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 const char *get_ir_alias_relation_name(ir_alias_relation rel)
60 #define X(a) case a: return #a
66 panic("UNKNOWN alias relation");
71 unsigned get_irg_memory_disambiguator_options(const ir_graph *irg)
73 unsigned opt = irg->mem_disambig_opt;
74 if (opt & aa_opt_inherited)
75 return global_mem_disamgig_opt;
79 void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options)
81 irg->mem_disambig_opt = options & ~aa_opt_inherited;
84 void set_irp_memory_disambiguator_options(unsigned options)
86 global_mem_disamgig_opt = options;
89 ir_storage_class_class_t get_base_sc(ir_storage_class_class_t x)
91 return x & ~ir_sc_modifiers;
95 * Find the base address and entity of an Sel node.
98 * @param pEnt after return points to the base entity.
100 * @return the base address.
102 static ir_node *find_base_adr(const ir_node *sel, ir_entity **pEnt)
104 ir_node *ptr = get_Sel_ptr(sel);
106 while (is_Sel(ptr)) {
108 ptr = get_Sel_ptr(sel);
110 *pEnt = get_Sel_entity(sel);
115 * Check if a given Const node is greater or equal a given size.
117 * @param cns a Const node
118 * @param size a integer size
120 * @return ir_no_alias if the Const is greater, ir_may_alias else
122 static ir_alias_relation check_const(const ir_node *cns, int size)
124 ir_tarval *tv = get_Const_tarval(cns);
128 return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
129 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
130 return tarval_cmp(tv_size, tv) & (ir_relation_less_equal) ? ir_no_alias : ir_may_alias;
134 * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
136 * @param idx1 a node representing the first index
137 * @param idx2 a node representing the second index
138 * @param size an integer size
140 * @return ir_sure_alias iff idx1 == idx2
141 * ir_no_alias iff they ALWAYS differ more than size
144 static ir_alias_relation different_index(const ir_node *idx1, const ir_node *idx2, int size)
147 return ir_sure_alias;
148 if (is_Const(idx1) && is_Const(idx2)) {
149 /* both are const, we can compare them */
150 ir_tarval *tv1 = get_Const_tarval(idx1);
151 ir_tarval *tv2 = get_Const_tarval(idx2);
152 ir_tarval *tv, *tv_size;
156 return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
158 /* arg, modes may be different */
159 m1 = get_tarval_mode(tv1);
160 m2 = get_tarval_mode(tv2);
162 int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
165 /* m1 is a small mode, cast up */
166 m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
168 /* should NOT happen, but if it does we give up here */
171 tv1 = tarval_convert_to(tv1, m1);
172 } else if (size > 0) {
173 /* m2 is a small mode, cast up */
174 m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
176 /* should NOT happen, but if it does we give up here */
179 tv2 = tarval_convert_to(tv2, m2);
181 /* here the size should be identical, check for signed */
182 if (get_mode_sign(m1) != get_mode_sign(m2)) {
183 /* find the signed */
184 if (mode_is_signed(m2)) {
191 /* m1 is now the signed one */
192 if (!tarval_is_negative(tv1)) {
193 /* tv1 is signed, but >= 0, simply cast into unsigned */
194 tv1 = tarval_convert_to(tv1, m2);
196 tv_size = new_tarval_from_long(size, m2);
198 if (tarval_cmp(tv2, tv_size) & (ir_relation_greater_equal)) {
199 /* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
202 /* tv_size > tv2, so we can subtract without overflow */
203 tv2 = tarval_sub(tv_size, tv2, NULL);
205 /* tv1 is < 0, so we can negate it */
206 tv1 = tarval_neg(tv1);
208 /* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
209 tv1 = tarval_convert_to(tv1, m2);
211 /* now we can compare without overflow */
212 return tarval_cmp(tv1, tv2) & (ir_relation_greater_equal) ? ir_no_alias : ir_may_alias;
