return may_alias;
} /* different_types */
-/**
- * Check if an offset is a constant and these constant is bigger or equal
- * than a given size.
- */
-static int check_const_offset(ir_node *offset, int size) {
- ir_mode *mode = get_irn_mode(offset);
-
- /* ok, we found an offset, check for constant */
- if (is_Const(offset) && mode_is_int(mode)) {
- tarval *tv = new_tarval_from_long(size, mode);
-
- /* size <= offset ? */
- if (tarval_cmp(tv, get_Const_tarval(offset)) & (pn_Cmp_Eq|pn_Cmp_Lt))
- return 1;
- }
- return 0;
-} /* check_const_offset */
-
-/**
- * Check if we can determine that the two pointers always have an offset bigger
- * than size.
- */
-static ir_alias_relation _different_pointer(ir_node *adr1, ir_node *adr2, int size) {
- int found = 0;
-
- if (is_Add(adr1)) {
- /* first address is the result of a pointer addition */
- ir_node *l1 = get_Add_left(adr1);
- ir_node *r1 = get_Add_right(adr1);
-
- if (l1 == adr2) {
- found = check_const_offset(r1, size);
- } else if (r1 == adr2) {
- found = check_const_offset(l1, size);
- } else if (is_Add(adr2)) {
- /* second address is the result of a pointer addition */
- ir_node *l2 = get_Add_left(adr2);
- ir_node *r2 = get_Add_right(adr2);
-
- if (l1 == l2) {
- return _different_pointer(r1, r2, size);
- } else if (l1 == r2) {
- return _different_pointer(r1, l2, size);
- } else if (r1 == l2) {
- return _different_pointer(l1, r2, size);
- } else if (r1 == r2) {
- return _different_pointer(l1, l2, size);
- }
- }
- } else if (is_Add(adr2)) {
- /* second address is the result of a pointer addition */
- ir_node *l2 = get_Add_left(adr2);
- ir_node *r2 = get_Add_right(adr2);
-
- if (l2 == adr1) {
- found = check_const_offset(r2, size);
- } else if (r2 == adr1) {
- found = check_const_offset(l2, size);
- }
- } else {
- return different_index(adr1, adr2, size);
- }
- return found ? no_alias : may_alias;
-} /* _different_pointer */
-
-/**
- * Check if we can determine that the two pointers always have an offset bigger
- * then the maximum size of mode1, mode2
- */
-static ir_alias_relation different_pointer(ir_node *adr1, ir_mode *mode1, ir_node *adr2, ir_mode *mode2) {
- int size = get_mode_size_bytes(mode1);
- int n = get_mode_size_bytes(mode2);
-
- if (n > size)
- size = n;
- return _different_pointer(adr1, adr2, size);
-} /* different_pointer */
-
/**
* Returns non-zero if a node is a routine parameter.
*
* @param node the Proj node to test
*/
static int is_arg_Proj(ir_node *node) {
+ if (! is_Proj(node))
+ return 0;
node = get_Proj_pred(node);
if (! is_Proj(node))
return 0;
return is_SymConst_addr_ent(irn);
} /* is_global_var */
+/**
+ * classify storage locations.
+ * Except STORAGE_CLASS_POINTER they are all disjoint.
+ * STORAGE_CLASS_POINTER potentially aliases all classes which don't have a
+ * NOTTAKEN modifier.
