2 * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Memory disambiguator
23 * @author Michael Beck
34 #include "irgraph_t.h"
36 #include "irmemory_t.h"
49 /** The debug handle. */
50 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
51 DEBUG_ONLY(static firm_dbg_module_t *dbgcall = NULL;)
53 /** The source language specific language disambiguator function. */
54 static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
56 /** The global memory disambiguator options. */
57 static unsigned global_mem_disamgig_opt = aa_opt_no_opt;
59 /* Returns a human readable name for an alias relation. */
60 const char *get_ir_alias_relation_name(ir_alias_relation rel)
62 #define X(a) case a: return #a
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 */
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);
112 } /* find_base_adr */
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 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) & (pn_Cmp_Eq|pn_Cmp_Lt) ? 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 tarval *tv1 = get_Const_tarval(idx1);
151 tarval *tv2 = get_Const_tarval(idx2);
152 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) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
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) & (pn_Cmp_Eq|pn_Cmp_Gt) ? ir_no_alias : ir_may_alias;
216 if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) {
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) & (pn_Cmp_Eq|pn_Cmp_Lt) ? 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);
295 } /* different_index */
298 * Two Sel addresses have the same base address, check if there 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;
351 } /* different_sel_offsets */
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;
365 ent1 = get_Global_entity(adr1);
366 else if (is_Sel(adr1))
367 ent1 = get_Sel_entity(adr1);
370 ent2 = get_Global_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 */
401 } /* 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_Global(node)) {
418 ir_entity *ent = get_Global_entity(node);
420 if (get_entity_additional_properties(ent) & mtp_property_malloc)
425 } /* is_malloc_Result */
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_Global(irn)) {
433 ir_entity *entity = get_Global_entity(irn);
434 res = ir_sc_globalvar;
435 if (! (get_entity_usage(entity) & ir_usage_address_taken))
436 res |= ir_sc_modifier_nottaken;
437 } else if (irn == get_irg_frame(irg)) {
438 res = ir_sc_localvar;
439 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
440 res |= ir_sc_modifier_nottaken;
441 } else if (irn == get_irg_tls(irg)) {
443 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
444 res |= ir_sc_modifier_nottaken;
445 } else if (is_Proj(irn) && is_malloc_Result(irn)) {
446 return ir_sc_malloced;
447 } else if (is_Const(irn)) {
448 return ir_sc_globaladdr;
449 } else if (is_arg_Proj(irn)) {
450 res |= ir_sc_modifier_argument;
457 * If adr represents a Bitfield Sel, skip it
459 static const ir_node *skip_Bitfield_Sels(const ir_node *adr)
462 ir_entity *ent = get_Sel_entity(adr);
463 ir_type *bf_type = get_entity_type(ent);
465 /* is it a bitfield type? */
466 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
467 adr = get_Sel_ptr(adr);
473 * Determine the alias relation between two addresses.
475 * @param addr1 pointer address of the first memory operation
476 * @param mode1 the mode of the accessed data through addr1
477 * @param addr2 pointer address of the second memory operation
478 * @param mode2 the mode of the accessed data through addr2
480 * @return found memory relation
482 static ir_alias_relation _get_alias_relation(
483 const ir_node *adr1, const ir_mode *mode1,
484 const ir_node *adr2, const ir_mode *mode2)
486 ir_entity *ent1, *ent2;
490 const ir_node *base1;
491 const ir_node *base2;
492 const ir_node *orig_adr1 = adr1;
493 const ir_node *orig_adr2 = adr2;
496 ir_storage_class_class_t class1, class2, mod1, mod2;
497 int have_const_offsets;
499 if (! get_opt_alias_analysis())
503 return ir_sure_alias;
505 irg = get_irn_irg(adr1);
506 options = get_irg_memory_disambiguator_options(irg);
508 /* The Armageddon switch */
509 if (options & aa_opt_no_alias)
512 /* do the addresses have constants offsets?