216 if (tarval_cmp(tv1, tv2) == ir_relation_greater) {
221 /* tv1 is now the "smaller" one */
222 tv = tarval_sub(tv2, tv1, NULL);
223 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
224 return tarval_cmp(tv_size, tv) & (ir_relation_less_equal) ? ir_no_alias : ir_may_alias;
227 /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
229 ir_node *l1 = get_Add_left(idx1);
230 ir_node *r1 = get_Add_right(idx1);
235 return check_const(r1, size);
238 /* both are Adds, check if they are of x + a == x + b kind */
239 ir_node *l2 = get_Add_left(idx2);
240 ir_node *r2 = get_Add_right(idx2);
243 return different_index(r1, r2, size);
245 return different_index(r1, l2, size);
247 return different_index(l1, l2, size);
249 return different_index(l1, r2, size);
253 ir_node *l2 = get_Add_left(idx2);
254 ir_node *r2 = get_Add_right(idx2);
259 return check_const(r2, size);
264 ir_node *l1 = get_Sub_left(idx1);
265 ir_node *r1 = get_Sub_right(idx1);
270 return check_const(r1, size);
274 /* both are Subs, check if they are of x - a == x - b kind */
275 ir_node *l2 = get_Sub_left(idx2);
278 ir_node *r2 = get_Sub_right(idx2);
279 return different_index(r1, r2, size);
284 ir_node *l2 = get_Sub_left(idx2);
285 ir_node *r2 = get_Sub_right(idx2);
290 return check_const(r2, size);
298 * Two Sel addresses have the same base address, check if their offsets are
301 * @param adr1 The first address.
302 * @param adr2 The second address.
304 static ir_alias_relation different_sel_offsets(const ir_node *sel1, const ir_node *sel2)
306 /* seems to be broken */
310 ir_entity *ent1 = get_Sel_entity(sel1);
311 ir_entity *ent2 = get_Sel_entity(sel2);
312 int i, check_arr = 0;
317 ir_type *tp1 = get_entity_type(ent1);
318 ir_type *tp2 = get_entity_type(ent2);
322 else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
323 get_type_size_bits(tp1) == get_type_size_bits(tp2))
327 /* we select an entity of same size, check for indexes */
328 int n = get_Sel_n_indexs(sel1);
331 if (n > 0 && n == get_Sel_n_indexs(sel2)) {
332 /* same non-zero number of indexes, an array access, check */
333 for (i = 0; i < n; ++i) {
334 ir_node *idx1 = get_Sel_index(sel1, i);
335 ir_node *idx2 = get_Sel_index(sel2, i);
336 ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
338 if (res == may_alias)
340 else if (res == no_alias)
343 /* if we have at least one no_alias, there is no alias relation, else we have sure */
344 return have_no > 0 ? no_alias : sure_alias;
348 (void) different_index;
354 * Determine the alias relation by checking if adr1 and adr2 are pointer
357 * @param adr1 The first address.
358 * @param adr2 The second address.
360 static ir_alias_relation different_types(const ir_node *adr1, const ir_node *adr2)
362 ir_entity *ent1 = NULL, *ent2 = NULL;
364 if (is_SymConst_addr_ent(adr1))
365 ent1 = get_SymConst_entity(adr1);
366 else if (is_Sel(adr1))
367 ent1 = get_Sel_entity(adr1);
369 if (is_SymConst_addr_ent(adr2))
370 ent2 = get_SymConst_entity(adr2);
371 else if (is_Sel(adr2))
372 ent2 = get_Sel_entity(adr2);
374 if (ent1 != NULL && ent2 != NULL) {
375 ir_type *tp1 = get_entity_type(ent1);
376 ir_type *tp2 = get_entity_type(ent2);
379 /* do deref until no pointer types are found */
380 while (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
381 tp1 = get_pointer_points_to_type(tp1);
382 tp2 = get_pointer_points_to_type(tp2);
385 if (get_type_tpop(tp1) != get_type_tpop(tp2)) {
386 /* different type structure */
389 if (is_Class_type(tp1)) {
390 /* check class hierarchy */
391 if (! is_SubClass_of(tp1, tp2) &&
392 ! is_SubClass_of(tp2, tp1))
395 /* different types */
404 * Returns non-zero if a node is a result on a malloc-like routine.