+ */
+typedef enum {
+ STORAGE_CLASS_POINTER = 0x0000,
+ STORAGE_CLASS_GLOBALVAR = 0x0001,
+ STORAGE_CLASS_LOCALVAR = 0x0002,
+ STORAGE_CLASS_ARGUMENT = 0x0003,
+ STORAGE_CLASS_TLS = 0x0004,
+ STORAGE_CLASS_MALLOCED = 0x0005,
+
+ STORAGE_CLASS_MODIFIER_NOTTAKEN = 0x1000,
+} storage_class_class_t;
+
+static storage_class_class_t classify_pointer(ir_graph *irg, ir_node *irn)
+{
+ if(is_SymConst_addr_ent(irn)) {
+ ir_entity *entity = get_SymConst_entity(irn);
+ storage_class_class_t res = STORAGE_CLASS_GLOBALVAR;
+ if (get_entity_address_taken(entity) == ir_address_not_taken) {
+ res |= STORAGE_CLASS_MODIFIER_NOTTAKEN;
+ }
+ return res;
+ } else if(irn == get_irg_frame(irg)) {
+ /* TODO: we already skipped sels so we can't determine address_taken */
+ return STORAGE_CLASS_LOCALVAR;
+ } else if(is_arg_Proj(irn)) {
+ return STORAGE_CLASS_ARGUMENT;
+ } else if(irn == get_irg_tls(irg)) {
+ /* TODO: we already skipped sels so we can't determine address_taken */
+ return STORAGE_CLASS_TLS;
+ } else if (is_Proj(irn) && is_malloc_Result(irn)) {
+ return STORAGE_CLASS_MALLOCED;
+ }
+
+ return STORAGE_CLASS_POINTER;
+}
+
/**
* Determine the alias relation between two addresses.
*/
ir_node *adr1, ir_mode *mode1,
ir_node *adr2, ir_mode *mode2)
{
- ir_opcode op1, op2;
- ir_entity *ent1, *ent2;
- unsigned options;
- ir_alias_relation rel;
+ ir_entity *ent1, *ent2;
+ unsigned options;
+ long offset1 = 0;
+ long offset2 = 0;
+ ir_node *base1;
+ ir_node *base2;
+ ir_node *orig_adr1 = adr1;
+ ir_node *orig_adr2 = adr2;
+ unsigned mode_size;
+ storage_class_class_t class1;
+ storage_class_class_t class2;
if (! get_opt_alias_analysis())
return may_alias;
if (options & aa_opt_no_alias)
return no_alias;
- /* Two save some code, sort the addresses by its id's. Beware, this
- might break some things, so better check here. */
- assert(iro_SymConst < iro_Sel && iro_Sel < iro_Proj && "Code dependence broken");
- op1 = get_irn_opcode(adr1);
- op2 = get_irn_opcode(adr2);
+ /* do the addresses have constants offsets?
+ * Note: nodes are normalized to have constants at right inputs,
+ * sub X, C is normalized to add X, -C
+ * */
+ while (is_Add(adr1)) {
+ ir_node *add_right = get_Add_right(adr1);
+ if (is_Const(add_right)) {
+ tarval *tv = get_Const_tarval(add_right);
+ offset1 += get_tarval_long(tv);
+ adr1 = get_Add_left(adr1);
+ continue;
+ }
+ break;
+ }
+ while (is_Add(adr2)) {
+ ir_node *add_right = get_Add_right(adr2);
+ if (is_Const(add_right)) {
+ tarval *tv = get_Const_tarval(add_right);
+ offset2 += get_tarval_long(tv);
+ adr2 = get_Add_left(adr2);
+ continue;
+ }
+ break;
+ }
- if (op1 > op2) {
- ir_node *t = adr1;
- ir_mode *m = mode1;
- adr1 = adr2;
- mode1 = mode2;
- adr2 = t;
- mode2 = m;
+ mode_size = get_mode_size_bytes(mode1);
+ if (get_mode_size_bytes(mode2) > mode_size) {
+ mode_size = get_mode_size_bytes(mode2);
}
- /* some pointers, check if they have the same base but different offset */
- rel = different_pointer(adr1, mode1, adr2, mode2);
- if (rel != may_alias)
- return rel;
+ /* same base address -> compare offsets */
+ if (adr1 == adr2) {
+ if(labs(offset2 - offset1) >= mode_size)
+ return no_alias;
+ else
+ return sure_alias;
+ }
- if (is_global_var(adr1)) {
- /* first address is a global variable */
+ /* skip sels */
+ base1 = adr1;
+ base2 = adr2;
+ if (is_Sel(adr1)) {
+ adr1 = find_base_adr(adr1, &ent1);
+ }
+ if (is_Sel(adr2)) {
+ adr2 = find_base_adr(adr2, &ent2);
+ }
- if (is_global_var(adr2)) {
- /* both addresses are global variables and we know
- they are different (R1 a) */
