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"
48 /** The debug handle. */
49 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
50 DEBUG_ONLY(static firm_dbg_module_t *dbgcall = NULL;)
52 /** The source language specific language disambiguator function. */
53 static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
55 /** The global memory disambiguator options. */
56 static unsigned global_mem_disamgig_opt = aa_opt_no_opt;
58 /* Returns a human readable name for an alias relation. */
59 const char *get_ir_alias_relation_name(ir_alias_relation rel) {
60 #define X(a) case a: return #a
65 default: assert(0); return "UNKNOWN";
70 /* Get the memory disambiguator options for a graph. */
71 unsigned get_irg_memory_disambiguator_options(ir_graph *irg) {
72 unsigned opt = irg->mem_disambig_opt;
73 if (opt & aa_opt_inherited)
74 return global_mem_disamgig_opt;
76 } /* get_irg_memory_disambiguator_options */
78 /* Set the memory disambiguator options for a graph. */
79 void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options) {
80 irg->mem_disambig_opt = options & ~aa_opt_inherited;
81 } /* set_irg_memory_disambiguator_options */
83 /* Set the global disambiguator options for all graphs not having local options. */
84 void set_irp_memory_disambiguator_options(unsigned options) {
85 global_mem_disamgig_opt = options;
86 } /* set_irp_memory_disambiguator_options */
89 * Find the base address and entity of an Sel node.
92 * @param pEnt after return points to the base entity.
94 * @return the base address.
96 static ir_node *find_base_adr(ir_node *sel, ir_entity **pEnt) {
97 ir_node *ptr = get_Sel_ptr(sel);
101 ptr = get_Sel_ptr(sel);
103 *pEnt = get_Sel_entity(sel);
105 } /* find_base_adr */
108 * Check if a given Const node is greater or equal a given size.
110 * @param cns a Const node
111 * @param size a integer size
113 * @return ir_no_alias if the Const is greater, ir_may_alias else
115 static ir_alias_relation check_const(ir_node *cns, int size) {
116 tarval *tv = get_Const_tarval(cns);
120 return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
121 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
122 return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
126 * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
128 * @param idx1 a node representing the first index
129 * @param idx2 a node representing the second index
130 * @param size an integer size
132 * @return ir_sure_alias iff idx1 == idx2
133 * ir_no_alias iff they ALWAYS differ more than size
136 static ir_alias_relation different_index(ir_node *idx1, ir_node *idx2, int size) {
138 return ir_sure_alias;
139 if (is_Const(idx1) && is_Const(idx2)) {
140 /* both are const, we can compare them */
141 tarval *tv1 = get_Const_tarval(idx1);
142 tarval *tv2 = get_Const_tarval(idx2);
143 tarval *tv, *tv_size;
147 return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
149 /* arg, modes may be different */
150 m1 = get_tarval_mode(tv1);
151 m2 = get_tarval_mode(tv2);
153 int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
156 /* m1 is a small mode, cast up */
157 m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
159 /* should NOT happen, but if it does we give up here */
162 tv1 = tarval_convert_to(tv1, m1);
163 } else if (size > 0) {
164 /* m2 is a small mode, cast up */
165 m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
167 /* should NOT happen, but if it does we give up here */
170 tv2 = tarval_convert_to(tv2, m2);
172 /* here the size should be identical, check for signed */
173 if (get_mode_sign(m1) != get_mode_sign(m2)) {
174 /* find the signed */
175 if (mode_is_signed(m2)) {
182 /* m1 is now the signed one */
183 if (tarval_cmp(tv1, get_tarval_null(m1)) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
184 /* tv1 is signed, but >= 0, simply cast into unsigned */
185 tv1 = tarval_convert_to(tv1, m2);
187 tv_size = new_tarval_from_long(size, m2);
189 if (tarval_cmp(tv2, tv_size) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
190 /* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
