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
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
68 panic("UNKNOWN alias relation");
73 /* Get the memory disambiguator options for a graph. */
74 unsigned get_irg_memory_disambiguator_options(const ir_graph *irg)
76 unsigned opt = irg->mem_disambig_opt;
77 if (opt & aa_opt_inherited)
78 return global_mem_disamgig_opt;
80 } /* get_irg_memory_disambiguator_options */
82 /* Set the memory disambiguator options for a graph. */
83 void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options)
85 irg->mem_disambig_opt = options & ~aa_opt_inherited;
86 } /* set_irg_memory_disambiguator_options */
88 /* Set the global disambiguator options for all graphs not having local options. */
89 void set_irp_memory_disambiguator_options(unsigned options)
91 global_mem_disamgig_opt = options;
92 } /* set_irp_memory_disambiguator_options */
94 /* Get the base storage class (ignore modifier) */
95 ir_storage_class_class_t get_base_sc(ir_storage_class_class_t x)
97 return x & ~ir_sc_modifiers;
101 * Find the base address and entity of an Sel node.
103 * @param sel the node
104 * @param pEnt after return points to the base entity.
106 * @return the base address.
108 static ir_node *find_base_adr(const ir_node *sel, ir_entity **pEnt)
110 ir_node *ptr = get_Sel_ptr(sel);
112 while (is_Sel(ptr)) {
114 ptr = get_Sel_ptr(sel);
116 *pEnt = get_Sel_entity(sel);
118 } /* find_base_adr */
121 * Check if a given Const node is greater or equal a given size.
123 * @param cns a Const node
124 * @param size a integer size
126 * @return ir_no_alias if the Const is greater, ir_may_alias else
128 static ir_alias_relation check_const(const ir_node *cns, int size)
130 ir_tarval *tv = get_Const_tarval(cns);
134 return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
135 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
136 return tarval_cmp(tv_size, tv) & (ir_relation_less_equal) ? ir_no_alias : ir_may_alias;
140 * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
142 * @param idx1 a node representing the first index
143 * @param idx2 a node representing the second index
144 * @param size an integer size
146 * @return ir_sure_alias iff idx1 == idx2
147 * ir_no_alias iff they ALWAYS differ more than size
150 static ir_alias_relation different_index(const ir_node *idx1, const ir_node *idx2, int size)
153 return ir_sure_alias;
154 if (is_Const(idx1) && is_Const(idx2)) {
155 /* both are const, we can compare them */
156 ir_tarval *tv1 = get_Const_tarval(idx1);
157 ir_tarval *tv2 = get_Const_tarval(idx2);
158 ir_tarval *tv, *tv_size;
162 return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
164 /* arg, modes may be different */
165 m1 = get_tarval_mode(tv1);
166 m2 = get_tarval_mode(tv2);
168 int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
171 /* m1 is a small mode, cast up */
172 m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
174 /* should NOT happen, but if it does we give up here */
177 tv1 = tarval_convert_to(tv1, m1);
178 } else if (size > 0) {
179 /* m2 is a small mode, cast up */
180 m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
182 /* should NOT happen, but if it does we give up here */
185 tv2 = tarval_convert_to(tv2, m2);
187 /* here the size should be identical, check for signed */
188 if (get_mode_sign(m1) != get_mode_sign(m2)) {
189 /* find the signed */
190 if (mode_is_signed(m2)) {
197 /* m1 is now the signed one */
198 if (!tarval_is_negative(tv1)) {
199 /* tv1 is signed, but >= 0, simply cast into unsigned */
200 tv1 = tarval_convert_to(tv1, m2);
202 tv_size = new_tarval_from_long(size, m2);
204 if (tarval_cmp(tv2, tv_size) & (ir_relation_greater_equal)) {
205 /* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
208 /* tv_size > tv2, so we can subtract without overflow */
209 tv2 = tarval_sub(tv_size, tv2, NULL);
211 /* tv1 is < 0, so we can negate it */
212 tv1 = tarval_neg(tv1);