406 * @param node the Proj node to test
408 static int is_malloc_Result(const ir_node *node)
410 node = get_Proj_pred(node);
413 node = get_Proj_pred(node);
416 node = get_Call_ptr(node);
417 if (is_SymConst_addr_ent(node)) {
418 ir_entity *ent = get_SymConst_entity(node);
420 if (get_entity_additional_properties(ent) & mtp_property_malloc)
427 ir_storage_class_class_t classify_pointer(const ir_node *irn,
428 const ir_entity *ent)
430 ir_graph *irg = get_irn_irg(irn);
431 ir_storage_class_class_t res = ir_sc_pointer;
432 if (is_SymConst_addr_ent(irn)) {
433 ir_entity *entity = get_SymConst_entity(irn);
434 ir_type *owner = get_entity_owner(entity);
435 res = owner == get_tls_type() ? ir_sc_tls : ir_sc_globalvar;
436 if (! (get_entity_usage(entity) & ir_usage_address_taken))
437 res |= ir_sc_modifier_nottaken;
438 } else if (irn == get_irg_frame(irg)) {
439 res = ir_sc_localvar;
440 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
441 res |= ir_sc_modifier_nottaken;
442 } else if (is_Proj(irn) && is_malloc_Result(irn)) {
443 return ir_sc_malloced;
444 } else if (is_Const(irn)) {
445 return ir_sc_globaladdr;
446 } else if (is_arg_Proj(irn)) {
447 res |= ir_sc_modifier_argument;
454 * If adr represents a Bitfield Sel, skip it
456 static const ir_node *skip_Bitfield_Sels(const ir_node *adr)
459 ir_entity *ent = get_Sel_entity(adr);
460 ir_type *bf_type = get_entity_type(ent);
462 /* is it a bitfield type? */
463 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
464 adr = get_Sel_ptr(adr);
470 * Determine the alias relation between two addresses.
472 * @param addr1 pointer address of the first memory operation
473 * @param mode1 the mode of the accessed data through addr1
474 * @param addr2 pointer address of the second memory operation
475 * @param mode2 the mode of the accessed data through addr2
477 * @return found memory relation
479 static ir_alias_relation _get_alias_relation(
480 const ir_node *adr1, const ir_mode *mode1,
481 const ir_node *adr2, const ir_mode *mode2)
483 ir_entity *ent1, *ent2;
487 const ir_node *base1;
488 const ir_node *base2;
489 const ir_node *orig_adr1 = adr1;
490 const ir_node *orig_adr2 = adr2;
493 ir_storage_class_class_t class1, class2, mod1, mod2;
494 int have_const_offsets;
496 if (! get_opt_alias_analysis())
500 return ir_sure_alias;
502 irg = get_irn_irg(adr1);
503 options = get_irg_memory_disambiguator_options(irg);
505 /* The Armageddon switch */
506 if (options & aa_opt_no_alias)
509 /* do the addresses have constants offsets?