- if (get_SymConst_entity(adr1) != get_SymConst_entity(adr2))
- return no_alias;
- else {
- /* equal entity addresses */
- return sure_alias;
- }
- } else if (is_Sel(adr2)) {
- ir_node *base2 = find_base_adr(adr2, &ent2);
+ /* same base address -> compare sel entities*/
+ if (adr1 == adr2 && base1 != adr1 && base2 != adr2) {
+ if (ent1 != ent2)
+ return no_alias;
+ else
+ return different_sel_offsets(base1, base2);
+ }
- if (is_global_var(base2)) {
- /* base2 address is a global var (R1 a) */
- if (adr1 != base2)
- return no_alias;
- } else if (base2 == get_irg_frame(irg)) {
- /* the second one is a local variable so they are always
- different (R1 b) */
- return no_alias;
- } else if (base2 == get_irg_tls(irg)) {
- /* the second one is a TLS variable so they are always
- different (R1 c) */
- return no_alias;
- } else if (is_Proj(base2)) {
- if (is_malloc_Result(base2)) {
- /* the second one is an offset from a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory, (R1 f) */
- return no_alias;
- }
- }
- } else if (is_Proj(adr2)) {
- if (is_malloc_Result(adr2)) {
- /* the second one is a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory, (R1 f) */
- return no_alias;
- }
- }
+ class1 = classify_pointer(irg, adr1);
+ class2 = classify_pointer(irg, adr2);
- /* Here we are: the first is a global var, the second some pointer. */
- ent1 = get_SymConst_entity(adr1);
- if (get_entity_address_taken(ent1) == ir_address_not_taken) {
- /* The address of the global variable was never taken, so
- the pointer cannot match (R2). */
+ if (class1 == STORAGE_CLASS_POINTER) {
+ if (class2 & STORAGE_CLASS_MODIFIER_NOTTAKEN) {
return no_alias;
+ } else {
+ return may_alias;
}
- } else if (is_Sel(adr1)) {
- /* the first address is a Sel */
- ir_node *base1 = find_base_adr(adr1, &ent1);
-
- if (base1 == get_irg_frame(irg)) {
- /* first is a local variable ent1 */
- if (is_Sel(adr2)) {
- /* the second address is a Sel */
- ir_node *base2 = find_base_adr(adr2, &ent2);
-
- if (base1 == base2) {
- /* identical bases: both are local variables */
- if (ent1 != ent2) {
- /* both addresses are local variables and we know
- they are different (R1 a) */
- return no_alias;
- } else {
- /* same local var */
- return different_sel_offsets(adr1, adr2);
- }
- } else if (base2 == get_irg_tls(irg)) {
- /* the second one is a TLS variable so they are always
- different (R1 d) */
- return no_alias;
- } else if (is_Proj(base2)) {
- if (is_arg_Proj(base2)) {
- /* the second one is an offset from a parameter so they are
- always different (R1 e) */
- return no_alias;
- } else if (is_malloc_Result(base2)) {
- /* the second one is an offset from a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 g) */
- return no_alias;
- }
- }
- } else if (is_Proj(adr2)) {
- if (is_arg_Proj(adr2)) {
- /* a local variable and a parameter are always different (R1 e) */
- return no_alias;
- } else if (is_malloc_Result(adr2)) {
- /* the second one is a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 g) */
- return no_alias;
- }
- }
- } else if (base1 == get_irg_tls(irg)) {
- /* the first is a TLS variable */
- if (is_Sel(adr2)) {
- /* the second address is a Sel */
- ir_node *base2 = find_base_adr(adr2, &ent2);
-
- if (base1 == base2) {
- if (ent1 != ent2) {
- /* both addresses are tls variables and we know
- they are different (R1 a) */
- return no_alias;
- } else {
- /* same tls var */
- return different_sel_offsets(adr1, adr2);
- }
- } else if (base2 == get_irg_frame(irg)) {
- /* the first one is a tls variable, the second a local one,