214 /* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
215 tv1 = tarval_convert_to(tv1, m2);
217 /* now we can compare without overflow */
218 return tarval_cmp(tv1, tv2) & (ir_relation_greater_equal) ? ir_no_alias : ir_may_alias;
222 if (tarval_cmp(tv1, tv2) == ir_relation_greater) {
227 /* tv1 is now the "smaller" one */
228 tv = tarval_sub(tv2, tv1, NULL);
229 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
230 return tarval_cmp(tv_size, tv) & (ir_relation_less_equal) ? ir_no_alias : ir_may_alias;
233 /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
235 ir_node *l1 = get_Add_left(idx1);
236 ir_node *r1 = get_Add_right(idx1);
241 return check_const(r1, size);
244 /* both are Adds, check if they are of x + a == x + b kind */
245 ir_node *l2 = get_Add_left(idx2);
246 ir_node *r2 = get_Add_right(idx2);
249 return different_index(r1, r2, size);
251 return different_index(r1, l2, size);
253 return different_index(l1, l2, size);
255 return different_index(l1, r2, size);
259 ir_node *l2 = get_Add_left(idx2);
260 ir_node *r2 = get_Add_right(idx2);
265 return check_const(r2, size);
270 ir_node *l1 = get_Sub_left(idx1);
271 ir_node *r1 = get_Sub_right(idx1);
276 return check_const(r1, size);
280 /* both are Subs, check if they are of x - a == x - b kind */
281 ir_node *l2 = get_Sub_left(idx2);
284 ir_node *r2 = get_Sub_right(idx2);
285 return different_index(r1, r2, size);
290 ir_node *l2 = get_Sub_left(idx2);
291 ir_node *r2 = get_Sub_right(idx2);
296 return check_const(r2, size);
301 } /* different_index */
304 * Two Sel addresses have the same base address, check if there offsets are
307 * @param adr1 The first address.
308 * @param adr2 The second address.
310 static ir_alias_relation different_sel_offsets(const ir_node *sel1, const ir_node *sel2)
312 /* seems to be broken */
316 ir_entity *ent1 = get_Sel_entity(sel1);
317 ir_entity *ent2 = get_Sel_entity(sel2);
318 int i, check_arr = 0;
323 ir_type *tp1 = get_entity_type(ent1);
324 ir_type *tp2 = get_entity_type(ent2);
328 else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
329 get_type_size_bits(tp1) == get_type_size_bits(tp2))
333 /* we select an entity of same size, check for indexes */
334 int n = get_Sel_n_indexs(sel1);
337 if (n > 0 && n == get_Sel_n_indexs(sel2)) {
338 /* same non-zero number of indexes, an array access, check */
339 for (i = 0; i < n; ++i) {
340 ir_node *idx1 = get_Sel_index(sel1, i);
341 ir_node *idx2 = get_Sel_index(sel2, i);
342 ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
344 if (res == may_alias)
346 else if (res == no_alias)
349 /* if we have at least one no_alias, there is no alias relation, else we have sure */
350 return have_no > 0 ? no_alias : sure_alias;
354 (void) different_index;
357 } /* different_sel_offsets */
360 * Determine the alias relation by checking if adr1 and adr2 are pointer
363 * @param adr1 The first address.
364 * @param adr2 The second address.
366 static ir_alias_relation different_types(const ir_node *adr1, const ir_node *adr2)
368 ir_entity *ent1 = NULL, *ent2 = NULL;
371 ent1 = get_Global_entity(adr1);
372 else if (is_Sel(adr1))
373 ent1 = get_Sel_entity(adr1);
376 ent2 = get_Global_entity(adr2);
377 else if (is_Sel(adr2))
378 ent2 = get_Sel_entity(adr2);
380 if (ent1 != NULL && ent2 != NULL) {
381 ir_type *tp1 = get_entity_type(ent1);
382 ir_type *tp2 = get_entity_type(ent2);
385 /* do deref until no pointer types are found */
386 while (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
387 tp1 = get_pointer_points_to_type(tp1);
388 tp2 = get_pointer_points_to_type(tp2);
391 if (get_type_tpop(tp1) != get_type_tpop(tp2)) {
392 /* different type structure */
395 if (is_Class_type(tp1)) {
396 /* check class hierarchy */
397 if (! is_SubClass_of(tp1, tp2) &&
398 ! is_SubClass_of(tp2, tp1))
401 /* different types */
407 } /* different_types */
410 * Returns non-zero if a node is a result on a malloc-like routine.