510 * Note: nodes are normalized to have constants at right inputs,
511 * sub X, C is normalized to add X, -C
513 have_const_offsets = 1;
514 while (is_Add(adr1)) {
515 ir_node *add_right = get_Add_right(adr1);
516 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
517 ir_tarval *tv = get_Const_tarval(add_right);
518 offset1 += get_tarval_long(tv);
519 adr1 = get_Add_left(adr1);
520 } else if (mode_is_reference(get_irn_mode(add_right))) {
522 have_const_offsets = 0;
524 adr1 = get_Add_left(adr1);
525 have_const_offsets = 0;
528 while (is_Add(adr2)) {
529 ir_node *add_right = get_Add_right(adr2);
530 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
531 ir_tarval *tv = get_Const_tarval(add_right);
532 offset2 += get_tarval_long(tv);
533 adr2 = get_Add_left(adr2);
534 } else if (mode_is_reference(get_irn_mode(add_right))) {
536 have_const_offsets = 0;
538 adr2 = get_Add_left(adr2);
539 have_const_offsets = 0;
543 mode_size = get_mode_size_bytes(mode1);
544 if (get_mode_size_bytes(mode2) > mode_size) {
545 mode_size = get_mode_size_bytes(mode2);
548 /* same base address -> compare offsets if possible.
549 * FIXME: type long is not sufficient for this task ...
551 if (adr1 == adr2 && have_const_offsets) {
552 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
555 return ir_sure_alias;
559 * Bitfields can be constructed as Sels from its base address.
560 * As they have different entities, the disambiguator would find that they are
561 * alias free. While this is true for its values, it is false for the addresses
562 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
563 * So, skip those bitfield selecting Sel's.
565 adr1 = skip_Bitfield_Sels(adr1);
566 adr2 = skip_Bitfield_Sels(adr2);
574 base1 = find_base_adr(adr1, &ent1);
577 base2 = find_base_adr(adr2, &ent2);
580 /* same base address -> compare Sel entities */
581 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
584 else if (have_const_offsets)
585 return different_sel_offsets(adr1, adr2);
588 mod1 = classify_pointer(base1, ent1);
589 mod2 = classify_pointer(base2, ent2);
591 class1 = get_base_sc(mod1);
592 class2 = get_base_sc(mod2);
594 /* struct-access cannot alias with variables */
595 if (ent1 == NULL && ent2 != NULL && is_compound_type(get_entity_owner(ent2))
596 && (class1 == ir_sc_globalvar || class1 == ir_sc_localvar || class1 == ir_sc_tls || class1 == ir_sc_globaladdr)) {
599 if (ent2 == NULL && ent1 != NULL && is_compound_type(get_entity_owner(ent1))
600 && (class2 == ir_sc_globalvar || class2 == ir_sc_localvar || class2 == ir_sc_tls || class2 == ir_sc_globaladdr)) {
604 if (class1 == ir_sc_pointer || class2 == ir_sc_pointer) {
605 /* swap pointer class to class1 */
606 if (class2 == ir_sc_pointer) {
607 ir_storage_class_class_t temp = mod1;
610 class1 = get_base_sc(mod1);
611 class2 = get_base_sc(mod2);
613 /* a pointer and an object whose address was never taken */
614 if (mod2 & ir_sc_modifier_nottaken) {
617 if (mod1 & ir_sc_modifier_argument) {
618 if ( (options & aa_opt_no_alias_args)
619 && (mod2 & ir_sc_modifier_argument))
621 if ( (options & aa_opt_no_alias_args_global)
622 && (class2 == ir_sc_globalvar
623 || class2 == ir_sc_tls
624 || class2 == ir_sc_globaladdr))
627 } else if (class1 != class2) {
628 /* two objects from different memory spaces */
631 /* both classes are equal */
632 if (class1 == ir_sc_globalvar) {
633 ir_entity *entity1 = get_SymConst_entity(base1);
634 ir_entity *entity2 = get_SymConst_entity(base2);
635 if (entity1 != entity2)
638 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
640 } else if (class1 == ir_sc_globaladdr) {
641 ir_tarval *tv = get_Const_tarval(base1);
642 offset1 += get_tarval_long(tv);
643 tv = get_Const_tarval(base2);
644 offset2 += get_tarval_long(tv);
646 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
649 return ir_sure_alias;
653 /* Type based alias analysis */
654 if (options & aa_opt_type_based) {
655 ir_alias_relation rel;
657 if (options & aa_opt_byte_type_may_alias) {