193 /* tv_size > tv2, so we can subtract without overflow */
194 tv2 = tarval_sub(tv_size, tv2, NULL);
196 /* tv1 is < 0, so we can negate it */
197 tv1 = tarval_neg(tv1);
199 /* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
200 tv1 = tarval_convert_to(tv1, m2);
202 /* now we can compare without overflow */
203 return tarval_cmp(tv1, tv2) & (pn_Cmp_Eq|pn_Cmp_Gt) ? ir_no_alias : ir_may_alias;
207 if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) {
212 /* tv1 is now the "smaller" one */
213 tv = tarval_sub(tv2, tv1, NULL);
214 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
215 return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
218 /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
220 ir_node *l1 = get_Add_left(idx1);
221 ir_node *r1 = get_Add_right(idx1);
226 return check_const(r1, size);
229 /* both are Adds, check if they are of x + a == x + b kind */
230 ir_node *l2 = get_Add_left(idx2);
231 ir_node *r2 = get_Add_right(idx2);
234 return different_index(r1, r2, size);
236 return different_index(r1, l2, size);
238 return different_index(l1, l2, size);
240 return different_index(l1, r2, size);
244 ir_node *l2 = get_Add_left(idx2);
245 ir_node *r2 = get_Add_right(idx2);
250 return check_const(r2, size);
255 ir_node *l1 = get_Sub_left(idx1);
256 ir_node *r1 = get_Sub_right(idx1);
261 return check_const(r1, size);
265 /* both are Subs, check if they are of x - a == x - b kind */
266 ir_node *l2 = get_Sub_left(idx2);
269 ir_node *r2 = get_Sub_right(idx2);
270 return different_index(r1, r2, size);
275 ir_node *l2 = get_Sub_left(idx2);
276 ir_node *r2 = get_Sub_right(idx2);
281 return check_const(r2, size);
286 } /* different_index */
289 * Two Sel addresses have the same base address, check if there offsets are
292 * @param adr1 The first address.
293 * @param adr2 The second address.
295 static ir_alias_relation different_sel_offsets(ir_node *sel1, ir_node *sel2) {
296 /* seems to be broken */
300 ir_entity *ent1 = get_Sel_entity(sel1);
301 ir_entity *ent2 = get_Sel_entity(sel2);
302 int i, check_arr = 0;
307 ir_type *tp1 = get_entity_type(ent1);
308 ir_type *tp2 = get_entity_type(ent2);
312 else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
313 get_type_size_bits(tp1) == get_type_size_bits(tp2))
317 /* we select an entity of same size, check for indexes */
318 int n = get_Sel_n_indexs(sel1);
321 if (n > 0 && n == get_Sel_n_indexs(sel2)) {
322 /* same non-zero number of indexes, an array access, check */
323 for (i = 0; i < n; ++i) {
324 ir_node *idx1 = get_Sel_index(sel1, i);
325 ir_node *idx2 = get_Sel_index(sel2, i);
326 ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
328 if (res == may_alias)
330 else if (res == no_alias)
333 /* if we have at least one no_alias, there is no alias relation, else we have sure */
334 return have_no > 0 ? no_alias : sure_alias;
338 (void) different_index;
341 } /* different_sel_offsets */
344 * Determine the alias relation by checking if adr1 and adr2 are pointer
347 * @param adr1 The first address.
348 * @param adr2 The second address.
350 static ir_alias_relation different_types(ir_node *adr1, ir_node *adr2)
352 ir_entity *ent1 = NULL, *ent2 = NULL;
355 ent1 = get_Global_entity(adr1);
356 else if (is_Sel(adr1))
357 ent1 = get_Sel_entity(adr1);
360 ent2 = get_Global_entity(adr2);
361 else if (is_Sel(adr2))
362 ent2 = get_Sel_entity(adr2);
364 if (ent1 != NULL && ent2 != NULL) {
365 ir_type *tp1 = get_entity_type(ent1);
366 ir_type *tp2 = get_entity_type(ent2);
369 /* do deref until no pointer types are found */
370 while (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
371 tp1 = get_pointer_points_to_type(tp1);
372 tp2 = get_pointer_points_to_type(tp2);
375 if (get_type_tpop(tp1) != get_type_tpop(tp2)) {
376 /* different type structure */
379 if (is_Class_type(tp1)) {
380 /* check class hierarchy */
381 if (! is_SubClass_of(tp1, tp2) &&
382 ! is_SubClass_of(tp2, tp1))
385 /* different types */
391 } /* different_types */
394 * Returns non-zero if a node is a result on a malloc-like routine.
