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, mod1, mod2;
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 mod1 = classify_pointer(irg, base1, ent1);
585 mod2 = classify_pointer(irg, base2, ent2);
587 class1 = GET_BASE_SC(mod1);
588 class2 = GET_BASE_SC(mod2);
590 if (class1 == ir_sc_pointer) {
591 if (mod2 & ir_sc_modifier_nottaken) {
592 /* a pointer and an object whose objects was never taken */
595 } else if (class2 == ir_sc_pointer) {
596 if (mod1 & ir_sc_modifier_nottaken) {
597 /* a pointer and an object whose objects was never taken */
600 } else if (class1 == ir_sc_argument) {
603 /* both arguments may be alias free if specified in the options */
604 if (options & aa_opt_no_alias_args) {
605 if (get_Proj_proj(base1) != get_Proj_proj(base2))
613 case ir_sc_globalvar:
615 case ir_sc_globaladdr:
616 /* if the address was never taken */
617 if (mod2 & ir_sc_modifier_nottaken)
619 /* or an argument and a global are alias free if specified */
620 if (options & aa_opt_no_alias_args_global)
624 /* two objects from different memory spaces */
627 } else if (class2 == ir_sc_argument) {
629 case ir_sc_globalvar:
631 case ir_sc_globaladdr:
632 /* if the address was never taken */
633 if (mod1 & ir_sc_modifier_nottaken)
635 /* or an argument and a global are alias free if specified */
636 if (options & aa_opt_no_alias_args_global)
640 /* two objects from different memory spaces */
643 } else if (class1 != class2) {
644 /* two objects from different memory spaces */
647 /* both classes are equal */
648 if (class1 == ir_sc_globalvar) {
649 ir_entity *entity1 = get_SymConst_entity(base1);
650 ir_entity *entity2 = get_SymConst_entity(base2);
651 if (entity1 != entity2)
654 /* for some reason CSE didn't happen yet for the 2 SymConsts... */
656 } else if (class1 == ir_sc_globaladdr) {
657 tarval *tv = get_Const_tarval(base1);
658 offset1 += get_tarval_long(tv);
659 tv = get_Const_tarval(base2);
660 offset2 += get_tarval_long(tv);
662 if ((unsigned long)labs(offset2 - offset1) >= mode_size)
665 return ir_sure_alias;
669 /* Type based alias analysis */
670 if (options & aa_opt_type_based) {
671 ir_alias_relation rel;
673 if (options & aa_opt_byte_type_may_alias) {
674 if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
675 /* One of the modes address a byte. Assume a ir_may_alias and leave
676 the type based check. */
677 goto leave_type_based_alias;
680 /* cheap check: If the mode sizes did not match, the types MUST be different */
681 if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
684 /* cheap test: if only one is a reference mode, no alias */
685 if (mode_is_reference(mode1) != mode_is_reference(mode2))
688 /* cheap test: if arithmetic is different, no alias */
689 if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
693 rel = different_types(orig_adr1, orig_adr2);
694 if (rel != ir_may_alias)
696 leave_type_based_alias:;
699 /* do we have a language specific memory disambiguator? */
700 if (language_disambuigator != NULL) {
701 ir_alias_relation rel = language_disambuigator(irg, orig_adr1, mode1, orig_adr2, mode2);
702 if (rel != ir_may_alias)
706 /* access points-to information here */
708 } /* _get_alias_relation */
711 * Determine the alias relation between two addresses.
713 ir_alias_relation get_alias_relation(
715 ir_node *adr1, ir_mode *mode1,
716 ir_node *adr2, ir_mode *mode2)
718 ir_alias_relation rel = _get_alias_relation(irg, adr1, mode1, adr2, mode2);
719 DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
721 } /* get_alias_relation */
723 /* Set a source language specific memory disambiguator function. */
724 void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func) {
725 language_disambuigator = func;
726 } /* set_language_memory_disambiguator */
728 /** The result cache for the memory disambiguator. */
729 static set *result_cache = NULL;
731 /** An entry in the relation cache. */
732 typedef struct mem_disambig_entry {
733 ir_node *adr1; /**< The first address. */
734 ir_node *adr2; /**< The second address. */
735 ir_alias_relation result; /**< The alias relation result. */
736 } mem_disambig_entry;
738 #define HASH_ENTRY(adr1, adr2) (HASH_PTR(adr1) ^ HASH_PTR(adr2))
741 * Compare two relation cache entries.
