} /* different_index */
/**
- * Two Sel addresses have the same base address, check if there offsets are different.
+ * Two Sel addresses have the same base address, check if there offsets are
+ * different.
*
* @param adr1 The first address.
* @param adr2 The second address.
{
ir_entity *ent1 = NULL, *ent2 = NULL;
- if (is_SymConst_addr_ent(adr1))
- ent1 = get_SymConst_entity(adr1);
+ if (is_Global(adr1))
+ ent1 = get_Global_entity(adr1);
else if (is_Sel(adr1))
ent1 = get_Sel_entity(adr1);
- if (is_SymConst_addr_ent(adr2))
- ent2 = get_SymConst_entity(adr2);
+ if (is_Global(adr2))
+ ent2 = get_Global_entity(adr2);
else if (is_Sel(adr2))
ent2 = get_Sel_entity(adr2);
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 then 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;
if (! is_Call(node))
return 0;
node = get_Call_ptr(node);
- if (is_SymConst_addr_ent(node)) {
- ir_entity *ent = get_SymConst_entity(node);
+ if (is_Global(node)) {
+ ir_entity *ent = get_Global_entity(node);
if (get_entity_additional_properties(ent) & mtp_property_malloc)
return 1;
} /* is_malloc_Result */
/**
- * Returns true if an address represents a global variable.
+ * 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;
+
+/**
+ * Classify a base pointer.
*
- * @param irn the node representing the address
+ * @param irg the graph of the pointer
+ * @param irn the node representing the base address
+ * @param ent the base entity of the base address iff any
*/
-static INLINE int is_global_var(ir_node *irn) {
- return is_SymConst_addr_ent(irn);
-} /* is_global_var */
+static storage_class_class_t classify_pointer(ir_graph *irg, ir_node *irn, ir_entity *ent)
+{
+ storage_class_class_t res = STORAGE_CLASS_POINTER;
+ if (is_Global(irn)) {
+ ir_entity *entity = get_Global_entity(irn);
+ res = STORAGE_CLASS_GLOBALVAR;
+ if (get_entity_address_taken(entity) == ir_address_not_taken)
+ res |= STORAGE_CLASS_MODIFIER_NOTTAKEN;
+ } else if (irn == get_irg_frame(irg)) {
+ res = STORAGE_CLASS_LOCALVAR;
+ if (ent != NULL && get_entity_address_taken(ent) == ir_address_not_taken)
+ res |= STORAGE_CLASS_MODIFIER_NOTTAKEN;
+ } else if (is_arg_Proj(irn)) {
+ return STORAGE_CLASS_ARGUMENT;
+ } else if (irn == get_irg_tls(irg)) {
+ res = STORAGE_CLASS_TLS;
+ if (ent != NULL && get_entity_address_taken(ent) == ir_address_not_taken)
+ res |= STORAGE_CLASS_MODIFIER_NOTTAKEN;
+ } else if (is_Proj(irn) && is_malloc_Result(irn)) {
+ return STORAGE_CLASS_MALLOCED;
+ }
+
+ return res;
+}
+
+/**
+ * If adr represents a Bitfield Sel, skip it
+ */
+static ir_node *skip_Bitfield_Sels(ir_node *adr) {
+ if (is_Sel(adr)) {
+ ir_entity *ent = get_Sel_entity(adr);
+ ir_type *bf_type = get_entity_type(ent);
+
+ /* is it a bitfield type? */
+ if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
+ adr = get_Sel_ptr(adr);
+ }
+ return adr;
+}
/**
* 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_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, class2;
+ int have_const_offsets;
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
+ */
+ have_const_offsets = 1;
+ 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);
+ } else if (mode_is_reference(get_irn_mode(add_right))) {
+ adr1 = add_right;
+ have_const_offsets = 0;
+ } else {
+ adr1 = get_Add_left(adr1);
+ have_const_offsets = 0;
+ }
+ }
+ 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);
+ } else if (mode_is_reference(get_irn_mode(add_right))) {
+ adr2 = add_right;
+ have_const_offsets = 0;
+ } else {
+ adr2 = get_Add_left(adr2);
+ have_const_offsets = 0;
+ }
+ }
- 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);
}
- if (is_global_var(adr1)) {
- /* first address is a global variable */
+ /* same base address -> compare offsets if possible.
+ * FIXME: type long is not sufficient for this task ...
+ */
+ if (adr1 == adr2 && have_const_offsets) {
+ if ((unsigned long)labs(offset2 - offset1) >= mode_size)
+ return no_alias;
+ else
+ return sure_alias;
+ }
- 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);
+ /*
+ * Bitfields can be constructed as Sels from its base address.
+ * As they have different entities, the disambiguator would find that they are
+ * alias free. While this is true vor it's values, it is false for the addresses
+ * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
+ * So, skip those bitfield selecting Sel's.