513 * Note: nodes are normalized to have constants at right inputs,
514 * sub X, C is normalized to add X, -C
516 have_const_offsets = 1;
517 while (is_Add(adr1)) {
518 ir_node *add_right = get_Add_right(adr1);
519 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
520 tarval *tv = get_Const_tarval(add_right);
521 offset1 += get_tarval_long(tv);
522 adr1 = get_Add_left(adr1);
523 } else if (mode_is_reference(get_irn_mode(add_right))) {
525 have_const_offsets = 0;
527 adr1 = get_Add_left(adr1);
528 have_const_offsets = 0;
531 while (is_Add(adr2)) {
532 ir_node *add_right = get_Add_right(adr2);
533 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
534 tarval *tv = get_Const_tarval(add_right);
535 offset2 += get_tarval_long(tv);
536 adr2 = get_Add_left(adr2);
537 } else if (mode_is_reference(get_irn_mode(add_right))) {
539 have_const_offsets = 0;
541 adr2 = get_Add_left(adr2);
542 have_const_offsets = 0;
546 mode_size = get_mode_size_bytes(mode1);
547 if (get_mode_size_bytes(mode2) > mode_size) {
548 mode_size = get_mode_size_bytes(mode2);
551 /* same base address -> compare offsets if possible.
552 * FIXME: type long is not sufficient for this task ...
554 if (adr1 == adr2 && have_const_offsets) {
555 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
558 return ir_sure_alias;
562 * Bitfields can be constructed as Sels from its base address.
563 * As they have different entities, the disambiguator would find that they are
564 * alias free. While this is true for it's values, it is false for the addresses
565 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
566 * So, skip those bitfield selecting Sel's.
568 adr1 = skip_Bitfield_Sels(adr1);
569 adr2 = skip_Bitfield_Sels(adr2);
577 base1 = find_base_adr(adr1, &ent1);
580 base2 = find_base_adr(adr2, &ent2);
583 /* same base address -> compare Sel entities */
584 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
587 else if (have_const_offsets)
588 return different_sel_offsets(adr1, adr2);
591 mod1 = classify_pointer(base1, ent1);
592 mod2 = classify_pointer(base2, ent2);
594 class1 = GET_BASE_SC(mod1);
595 class2 = GET_BASE_SC(mod2);
597 if (class1 == ir_sc_pointer || class2 == ir_sc_pointer) {
598 /* swap pointer class to class1 */
599 if (class2 == ir_sc_pointer) {
600 ir_storage_class_class_t temp = mod1;
603 class1 = GET_BASE_SC(mod1);
604 class2 = GET_BASE_SC(mod2);
606 /* a pointer and an object whose address was never taken */
607 if (mod2 & ir_sc_modifier_nottaken) {
610 if (mod1 & ir_sc_modifier_argument) {
611 if ( (options & aa_opt_no_alias_args)
612 && (mod2 & ir_sc_modifier_argument))
614 if ( (options & aa_opt_no_alias_args_global)
615 && (class2 == ir_sc_globalvar
616 || class2 == ir_sc_tls
617 || class2 == ir_sc_globaladdr))
620 } else if (class1 != class2) {
621 /* two objects from different memory spaces */
624 /* both classes are equal */
625 if (class1 == ir_sc_globalvar) {
626 ir_entity *entity1 = get_SymConst_entity(base1);
627 ir_entity *entity2 = get_SymConst_entity(base2);
628 if (entity1 != entity2)
631 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
633 } else if (class1 == ir_sc_globaladdr) {
634 tarval *tv = get_Const_tarval(base1);
635 offset1 += get_tarval_long(tv);
636 tv = get_Const_tarval(base2);
637 offset2 += get_tarval_long(tv);
639 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
642 return ir_sure_alias;
646 /* Type based alias analysis */
647 if (options & aa_opt_type_based) {
648 ir_alias_relation rel;
650 if (options & aa_opt_byte_type_may_alias) {
651 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
652 /* One of the modes address a byte. Assume a ir_may_alias and leave
653 the type based check. */
654 goto leave_type_based_alias;
657 /* cheap check: If the mode sizes did not match, the types MUST be different */
658 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
661 /* cheap test: if only one is a reference mode, no alias */
662 if (mode_is_reference(mode1) != mode_is_reference(mode2))
665 /* cheap test: if arithmetic is different, no alias */
666 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
670 rel = different_types(orig_adr1, orig_adr2);
671 if (rel != ir_may_alias)
673 leave_type_based_alias:;
676 /* do we have a language specific memory disambiguator? */
677 if (language_disambuigator != NULL) {
678 ir_alias_relation rel = language_disambuigator(orig_adr1, mode1, orig_adr2, mode2);
679 if (rel != ir_may_alias)
683 /* access points-to information here */
685 } /* _get_alias_relation */
688 * Determine the alias relation between two addresses.
