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
36 #include "irgraph_t.h"
38 #include "irmemory_t.h"
50 /** The debug handle. */
51 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
52 DEBUG_ONLY(static firm_dbg_module_t *dbgcall = NULL;)
54 /** The source language specific language disambiguator function. */
55 static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
57 /** The global memory disambiguator options. */
58 static unsigned global_mem_disamgig_opt = aa_opt_no_opt;
60 /* Returns a human readable name for an alias relation. */
61 const char *get_ir_alias_relation_name(ir_alias_relation rel) {
62 #define X(a) case a: return #a
67 default: assert(0); return "UNKNOWN";
72 /* Get the memory disambiguator options for a graph. */
73 unsigned get_irg_memory_disambiguator_options(ir_graph *irg) {
74 unsigned opt = irg->mem_disambig_opt;
75 if (opt & aa_opt_inherited)
76 return global_mem_disamgig_opt;
78 } /* get_irg_memory_disambiguator_options */
80 /* Set the memory disambiguator options for a graph. */
81 void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options) {
82 irg->mem_disambig_opt = options & ~aa_opt_inherited;
83 } /* set_irg_memory_disambiguator_options */
85 /* Set the global disambiguator options for all graphs not having local options. */
86 void set_irp_memory_disambiguator_options(unsigned options) {
87 global_mem_disamgig_opt = options;
88 } /* set_irp_memory_disambiguator_options */
91 * Find the base address and entity of an Sel node.
94 * @param pEnt after return points to the base entity.
96 * @return the base address.
98 static ir_node *find_base_adr(ir_node *sel, ir_entity **pEnt) {
99 ir_node *ptr = get_Sel_ptr(sel);
101 while (is_Sel(ptr)) {
103 ptr = get_Sel_ptr(sel);
105 *pEnt = get_Sel_entity(sel);
107 } /* find_base_adr */
110 * Check if a given Const node is greater or equal a given size.
112 * @param cns a Const node
113 * @param size a integer size
115 * @return ir_no_alias if the Const is greater, ir_may_alias else
117 static ir_alias_relation check_const(ir_node *cns, int size) {
118 tarval *tv = get_Const_tarval(cns);
122 return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
123 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
124 return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
128 * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
130 * @param idx1 a node representing the first index
131 * @param idx2 a node representing the second index
132 * @param size an integer size
134 * @return ir_sure_alias iff idx1 == idx2
135 * ir_no_alias iff they ALWAYS differ more than size
138 static ir_alias_relation different_index(ir_node *idx1, ir_node *idx2, int size) {
140 return ir_sure_alias;
141 if (is_Const(idx1) && is_Const(idx2)) {
142 /* both are const, we can compare them */
143 tarval *tv1 = get_Const_tarval(idx1);
144 tarval *tv2 = get_Const_tarval(idx2);
145 tarval *tv, *tv_size;
149 return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
151 /* arg, modes may be different */
152 m1 = get_tarval_mode(tv1);
153 m2 = get_tarval_mode(tv2);
155 int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
158 /* m1 is a small mode, cast up */
159 m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
161 /* should NOT happen, but if it does we give up here */
164 tv1 = tarval_convert_to(tv1, m1);
165 } else if (size > 0) {
166 /* m2 is a small mode, cast up */
167 m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
169 /* should NOT happen, but if it does we give up here */
172 tv2 = tarval_convert_to(tv2, m2);
174 /* here the size should be identical, check for signed */
175 if (get_mode_sign(m1) != get_mode_sign(m2)) {
176 /* find the signed */
177 if (mode_is_signed(m2)) {