743 static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size) {
744 const mem_disambig_entry *p1 = elt;
745 const mem_disambig_entry *p2 = key;
748 return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2;
749 } /* cmp_mem_disambig_entry */
752 * Initialize the relation cache.
754 void mem_disambig_init(void) {
755 result_cache = new_set(cmp_mem_disambig_entry, 8);
756 } /* mem_disambig_init */
759 * Determine the alias relation between two addresses.
761 ir_alias_relation get_alias_relation_ex(
763 ir_node *adr1, ir_mode *mode1,
764 ir_node *adr2, ir_mode *mode2)
766 mem_disambig_entry key, *entry;
768 ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
770 if (! get_opt_alias_analysis())
773 if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
781 entry = set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
783 return entry->result;
785 key.result = get_alias_relation(irg, adr1, mode1, adr2, mode2);
787 set_insert(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
789 } /* get_alias_relation_ex */
791 /* Free the relation cache. */
792 void mem_disambig_term(void) {
793 if (result_cache != NULL) {
794 del_set(result_cache);
797 } /* mem_disambig_term */
800 * Check the mode of a Load/Store with the mode of the entity
802 * If the mode of the entity and the Load/Store mode do not match, we
803 * have the bad reinterpret case:
806 * char b = *(char *)&i;
808 * We do NOT count this as one value and return address_taken
810 * However, we support an often used case. If the mode is two-complement
811 * we allow casts between signed/unsigned.
813 * @param mode the mode of the Load/Store
814 * @param ent_mode the mode of the accessed entity
816 * @return non-zero if the Load/Store is a hidden cast, zero else
818 static int is_hidden_cast(ir_mode *mode, ir_mode *ent_mode) {
819 if (ent_mode == NULL)
822 if (ent_mode != mode) {
823 if (ent_mode == NULL ||
824 get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
825 get_mode_sort(ent_mode) != get_mode_sort(mode) ||
826 get_mode_arithmetic(ent_mode) != irma_twos_complement ||
827 get_mode_arithmetic(mode) != irma_twos_complement)
831 } /* is_hidden_cast */
834 * Determine the usage state of a node (or its successor Sels).
836 * @param irn the node
838 static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity) {
840 ir_mode *emode, *mode;
843 ir_entity_usage res = 0;
845 for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
846 ir_node *succ = get_irn_out(irn, i);
848 switch (get_irn_opcode(succ)) {
850 /* beware: irn might be a Id node here, so irn might be not
851 equal to get_Load_ptr(succ) */
852 res |= ir_usage_read;
854 /* check if this load is not a hidden conversion */
855 mode = get_Load_mode(succ);
856 emode = get_type_mode(get_entity_type(entity));
857 if (is_hidden_cast(mode, emode))
858 res |= ir_usage_reinterpret_cast;
862 /* check that the node is not the Store's value */
863 if (irn == get_Store_value(succ)) {
864 res |= ir_usage_unknown;
866 if (irn == get_Store_ptr(succ)) {
867 res |= ir_usage_write;
869 /* check if this Store is not a hidden conversion */
870 value = get_Store_value(succ);
871 mode = get_irn_mode(value);
872 emode = get_type_mode(get_entity_type(entity));
873 if (is_hidden_cast(mode, emode))
874 res |= ir_usage_reinterpret_cast;
876 assert(irn != get_Store_mem(succ));
880 /* CopyB are like Loads/Stores */
881 tp = get_entity_type(entity);
882 if (tp != get_CopyB_type(succ)) {
883 /* bad, different types, might be a hidden conversion */
884 res |= ir_usage_reinterpret_cast;
886 if (irn == get_CopyB_dst(succ)) {
887 res |= ir_usage_write;
889 assert(irn == get_CopyB_src(succ));
890 res |= ir_usage_read;
896 /* Check the successor of irn. */
897 res |= determine_entity_usage(succ, entity);
900 ir_entity *entity = get_Sel_entity(succ);
901 /* this analyis can't handle unions correctly */
902 if (is_Union_type(get_entity_owner(entity))) {
903 res |= ir_usage_unknown;
906 /* Check the successor of irn. */
907 res |= determine_entity_usage(succ, entity);
912 if (irn == get_Call_ptr(succ)) {
913 /* TODO: we could check for reinterpret casts here...