658 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
659 /* One of the modes address a byte. Assume a ir_may_alias and leave
660 the type based check. */
661 goto leave_type_based_alias;
664 /* cheap check: If the mode sizes did not match, the types MUST be different */
665 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
668 /* cheap test: if only one is a reference mode, no alias */
669 if (mode_is_reference(mode1) != mode_is_reference(mode2))
672 /* cheap test: if arithmetic is different, no alias */
673 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
677 rel = different_types(orig_adr1, orig_adr2);
678 if (rel != ir_may_alias)
680 leave_type_based_alias:;
683 /* do we have a language specific memory disambiguator? */
684 if (language_disambuigator != NULL) {
685 ir_alias_relation rel = language_disambuigator(orig_adr1, mode1, orig_adr2, mode2);
686 if (rel != ir_may_alias)
690 /* access points-to information here */
694 ir_alias_relation get_alias_relation(
695 const ir_node *adr1, const ir_mode *mode1,
696 const ir_node *adr2, const ir_mode *mode2)
698 ir_alias_relation rel = _get_alias_relation(adr1, mode1, adr2, mode2);
699 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
703 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func)
705 language_disambuigator = func;
708 /** The result cache for the memory disambiguator. */
709 static set *result_cache = NULL;
711 /** An entry in the relation cache. */
712 typedef struct mem_disambig_entry {
713 const ir_node *adr1; /**< The first address. */
714 const ir_mode *mode1; /**< The first address mode. */
715 const ir_node *adr2; /**< The second address. */
716 const ir_mode *mode2; /**< The second address mode. */
717 ir_alias_relation result; /**< The alias relation result. */
718 } mem_disambig_entry;
720 #define HASH_ENTRY(adr1, adr2) (hash_ptr(adr1) ^ hash_ptr(adr2))
723 * Compare two relation cache entries.
725 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size)
727 const mem_disambig_entry *p1 = (const mem_disambig_entry*) elt;
728 const mem_disambig_entry *p2 = (const mem_disambig_entry*) key;
731 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2 &&
732 p1->mode1 == p2->mode1 && p1->mode2 == p2->mode2;
735 void mem_disambig_init(void)
737 result_cache = new_set(cmp_mem_disambig_entry, 8);
740 ir_alias_relation get_alias_relation_ex(
741 const ir_node *adr1, const ir_mode *mode1,
742 const ir_node *adr2, const ir_mode *mode2)
744 mem_disambig_entry key, *entry;
746 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
748 if (! get_opt_alias_analysis())
751 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
752 const ir_node *t = adr1;
761 entry = (mem_disambig_entry*) set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
763 return entry->result;
765 key.result = get_alias_relation(adr1, mode1, adr2, mode2);
767 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
771 void mem_disambig_term(void)
773 if (result_cache != NULL) {
774 del_set(result_cache);
780 * Check the mode of a Load/Store with the mode of the entity
782 * If the mode of the entity and the Load/Store mode do not match, we
783 * have the bad reinterpret case:
786 * char b = *(char *)&i;
788 * We do NOT count this as one value and return address_taken
790 * However, we support an often used case. If the mode is two-complement
791 * we allow casts between signed/unsigned.
793 * @param mode the mode of the Load/Store
794 * @param ent_mode the mode of the accessed entity
796 * @return non-zero if the Load/Store is a hidden cast, zero else
798 static int is_hidden_cast(const ir_mode *mode, const ir_mode *ent_mode)
800 if (ent_mode == NULL)
803 if (ent_mode != mode) {
804 if (ent_mode == NULL ||
805 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
806 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
807 get_mode_arithmetic(mode) != irma_twos_complement)
814 * Determine the usage state of a node (or its successor Sels).