396 * @param node the Proj node to test
398 static int is_malloc_Result(ir_node *node) {
399 node = get_Proj_pred(node);
402 node = get_Proj_pred(node);
405 node = get_Call_ptr(node);
406 if (is_Global(node)) {
407 ir_entity *ent = get_Global_entity(node);
409 if (get_entity_additional_properties(ent) & mtp_property_malloc)
414 } /* is_malloc_Result */
417 * Classify a base pointer.
419 * @param irg the graph of the pointer
420 * @param irn the node representing the base address
421 * @param ent the base entity of the base address iff any
423 ir_storage_class_class_t classify_pointer(ir_graph *irg, ir_node *irn, ir_entity *ent)
425 ir_storage_class_class_t res = ir_sc_pointer;
426 if (is_Global(irn)) {
427 ir_entity *entity = get_Global_entity(irn);
428 res = ir_sc_globalvar;
429 if (! (get_entity_usage(entity) & ir_usage_address_taken))
430 res |= ir_sc_modifier_nottaken;
431 } else if (irn == get_irg_frame(irg)) {
432 res = ir_sc_localvar;
433 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
434 res |= ir_sc_modifier_nottaken;
435 } else if (is_arg_Proj(irn)) {
436 return ir_sc_argument;
437 } else if (irn == get_irg_tls(irg)) {
439 if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
440 res |= ir_sc_modifier_nottaken;
441 } else if (is_Proj(irn) && is_malloc_Result(irn)) {
442 return ir_sc_malloced;
443 } else if (is_Const(irn)) {
444 return ir_sc_globaladdr;
451 * If adr represents a Bitfield Sel, skip it
453 static ir_node *skip_Bitfield_Sels(ir_node *adr) {
455 ir_entity *ent = get_Sel_entity(adr);
456 ir_type *bf_type = get_entity_type(ent);
458 /* is it a bitfield type? */
459 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
460 adr = get_Sel_ptr(adr);
466 * Determine the alias relation between two addresses.
468 * @param irg the graph of both memory operations
469 * @param addr1 pointer address of the first memory operation
470 * @param mode1 the mode of the accessed data through addr1
471 * @param addr2 pointer address of the second memory operation
472 * @param mode2 the mode of the accessed data through addr2
474 * @return found memory relation
476 static ir_alias_relation _get_alias_relation(
478 ir_node *adr1, ir_mode *mode1,
479 ir_node *adr2, ir_mode *mode2)
481 ir_entity *ent1, *ent2;
487 ir_node *orig_adr1 = adr1;
488 ir_node *orig_adr2 = adr2;
490 ir_storage_class_class_t class1, class2;
491 int have_const_offsets;
493 if (! get_opt_alias_analysis())
497 return ir_sure_alias;
499 options = get_irg_memory_disambiguator_options(irg);
501 /* The Armageddon switch */
502 if (options & aa_opt_no_alias)
505 /* do the addresses have constants offsets?