690 ir_alias_relation get_alias_relation(
691 const ir_node *adr1, const ir_mode *mode1,
692 const ir_node *adr2, const ir_mode *mode2)
694 ir_alias_relation rel = _get_alias_relation(adr1, mode1, adr2, mode2);
695 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
697 } /* get_alias_relation */
699 /* Set a source language specific memory disambiguator function. */
700 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func)
702 language_disambuigator = func;
703 } /* set_language_memory_disambiguator */
705 /** The result cache for the memory disambiguator. */
706 static set *result_cache = NULL;
708 /** An entry in the relation cache. */
709 typedef struct mem_disambig_entry {
710 const ir_node *adr1; /**< The first address. */
711 const ir_mode *mode1; /**< The first address mode. */
712 const ir_node *adr2; /**< The second address. */
713 const ir_mode *mode2; /**< The second address mode. */
714 ir_alias_relation result; /**< The alias relation result. */
715 } mem_disambig_entry;
717 #define HASH_ENTRY(adr1, adr2) (HASH_PTR(adr1) ^ HASH_PTR(adr2))
720 * Compare two relation cache entries.
722 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size)
724 const mem_disambig_entry *p1 = elt;
725 const mem_disambig_entry *p2 = key;
728 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2 &&
729 p1->mode1 == p2->mode1 && p1->mode2 == p2->mode2;
730 } /* cmp_mem_disambig_entry */
733 * Initialize the relation cache.
735 void mem_disambig_init(void)
737 result_cache = new_set(cmp_mem_disambig_entry, 8);
738 } /* mem_disambig_init */
741 * Determine the alias relation between two addresses.
743 ir_alias_relation get_alias_relation_ex(
744 const ir_node *adr1, const ir_mode *mode1,
745 const ir_node *adr2, const ir_mode *mode2)
747 mem_disambig_entry key, *entry;
749 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
751 if (! get_opt_alias_analysis())
754 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
755 const ir_node *t = adr1;
764 entry = set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
766 return entry->result;
768 key.result = get_alias_relation(adr1, mode1, adr2, mode2);
770 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
772 } /* get_alias_relation_ex */
774 /* Free the relation cache. */
775 void mem_disambig_term(void)
777 if (result_cache != NULL) {
778 del_set(result_cache);
781 } /* mem_disambig_term */
784 * Check the mode of a Load/Store with the mode of the entity
786 * If the mode of the entity and the Load/Store mode do not match, we
787 * have the bad reinterpret case:
790 * char b = *(char *)&i;
792 * We do NOT count this as one value and return address_taken
794 * However, we support an often used case. If the mode is two-complement
795 * we allow casts between signed/unsigned.
797 * @param mode the mode of the Load/Store
798 * @param ent_mode the mode of the accessed entity
800 * @return non-zero if the Load/Store is a hidden cast, zero else
802 static int is_hidden_cast(const ir_mode *mode, const ir_mode *ent_mode)
804 if (ent_mode == NULL)
807 if (ent_mode != mode) {
808 if (ent_mode == NULL ||
809 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
810 get_mode_sort(ent_mode) != get_mode_sort(mode) ||
811 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
812 get_mode_arithmetic(mode) != irma_twos_complement)
816 } /* is_hidden_cast */
819 * Determine the usage state of a node (or its successor Sels).