914 * But I doubt anyone is interested in that bit for
915 * function entities and I'm too lazy to write the code now.
917 res |= ir_usage_read;
919 assert(irn != get_Call_mem(succ));
920 res |= ir_usage_unknown;
924 /* skip identities */
926 res |= determine_entity_usage(succ, entity);
932 for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
934 ir_node *pred = get_Tuple_pred(succ, input_nr);
937 /* we found one input */
938 for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
939 ir_node *proj = get_irn_out(succ, k);
941 if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
942 res |= determine_entity_usage(proj, entity);
952 /* another op, we don't know anything (we could do more advanced
953 * things like a dataflow analysis here) */
954 res |= ir_usage_unknown;
963 * Update the usage flags of all frame entities.
965 static void analyse_irg_entity_usage(ir_graph *irg) {
966 ir_type *ft = get_irg_frame_type(irg);
968 int i, j, k, static_link_arg;
970 /* set initial state to not_taken, as this is the "smallest" state */
971 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
972 ir_entity *ent = get_class_member(ft, i);
974 /* methods can only be analyzed globally */
975 if (! is_method_entity(ent)) {
976 ir_entity_usage flags =
977 get_entity_stickyness(ent) == stickyness_sticky ? ir_usage_unknown : 0;
978 set_entity_usage(ent, flags);
982 assure_irg_outs(irg);
984 irg_frame = get_irg_frame(irg);
986 for (i = get_irn_n_outs(irg_frame) - 1; i >= 0; --i) {
987 ir_node *succ = get_irn_out(irg_frame, i);
989 ir_entity_usage flags;
994 entity = get_Sel_entity(succ);
995 flags = get_entity_usage(entity);
996 flags |= determine_entity_usage(succ, entity);
997 set_entity_usage(entity, flags);
1000 /* check inner functions accessing outer frame */
1001 static_link_arg = 0;
1002 for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
1003 ir_entity *ent = get_class_member(ft, i);
1004 ir_graph *inner_irg;
1007 if (! is_method_entity(ent))
1009 if (get_entity_peculiarity(ent) == peculiarity_description)
1012 inner_irg = get_entity_irg(ent);
1013 assure_irg_outs(inner_irg);
1014 args = get_irg_args(inner_irg);
1015 for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
1016 ir_node *arg = get_irn_out(args, j);
1018 if (get_Proj_proj(arg) == static_link_arg) {
1019 for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
1020 ir_node *succ = get_irn_out(arg, k);
1023 ir_entity *entity = get_Sel_entity(succ);
1025 if (get_entity_owner(entity) == ft) {
1026 /* found an access to the outer frame */
1027 ir_entity_usage flags;
1029 flags = get_entity_usage(entity);
1030 flags |= determine_entity_usage(succ, entity);
1031 set_entity_usage(entity, flags);
1041 irg->entity_usage_state = ir_entity_usage_computed;
1044 ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg) {
1045 return irg->entity_usage_state;
1048 void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state) {
1049 irg->entity_usage_state = state;
1052 void assure_irg_entity_usage_computed(ir_graph *irg) {
1053 if (irg->entity_usage_state != ir_entity_usage_not_computed)
1056 analyse_irg_entity_usage(irg);
1061 * Initialize the entity_usage flag for a global type like type.