506 * Note: nodes are normalized to have constants at right inputs,
507 * sub X, C is normalized to add X, -C
509 have_const_offsets = 1;
510 while (is_Add(adr1)) {
511 ir_node *add_right = get_Add_right(adr1);
512 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
513 tarval *tv = get_Const_tarval(add_right);
514 offset1 += get_tarval_long(tv);
515 adr1 = get_Add_left(adr1);
516 } else if (mode_is_reference(get_irn_mode(add_right))) {
518 have_const_offsets = 0;
520 adr1 = get_Add_left(adr1);
521 have_const_offsets = 0;
524 while (is_Add(adr2)) {
525 ir_node *add_right = get_Add_right(adr2);
526 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
527 tarval *tv = get_Const_tarval(add_right);
528 offset2 += get_tarval_long(tv);
529 adr2 = get_Add_left(adr2);
530 } else if (mode_is_reference(get_irn_mode(add_right))) {
532 have_const_offsets = 0;
534 adr2 = get_Add_left(adr2);
535 have_const_offsets = 0;
539 mode_size = get_mode_size_bytes(mode1);
540 if (get_mode_size_bytes(mode2) > mode_size) {
541 mode_size = get_mode_size_bytes(mode2);
544 /* same base address -> compare offsets if possible.
545 * FIXME: type long is not sufficient for this task ...
547 if (adr1 == adr2 && have_const_offsets) {
548 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
551 return ir_sure_alias;
555 * Bitfields can be constructed as Sels from its base address.
556 * As they have different entities, the disambiguator would find that they are
557 * alias free. While this is true for it's values, it is false for the addresses
558 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
559 * So, skip those bitfield selecting Sel's.
561 adr1 = skip_Bitfield_Sels(adr1);
562 adr2 = skip_Bitfield_Sels(adr2);
570 base1 = find_base_adr(adr1, &ent1);
573 base2 = find_base_adr(adr2, &ent2);
576 /* same base address -> compare Sel entities */
577 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
580 else if (have_const_offsets)
581 return different_sel_offsets(adr1, adr2);
584 class1 = classify_pointer(irg, base1, ent1);
585 class2 = classify_pointer(irg, base2, ent2);
587 if (class1 == ir_sc_pointer) {
588 if (class2 & ir_sc_modifier_nottaken) {
589 /* a pointer and an object whose objects was never taken */
592 } else if (class2 == ir_sc_pointer) {
593 if (class1 & ir_sc_modifier_nottaken) {
594 /* a pointer and an object whose objects was never taken */
597 } else if (class1 != class2) {
598 /* two objects from different memory spaces */
601 /* both classes are equal */
602 if (class1 == ir_sc_globalvar) {
603 ir_entity *entity1 = get_SymConst_entity(base1);
604 ir_entity *entity2 = get_SymConst_entity(base2);
605 if (entity1 != entity2)
608 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
610 } else if (class1 == ir_sc_globaladdr) {
611 tarval *tv = get_Const_tarval(base1);
612 offset1 += get_tarval_long(tv);
613 tv = get_Const_tarval(base2);
614 offset2 += get_tarval_long(tv);
616 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
619 return ir_sure_alias;
623 /* Type based alias analysis */
624 if (options & aa_opt_type_based) {
625 ir_alias_relation rel;
627 if (options & aa_opt_byte_type_may_alias) {
628 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
629 /* One of the modes address a byte. Assume a ir_may_alias and leave
630 the type based check. */
631 goto leave_type_based_alias;
634 /* cheap check: If the mode sizes did not match, the types MUST be different */
635 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
638 /* cheap test: if only one is a reference mode, no alias */
639 if (mode_is_reference(mode1) != mode_is_reference(mode2))
642 /* cheap test: if arithmetic is different, no alias */
643 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
647 rel = different_types(orig_adr1, orig_adr2);
648 if (rel != ir_may_alias)
650 leave_type_based_alias:;
653 /* do we have a language specific memory disambiguator? */
654 if (language_disambuigator) {
655 ir_alias_relation rel = (*language_disambuigator)(irg, orig_adr1, mode1, orig_adr2, mode2);
656 if (rel != ir_may_alias)
660 /* access points-to information here */
662 } /* _get_alias_relation */
665 * Determine the alias relation between two addresses.