184 /* m1 is now the signed one */
185 if (tarval_cmp(tv1, get_tarval_null(m1)) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
186 /* tv1 is signed, but >= 0, simply cast into unsigned */
187 tv1 = tarval_convert_to(tv1, m2);
189 tv_size = new_tarval_from_long(size, m2);
191 if (tarval_cmp(tv2, tv_size) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
192 /* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
195 /* tv_size > tv2, so we can subtract without overflow */
196 tv2 = tarval_sub(tv_size, tv2, NULL);
198 /* tv1 is < 0, so we can negate it */
199 tv1 = tarval_neg(tv1);
201 /* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
202 tv1 = tarval_convert_to(tv1, m2);
204 /* now we can compare without overflow */
205 return tarval_cmp(tv1, tv2) & (pn_Cmp_Eq|pn_Cmp_Gt) ? ir_no_alias : ir_may_alias;
209 if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) {
214 /* tv1 is now the "smaller" one */
215 tv = tarval_sub(tv2, tv1, NULL);
216 tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
217 return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
220 /* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
222 ir_node *l1 = get_Add_left(idx1);
223 ir_node *r1 = get_Add_right(idx1);
228 return check_const(r1, size);
231 /* both are Adds, check if they are of x + a == x + b kind */
232 ir_node *l2 = get_Add_left(idx2);
233 ir_node *r2 = get_Add_right(idx2);
236 return different_index(r1, r2, size);
238 return different_index(r1, l2, size);
240 return different_index(l1, l2, size);
242 return different_index(l1, r2, size);
246 ir_node *l2 = get_Add_left(idx2);
247 ir_node *r2 = get_Add_right(idx2);
252 return check_const(r2, size);
257 ir_node *l1 = get_Sub_left(idx1);
258 ir_node *r1 = get_Sub_right(idx1);
263 return check_const(r1, size);
267 /* both are Subs, check if they are of x - a == x - b kind */
268 ir_node *l2 = get_Sub_left(idx2);
271 ir_node *r2 = get_Sub_right(idx2);
272 return different_index(r1, r2, size);
277 ir_node *l2 = get_Sub_left(idx2);
278 ir_node *r2 = get_Sub_right(idx2);
283 return check_const(r2, size);
288 } /* different_index */
291 * Two Sel addresses have the same base address, check if there offsets are
294 * @param adr1 The first address.
295 * @param adr2 The second address.
297 static ir_alias_relation different_sel_offsets(ir_node *sel1, ir_node *sel2) {
298 /* seems to be broken */
302 ir_entity *ent1 = get_Sel_entity(sel1);
303 ir_entity *ent2 = get_Sel_entity(sel2);
304 int i, check_arr = 0;
309 ir_type *tp1 = get_entity_type(ent1);
310 ir_type *tp2 = get_entity_type(ent2);
314 else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
315 get_type_size_bits(tp1) == get_type_size_bits(tp2))
319 /* we select an entity of same size, check for indexes */
320 int n = get_Sel_n_indexs(sel1);
323 if (n > 0 && n == get_Sel_n_indexs(sel2)) {
324 /* same non-zero number of indexes, an array access, check */
325 for (i = 0; i < n; ++i) {
326 ir_node *idx1 = get_Sel_index(sel1, i);
327 ir_node *idx2 = get_Sel_index(sel2, i);
328 ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
330 if (res == may_alias)
332 else if (res == no_alias)
335 /* if we have at least one no_alias, there is no alias relation, else we have sure */
336 return have_no > 0 ? no_alias : sure_alias;
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;
449 * If adr represents a Bitfield Sel, skip it
451 static ir_node *skip_Bitfield_Sels(ir_node *adr) {
453 ir_entity *ent = get_Sel_entity(adr);
454 ir_type *bf_type = get_entity_type(ent);
456 /* is it a bitfield type? */
457 if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
458 adr = get_Sel_ptr(adr);
464 * Determine the alias relation between two addresses.