816 * @param irn the node
818 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity)
821 ir_mode *emode, *mode;
826 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
827 ir_node *succ = get_irn_out(irn, i);
829 switch (get_irn_opcode(succ)) {
831 /* beware: irn might be a Id node here, so irn might be not
832 equal to get_Load_ptr(succ) */
833 res |= ir_usage_read;
835 /* check if this load is not a hidden conversion */
836 mode = get_Load_mode(succ);
837 emode = get_type_mode(get_entity_type(entity));
838 if (is_hidden_cast(mode, emode))
839 res |= ir_usage_reinterpret_cast;
843 /* check that the node is not the Store's value */
844 if (irn == get_Store_value(succ)) {
845 res |= ir_usage_unknown;
847 if (irn == get_Store_ptr(succ)) {
848 res |= ir_usage_write;
850 /* check if this Store is not a hidden conversion */
851 value = get_Store_value(succ);
852 mode = get_irn_mode(value);
853 emode = get_type_mode(get_entity_type(entity));
854 if (is_hidden_cast(mode, emode))
855 res |= ir_usage_reinterpret_cast;
857 assert(irn != get_Store_mem(succ));
861 /* CopyB are like Loads/Stores */
862 tp = get_entity_type(entity);
863 if (tp != get_CopyB_type(succ)) {
864 /* bad, different types, might be a hidden conversion */
865 res |= ir_usage_reinterpret_cast;
867 if (irn == get_CopyB_dst(succ)) {
868 res |= ir_usage_write;
870 assert(irn == get_CopyB_src(succ));
871 res |= ir_usage_read;
877 /* Check the successor of irn. */
878 res |= determine_entity_usage(succ, entity);
881 ir_entity *sel_entity = get_Sel_entity(succ);
882 /* this analysis can't handle unions correctly */
883 if (is_Union_type(get_entity_owner(sel_entity))) {
884 res |= ir_usage_unknown;
887 /* Check the successor of irn. */
888 res |= determine_entity_usage(succ, sel_entity);
893 if (irn == get_Call_ptr(succ)) {
894 /* TODO: we could check for reinterpret casts here...
895 * But I doubt anyone is interested in that bit for
896 * function entities and I'm too lazy to write the code now.
898 res |= ir_usage_read;
900 assert(irn != get_Call_mem(succ));
901 res |= ir_usage_unknown;
905 /* skip identities */
907 res |= determine_entity_usage(succ, entity);
913 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
915 ir_node *pred = get_Tuple_pred(succ, input_nr);
918 /* we found one input */
919 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
920 ir_node *proj = get_irn_out(succ, k);
922 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
923 res |= determine_entity_usage(proj, entity);
933 /* another op, we don't know anything (we could do more advanced
934 * things like a dataflow analysis here) */
935 res |= ir_usage_unknown;
940 return (ir_entity_usage) res;
944 * Update the usage flags of all frame entities.
946 static void analyse_irg_entity_usage(ir_graph *irg)
948 ir_type *ft = get_irg_frame_type(irg);
951 int j, k, static_link_arg;
953 assure_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_OUTS);
955 /* set initial state to not_taken, as this is the "smallest" state */
956 for (i = 0, n = get_class_n_members(ft); i < n; ++i) {
957 ir_entity *ent = get_class_member(ft, i);
959 /* methods can only be analyzed globally */
960 if (! is_method_entity(ent)) {
961 ir_entity_usage flags = ir_usage_none;
962 if (get_entity_linkage(ent) & IR_LINKAGE_HIDDEN_USER)
963 flags = ir_usage_unknown;
964 set_entity_usage(ent, flags);
968 irg_frame = get_irg_frame(irg);
970 for (j = get_irn_n_outs(irg_frame) - 1; j >= 0; --j) {
971 ir_node *succ = get_irn_out(irg_frame, j);
978 entity = get_Sel_entity(succ);
979 flags = get_entity_usage(entity);
980 flags |= determine_entity_usage(succ, entity);
981 set_entity_usage(entity, (ir_entity_usage) flags);
984 /* check inner functions accessing outer frame */
986 for (i = 0, n = get_class_n_members(ft); i < n; ++i) {
987 ir_entity *ent = get_class_member(ft, i);
991 if (! is_method_entity(ent))
994 inner_irg = get_entity_irg(ent);
995 if (inner_irg == NULL)
998 assure_irg_outs(inner_irg);
999 args = get_irg_args(inner_irg);
1000 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
1001 ir_node *arg = get_irn_out(args, j);
1003 if (get_Proj_proj(arg) == static_link_arg) {
1004 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
1005 ir_node *succ = get_irn_out(arg, k);
1008 ir_entity *entity = get_Sel_entity(succ);
1010 if (get_entity_owner(entity) == ft) {
1011 /* found an access to the outer frame */
1014 flags = get_entity_usage(entity);
1015 flags |= determine_entity_usage(succ, entity);
1016 set_entity_usage(entity, (ir_entity_usage) flags);
1025 add_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_ENTITY_USAGE);
1028 void assure_irg_entity_usage_computed(ir_graph *irg)
1030 if (irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_ENTITY_USAGE))
1033 analyse_irg_entity_usage(irg);
1038 * Initialize the entity_usage flag for a global type like type.