667 ir_alias_relation get_alias_relation(
669 ir_node *adr1, ir_mode *mode1,
670 ir_node *adr2, ir_mode *mode2)
672 ir_alias_relation rel = _get_alias_relation(irg, adr1, mode1, adr2, mode2);
673 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
675 } /* get_alias_relation */
677 /* Set a source language specific memory disambiguator function. */
678 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func) {
679 language_disambuigator = func;
680 } /* set_language_memory_disambiguator */
682 /** The result cache for the memory disambiguator. */
683 static set *result_cache = NULL;
685 /** An entry in the relation cache. */
686 typedef struct mem_disambig_entry {
687 ir_node *adr1; /**< The first address. */
688 ir_node *adr2; /**< The second address. */
689 ir_alias_relation result; /**< The alias relation result. */
690 } mem_disambig_entry;
692 #define HASH_ENTRY(adr1, adr2) (HASH_PTR(adr1) ^ HASH_PTR(adr2))
695 * Compare two relation cache entries.
697 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size) {
698 const mem_disambig_entry *p1 = elt;
699 const mem_disambig_entry *p2 = key;
702 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2;
703 } /* cmp_mem_disambig_entry */
706 * Initialize the relation cache.
708 void mem_disambig_init(void) {
709 result_cache = new_set(cmp_mem_disambig_entry, 8);
710 } /* mem_disambig_init */
713 * Determine the alias relation between two addresses.
715 ir_alias_relation get_alias_relation_ex(
717 ir_node *adr1, ir_mode *mode1,
718 ir_node *adr2, ir_mode *mode2)
720 mem_disambig_entry key, *entry;
722 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
724 if (! get_opt_alias_analysis())
727 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
735 entry = set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
737 return entry->result;
739 key.result = get_alias_relation(irg, adr1, mode1, adr2, mode2);
741 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
743 } /* get_alias_relation_ex */
745 /* Free the relation cache. */
746 void mem_disambig_term(void) {
748 del_set(result_cache);
751 } /* mem_disambig_term */
754 * Check the mode of a Load/Store with the mode of the entity
756 * If the mode of the entity and the Load/Store mode do not match, we
757 * have the bad reinterpret case:
760 * char b = *(char *)&i;
762 * We do NOT count this as one value and return address_taken
764 * However, we support an often used case. If the mode is two-complement
765 * we allow casts between signed/unsigned.
767 * @param mode the mode of the Load/Store
768 * @param ent_mode the mode of the accessed entity
770 * @return non-zero if the Load/Store is a hidden cast, zero else
772 static int is_hidden_cast(ir_mode *mode, ir_mode *ent_mode) {
773 if (ent_mode == NULL)
776 if (ent_mode != mode) {
777 if (ent_mode == NULL ||
778 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
779 get_mode_sort(ent_mode) != get_mode_sort(mode) ||
780 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
781 get_mode_arithmetic(mode) != irma_twos_complement)
785 } /* is_hidden_cast */
788 * Determine the usage state of a node (or its successor Sels).
790 * @param irn the node
792 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity) {
794 ir_mode *emode, *mode;
797 ir_entity_usage res = 0;
799 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
800 ir_node *succ = get_irn_out(irn, i);
802 switch (get_irn_opcode(succ)) {
804 /* beware: irn might be a Id node here, so irn might be not
805 equal to get_Load_ptr(succ) */
806 res |= ir_usage_read;
808 /* check if this load is not a hidden conversion */
809 mode = get_Load_mode(succ);
810 emode = get_type_mode(get_entity_type(entity));
811 if (is_hidden_cast(mode, emode))
812 res |= ir_usage_reinterpret_cast;
816 /* check that the node is not the Store's value */
817 if (irn == get_Store_value(succ)) {
818 res |= ir_usage_unknown;
820 if (irn == get_Store_ptr(succ)) {
821 res |= ir_usage_write;
823 /* check if this Store is not a hidden conversion */
824 value = get_Store_value(succ);
825 mode = get_irn_mode(value);
826 emode = get_type_mode(get_entity_type(entity));
827 if (is_hidden_cast(mode, emode))
828 res |= ir_usage_reinterpret_cast;
830 assert(irn != get_Store_mem(succ));
834 /* CopyB are like Loads/Stores */
835 tp = get_entity_type(entity);
836 if (tp != get_CopyB_type(succ)) {
837 /* bad, different types, might be a hidden conversion */
838 res |= ir_usage_reinterpret_cast;
840 if (irn == get_CopyB_dst(succ)) {
841 res |= ir_usage_write;
843 assert(irn == get_CopyB_src(succ));
844 res |= ir_usage_read;
851 /* Check the successor of irn. */
852 res |= determine_entity_usage(succ, entity);
857 if (irn == get_Call_ptr(succ)) {
858 /* TODO: we could check for reinterpret casts here...