466 * @param irg the graph of both memory operations
467 * @param addr1 pointer address of the first memory operation
468 * @param mode1 the mode of the accessed data through addr1
469 * @param addr2 pointer address of the second memory operation
470 * @param mode2 the mode of the accessed data through addr2
472 * @return found memory relation
474 static ir_alias_relation _get_alias_relation(
476 ir_node *adr1, ir_mode *mode1,
477 ir_node *adr2, ir_mode *mode2)
479 ir_entity *ent1, *ent2;
485 ir_node *orig_adr1 = adr1;
486 ir_node *orig_adr2 = adr2;
488 ir_storage_class_class_t class1, class2;
489 int have_const_offsets;
491 if (! get_opt_alias_analysis())
495 return ir_sure_alias;
497 options = get_irg_memory_disambiguator_options(irg);
499 /* The Armageddon switch */
500 if (options & aa_opt_no_alias)
503 /* do the addresses have constants offsets?
504 * Note: nodes are normalized to have constants at right inputs,
505 * sub X, C is normalized to add X, -C
507 have_const_offsets = 1;
508 while (is_Add(adr1)) {
509 ir_node *add_right = get_Add_right(adr1);
510 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
511 tarval *tv = get_Const_tarval(add_right);
512 offset1 += get_tarval_long(tv);
513 adr1 = get_Add_left(adr1);
514 } else if (mode_is_reference(get_irn_mode(add_right))) {
516 have_const_offsets = 0;
518 adr1 = get_Add_left(adr1);
519 have_const_offsets = 0;
522 while (is_Add(adr2)) {
523 ir_node *add_right = get_Add_right(adr2);
524 if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
525 tarval *tv = get_Const_tarval(add_right);
526 offset2 += get_tarval_long(tv);
527 adr2 = get_Add_left(adr2);
528 } else if (mode_is_reference(get_irn_mode(add_right))) {
530 have_const_offsets = 0;
532 adr2 = get_Add_left(adr2);
533 have_const_offsets = 0;
537 mode_size = get_mode_size_bytes(mode1);
538 if (get_mode_size_bytes(mode2) > mode_size) {
539 mode_size = get_mode_size_bytes(mode2);
542 /* same base address -> compare offsets if possible.
543 * FIXME: type long is not sufficient for this task ...
545 if (adr1 == adr2 && have_const_offsets) {
546 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
549 return ir_sure_alias;
553 * Bitfields can be constructed as Sels from its base address.
554 * As they have different entities, the disambiguator would find that they are
555 * alias free. While this is true for it's values, it is false for the addresses
556 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
557 * So, skip those bitfield selecting Sel's.
559 adr1 = skip_Bitfield_Sels(adr1);
560 adr2 = skip_Bitfield_Sels(adr2);
568 base1 = find_base_adr(adr1, &ent1);
571 base2 = find_base_adr(adr2, &ent2);
574 /* same base address -> compare Sel entities */
575 if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
578 else if (have_const_offsets)
579 return different_sel_offsets(adr1, adr2);
582 class1 = classify_pointer(irg, base1, ent1);
583 class2 = classify_pointer(irg, base2, ent2);
585 if (class1 == ir_sc_pointer) {
586 if (class2 & ir_sc_modifier_nottaken) {
587 /* a pointer and an object whose objects was never taken */
590 } else if (class2 == ir_sc_pointer) {
591 if (class1 & ir_sc_modifier_nottaken) {
592 /* a pointer and an object whose objects was never taken */
595 } else if (class1 != class2) {
596 /* two objects from different memory spaces */
599 /* both classes are equal */
600 if (class1 == ir_sc_globalvar) {
601 ir_entity *entity1 = get_SymConst_entity(base1);
602 ir_entity *entity2 = get_SymConst_entity(base2);
603 if (entity1 != entity2)
606 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
611 /* Type based alias analysis */
612 if (options & aa_opt_type_based) {
613 ir_alias_relation rel;
615 if (options & aa_opt_byte_type_may_alias) {
616 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
617 /* One of the modes address a byte. Assume a ir_may_alias and leave
618 the type based check. */
619 goto leave_type_based_alias;
622 /* cheap check: If the mode sizes did not match, the types MUST be different */
623 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
626 /* cheap test: if only one is a reference mode, no alias */
627 if (mode_is_reference(mode1) != mode_is_reference(mode2))
630 /* cheap test: if arithmetic is different, no alias */
631 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
635 rel = different_types(orig_adr1, orig_adr2);
636 if (rel != ir_may_alias)
638 leave_type_based_alias:;
641 /* do we have a language specific memory disambiguator? */
642 if (language_disambuigator) {
643 ir_alias_relation rel = (*language_disambuigator)(irg, orig_adr1, mode1, orig_adr2, mode2);
644 if (rel != ir_may_alias)
648 /* access points-to information here */
650 } /* _get_alias_relation */
653 * Determine the alias relation between two addresses.