821 * @param irn the node
823 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity)
826 ir_mode *emode, *mode;
829 ir_entity_usage res = 0;
831 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
832 ir_node *succ = get_irn_out(irn, i);
834 switch (get_irn_opcode(succ)) {
836 /* beware: irn might be a Id node here, so irn might be not
837 equal to get_Load_ptr(succ) */
838 res |= ir_usage_read;
840 /* check if this load is not a hidden conversion */
841 mode = get_Load_mode(succ);
842 emode = get_type_mode(get_entity_type(entity));
843 if (is_hidden_cast(mode, emode))
844 res |= ir_usage_reinterpret_cast;
848 /* check that the node is not the Store's value */
849 if (irn == get_Store_value(succ)) {
850 res |= ir_usage_unknown;
852 if (irn == get_Store_ptr(succ)) {
853 res |= ir_usage_write;
855 /* check if this Store is not a hidden conversion */
856 value = get_Store_value(succ);
857 mode = get_irn_mode(value);
858 emode = get_type_mode(get_entity_type(entity));
859 if (is_hidden_cast(mode, emode))
860 res |= ir_usage_reinterpret_cast;
862 assert(irn != get_Store_mem(succ));
866 /* CopyB are like Loads/Stores */
867 tp = get_entity_type(entity);
868 if (tp != get_CopyB_type(succ)) {
869 /* bad, different types, might be a hidden conversion */
870 res |= ir_usage_reinterpret_cast;
872 if (irn == get_CopyB_dst(succ)) {
873 res |= ir_usage_write;
875 assert(irn == get_CopyB_src(succ));
876 res |= ir_usage_read;
882 /* Check the successor of irn. */
883 res |= determine_entity_usage(succ, entity);
886 ir_entity *entity = get_Sel_entity(succ);
887 /* this analysis can't handle unions correctly */
888 if (is_Union_type(get_entity_owner(entity))) {
889 res |= ir_usage_unknown;
892 /* Check the successor of irn. */
893 res |= determine_entity_usage(succ, entity);
898 if (irn == get_Call_ptr(succ)) {
899 /* TODO: we could check for reinterpret casts here...
900 * But I doubt anyone is interested in that bit for
901 * function entities and I'm too lazy to write the code now.
903 res |= ir_usage_read;
905 assert(irn != get_Call_mem(succ));
906 res |= ir_usage_unknown;
910 /* skip identities */
912 res |= determine_entity_usage(succ, entity);
918 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
920 ir_node *pred = get_Tuple_pred(succ, input_nr);
923 /* we found one input */
924 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
925 ir_node *proj = get_irn_out(succ, k);
927 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
928 res |= determine_entity_usage(proj, entity);
938 /* another op, we don't know anything (we could do more advanced
939 * things like a dataflow analysis here) */
940 res |= ir_usage_unknown;
949 * Update the usage flags of all frame entities.
951 static void analyse_irg_entity_usage(ir_graph *irg)
953 ir_type *ft = get_irg_frame_type(irg);
955 int i, j, k, static_link_arg;
957 /* set initial state to not_taken, as this is the "smallest" state */
958 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
959 ir_entity *ent = get_class_member(ft, i);
961 /* methods can only be analyzed globally */
962 if (! is_method_entity(ent)) {
963 ir_entity_usage flags = 0;
964 if (get_entity_linkage(ent) & IR_LINKAGE_HIDDEN_USER)
965 flags = ir_usage_unknown;
966 set_entity_usage(ent, flags);
970 assure_irg_outs(irg);
972 irg_frame = get_irg_frame(irg);
974 for (i = get_irn_n_outs(irg_frame) - 1; i >= 0; --i) {
975 ir_node *succ = get_irn_out(irg_frame, i);
977 ir_entity_usage flags;
982 entity = get_Sel_entity(succ);
983 flags = get_entity_usage(entity);
984 flags |= determine_entity_usage(succ, entity);
985 set_entity_usage(entity, flags);
988 /* check inner functions accessing outer frame */
990 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
991 ir_entity *ent = get_class_member(ft, i);
995 if (! is_method_entity(ent))
998 inner_irg = get_entity_irg(ent);
999 if (inner_irg == NULL)
1002 assure_irg_outs(inner_irg);
1003 args = get_irg_args(inner_irg);
1004 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
1005 ir_node *arg = get_irn_out(args, j);
1007 if (get_Proj_proj(arg) == static_link_arg) {
1008 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
1009 ir_node *succ = get_irn_out(arg, k);
1012 ir_entity *entity = get_Sel_entity(succ);
1014 if (get_entity_owner(entity) == ft) {
1015 /* found an access to the outer frame */
1016 ir_entity_usage flags;
1018 flags = get_entity_usage(entity);
1019 flags |= determine_entity_usage(succ, entity);
1020 set_entity_usage(entity, flags);
1030 irg->entity_usage_state = ir_entity_usage_computed;
1033 ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg)
1035 return irg->entity_usage_state;
1038 void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state)
1040 irg->entity_usage_state = state;
1043 void assure_irg_entity_usage_computed(ir_graph *irg)
1045 if (irg->entity_usage_state != ir_entity_usage_not_computed)
1048 analyse_irg_entity_usage(irg);
1053 * Initialize the entity_usage flag for a global type like type.