412 * @param node the Proj node to test
414 static int is_malloc_Result(const ir_node *node)
416 node = get_Proj_pred(node);
419 node = get_Proj_pred(node);
422 node = get_Call_ptr(node);
423 if (is_Global(node)) {
424 ir_entity *ent = get_Global_entity(node);
426 if (get_entity_additional_properties(ent) & mtp_property_malloc)
431 } /* is_malloc_Result */
433 ir_storage_class_class_t classify_pointer(const ir_node *irn,
434 const ir_entity *ent)
436 ir_graph *irg = get_irn_irg(irn);
437 ir_storage_class_class_t res = ir_sc_pointer;
438 if (is_Global(irn)) {
439 ir_entity *entity = get_Global_entity(irn);
440 ir_type *owner = get_entity_owner(entity);
441 res = owner == get_tls_type() ? ir_sc_tls : ir_sc_globalvar;
442 if (! (get_entity_usage(entity) & ir_usage_address_taken))
443 res |= ir_sc_modifier_nottaken;
444 } else if (irn == get_irg_frame(irg)) {
445 res = ir_sc_localvar;
446 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
447 res |= ir_sc_modifier_nottaken;
448 } else if (is_Proj(irn) && is_malloc_Result(irn)) {
449 return ir_sc_malloced;
450 } else if (is_Const(irn)) {
451 return ir_sc_globaladdr;
452 } else if (is_arg_Proj(irn)) {
453 res |= ir_sc_modifier_argument;
460 * If adr represents a Bitfield Sel, skip it
462 static const ir_node *skip_Bitfield_Sels(const ir_node *adr)
465 ir_entity *ent = get_Sel_entity(adr);
466 ir_type *bf_type = get_entity_type(ent);
468 /* is it a bitfield type? */
469 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
470 adr = get_Sel_ptr(adr);
476 * Determine the alias relation between two addresses.
478 * @param addr1 pointer address of the first memory operation
479 * @param mode1 the mode of the accessed data through addr1
480 * @param addr2 pointer address of the second memory operation
481 * @param mode2 the mode of the accessed data through addr2
483 * @return found memory relation
485 static ir_alias_relation _get_alias_relation(
486 const ir_node *adr1, const ir_mode *mode1,
487 const ir_node *adr2, const ir_mode *mode2)
489 ir_entity *ent1, *ent2;
493 const ir_node *base1;
494 const ir_node *base2;
495 const ir_node *orig_adr1 = adr1;
496 const ir_node *orig_adr2 = adr2;
499 ir_storage_class_class_t class1, class2, mod1, mod2;
500 int have_const_offsets;
502 if (! get_opt_alias_analysis())
506 return ir_sure_alias;
508 irg = get_irn_irg(adr1);
509 options = get_irg_memory_disambiguator_options(irg);
511 /* The Armageddon switch */
512 if (options & aa_opt_no_alias)
515 /* do the addresses have constants offsets?