859 * But I doubt anyone is interested in that bit for
860 * function entities and I'm too lazy to write the code now.
862 res |= ir_usage_read;
864 assert(irn != get_Call_mem(succ));
865 res |= ir_usage_unknown;
869 /* skip identities */
871 res |= determine_entity_usage(succ, entity);
877 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
879 ir_node *pred = get_Tuple_pred(succ, input_nr);
882 /* we found one input */
883 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
884 ir_node *proj = get_irn_out(succ, k);
886 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
887 res |= determine_entity_usage(proj, entity);
897 /* another op, we don't know anything (we could do more advanced
898 * things like a dataflow analysis here) */
899 res |= ir_usage_unknown;
908 * Update the usage flags of all frame entities.
910 static void analyse_irg_entity_usage(ir_graph *irg) {
911 ir_type *ft = get_irg_frame_type(irg);
912 ir_node *irg_frame, *args, *arg;
913 int i, j, k, static_link_arg;
915 /* set initial state to not_taken, as this is the "smallest" state */
916 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
917 ir_entity *ent = get_class_member(ft, i);
919 /* methods can only be analyzed globally */
920 if (! is_method_entity(ent)) {
921 ir_entity_usage flags =
922 get_entity_stickyness(ent) == stickyness_sticky ? ir_usage_unknown : 0;
923 set_entity_usage(ent, flags);
927 assure_irg_outs(irg);
929 irg_frame = get_irg_frame(irg);
931 for (i = get_irn_n_outs(irg_frame) - 1; i >= 0; --i) {
932 ir_node *succ = get_irn_out(irg_frame, i);
934 ir_entity_usage flags;
939 entity = get_Sel_entity(succ);
940 flags = get_entity_usage(entity);
941 flags |= determine_entity_usage(succ, entity);
942 set_entity_usage(entity, flags);
945 /* check inner functions accessing outer frame */
947 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
948 ir_entity *ent = get_class_member(ft, i);
950 if (is_method_entity(ent)) {
951 ir_graph *inner_irg = get_entity_irg(ent);
954 assure_irg_outs(inner_irg);
955 args = get_irg_args(inner_irg);
956 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
957 ir_node *arg = get_irn_out(args, j);
959 if (get_Proj_proj(arg) == static_link_arg) {
960 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
961 ir_node *succ = get_irn_out(arg, k);
964 ir_entity *entity = get_Sel_entity(succ);
966 if (get_entity_owner(entity) == ft) {
967 /* found an access to the outer frame */
968 ir_entity_usage flags;
970 flags = get_entity_usage(entity);
971 flags |= determine_entity_usage(succ, entity);
972 set_entity_usage(entity, flags);
983 irg->entity_usage_state = ir_entity_usage_computed;
986 ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg) {
987 return irg->entity_usage_state;
990 void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state) {
991 irg->entity_usage_state = state;
994 void assure_irg_entity_usage_computed(ir_graph *irg) {
995 if (irg->entity_usage_state != ir_entity_usage_not_computed)
998 analyse_irg_entity_usage(irg);
1003 * Initialize the entity_usage flag for a global type like type.