1040 static void init_entity_usage(ir_type *tp)
1044 /* We have to be conservative: All external visible entities are unknown */
1045 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1046 ir_entity *ent = get_compound_member(tp, i);
1047 unsigned flags = ir_usage_none;
1049 if (entity_is_externally_visible(ent)) {
1050 flags |= ir_usage_unknown;
1052 set_entity_usage(ent, (ir_entity_usage) flags);
1057 * Mark all entities used in the initializer as unknown usage.
1059 * @param initializer the initializer to check
1061 static void check_initializer_nodes(ir_initializer_t *initializer)
1066 switch (initializer->kind) {
1067 case IR_INITIALIZER_CONST:
1068 /* let's check if it's an address */
1069 n = initializer->consti.value;
1070 if (is_SymConst_addr_ent(n)) {
1071 ir_entity *ent = get_SymConst_entity(n);
1072 set_entity_usage(ent, ir_usage_unknown);
1075 case IR_INITIALIZER_TARVAL:
1076 case IR_INITIALIZER_NULL:
1078 case IR_INITIALIZER_COMPOUND:
1079 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1080 ir_initializer_t *sub_initializer
1081 = initializer->compound.initializers[i];
1082 check_initializer_nodes(sub_initializer);
1086 panic("invalid initializer found");
1090 * Mark all entities used in the initializer for the given entity as unknown
1093 * @param ent the entity
1095 static void check_initializer(ir_entity *ent)
1097 /* Beware: Methods are always initialized with "themself". This does not
1098 * count as a taken address.
1099 * TODO: this initialisation with "themself" is wrong and should be removed
1101 if (is_Method_type(get_entity_type(ent)))
1104 if (ent->initializer != NULL) {
1105 check_initializer_nodes(ent->initializer);
1111 * Mark all entities used in initializers as unknown usage.
1113 * @param tp a compound type
1115 static void check_initializers(ir_type *tp)
1119 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1120 ir_entity *ent = get_compound_member(tp, i);
1122 check_initializer(ent);
1126 #ifdef DEBUG_libfirm
1128 * Print the entity usage flags of all entities of a given type for debugging.
1130 * @param tp a compound type
1132 static void print_entity_usage_flags(const ir_type *tp)
1135 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1136 ir_entity *ent = get_compound_member(tp, i);
1137 ir_entity_usage flags = get_entity_usage(ent);
1141 ir_printf("%+F:", ent);
1142 if (flags & ir_usage_address_taken)
1143 printf(" address_taken");
1144 if (flags & ir_usage_read)
1146 if (flags & ir_usage_write)
1148 if (flags & ir_usage_reinterpret_cast)
1149 printf(" reinterp_cast");
1153 #endif /* DEBUG_libfirm */
1156 * Post-walker: check for global entity address
1158 static void check_global_address(ir_node *irn, void *data)
1164 if (is_SymConst_addr_ent(irn)) {
1166 ent = get_SymConst_entity(irn);
1170 flags = get_entity_usage(ent);
1171 flags |= determine_entity_usage(irn, ent);
1172 set_entity_usage(ent, (ir_entity_usage) flags);
1176 * Update the entity usage flags of all global entities.