655 ir_alias_relation get_alias_relation(
657 ir_node *adr1, ir_mode *mode1,
658 ir_node *adr2, ir_mode *mode2)
660 ir_alias_relation rel = _get_alias_relation(irg, adr1, mode1, adr2, mode2);
661 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
663 } /* get_alias_relation */
665 /* Set a source language specific memory disambiguator function. */
666 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func) {
667 language_disambuigator = func;
668 } /* set_language_memory_disambiguator */
670 /** The result cache for the memory disambiguator. */
671 static set *result_cache = NULL;
673 /** An entry in the relation cache. */
674 typedef struct mem_disambig_entry {
675 ir_node *adr1; /**< The first address. */
676 ir_node *adr2; /**< The second address. */
677 ir_alias_relation result; /**< The alias relation result. */
678 } mem_disambig_entry;
680 #define HASH_ENTRY(adr1, adr2) (HASH_PTR(adr1) ^ HASH_PTR(adr2))
683 * Compare two relation cache entries.
685 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size) {
686 const mem_disambig_entry *p1 = elt;
687 const mem_disambig_entry *p2 = key;
690 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2;
691 } /* cmp_mem_disambig_entry */
694 * Initialize the relation cache.
696 void mem_disambig_init(void) {
697 result_cache = new_set(cmp_mem_disambig_entry, 8);
698 } /* mem_disambig_init */
701 * Determine the alias relation between two addresses.
703 ir_alias_relation get_alias_relation_ex(
705 ir_node *adr1, ir_mode *mode1,
706 ir_node *adr2, ir_mode *mode2)
708 mem_disambig_entry key, *entry;
710 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
712 if (! get_opt_alias_analysis())
715 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
723 entry = set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
725 return entry->result;
727 key.result = get_alias_relation(irg, adr1, mode1, adr2, mode2);
729 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
731 } /* get_alias_relation_ex */
733 /* Free the relation cache. */
734 void mem_disambig_term(void) {
736 del_set(result_cache);
739 } /* mem_disambig_term */
742 * Check the mode of a Load/Store with the mode of the entity
744 * If the mode of the entity and the Load/Store mode do not match, we
745 * have the bad reinterpret case:
748 * char b = *(char *)&i;
750 * We do NOT count this as one value and return address_taken
752 * However, we support an often used case. If the mode is two-complement
753 * we allow casts between signed/unsigned.
755 * @param mode the mode of the Load/Store
756 * @param ent_mode the mode of the accessed entity
758 * @return non-zero if the Load/Store is a hidden cast, zero else
760 static int is_hidden_cast(ir_mode *mode, ir_mode *ent_mode) {
761 if (ent_mode == NULL)
764 if (ent_mode != mode) {
765 if (ent_mode == NULL ||
766 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
767 get_mode_sort(ent_mode) != get_mode_sort(mode) ||
768 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
769 get_mode_arithmetic(mode) != irma_twos_complement)
773 } /* is_hidden_cast */
776 * Determine the usage state of a node (or its successor Sels).