1063 static void init_entity_usage(ir_type * tp) {
1066 /* We have to be conservative: All external visible entities are unknown */
1067 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1068 ir_entity *ent = get_compound_member(tp, i);
1069 ir_entity_usage flags = ir_usage_none;
1070 ir_visibility vis = get_entity_visibility(ent);
1072 if (vis == visibility_external_visible ||
1073 vis == visibility_external_allocated ||
1074 get_entity_stickyness(ent) == stickyness_sticky) {
1075 flags |= ir_usage_unknown;
1077 set_entity_usage(ent, flags);
1082 * Mark all entities used in the initializer as unknown usage.
1084 * @param initializer the initializer to check
1086 static void check_initializer_nodes(ir_initializer_t *initializer)
1091 switch (initializer->kind) {
1092 case IR_INITIALIZER_CONST:
1093 /* let's check if it's an address */
1094 n = initializer->consti.value;
1096 ir_entity *ent = get_Global_entity(n);
1097 set_entity_usage(ent, ir_usage_unknown);
1100 case IR_INITIALIZER_TARVAL:
1101 case IR_INITIALIZER_NULL:
1103 case IR_INITIALIZER_COMPOUND:
1104 for (i = 0; i < initializer->compound.n_initializers; ++i) {
1105 ir_initializer_t *sub_initializer
1106 = initializer->compound.initializers[i];
1107 check_initializer_nodes(sub_initializer);
1111 panic("invalid initializer found");
1112 } /* check_initializer_nodes */
1115 * Mark all entities used in the initializer for the given entity as unknown
1118 * @param ent the entity
1120 static void check_initializer(ir_entity *ent) {
1124 /* do not check uninitialized values */
1125 if (get_entity_variability(ent) == variability_uninitialized)
1128 /* Beware: Methods are always initialized with "themself". This does not
1129 count as a taken address. */
1130 if (is_Method_type(get_entity_type(ent)))
1133 if (ent->has_initializer) {
1134 check_initializer_nodes(ent->attr.initializer);
1135 } else if (is_atomic_entity(ent)) {
1136 /* let's check if it's an address */
1137 n = get_atomic_ent_value(ent);
1139 ir_entity *ent = get_Global_entity(n);
1140 set_entity_usage(ent, ir_usage_unknown);
1143 for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
1144 n = get_compound_ent_value(ent, i);
1146 /* let's check if it's an address */
1148 ir_entity *ent = get_Global_entity(n);
1149 set_entity_usage(ent, ir_usage_unknown);
1153 } /* check_initializer */
1157 * Mark all entities used in initializers as unknown usage.
1159 * @param tp a compound type
1161 static void check_initializers(ir_type *tp) {
1164 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1165 ir_entity *ent = get_compound_member(tp, i);
1167 check_initializer(ent);
1169 } /* check_initializers */
1171 #ifdef DEBUG_libfirm
1173 * Print the entity usage flags of all entities of a given type for debugging.
1175 * @param tp a compound type
1177 static void print_entity_usage_flags(ir_type *tp) {
1179 for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
1180 ir_entity *ent = get_compound_member(tp, i);
1181 ir_entity_usage flags = get_entity_usage(ent);
1185 ir_printf("%+F:", ent);
1186 if (flags & ir_usage_address_taken)
1187 printf(" address_taken");
1188 if (flags & ir_usage_read)
1190 if (flags & ir_usage_write)
1192 if (flags & ir_usage_reinterpret_cast)
1193 printf(" reinterp_cast");
1197 #endif /* DEBUG_libfirm */
1200 * Post-walker: check for global entity address
1202 static void check_global_address(ir_node *irn, void *env) {
1205 ir_entity_usage flags;
1207 if (is_Global(irn)) {
1209 ent = get_Global_entity(irn);
1210 } else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
1211 /* A TLS variable. */
1212 ent = get_Sel_entity(irn);
1216 flags = get_entity_usage(ent);
1217 flags |= determine_entity_usage(irn, ent);
1218 set_entity_usage(ent, flags);
1219 } /* check_global_address */
1222 * Update the entity usage flags of all global entities.
