);
707 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
711 /* Set a source language specific memory disambiguator function. */
712 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func)
714 language_disambuigator = func;
717 /** The result cache for the memory disambiguator. */
718 static set *result_cache = NULL;
720 /** An entry in the relation cache. */
721 typedef struct mem_disambig_entry {
722 const ir_node *adr1; /**< The first address. */
723 const ir_mode *mode1; /**< The first address mode. */
724 const ir_node *adr2; /**< The second address. */
725 const ir_mode *mode2; /**< The second address mode. */
726 ir_alias_relation result; /**< The alias relation result. */
727 } mem_disambig_entry;
729 #define HASH_ENTRY(adr1, adr2) (HASH_PTR(adr1) ^ HASH_PTR(adr2))
732 * Compare two relation cache entries.
734 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size)
736 const mem_disambig_entry *p1 = (const mem_disambig_entry*) elt;
737 const mem_disambig_entry *p2 = (const mem_disambig_entry*) key;
740 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2 &&
741 p1->mode1 == p2->mode1 && p1->mode2 == p2->mode2;
745 * Initialize the relation cache.
747 void mem_disambig_init(void)
749 result_cache = new_set(cmp_mem_disambig_entry, 8);
753 * Determine the alias relation between two addresses.
755 ir_alias_relation get_alias_relation_ex(
756 const ir_node *adr1, const ir_mode *mode1,
757 const ir_node *adr2, const ir_mode *mode2)
759 mem_disambig_entry key, *entry;
761 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
763 if (! get_opt_alias_analysis())
766 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
767 const ir_node *t = adr1;
776 entry = (mem_disambig_entry*) set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
778 return entry->result;
780 key.result = get_alias_relation(adr1, mode1, adr2, mode2);
782 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
786 /* Free the relation cache. */
787 void mem_disambig_term(void)
789 if (result_cache != NULL) {
790 del_set(result_cache);
796 * Check the mode of a Load/Store with the mode of the entity
798 * If the mode of the entity and the Load/Store mode do not match, we
799 * have the bad reinterpret case:
802 * char b = *(char *)&i;
804 * We do NOT count this as one value and return address_taken
806 * However, we support an often used case. If the mode is two-complement
807 * we allow casts between signed/unsigned.
809 * @param mode the mode of the Load/Store
810 * @param ent_mode the mode of the accessed entity
812 * @return non-zero if the Load/Store is a hidden cast, zero else
814 static int is_hidden_cast(const ir_mode *mode, const ir_mode *ent_mode)
816 if (ent_mode == NULL)
819 if (ent_mode != mode) {
820 if (ent_mode == NULL ||
821 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
822 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
823 get_mode_arithmetic(mode) != irma_twos_complement)
830 * Determine the usage state of a node (or its successor Sels).
832 * @param irn the node
834 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity)
837 ir_mode *emode, *mode;
842 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
843 ir_node *succ = get_irn_out(irn, i);
845 switch (get_irn_opcode(succ)) {
847 /* beware: irn might be a Id node here, so irn might be not
848 equal to get_Load_ptr(succ) */
849 res |= ir_usage_read;
851 /* check if this load is not a hidden conversion */
852 mode = get_Load_mode(succ);
853 emode = get_type_mode(get_entity_type(entity));
854 if (is_hidden_cast(mode, emode))
855 res |= ir_usage_reinterpret_cast;
859 /* check that the node is not the Store's value */
860 if (irn == get_Store_value(succ)) {
861 res |= ir_usage_unknown;
863 if (irn == get_Store_ptr(succ)) {
864 res |= ir_usage_write;
866 /* check if this Store is not a hidden conversion */
867 value = get_Store_value(succ);
868 mode = get_irn_mode(value);
869 emode = get_type_mode(get_entity_type(entity));
870 if (is_hidden_cast(mode, emode))
871 res |= ir_usage_reinterpret_cast;
873 assert(irn != get_Store_mem(succ));
877 /* CopyB are like Loads/Stores */
878 tp = get_entity_type(entity);
879 if (tp != get_CopyB_type(succ)) {
880 /* bad, different types, might be a hidden conversion */
881 res |= ir_usage_reinterpret_cast;
883 if (irn == get_CopyB_dst(succ)) {
884 res |= ir_usage_write;
886 assert(irn == get_CopyB_src(succ));
887 res |= ir_usage_read;
893 /* Check the successor of irn. */
894 res |= determine_entity_usage(succ, entity);
897 ir_entity *sel_entity = get_Sel_entity(succ);
898 /* this analysis can't handle unions correctly */
899 if (is_Union_type(get_entity_owner(sel_entity))) {
900 res |= ir_usage_unknown;
903 /* Check the successor of irn. */
904 res |= determine_entity_usage(succ, sel_entity);
909 if (irn == get_Call_ptr(succ)) {
910 /* TODO: we could check for reinterpret casts here...