778 * @param irn the node
780 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity) {
782 ir_mode *emode, *mode;
785 ir_entity_usage res = 0;
787 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
788 ir_node *succ = get_irn_out(irn, i);
790 switch (get_irn_opcode(succ)) {
792 assert(irn == get_Load_ptr(succ));
793 res |= ir_usage_read;
795 /* check if this load is not a hidden conversion */
796 mode = get_Load_mode(succ);
797 emode = get_type_mode(get_entity_type(entity));
798 if (is_hidden_cast(mode, emode))
799 res |= ir_usage_reinterpret_cast;
803 /* check that the node is not the Store's value */
804 if (irn == get_Store_value(succ)) {
805 res |= ir_usage_unknown;
807 if (irn == get_Store_ptr(succ)) {
808 res |= ir_usage_write;
810 /* check if this Store is not a hidden conversion */
811 value = get_Store_value(succ);
812 mode = get_irn_mode(value);
813 emode = get_type_mode(get_entity_type(entity));
814 if (is_hidden_cast(mode, emode))
815 res |= ir_usage_reinterpret_cast;
817 assert(irn != get_Store_mem(succ));
821 /* CopyB are like Loads/Stores */
822 tp = get_entity_type(entity);
823 if (tp != get_CopyB_type(succ)) {
824 /* bad, different types, might be a hidden conversion */
825 res |= ir_usage_reinterpret_cast;
827 if (irn == get_CopyB_dst(succ)) {
828 res |= ir_usage_write;
830 assert(irn == get_CopyB_src(succ));
831 res |= ir_usage_read;
838 /* Check the successor of irn. */
839 res |= determine_entity_usage(succ, entity);
844 if (irn == get_Call_ptr(succ)) {
845 /* TODO: we could check for reinterpret casts here...
846 * But I doubt anyone is interested in that bit for
847 * function entities and I'm too lazy to write the code now.
849 res |= ir_usage_read;
851 assert(irn != get_Call_mem(succ));
852 res |= ir_usage_unknown;
856 /* skip identities */
858 res |= determine_entity_usage(succ, entity);
864 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
866 ir_node *pred = get_Tuple_pred(succ, input_nr);
869 /* we found one input */
870 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
871 ir_node *proj = get_irn_out(succ, k);
873 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
874 res |= determine_entity_usage(proj, entity);
884 /* another op, we don't know anything (we could do more advanced
885 * things like a dataflow analysis here) */
886 res |= ir_usage_unknown;
895 * Update the usage flags of all frame entities.
897 static void analyse_irg_entity_usage(ir_graph *irg) {
898 ir_type *ft = get_irg_frame_type(irg);
902 /* set initial state to not_taken, as this is the "smallest" state */
903 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
904 ir_entity *ent = get_class_member(ft, i);
905 ir_entity_usage flags =
906 get_entity_stickyness(ent) == stickyness_sticky ? ir_usage_unknown : 0;
908 set_entity_usage(ent, flags);
911 assure_irg_outs(irg);
913 irg_frame = get_irg_frame(irg);
915 for (i = get_irn_n_outs(irg_frame) - 1; i >= 0; --i) {
916 ir_node *succ = get_irn_out(irg_frame, i);
918 ir_entity_usage flags;
923 entity = get_Sel_entity(succ);
924 flags = get_entity_usage(entity);
925 flags |= determine_entity_usage(succ, entity);
926 set_entity_usage(entity, flags);
930 irg->entity_usage_state = ir_entity_usage_computed;
933 ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg) {
934 return irg->entity_usage_state;
937 void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state) {
938 irg->entity_usage_state = state;
941 void assure_irg_entity_usage_computed(ir_graph *irg) {
942 if (irg->entity_usage_state != ir_entity_usage_not_computed)
945 analyse_irg_entity_usage(irg);
950 * Initialize the entity_usage flag for a global type like type.