- they are different (R1 d) */
- return no_alias;
- } else if (is_Proj(base2)) {
- if (is_malloc_Result(base2)) {
- /* the second one is an offset from a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 h) */
- return no_alias;
- }
- }
- } else if (is_Proj(adr2)) {
- if (is_malloc_Result(adr2)) {
- /* the second one is an offset from a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 h) */
- return no_alias;
- }
- }
- } else if (is_Proj(base1)) {
- if (is_arg_Proj(base1)) {
- /* the first one is an offset from a parameter */
- if (is_Sel(adr2)) {
- /* the second address is a Sel */
- ir_node *base2 = find_base_adr(adr2, &ent2);
-
- if (base2 == get_irg_frame(irg)) {
- /* the second one is a local variable so they are always
- different (R1 e) */
- return no_alias;
- } else if (is_Proj(base2)) {
- if (is_malloc_Result(base2)) {
- /* the second one is an offset from a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 í) */
- return no_alias;
- }
- }
- } else if (is_Proj(adr2)) {
- if (is_malloc_Result(adr2)) {
- /* the second one is a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 í) */
- return no_alias;
- }
- }
- }
- } else if (is_global_var(base1)) {
- /* the first one is an offset from a global variable */
- ent1 = get_SymConst_entity(base1);
- if (is_Sel(adr2)) {
- /* the second address is a Sel */
- ir_node *base2 = find_base_adr(adr2, &ent2);
-
- if (base1 == base2) {
- /* same global var */
- return different_sel_offsets(adr1, adr2);
- } else if (base2 == get_irg_frame(irg)) {
- /* the second one is a local variable so they are always
- different (R1 a) */
- return no_alias;
- } else if (base2 == get_irg_tls(irg)) {
- /* the second one is a TLS variable so they are always
- different (R1 a) */
- return no_alias;
- } else if (is_Proj(base2)) {
- if (is_arg_Proj(base2)) {
- if (get_entity_address_taken(ent1) == ir_address_not_taken) {
- /* The address of the global variable was never taken, so
- the pointer cannot match (R2). */
- return no_alias;
- }
- } else if (is_malloc_Result(base2)) {
- /* the second one is an offset from a result of a malloc like call, ie.
- freshly allocated non-aliases heap memory (R1 g) */
- return no_alias;
- }
- } else if (is_global_var(base2)) {
- ent2 = get_SymConst_entity(base2);
- /* both addresses are global variables and we know
- they are different (R1 a) */
- if (ent1 != ent2)
- return no_alias;
- }
- }
+ } else if (class2 == STORAGE_CLASS_POINTER) {
+ if (class1 & STORAGE_CLASS_MODIFIER_NOTTAKEN) {
+ return no_alias;
+ } else {
+ return may_alias;
}
- } else {
- /* Note: we cannot check for malloc result here, as we cannot be sure
- * the result is not stored anywhere after getting if.
- */
}
- if (options & aa_opt_type_based) { /* Type based alias analysis */
+ if (class1 != class2) {
+ return no_alias;
+ }
+
+ if (class1 == STORAGE_CLASS_GLOBALVAR) {
+ ir_entity *entity1 = get_SymConst_entity(adr1);
+ ir_entity *entity2 = get_SymConst_entity(adr2);
+ if(entity1 != entity2)
+ return no_alias;
+
+ /* for some reason CSE didn't work for the 2 symconsts... */
+ return may_alias;
+ }
+
+ /* Type based alias analysis */
+ if (options & aa_opt_type_based) {
ir_alias_relation rel;
if (options & aa_opt_byte_type_may_alias) {
/* do we have a language specific memory disambiguator? */
if (language_disambuigator) {
- ir_alias_relation rel = (*language_disambuigator)(irg, adr1, mode1, adr2, mode2);
+ ir_alias_relation rel = (*language_disambuigator)(irg, orig_adr1, mode1, orig_adr2, mode2);
if (rel != may_alias)
return rel;
}
projects / libfirm / commitdiff