911 * But I doubt anyone is interested in that bit for
912 * function entities and I'm too lazy to write the code now.
914 res |= ir_usage_read;
916 assert(irn != get_Call_mem(succ));
917 res |= ir_usage_unknown;
921 /* skip identities */
923 res |= determine_entity_usage(succ, entity);
929 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
931 ir_node *pred = get_Tuple_pred(succ, input_nr);
934 /* we found one input */
935 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
936 ir_node *proj = get_irn_out(succ, k);
938 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
939 res |= determine_entity_usage(proj, entity);
949 /* another op, we don't know anything (we could do more advanced
950 * things like a dataflow analysis here) */
951 res |= ir_usage_unknown;
956 return (ir_entity_usage) res;
960 * Update the usage flags of all frame entities.
962 static void analyse_irg_entity_usage(ir_graph *irg)
964 ir_type *ft = get_irg_frame_type(irg);
967 int j, k, static_link_arg;
969 /* set initial state to not_taken, as this is the "smallest" state */
970 for (i = 0, n = get_class_n_members(ft); i < n; ++i) {
971 ir_entity *ent = get_class_member(ft, i);
973 /* methods can only be analyzed globally */
974 if (! is_method_entity(ent)) {
975 ir_entity_usage flags = ir_usage_none;
976 if (get_entity_linkage(ent) & IR_LINKAGE_HIDDEN_USER)
977 flags = ir_usage_unknown;
978 set_entity_usage(ent, flags);
982 assure_irg_outs(irg);
984 irg_frame = get_irg_frame(irg);
986 for (j = get_irn_n_outs(irg_frame) - 1; j >= 0; --j) {
987 ir_node *succ = get_irn_out(irg_frame, j);
994 entity = get_Sel_entity(succ);
995 flags = get_entity_usage(entity);
996 flags |= determine_entity_usage(succ, entity);
997 set_entity_usage(entity, (ir_entity_usage) flags);
1000 /* check inner functions accessing outer frame */
1001 static_link_arg = 0;
1002 for (i = 0, n = get_class_n_members(ft); i < n; ++i) {
1003 ir_entity *ent = get_class_member(ft, i);
1004 ir_graph *inner_irg;
1007 if (! is_method_entity(ent))
1010 inner_irg = get_entity_irg(ent);
1011 if (inner_irg == NULL)
1014 assure_irg_outs(inner_irg);
1015 args = get_irg_args(inner_irg);
1016 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
1017 ir_node *arg = get_irn_out(args, j);
1019 if (get_Proj_proj(arg) == static_link_arg) {
1020 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
1021 ir_node *succ = get_irn_out(arg, k);
1024 ir_entity *entity = get_Sel_entity(succ);
1026 if (get_entity_owner(entity) == ft) {
1027 /* found an access to the outer frame */
1030 flags = get_entity_usage(entity);
1031 flags |= determine_entity_usage(succ, entity);
1032 set_entity_usage(entity, (ir_entity_usage) flags);
1042 set_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_ENTITY_USAGE);
1045 void assure_irg_entity_usage_computed(ir_graph *irg)
1047 if (is_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_ENTITY_USAGE))
1050 analyse_irg_entity_usage(irg);
1055 * Initialize the entity_usage flag for a global type like type.