+ */
+ adr1 = skip_Bitfield_Sels(adr1);
+ adr2 = skip_Bitfield_Sels(adr2);
+
+ /* skip sels */
+ base1 = adr1;
+ base2 = adr2;
+ ent1 = NULL;
+ ent2 = NULL;
+ if (is_Sel(adr1)) {
+ base1 = find_base_adr(adr1, &ent1);
+ }
+ if (is_Sel(adr2)) {
+ base2 = find_base_adr(adr2, &ent2);
+ }
- 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;
- }
- }
+ /* same base address -> compare sel entities */
+ if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
+ if (ent1 != ent2)
+ return no_alias;
+ else if (have_const_offsets)
+ return different_sel_offsets(adr1, adr2);
+ }
+
+ class1 = classify_pointer(irg, base1, ent1);
+ class2 = classify_pointer(irg, base2, ent2);
- /* 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.
- */
+ }
- /* some pointers, check if they have the same base buf constant offset */
- ir_alias_relation rel = different_pointer(adr1, mode1, adr2, mode2);
- if (rel != may_alias)
- return rel;
+ if (class1 != class2) {
+ return no_alias;
}
+ if (class1 == STORAGE_CLASS_GLOBALVAR) {
+ ir_entity *entity1 = get_SymConst_entity(base1);
+ ir_entity *entity2 = get_SymConst_entity(base2);
+ if (entity1 != entity2)
+ return no_alias;
+
+ /* for some reason CSE didn't happen yet for the 2 SymConsts... */
+ return may_alias;
+ }
- if (options & aa_opt_type_based) { /* Type based alias analysis */
+ /* Type based alias analysis */
+ if (options & aa_opt_type_based) {
ir_alias_relation rel;
if (options & aa_opt_byte_type_may_alias) {
return no_alias;
/* try rule R5 */
- rel = different_types(adr1, adr2);
+ rel = different_types(orig_adr1, orig_adr2);
if (rel != may_alias)
return rel;
leave_type_based_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;
}
ir_node *adr2, ir_mode *mode2)
{
ir_alias_relation rel = _get_alias_relation(irg, adr1, mode1, adr2, mode2);
- DB((dbg, LEVEL_1, "alias(%+F, %+f) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
+ DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
return rel;
} /* get_alias_relation */
{
mem_disambig_entry key, *entry;
+ ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
+
if (! get_opt_alias_analysis())
return may_alias;
* @param irn the node
*/
static ir_address_taken_state find_address_taken_state(ir_node *irn) {
- int i, j;
- ir_mode *emode, *mode;
- ir_node *value;
+ int i, j;
+ ir_mode *emode, *mode;
+ ir_node *value;
ir_entity *ent;
+ ir_type *tp;
for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
ir_node *succ = get_irn_out(irn, i);
return ir_address_taken;
break;
+ case iro_CopyB:
+ /* CopyB are like Loads/Stores */
+ ent = is_SymConst(irn) ? get_SymConst_entity(irn) : get_Sel_entity(irn);
+ tp = get_entity_type(ent);
+ if (tp != get_CopyB_type(succ)) {
+ /* bad, different types, might be a hidden conversion */
+ return ir_address_taken;
+ }
+ break;
+
case iro_Sel: {
/* Check the successor of irn. */
ir_address_taken_state res = find_address_taken_state(succ);
static void check_initializer_nodes(ir_initializer_t *initializer)
{
- switch(initializer->kind) {
+ switch (initializer->kind) {
case IR_INITIALIZER_CONST: {
ir_node *n = initializer->consti.value;
/* let's check if it's an address */
- if (is_SymConst_addr_ent(n)) {
- ir_entity *ent = get_SymConst_entity(n);
+ if (is_Global(n)) {
+ ir_entity *ent = get_Global_entity(n);
set_entity_address_taken(ent, ir_address_taken);
}
return;
case IR_INITIALIZER_COMPOUND: {
size_t i;
- for(i = 0; i < initializer->compound.n_initializers; ++i) {
+ for (i = 0; i < initializer->compound.n_initializers; ++i) {
ir_initializer_t *sub_initializer
= initializer->compound.initializers[i];
check_initializer_nodes(sub_initializer);
} else if (is_atomic_entity(ent)) {
/* let's check if it's an address */
n = get_atomic_ent_value(ent);
- if (is_SymConst_addr_ent(n)) {
- ir_entity *ent = get_SymConst_entity(n);
+ if (is_Global(n)) {
+ ir_entity *ent = get_Global_entity(n);
set_entity_address_taken(ent, ir_address_taken);
}
} else {
n = get_compound_ent_value(ent, i);
/* let's check if it's an address */
- if (is_SymConst_addr_ent(n)) {
- ir_entity *ent = get_SymConst_entity(n);
+ if (is_Global(n)) {
+ ir_entity *ent = get_Global_entity(n);
set_entity_address_taken(ent, ir_address_taken);
}
}
ir_entity *ent;
ir_address_taken_state state;
- if (is_SymConst_addr_ent(irn)) {
+ if (is_Global(irn)) {
/* A global. */
- ent = get_SymConst_entity(irn);
+ ent = get_Global_entity(irn);
} else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
/* A TLS variable. */
ent = get_Sel_entity(irn);