516 * Note: nodes are normalized to have constants at right inputs,
517 * sub X, C is normalized to add X, -C
519 have_const_offsets = 1;
520 while (is_Add(adr1)) {
521 ir_node *add_right = get_Add_right(adr1);
522 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
523 ir_tarval *tv = get_Const_tarval(add_right);
524 offset1 += get_tarval_long(tv);
525 adr1 = get_Add_left(adr1);
526 } else if (mode_is_reference(get_irn_mode(add_right))) {
528 have_const_offsets = 0;
530 adr1 = get_Add_left(adr1);
531 have_const_offsets = 0;
534 while (is_Add(adr2)) {
535 ir_node *add_right = get_Add_right(adr2);
536 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
537 ir_tarval *tv = get_Const_tarval(add_right);
538 offset2 += get_tarval_long(tv);
539 adr2 = get_Add_left(adr2);
540 } else if (mode_is_reference(get_irn_mode(add_right))) {
542 have_const_offsets = 0;
544 adr2 = get_Add_left(adr2);
545 have_const_offsets = 0;
549 mode_size = get_mode_size_bytes(mode1);
550 if (get_mode_size_bytes(mode2) > mode_size) {
551 mode_size = get_mode_size_bytes(mode2);
554 /* same base address -> compare offsets if possible.
555 * FIXME: type long is not sufficient for this task ...
557 if (adr1 == adr2 && have_const_offsets) {
558 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
561 return ir_sure_alias;
565 * Bitfields can be constructed as Sels from its base address.
566 * As they have different entities, the disambiguator would find that they are
567 * alias free. While this is true for its values, it is false for the addresses
568 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
569 * So, skip those bitfield selecting Sel's.
571 adr1 = skip_Bitfield_Sels(adr1);
572 adr2 = skip_Bitfield_Sels(adr2);
580 base1 = find_base_adr(adr1, &ent1);
583 base2 = find_base_adr(adr2, &ent2);
586 /* same base address -> compare Sel entities */
587 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
590 else if (have_const_offsets)
591 return different_sel_offsets(adr1, adr2);
594 mod1 = classify_pointer(base1, ent1);
595 mod2 = classify_pointer(base2, ent2);
597 class1 = get_base_sc(mod1);
598 class2 = get_base_sc(mod2);
600 if (class1 == ir_sc_pointer || class2 == ir_sc_pointer) {
601 /* swap pointer class to class1 */
602 if (class2 == ir_sc_pointer) {
603 ir_storage_class_class_t temp = mod1;
606 class1 = get_base_sc(mod1);
607 class2 = get_base_sc(mod2);
609 /* a pointer and an object whose address was never taken */
610 if (mod2 & ir_sc_modifier_nottaken) {
613 if (mod1 & ir_sc_modifier_argument) {
614 if ( (options & aa_opt_no_alias_args)
615 && (mod2 & ir_sc_modifier_argument))
617 if ( (options & aa_opt_no_alias_args_global)
618 && (class2 == ir_sc_globalvar
619 || class2 == ir_sc_tls
620 || class2 == ir_sc_globaladdr))
623 } else if (class1 != class2) {
624 /* two objects from different memory spaces */
627 /* both classes are equal */
628 if (class1 == ir_sc_globalvar) {
629 ir_entity *entity1 = get_SymConst_entity(base1);
630 ir_entity *entity2 = get_SymConst_entity(base2);
631 if (entity1 != entity2)
634 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
636 } else if (class1 == ir_sc_globaladdr) {
637 ir_tarval *tv = get_Const_tarval(base1);
638 offset1 += get_tarval_long(tv);
639 tv = get_Const_tarval(base2);
640 offset2 += get_tarval_long(tv);
642 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
645 return ir_sure_alias;
649 /* Type based alias analysis */
650 if (options & aa_opt_type_based) {
651 ir_alias_relation rel;
653 if (options & aa_opt_byte_type_may_alias) {
654 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
655 /* One of the modes address a byte. Assume a ir_may_alias and leave
656 the type based check. */
657 goto leave_type_based_alias;
660 /* cheap check: If the mode sizes did not match, the types MUST be different */
661 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
664 /* cheap test: if only one is a reference mode, no alias */
665 if (mode_is_reference(mode1) != mode_is_reference(mode2))
668 /* cheap test: if arithmetic is different, no alias */
669 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
673 rel = different_types(orig_adr1, orig_adr2);
674 if (rel != ir_may_alias)
676 leave_type_based_alias:;
679 /* do we have a language specific memory disambiguator? */
680 if (language_disambuigator != NULL) {
681 ir_alias_relation rel = language_disambuigator(orig_adr1, mode1, orig_adr2, mode2);
682 if (rel != ir_may_alias)
686 /* access points-to information here */
688 } /* _get_alias_relation */
691 * Determine the alias relation between two addresses.