1005 static void init_entity_usage(ir_type * tp) {
1008 /* We have to be conservative: All external visible entities are unknown */
1009 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1010 ir_entity *ent = get_compound_member(tp, i);
1011 ir_entity_usage flags = ir_usage_none;
1012 ir_visibility vis = get_entity_visibility(ent);
1014 if (vis == visibility_external_visible ||
1015 vis == visibility_external_allocated ||
1016 get_entity_stickyness(ent) == stickyness_sticky) {
1017 flags |= ir_usage_unknown;
1019 set_entity_usage(ent, flags);
1024 * Mark all entities used in the initializer as unknown usage.
1026 * @param initializer the initializer to check
1028 static void check_initializer_nodes(ir_initializer_t *initializer)
1033 switch (initializer->kind) {
1034 case IR_INITIALIZER_CONST:
1035 /* let's check if it's an address */
1036 n = initializer->consti.value;
1038 ir_entity *ent = get_Global_entity(n);
1039 set_entity_usage(ent, ir_usage_unknown);
1042 case IR_INITIALIZER_TARVAL:
1043 case IR_INITIALIZER_NULL:
1045 case IR_INITIALIZER_COMPOUND:
1046 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1047 ir_initializer_t *sub_initializer
1048 = initializer->compound.initializers[i];
1049 check_initializer_nodes(sub_initializer);
1053 panic("invalid initializer found");
1054 } /* check_initializer_nodes */
1057 * Mark all entities used in the initializer for the given entity as unknown
1060 * @param ent the entity
1062 static void check_initializer(ir_entity *ent) {
1066 /* do not check uninitialized values */
1067 if (get_entity_variability(ent) == variability_uninitialized)
1070 /* Beware: Methods are always initialized with "themself". This does not
1071 count as a taken address. */
1072 if (is_Method_type(get_entity_type(ent)))
1075 if (ent->has_initializer) {
1076 check_initializer_nodes(ent->attr.initializer);
1077 } else if (is_atomic_entity(ent)) {
1078 /* let's check if it's an address */
1079 n = get_atomic_ent_value(ent);
1081 ir_entity *ent = get_Global_entity(n);
1082 set_entity_usage(ent, ir_usage_unknown);
1085 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
1086 n = get_compound_ent_value(ent, i);
1088 /* let's check if it's an address */
1090 ir_entity *ent = get_Global_entity(n);
1091 set_entity_usage(ent, ir_usage_unknown);
1095 } /* check_initializer */
1099 * Mark all entities used in initializers as unknown usage.
1101 * @param tp a compound type
1103 static void check_initializers(ir_type *tp) {
1106 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1107 ir_entity *ent = get_compound_member(tp, i);
1109 check_initializer(ent);
1111 } /* check_initializers */
1113 #ifdef DEBUG_libfirm
1115 * Print the entity usage flags of all entities of a given type for debugging.
1117 * @param tp a compound type
1119 static void print_entity_usage_flags(ir_type *tp) {
1121 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1122 ir_entity *ent = get_compound_member(tp, i);
1123 ir_entity_usage flags = get_entity_usage(ent);
1127 ir_printf("%+F:", ent);
1128 if (flags & ir_usage_address_taken)
1129 printf(" address_taken");
1130 if (flags & ir_usage_read)
1132 if (flags & ir_usage_write)
1134 if (flags & ir_usage_reinterpret_cast)
1135 printf(" reinterp_cast");
1139 #endif /* DEBUG_libfirm */
1142 * Post-walker: check for global entity address
1144 static void check_global_address(ir_node *irn, void *env) {
1147 ir_entity_usage flags;
1149 if (is_Global(irn)) {
1151 ent = get_Global_entity(irn);
1152 } else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
1153 /* A TLS variable. */
1154 ent = get_Sel_entity(irn);
1158 flags = get_entity_usage(ent);
1159 flags |= determine_entity_usage(irn, ent);
1160 set_entity_usage(ent, flags);
1161 } /* check_global_address */
1164 * Update the entity usage flags of all global entities.