952 static void init_entity_usage(ir_type * tp) {
955 /* We have to be conservative: All external visible entities are unknown */
956 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
957 ir_entity *ent = get_compound_member(tp, i);
958 ir_entity_usage flags = ir_usage_none;
959 ir_visibility vis = get_entity_visibility(ent);
961 if (vis == visibility_external_visible ||
962 vis == visibility_external_allocated ||
963 get_entity_stickyness(ent) == stickyness_sticky) {
964 flags |= ir_usage_unknown;
966 set_entity_usage(ent, flags);
971 * Mark all entities used in the initializer as unknown usage.
973 * @param initializer the initializer to check
975 static void check_initializer_nodes(ir_initializer_t *initializer)
980 switch (initializer->kind) {
981 case IR_INITIALIZER_CONST:
982 /* let's check if it's an address */
983 n = initializer->consti.value;
985 ir_entity *ent = get_Global_entity(n);
986 set_entity_usage(ent, ir_usage_unknown);
989 case IR_INITIALIZER_TARVAL:
990 case IR_INITIALIZER_NULL:
992 case IR_INITIALIZER_COMPOUND:
993 for (i = 0; i < initializer->compound.n_initializers; ++i) {
994 ir_initializer_t *sub_initializer
995 = initializer->compound.initializers[i];
996 check_initializer_nodes(sub_initializer);
1000 panic("invalid initializer found");
1001 } /* check_initializer_nodes */
1004 * Mark all entities used in the initializer for the given entity as unknown
1007 * @param ent the entity
1009 static void check_initializer(ir_entity *ent) {
1013 /* do not check uninitialized values */
1014 if (get_entity_variability(ent) == variability_uninitialized)
1017 /* Beware: Methods are always initialized with "themself". This does not
1018 count as a taken address. */
1019 if (is_Method_type(get_entity_type(ent)))
1022 if (ent->has_initializer) {
1023 check_initializer_nodes(ent->attr.initializer);
1024 } else if (is_atomic_entity(ent)) {
1025 /* let's check if it's an address */
1026 n = get_atomic_ent_value(ent);
1028 ir_entity *ent = get_Global_entity(n);
1029 set_entity_usage(ent, ir_usage_unknown);
1032 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
1033 n = get_compound_ent_value(ent, i);
1035 /* let's check if it's an address */
1037 ir_entity *ent = get_Global_entity(n);
1038 set_entity_usage(ent, ir_usage_unknown);
1042 } /* check_initializer */
1046 * Mark all entities used in initializers as unknown usage.
1048 * @param tp a compound type
1050 static void check_initializers(ir_type *tp) {
1053 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1054 ir_entity *ent = get_compound_member(tp, i);
1056 check_initializer(ent);
1058 } /* check_initializers */
1060 #ifdef DEBUG_libfirm
1062 * Print the entity usage flags of all entities of a given type for debugging.
1064 * @param tp a compound type
1066 static void print_entity_usage_flags(ir_type *tp) {
1068 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1069 ir_entity *ent = get_compound_member(tp, i);
1070 ir_entity_usage flags = get_entity_usage(ent);
1074 ir_printf("%+F:", ent);
1075 if (flags & ir_usage_address_taken)
1076 printf(" address_taken");
1077 if (flags & ir_usage_read)
1079 if (flags & ir_usage_write)
1081 if (flags & ir_usage_reinterpret_cast)
1082 printf(" reinterp_cast");
1086 #endif /* DEBUG_libfirm */
1089 * Post-walker: check for global entity address
1091 static void check_global_address(ir_node *irn, void *env) {
1094 ir_entity_usage flags;
1096 if (is_Global(irn)) {
1098 ent = get_Global_entity(irn);
1099 } else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
1100 /* A TLS variable. */
1101 ent = get_Sel_entity(irn);
1105 flags = get_entity_usage(ent);
1106 flags |= determine_entity_usage(irn, ent);
1107 set_entity_usage(ent, flags);
1108 } /* check_global_address */
1111 * Update the entity usage flags of all global entities.