693 ir_alias_relation get_alias_relation(
694 const ir_node *adr1, const ir_mode *mode1,
695 const ir_node *adr2, const ir_mode *mode2)
697 ir_alias_relation rel = _get_alias_relation(adr1, mode1, adr2, mode2);
698 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
700 } /* get_alias_relation */
702 /* Set a source language specific memory disambiguator function. */
703 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func)
705 language_disambuigator = func;
706 } /* set_language_memory_disambiguator */
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;
733 } /* cmp_mem_disambig_entry */
736 * Initialize the relation cache.
738 void mem_disambig_init(void)
740 result_cache = new_set(cmp_mem_disambig_entry, 8);
741 } /* mem_disambig_init */
744 * Determine the alias relation between two addresses.
746 ir_alias_relation get_alias_relation_ex(
747 const ir_node *adr1, const ir_mode *mode1,
748 const ir_node *adr2, const ir_mode *mode2)
750 mem_disambig_entry key, *entry;
752 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
754 if (! get_opt_alias_analysis())
757 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
758 const ir_node *t = adr1;
767 entry = (mem_disambig_entry*) set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
769 return entry->result;
771 key.result = get_alias_relation(adr1, mode1, adr2, mode2);
773 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
775 } /* get_alias_relation_ex */
777 /* Free the relation cache. */
778 void mem_disambig_term(void)
780 if (result_cache != NULL) {
781 del_set(result_cache);
784 } /* mem_disambig_term */
787 * Check the mode of a Load/Store with the mode of the entity
789 * If the mode of the entity and the Load/Store mode do not match, we
790 * have the bad reinterpret case:
793 * char b = *(char *)&i;
795 * We do NOT count this as one value and return address_taken
797 * However, we support an often used case. If the mode is two-complement
798 * we allow casts between signed/unsigned.
800 * @param mode the mode of the Load/Store
801 * @param ent_mode the mode of the accessed entity
803 * @return non-zero if the Load/Store is a hidden cast, zero else
805 static int is_hidden_cast(const ir_mode *mode, const ir_mode *ent_mode)
807 if (ent_mode == NULL)
810 if (ent_mode != mode) {
811 if (ent_mode == NULL ||
812 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
813 get_mode_sort(ent_mode) != get_mode_sort(mode) ||
814 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
815 get_mode_arithmetic(mode) != irma_twos_complement)
819 } /* is_hidden_cast */
822 * Determine the usage state of a node (or its successor Sels).
824 * @param irn the node
826 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity)
829 ir_mode *emode, *mode;
834 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
835 ir_node *succ = get_irn_out(irn, i);
837 switch (get_irn_opcode(succ)) {
839 /* beware: irn might be a Id node here, so irn might be not
840 equal to get_Load_ptr(succ) */
841 res |= ir_usage_read;
843 /* check if this load is not a hidden conversion */
844 mode = get_Load_mode(succ);
845 emode = get_type_mode(get_entity_type(entity));
846 if (is_hidden_cast(mode, emode))
847 res |= ir_usage_reinterpret_cast;
851 /* check that the node is not the Store's value */
852 if (irn == get_Store_value(succ)) {
853 res |= ir_usage_unknown;
855 if (irn == get_Store_ptr(succ)) {
856 res |= ir_usage_write;
858 /* check if this Store is not a hidden conversion */
859 value = get_Store_value(succ);
860 mode = get_irn_mode(value);
861 emode = get_type_mode(get_entity_type(entity));
862 if (is_hidden_cast(mode, emode))
863 res |= ir_usage_reinterpret_cast;
865 assert(irn != get_Store_mem(succ));
869 /* CopyB are like Loads/Stores */
870 tp = get_entity_type(entity);
871 if (tp != get_CopyB_type(succ)) {
872 /* bad, different types, might be a hidden conversion */
873 res |= ir_usage_reinterpret_cast;
875 if (irn == get_CopyB_dst(succ)) {
876 res |= ir_usage_write;
878 assert(irn == get_CopyB_src(succ));
879 res |= ir_usage_read;
885 /* Check the successor of irn. */
886 res |= determine_entity_usage(succ, entity);
889 ir_entity *entity = get_Sel_entity(succ);
890 /* this analysis can't handle unions correctly */
891 if (is_Union_type(get_entity_owner(entity))) {
892 res |= ir_usage_unknown;
895 /* Check the successor of irn. */
896 res |= determine_entity_usage(succ, entity);
901 if (irn == get_Call_ptr(succ)) {
902 /* TODO: we could check for reinterpret casts here...