1055 static void init_entity_usage(ir_type *tp)
1059 /* We have to be conservative: All external visible entities are unknown */
1060 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1061 ir_entity *ent = get_compound_member(tp, i);
1062 ir_entity_usage flags = ir_usage_none;
1064 if (entity_is_externally_visible(ent)) {
1065 flags |= ir_usage_unknown;
1067 set_entity_usage(ent, flags);
1072 * Mark all entities used in the initializer as unknown usage.
1074 * @param initializer the initializer to check
1076 static void check_initializer_nodes(ir_initializer_t *initializer)
1081 switch (initializer->kind) {
1082 case IR_INITIALIZER_CONST:
1083 /* let's check if it's an address */
1084 n = initializer->consti.value;
1086 ir_entity *ent = get_Global_entity(n);
1087 set_entity_usage(ent, ir_usage_unknown);
1090 case IR_INITIALIZER_TARVAL:
1091 case IR_INITIALIZER_NULL:
1093 case IR_INITIALIZER_COMPOUND:
1094 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1095 ir_initializer_t *sub_initializer
1096 = initializer->compound.initializers[i];
1097 check_initializer_nodes(sub_initializer);
1101 panic("invalid initializer found");
1102 } /* check_initializer_nodes */
1105 * Mark all entities used in the initializer for the given entity as unknown
1108 * @param ent the entity
1110 static void check_initializer(ir_entity *ent)
1115 /* Beware: Methods are always initialized with "themself". This does not
1116 * count as a taken address.
1117 * TODO: this initialisation with "themself" is wrong and should be removed
1119 if (is_Method_type(get_entity_type(ent)))
1122 if (ent->initializer != NULL) {
1123 check_initializer_nodes(ent->initializer);
1124 } else if (entity_has_compound_ent_values(ent)) {
1125 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
1126 n = get_compound_ent_value(ent, i);
1128 /* let's check if it's an address */
1130 ir_entity *ent = get_Global_entity(n);
1131 set_entity_usage(ent, ir_usage_unknown);
1139 * Mark all entities used in initializers as unknown usage.
1141 * @param tp a compound type
1143 static void check_initializers(ir_type *tp)
1147 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1148 ir_entity *ent = get_compound_member(tp, i);
1150 check_initializer(ent);
1152 } /* check_initializers */
1154 #ifdef DEBUG_libfirm
1156 * Print the entity usage flags of all entities of a given type for debugging.