1178 static void analyse_irp_globals_entity_usage(void)
1183 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1184 ir_type *type = get_segment_type(s);
1185 init_entity_usage(type);
1188 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1189 ir_type *type = get_segment_type(s);
1190 check_initializers(type);
1193 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
1194 ir_graph *irg = get_irp_irg(i);
1196 assure_irg_outs(irg);
1197 irg_walk_graph(irg, NULL, check_global_address, NULL);
1200 #ifdef DEBUG_libfirm
1201 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1202 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1203 print_entity_usage_flags(get_segment_type(s));
1206 #endif /* DEBUG_libfirm */
1209 irp->globals_entity_usage_state = ir_entity_usage_computed;
1212 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void)
1214 return irp->globals_entity_usage_state;
1217 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state)
1219 irp->globals_entity_usage_state = state;
1222 void assure_irp_globals_entity_usage_computed(void)
1224 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1227 analyse_irp_globals_entity_usage();
1230 void firm_init_memory_disambiguator(void)
1232 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1233 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1237 /** Maps method types to cloned method types. */
1238 static pmap *mtp_map;
1241 * Clone a method type if not already cloned.
1243 * @param tp the type to clone
1245 static ir_type *clone_type_and_cache(ir_type *tp)
1247 ir_type *res = pmap_get(ir_type, mtp_map, tp);
1250 res = clone_type_method(tp);
1251 pmap_insert(mtp_map, tp, res);
1258 * Walker: clone all call types of Calls to methods having the
1259 * mtp_property_private property set.
1261 static void update_calls_to_private(ir_node *call, void *env)
1264 if (is_Call(call)) {
1265 ir_node *ptr = get_Call_ptr(call);
1267 if (is_SymConst(ptr)) {
1268 ir_entity *ent = get_SymConst_entity(ptr);
1269 ir_type *ctp = get_Call_type(call);
1271 if (get_entity_additional_properties(ent) & mtp_property_private) {
1272 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1273 ctp = clone_type_and_cache(ctp);
1274 add_method_additional_properties(ctp, mtp_property_private);
1275 set_Call_type(call, ctp);
1276 DB((dbgcall, LEVEL_1, "changed call to private method %+F using cloned type %+F\n", ent, ctp));
1283 void mark_private_methods(void)
1288 assure_irp_globals_entity_usage_computed();
1290 mtp_map = pmap_create();
1292 /* first step: change the calling conventions of the local non-escaped entities */
1293 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
1294 ir_graph *irg = get_irp_irg(i);
1295 ir_entity *ent = get_irg_entity(irg);
1296 ir_entity_usage flags = get_entity_usage(ent);
1298 if (!(flags & ir_usage_address_taken) && !entity_is_externally_visible(ent)) {
1299 ir_type *mtp = get_entity_type(ent);
1301 add_entity_additional_properties(ent, mtp_property_private);
1302 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1303 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1304 /* need a new type */
1305 mtp = clone_type_and_cache(mtp);
1306 add_method_additional_properties(mtp, mtp_property_private);
1307 set_entity_type(ent, mtp);
1308 DB((dbgcall, LEVEL_2, "changed entity type of %+F to %+F\n", ent, mtp));
1315 all_irg_walk(NULL, update_calls_to_private, NULL);
1317 pmap_destroy(mtp_map);
1320 ir_prog_pass_t *mark_private_methods_pass(const char *name)
1322 return def_prog_pass(name ? name : "mark_private_methods", mark_private_methods);