903 * But I doubt anyone is interested in that bit for
904 * function entities and I'm too lazy to write the code now.
906 res |= ir_usage_read;
908 assert(irn != get_Call_mem(succ));
909 res |= ir_usage_unknown;
913 /* skip identities */
915 res |= determine_entity_usage(succ, entity);
921 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
923 ir_node *pred = get_Tuple_pred(succ, input_nr);
926 /* we found one input */
927 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
928 ir_node *proj = get_irn_out(succ, k);
930 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
931 res |= determine_entity_usage(proj, entity);
941 /* another op, we don't know anything (we could do more advanced
942 * things like a dataflow analysis here) */
943 res |= ir_usage_unknown;
948 return (ir_entity_usage) res;
952 * Update the usage flags of all frame entities.
954 static void analyse_irg_entity_usage(ir_graph *irg)
956 ir_type *ft = get_irg_frame_type(irg);
959 int j, k, static_link_arg;
961 /* set initial state to not_taken, as this is the "smallest" state */
962 for (i = 0, n = get_class_n_members(ft); i < n; ++i) {
963 ir_entity *ent = get_class_member(ft, i);
965 /* methods can only be analyzed globally */
966 if (! is_method_entity(ent)) {
967 ir_entity_usage flags = ir_usage_none;
968 if (get_entity_linkage(ent) & IR_LINKAGE_HIDDEN_USER)
969 flags = ir_usage_unknown;
970 set_entity_usage(ent, flags);
974 assure_irg_outs(irg);
976 irg_frame = get_irg_frame(irg);
978 for (j = get_irn_n_outs(irg_frame) - 1; j >= 0; --j) {
979 ir_node *succ = get_irn_out(irg_frame, j);
986 entity = get_Sel_entity(succ);
987 flags = get_entity_usage(entity);
988 flags |= determine_entity_usage(succ, entity);
989 set_entity_usage(entity, (ir_entity_usage) flags);
992 /* check inner functions accessing outer frame */
994 for (i = 0, n = get_class_n_members(ft); i < n; ++i) {
995 ir_entity *ent = get_class_member(ft, i);
999 if (! is_method_entity(ent))
1002 inner_irg = get_entity_irg(ent);
1003 if (inner_irg == NULL)
1006 assure_irg_outs(inner_irg);
1007 args = get_irg_args(inner_irg);
1008 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
1009 ir_node *arg = get_irn_out(args, j);
1011 if (get_Proj_proj(arg) == static_link_arg) {
1012 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
1013 ir_node *succ = get_irn_out(arg, k);
1016 ir_entity *entity = get_Sel_entity(succ);
1018 if (get_entity_owner(entity) == ft) {
1019 /* found an access to the outer frame */
1022 flags = get_entity_usage(entity);
1023 flags |= determine_entity_usage(succ, entity);
1024 set_entity_usage(entity, (ir_entity_usage) flags);
1034 irg->entity_usage_state = ir_entity_usage_computed;
1037 ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg)
1039 return irg->entity_usage_state;
1042 void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state)
1044 irg->entity_usage_state = state;
1047 void assure_irg_entity_usage_computed(ir_graph *irg)
1049 if (irg->entity_usage_state != ir_entity_usage_not_computed)
1052 analyse_irg_entity_usage(irg);
1057 * Initialize the entity_usage flag for a global type like type.