1158 * @param tp a compound type
1160 static void print_entity_usage_flags(ir_type *tp)
1163 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1164 ir_entity *ent = get_compound_member(tp, i);
1165 ir_entity_usage flags = get_entity_usage(ent);
1169 ir_printf("%+F:", ent);
1170 if (flags & ir_usage_address_taken)
1171 printf(" address_taken");
1172 if (flags & ir_usage_read)
1174 if (flags & ir_usage_write)
1176 if (flags & ir_usage_reinterpret_cast)
1177 printf(" reinterp_cast");
1181 #endif /* DEBUG_libfirm */
1184 * Post-walker: check for global entity address
1186 static void check_global_address(ir_node *irn, void *env)
1190 ir_entity_usage flags;
1192 if (is_Global(irn)) {
1194 ent = get_Global_entity(irn);
1195 } else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
1196 /* A TLS variable. */
1197 ent = get_Sel_entity(irn);
1201 flags = get_entity_usage(ent);
1202 flags |= determine_entity_usage(irn, ent);
1203 set_entity_usage(ent, 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 = get_irp_n_irgs() - 1; i >= 0; --i) {
1225 ir_graph *irg = get_irp_irg(i);
1227 assure_irg_outs(irg);
1228 irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
1231 #ifdef DEBUG_libfirm
1232 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1234 for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
1235 print_entity_usage_flags(get_segment_type(s));
1238 #endif /* DEBUG_libfirm */
1241 irp->globals_entity_usage_state = ir_entity_usage_computed;
1244 /* Returns the current address taken state of the globals. */
1245 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void)
1247 return irp->globals_entity_usage_state;
1250 /* Sets the current address taken state of the graph. */
1251 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state)
1253 irp->globals_entity_usage_state = state;
1256 /* Assure that the address taken flag is computed for the globals. */
1257 void assure_irp_globals_entity_usage_computed(void)
1259 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1262 analyse_irp_globals_entity_usage();
1265 void firm_init_memory_disambiguator(void)
1267 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1268 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1272 /** Maps method types to cloned method types. */
1273 static pmap *mtp_map;
1276 * Clone a method type if not already cloned.
1278 * @param tp the type to clone
1280 static ir_type *clone_type_and_cache(ir_type *tp)
1283 pmap_entry *e = pmap_find(mtp_map, tp);
1288 res = clone_type_method(tp);
1289 pmap_insert(mtp_map, tp, res);
1292 } /* clone_type_and_cache */
1295 * Walker: clone all call types of Calls to methods having the
1296 * mtp_property_private property set.
1298 static void update_calls_to_private(ir_node *call, void *env)
1301 if (is_Call(call)) {
1302 ir_node *ptr = get_Call_ptr(call);
1304 if (is_SymConst(ptr)) {
1305 ir_entity *ent = get_SymConst_entity(ptr);
1306 ir_type *ctp = get_Call_type(call);
1308 if (get_entity_additional_properties(ent) & mtp_property_private) {
1309 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1310 ctp = clone_type_and_cache(ctp);
1311 set_method_additional_property(ctp, mtp_property_private);
1312 set_Call_type(call, ctp);
1313 DB((dbgcall, LEVEL_1, "changed call to private method %+F using cloned type %+F\n", ent, ctp));
1318 } /* update_calls_to_private */
1320 /* Mark all private methods, i.e. those of which all call sites are known. */
1321 void mark_private_methods(void)
1326 assure_irp_globals_entity_usage_computed();
1328 mtp_map = pmap_create();
1330 /* first step: change the calling conventions of the local non-escaped entities */
1331 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1332 ir_graph *irg = get_irp_irg(i);
1333 ir_entity *ent = get_irg_entity(irg);
1334 ir_entity_usage flags = get_entity_usage(ent);
1336 if (!entity_is_externally_visible(ent) &&
1337 !(flags & ir_usage_address_taken)) {
1338 ir_type *mtp = get_entity_type(ent);
1340 set_entity_additional_property(ent, mtp_property_private);
1341 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1342 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1343 /* need a new type */
1344 mtp = clone_type_and_cache(mtp);
1345 set_method_additional_property(mtp, mtp_property_private);
1346 set_entity_type(ent, mtp);
1347 DB((dbgcall, LEVEL_2, "changed entity type of %+F to %+F\n", ent, mtp));
1354 all_irg_walk(NULL, update_calls_to_private, NULL);
1356 pmap_destroy(mtp_map);
1357 } /* mark_private_methods */
1359 /* create a pass for mark_private_methods() */
1360 ir_prog_pass_t *mark_private_methods_pass(const char *name)
1362 return def_prog_pass(name ? name : "mark_private_methods", mark_private_methods);
1363 } /* mark_private_methods_pass */