1057 static void init_entity_usage(ir_type *tp)
1061 /* We have to be conservative: All external visible entities are unknown */
1062 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1063 ir_entity *ent = get_compound_member(tp, i);
1064 unsigned flags = ir_usage_none;
1066 if (entity_is_externally_visible(ent)) {
1067 flags |= ir_usage_unknown;
1069 set_entity_usage(ent, (ir_entity_usage) flags);
1074 * Mark all entities used in the initializer as unknown usage.
1076 * @param initializer the initializer to check
1078 static void check_initializer_nodes(ir_initializer_t *initializer)
1083 switch (initializer->kind) {
1084 case IR_INITIALIZER_CONST:
1085 /* let's check if it's an address */
1086 n = initializer->consti.value;
1087 if (is_SymConst_addr_ent(n)) {
1088 ir_entity *ent = get_SymConst_entity(n);
1089 set_entity_usage(ent, ir_usage_unknown);
1092 case IR_INITIALIZER_TARVAL:
1093 case IR_INITIALIZER_NULL:
1095 case IR_INITIALIZER_COMPOUND:
1096 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1097 ir_initializer_t *sub_initializer
1098 = initializer->compound.initializers[i];
1099 check_initializer_nodes(sub_initializer);
1103 panic("invalid initializer found");
1107 * Mark all entities used in the initializer for the given entity as unknown
1110 * @param ent the entity
1112 static void check_initializer(ir_entity *ent)
1114 /* Beware: Methods are always initialized with "themself". This does not
1115 * count as a taken address.
1116 * TODO: this initialisation with "themself" is wrong and should be removed
1118 if (is_Method_type(get_entity_type(ent)))
1121 if (ent->initializer != NULL) {
1122 check_initializer_nodes(ent->initializer);
1123 } else if (entity_has_compound_ent_values(ent)) {
1126 for (i = 0, n = get_compound_ent_n_values(ent); i < n; ++i) {
1127 ir_node *irn = get_compound_ent_value(ent, i);
1129 /* let's check if it's an address */
1130 if (is_SymConst_addr_ent(irn)) {
1131 ir_entity *symconst_ent = get_SymConst_entity(irn);
1132 set_entity_usage(symconst_ent, ir_usage_unknown);
1140 * Mark all entities used in initializers as unknown usage.
1142 * @param tp a compound type
1144 static void check_initializers(ir_type *tp)
1148 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1149 ir_entity *ent = get_compound_member(tp, i);
1151 check_initializer(ent);
1155 #ifdef DEBUG_libfirm
1157 * Print the entity usage flags of all entities of a given type for debugging.
1159 * @param tp a compound type
1161 static void print_entity_usage_flags(const ir_type *tp)
1164 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1165 ir_entity *ent = get_compound_member(tp, i);
1166 ir_entity_usage flags = get_entity_usage(ent);
1170 ir_printf("%+F:", ent);
1171 if (flags & ir_usage_address_taken)
1172 printf(" address_taken");
1173 if (flags & ir_usage_read)
1175 if (flags & ir_usage_write)
1177 if (flags & ir_usage_reinterpret_cast)
1178 printf(" reinterp_cast");
1182 #endif /* DEBUG_libfirm */
1185 * Post-walker: check for global entity address
1187 static void check_global_address(ir_node *irn, void *data)
1193 if (is_SymConst_addr_ent(irn)) {
1195 ent = get_SymConst_entity(irn);
1199 flags = get_entity_usage(ent);
1200 flags |= determine_entity_usage(irn, ent);
1201 set_entity_usage(ent, (ir_entity_usage) flags);
1205 * Update the entity usage flags of all global entities.