1113 static void analyse_irp_globals_entity_usage(void) {
1117 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1118 ir_type *type = get_segment_type(s);
1119 init_entity_usage(type);
1122 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1123 ir_type *type = get_segment_type(s);
1124 check_initializers(type);
1127 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1128 ir_graph *irg = get_irp_irg(i);
1130 assure_irg_outs(irg);
1131 irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
1134 #ifdef DEBUG_libfirm
1135 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1137 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1138 print_entity_usage_flags(get_segment_type(s));
1141 #endif /* DEBUG_libfirm */
1144 irp->globals_entity_usage_state = ir_entity_usage_computed;
1147 /* Returns the current address taken state of the globals. */
1148 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void) {
1149 return irp->globals_entity_usage_state;
1152 /* Sets the current address taken state of the graph. */
1153 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state) {
1154 irp->globals_entity_usage_state = state;
1157 /* Assure that the address taken flag is computed for the globals. */
1158 void assure_irp_globals_entity_usage_computed(void) {
1159 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1162 analyse_irp_globals_entity_usage();
1165 void firm_init_memory_disambiguator(void) {
1166 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1167 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1171 /** Maps method types to cloned method types. */
1172 static pmap *mtp_map;
1175 * Clone a method type if not already cloned.
1177 * @param tp the type to clone
1179 static ir_type *clone_type_and_cache(ir_type *tp) {
1180 static ident *prefix = NULL;
1182 pmap_entry *e = pmap_find(mtp_map, tp);
1188 prefix = new_id_from_chars("C", 1);
1190 res = clone_type_method(tp, prefix);
1191 pmap_insert(mtp_map, tp, res);
1192 DB((dbgcall, LEVEL_2, "cloned type %+F into %+F\n", tp, res));
1195 } /* clone_type_and_cache */
1198 * Walker: clone all call types of Calls to methods having the
1199 * mtp_property_private property set.
1201 static void update_calls_to_private(ir_node *call, void *env) {
1203 if (is_Call(call)) {
1204 ir_node *ptr = get_Call_ptr(call);
1206 if (is_SymConst(ptr)) {
1207 ir_entity *ent = get_SymConst_entity(ptr);
1208 ir_type *ctp = get_Call_type(call);
1210 if (get_entity_additional_properties(ent) & mtp_property_private) {
1211 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1212 ctp = clone_type_and_cache(ctp);
1213 set_method_additional_property(ctp, mtp_property_private);
1214 set_Call_type(call, ctp);
1215 DB((dbgcall, LEVEL_1, "changed call to private method %+F\n", ent));
1220 } /* update_calls_to_private */
1222 /* Mark all private methods, i.e. those of which all call sites are known. */
1223 void mark_private_methods(void) {
1227 assure_irp_globals_entity_usage_computed();
1229 mtp_map = pmap_create();
1231 /* first step: change the calling conventions of the local non-escaped entities */
1232 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1233 ir_graph *irg = get_irp_irg(i);
1234 ir_entity *ent = get_irg_entity(irg);
1235 ir_entity_usage flags = get_entity_usage(ent);
1237 /* If an entity is sticky, it might be called from external
1238 places (like inline assembler), so do NOT mark it as private. */
1239 if (get_entity_visibility(ent) == visibility_local &&
1240 !(flags & ir_usage_address_taken) &&
1241 get_entity_stickyness(ent) != stickyness_sticky) {
1242 ir_type *mtp = get_entity_type(ent);
1244 set_entity_additional_property(ent, mtp_property_private);
1245 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1246 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1247 /* need a new type */
1248 mtp = clone_type_and_cache(mtp);
1249 set_entity_type(ent, mtp);
1250 set_method_additional_property(mtp, mtp_property_private);
1257 all_irg_walk(NULL, update_calls_to_private, NULL);
1259 pmap_destroy(mtp_map);
1260 } /* mark_private_methods */