1166 static void analyse_irp_globals_entity_usage(void) {
1170 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1171 ir_type *type = get_segment_type(s);
1172 init_entity_usage(type);
1175 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1176 ir_type *type = get_segment_type(s);
1177 check_initializers(type);
1180 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1181 ir_graph *irg = get_irp_irg(i);
1183 assure_irg_outs(irg);
1184 irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
1187 #ifdef DEBUG_libfirm
1188 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1190 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1191 print_entity_usage_flags(get_segment_type(s));
1194 #endif /* DEBUG_libfirm */
1197 irp->globals_entity_usage_state = ir_entity_usage_computed;
1200 /* Returns the current address taken state of the globals. */
1201 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void) {
1202 return irp->globals_entity_usage_state;
1205 /* Sets the current address taken state of the graph. */
1206 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state) {
1207 irp->globals_entity_usage_state = state;
1210 /* Assure that the address taken flag is computed for the globals. */
1211 void assure_irp_globals_entity_usage_computed(void) {
1212 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1215 analyse_irp_globals_entity_usage();
1218 void firm_init_memory_disambiguator(void) {
1219 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1220 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1224 /** Maps method types to cloned method types. */
1225 static pmap *mtp_map;
1228 * Clone a method type if not already cloned.
1230 * @param tp the type to clone
1232 static ir_type *clone_type_and_cache(ir_type *tp) {
1233 static ident *prefix = NULL;
1235 pmap_entry *e = pmap_find(mtp_map, tp);
1241 prefix = new_id_from_chars("C", 1);
1243 res = clone_type_method(tp, prefix);
1244 pmap_insert(mtp_map, tp, res);
1245 DB((dbgcall, LEVEL_2, "cloned type %+F into %+F\n", tp, res));
1248 } /* clone_type_and_cache */
1251 * Walker: clone all call types of Calls to methods having the
1252 * mtp_property_private property set.
1254 static void update_calls_to_private(ir_node *call, void *env) {
1256 if (is_Call(call)) {
1257 ir_node *ptr = get_Call_ptr(call);
1259 if (is_SymConst(ptr)) {
1260 ir_entity *ent = get_SymConst_entity(ptr);
1261 ir_type *ctp = get_Call_type(call);
1263 if (get_entity_additional_properties(ent) & mtp_property_private) {
1264 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1265 ctp = clone_type_and_cache(ctp);
1266 set_method_additional_property(ctp, mtp_property_private);
1267 set_Call_type(call, ctp);
1268 DB((dbgcall, LEVEL_1, "changed call to private method %+F\n", ent));
1273 } /* update_calls_to_private */
1275 /* Mark all private methods, i.e. those of which all call sites are known. */
1276 void mark_private_methods(void) {
1280 assure_irp_globals_entity_usage_computed();
1282 mtp_map = pmap_create();
1284 /* first step: change the calling conventions of the local non-escaped entities */
1285 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1286 ir_graph *irg = get_irp_irg(i);
1287 ir_entity *ent = get_irg_entity(irg);
1288 ir_entity_usage flags = get_entity_usage(ent);
1290 /* If an entity is sticky, it might be called from external
1291 places (like inline assembler), so do NOT mark it as private. */
1292 if (get_entity_visibility(ent) == visibility_local &&
1293 !(flags & ir_usage_address_taken) &&
1294 get_entity_stickyness(ent) != stickyness_sticky) {
1295 ir_type *mtp = get_entity_type(ent);
1297 set_entity_additional_property(ent, mtp_property_private);
1298 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1299 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1300 /* need a new type */
1301 mtp = clone_type_and_cache(mtp);
1302 set_entity_type(ent, mtp);
1303 set_method_additional_property(mtp, mtp_property_private);
1310 all_irg_walk(NULL, update_calls_to_private, NULL);
1312 pmap_destroy(mtp_map);
1313 } /* mark_private_methods */