1207 static void analyse_irp_globals_entity_usage(void)
1212 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1213 ir_type *type = get_segment_type(s);
1214 init_entity_usage(type);
1217 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1218 ir_type *type = get_segment_type(s);
1219 check_initializers(type);
1222 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
1223 ir_graph *irg = get_irp_irg(i);
1225 assure_irg_outs(irg);
1226 irg_walk_graph(irg, NULL, check_global_address, NULL);
1229 #ifdef DEBUG_libfirm
1230 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1231 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1232 print_entity_usage_flags(get_segment_type(s));
1235 #endif /* DEBUG_libfirm */
1238 irp->globals_entity_usage_state = ir_entity_usage_computed;
1241 /* Returns the current address taken state of the globals. */
1242 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void)
1244 return irp->globals_entity_usage_state;
1247 /* Sets the current address taken state of the graph. */
1248 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state)
1250 irp->globals_entity_usage_state = state;
1253 /* Assure that the address taken flag is computed for the globals. */
1254 void assure_irp_globals_entity_usage_computed(void)
1256 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1259 analyse_irp_globals_entity_usage();
1262 void firm_init_memory_disambiguator(void)
1264 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1265 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1269 /** Maps method types to cloned method types. */
1270 static pmap *mtp_map;
1273 * Clone a method type if not already cloned.
1275 * @param tp the type to clone
1277 static ir_type *clone_type_and_cache(ir_type *tp)
1280 pmap_entry *e = pmap_find(mtp_map, tp);
1283 return (ir_type*) e->value;
1285 res = clone_type_method(tp);
1286 pmap_insert(mtp_map, tp, res);
1292 * Walker: clone all call types of Calls to methods having the
1293 * mtp_property_private property set.
1295 static void update_calls_to_private(ir_node *call, void *env)
1298 if (is_Call(call)) {
1299 ir_node *ptr = get_Call_ptr(call);
1301 if (is_SymConst(ptr)) {
1302 ir_entity *ent = get_SymConst_entity(ptr);
1303 ir_type *ctp = get_Call_type(call);
1305 if (get_entity_additional_properties(ent) & mtp_property_private) {
1306 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1307 ctp = clone_type_and_cache(ctp);
1308 add_method_additional_properties(ctp, mtp_property_private);
1309 set_Call_type(call, ctp);
1310 DB((dbgcall, LEVEL_1, "changed call to private method %+F using cloned type %+F\n", ent, ctp));
1317 /* Mark all private methods, i.e. those of which all call sites are known. */
1318 void mark_private_methods(void)
1323 assure_irp_globals_entity_usage_computed();
1325 mtp_map = pmap_create();
1327 /* first step: change the calling conventions of the local non-escaped entities */
1328 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
1329 ir_graph *irg = get_irp_irg(i);
1330 ir_entity *ent = get_irg_entity(irg);
1331 ir_entity_usage flags = get_entity_usage(ent);
1333 if (!(flags & ir_usage_address_taken) && !entity_is_externally_visible(ent)) {
1334 ir_type *mtp = get_entity_type(ent);
1336 add_entity_additional_properties(ent, mtp_property_private);
1337 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1338 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1339 /* need a new type */
1340 mtp = clone_type_and_cache(mtp);
1341 add_method_additional_properties(mtp, mtp_property_private);
1342 set_entity_type(ent, mtp);
1343 DB((dbgcall, LEVEL_2, "changed entity type of %+F to %+F\n", ent, mtp));
1350 all_irg_walk(NULL, update_calls_to_private, NULL);
1352 pmap_destroy(mtp_map);
1355 /* create a pass for mark_private_methods() */
1356 ir_prog_pass_t *mark_private_methods_pass(const char *name)
1358 return def_prog_pass(name ? name : "mark_private_methods", mark_private_methods);