1059 static void init_entity_usage(ir_type *tp)
1063 /* We have to be conservative: All external visible entities are unknown */
1064 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1065 ir_entity *ent = get_compound_member(tp, i);
1066 unsigned flags = ir_usage_none;
1068 if (entity_is_externally_visible(ent)) {
1069 flags |= ir_usage_unknown;
1071 set_entity_usage(ent, (ir_entity_usage) flags);
1076 * Mark all entities used in the initializer as unknown usage.
1078 * @param initializer the initializer to check
1080 static void check_initializer_nodes(ir_initializer_t *initializer)
1085 switch (initializer->kind) {
1086 case IR_INITIALIZER_CONST:
1087 /* let's check if it's an address */
1088 n = initializer->consti.value;
1090 ir_entity *ent = get_Global_entity(n);
1091 set_entity_usage(ent, ir_usage_unknown);
1094 case IR_INITIALIZER_TARVAL:
1095 case IR_INITIALIZER_NULL:
1097 case IR_INITIALIZER_COMPOUND:
1098 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1099 ir_initializer_t *sub_initializer
1100 = initializer->compound.initializers[i];
1101 check_initializer_nodes(sub_initializer);
1105 panic("invalid initializer found");
1106 } /* check_initializer_nodes */
1109 * Mark all entities used in the initializer for the given entity as unknown
1112 * @param ent the entity
1114 static void check_initializer(ir_entity *ent)
1116 /* Beware: Methods are always initialized with "themself". This does not
1117 * count as a taken address.
1118 * TODO: this initialisation with "themself" is wrong and should be removed
1120 if (is_Method_type(get_entity_type(ent)))
1123 if (ent->initializer != NULL) {
1124 check_initializer_nodes(ent->initializer);
1125 } else if (entity_has_compound_ent_values(ent)) {
1128 for (i = 0, n = get_compound_ent_n_values(ent); i < n; ++i) {
1129 ir_node *irn = get_compound_ent_value(ent, i);
1131 /* let's check if it's an address */
1132 if (is_Global(irn)) {
1133 ir_entity *ent = get_Global_entity(irn);
1134 set_entity_usage(ent, ir_usage_unknown);
1142 * Mark all entities used in initializers as unknown usage.
1144 * @param tp a compound type
1146 static void check_initializers(ir_type *tp)
1150 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1151 ir_entity *ent = get_compound_member(tp, i);
1153 check_initializer(ent);
1155 } /* check_initializers */
1157 #ifdef DEBUG_libfirm
1159 * Print the entity usage flags of all entities of a given type for debugging.
1161 * @param tp a compound type
1163 static void print_entity_usage_flags(const ir_type *tp)
1166 for (i = 0, n = get_compound_n_members(tp); i < n; ++i) {
1167 ir_entity *ent = get_compound_member(tp, i);
1168 ir_entity_usage flags = get_entity_usage(ent);
1172 ir_printf("%+F:", ent);
1173 if (flags & ir_usage_address_taken)
1174 printf(" address_taken");
1175 if (flags & ir_usage_read)
1177 if (flags & ir_usage_write)
1179 if (flags & ir_usage_reinterpret_cast)
1180 printf(" reinterp_cast");
1184 #endif /* DEBUG_libfirm */
1187 * Post-walker: check for global entity address
1189 static void check_global_address(ir_node *irn, void *data)
1195 if (is_Global(irn)) {
1197 ent = get_Global_entity(irn);
1201 flags = get_entity_usage(ent);
1202 flags |= determine_entity_usage(irn, ent);
1203 set_entity_usage(ent, (ir_entity_usage) flags);
1204 } /* check_global_address */
1207 * Update the entity usage flags of all global entities.