1224 static void analyse_irp_globals_entity_usage(void) {
1228 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1229 ir_type *type = get_segment_type(s);
1230 init_entity_usage(type);
1233 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1234 ir_type *type = get_segment_type(s);
1235 check_initializers(type);
1238 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1239 ir_graph *irg = get_irp_irg(i);
1241 assure_irg_outs(irg);
1242 irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
1245 #ifdef DEBUG_libfirm
1246 if (firm_dbg_get_mask(dbg) & LEVEL_1) {
1248 for (s = IR_SEGMENT_FIRST; s < IR_SEGMENT_COUNT; ++s) {
1249 print_entity_usage_flags(get_segment_type(s));
1252 #endif /* DEBUG_libfirm */
1255 irp->globals_entity_usage_state = ir_entity_usage_computed;
1258 /* Returns the current address taken state of the globals. */
1259 ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void) {
1260 return irp->globals_entity_usage_state;
1263 /* Sets the current address taken state of the graph. */
1264 void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state) {
1265 irp->globals_entity_usage_state = state;
1268 /* Assure that the address taken flag is computed for the globals. */
1269 void assure_irp_globals_entity_usage_computed(void) {
1270 if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
1273 analyse_irp_globals_entity_usage();
1276 void firm_init_memory_disambiguator(void) {
1277 FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
1278 FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
1282 /** Maps method types to cloned method types. */
1283 static pmap *mtp_map;
1286 * Clone a method type if not already cloned.
1288 * @param tp the type to clone
1290 static ir_type *clone_type_and_cache(ir_type *tp) {
1291 static ident *prefix = NULL;
1293 pmap_entry *e = pmap_find(mtp_map, tp);
1299 prefix = new_id_from_chars("C", 1);
1301 res = clone_type_method(tp, prefix);
1302 pmap_insert(mtp_map, tp, res);
1303 DB((dbgcall, LEVEL_2, "cloned type %+F into %+F\n", tp, res));
1306 } /* clone_type_and_cache */
1309 * Walker: clone all call types of Calls to methods having the
1310 * mtp_property_private property set.
1312 static void update_calls_to_private(ir_node *call, void *env) {
1314 if (is_Call(call)) {
1315 ir_node *ptr = get_Call_ptr(call);
1317 if (is_SymConst(ptr)) {
1318 ir_entity *ent = get_SymConst_entity(ptr);
1319 ir_type *ctp = get_Call_type(call);
1321 if (get_entity_additional_properties(ent) & mtp_property_private) {
1322 if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
1323 ctp = clone_type_and_cache(ctp);
1324 set_method_additional_property(ctp, mtp_property_private);
1325 set_Call_type(call, ctp);
1326 DB((dbgcall, LEVEL_1, "changed call to private method %+F\n", ent));
1331 } /* update_calls_to_private */
1333 /* Mark all private methods, i.e. those of which all call sites are known. */
1334 void mark_private_methods(void) {
1338 assure_irp_globals_entity_usage_computed();
1340 mtp_map = pmap_create();
1342 /* first step: change the calling conventions of the local non-escaped entities */
1343 for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
1344 ir_graph *irg = get_irp_irg(i);
1345 ir_entity *ent = get_irg_entity(irg);
1346 ir_entity_usage flags = get_entity_usage(ent);
1348 /* If an entity is sticky, it might be called from external
1349 places (like inline assembler), so do NOT mark it as private. */
1350 if (get_entity_visibility(ent) == visibility_local &&
1351 !(flags & ir_usage_address_taken) &&
1352 get_entity_stickyness(ent) != stickyness_sticky) {
1353 ir_type *mtp = get_entity_type(ent);
1355 set_entity_additional_property(ent, mtp_property_private);
1356 DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
1357 if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
1358 /* need a new type */
1359 mtp = clone_type_and_cache(mtp);
1360 set_entity_type(ent, mtp);
1361 set_method_additional_property(mtp, mtp_property_private);
1368 all_irg_walk(NULL, update_calls_to_private, NULL);
1370 pmap_destroy(mtp_map);
1371 } /* mark_private_methods */