1209 static void analyse_irp_globals_entity_usage(void)
1214 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1215 ir_type *type = get_segment_type(s);
1216 init_entity_usage(type);
1219 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1220 ir_type *type = get_segment_type(s);
1221 check_initializers(type);
1224 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
1225 ir_graph *irg = get_irp_irg(i);
1227 assure_irg_outs(irg);
1228 irg_walk_graph(irg, NULL, check_global_address, NULL);
1231 #ifdef DEBUG_libfirm
1232 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1233 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1234 print_entity_usage_flags(get_segment_type(s));
1237 #endif /* DEBUG_libfirm */
1240 irp->globals_entity_usage_state = ir_entity_usage_computed;
1243 /* Returns the current address taken state of the globals. */
1244 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void)
1246 return irp->globals_entity_usage_state;
1249 /* Sets the current address taken state of the graph. */
1250 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state)
1252 irp->globals_entity_usage_state = state;
1255 /* Assure that the address taken flag is computed for the globals. */
1256 void assure_irp_globals_entity_usage_computed(void)
1258 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1261 analyse_irp_globals_entity_usage();
1264 void firm_init_memory_disambiguator(void)
1266 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1267 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1271 /** Maps method types to cloned method types. */
1272 static pmap *mtp_map;
1275 * Clone a method type if not already cloned.
1277 * @param tp the type to clone
1279 static ir_type *clone_type_and_cache(ir_type *tp)
1282 pmap_entry *e = pmap_find(mtp_map, tp);
1285 return (ir_type*) e->value;
1287 res = clone_type_method(tp);
1288 pmap_insert(mtp_map, tp, res);
1291 } /* clone_type_and_cache */
1294 * Walker: clone all call types of Calls to methods having the
1295 * mtp_property_private property set.
1297 static void update_calls_to_private(ir_node *call, void *env)
1300 if (is_Call(call)) {
1301 ir_node *ptr = get_Call_ptr(call);
1303 if (is_SymConst(ptr)) {
1304 ir_entity *ent = get_SymConst_entity(ptr);
1305 ir_type *ctp = get_Call_type(call);
1307 if (get_entity_additional_properties(ent) & mtp_property_private) {
1308 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1309 ctp = clone_type_and_cache(ctp);
1310 add_method_additional_properties(ctp, mtp_property_private);
1311 set_Call_type(call, ctp);
1312 DB((dbgcall, LEVEL_1, "changed call to private method %+F using cloned type %+F\n", ent, ctp));
1317 } /* update_calls_to_private */
1319 /* Mark all private methods, i.e. those of which all call sites are known. */
1320 void mark_private_methods(void)
1325 assure_irp_globals_entity_usage_computed();
1327 mtp_map = pmap_create();
1329 /* first step: change the calling conventions of the local non-escaped entities */
1330 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
1331 ir_graph *irg = get_irp_irg(i);
1332 ir_entity *ent = get_irg_entity(irg);
1333 ir_entity_usage flags = get_entity_usage(ent);
1335 if (!(flags & ir_usage_address_taken) && !entity_is_externally_visible(ent)) {
1336 ir_type *mtp = get_entity_type(ent);
1338 add_entity_additional_properties(ent, mtp_property_private);
1339 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1340 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1341 /* need a new type */
1342 mtp = clone_type_and_cache(mtp);
1343 add_method_additional_properties(mtp, mtp_property_private);
1344 set_entity_type(ent, mtp);
1345 DB((dbgcall, LEVEL_2, "changed entity type of %+F to %+F\n", ent, mtp));
1352 all_irg_walk(NULL, update_calls_to_private, NULL);
1354 pmap_destroy(mtp_map);
1355 } /* mark_private_methods */
1357 /* create a pass for mark_private_methods() */
1358 ir_prog_pass_t *mark_private_methods_pass(const char *name)
1360 return def_prog_pass(name ? name : "mark_private_methods", mark_private_methods);
1361 } /* mark_private_methods_pass */