#include "irouts.h"
#include "irgwalk.h"
#include "irprintf.h"
+#include "debug.h"
+
+/** The debug handle. */
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
/** The source language specific language disambiguator function. */
static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
} /* different_offsets */
/**
- * idx1 and idx2 represent two integer indexes. Check if they could be classified
+ * Check if a given Const node is greater or equal a given size.
+ *
+ * @return no_alias if the Const is greater, may_alias else
*/
-static ir_alias_relation different_index(ir_node *idx1, ir_node *idx2) {
- ir_alias_relation res = may_alias;
+static ir_alias_relation check_const(ir_node *cns, int size) {
+ tarval *tv = get_Const_tarval(cns);
+ tarval *tv_size;
+
+ if (size == 0)
+ return classify_tarval(tv) != TV_CLASSIFY_NULL ? no_alias : may_alias;
+ tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
+ return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? no_alias : may_alias;
+} /* check_const */
+/**
+ * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
+ *
+ * @return sure_alias iff idx1 == idx2
+ * no_alias iff they ALWAYS differ more than size
+ * may_alias else
+ */
+static ir_alias_relation different_index(ir_node *idx1, ir_node *idx2, int size) {
if (idx1 == idx2)
return sure_alias;
if (is_Const(idx1) && is_Const(idx2)) {
/* both are const, we can compare them */
- return get_Const_tarval(idx1) == get_Const_tarval(idx2) ? sure_alias : no_alias;
+ tarval *tv1 = get_Const_tarval(idx1);
+ tarval *tv2 = get_Const_tarval(idx2);
+ tarval *tv, *tv_size;
+
+ if (size == 0)
+ return tv1 == tv2 ? sure_alias : no_alias;
+
+ if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) {
+ tarval *t = tv1;
+ tv1 = tv2;
+ tv2 = t;
+ }
+ /* tv1 is now the "smaller" one */
+ tv = tarval_sub(tv2, tv1);
+ tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
+ return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? no_alias : may_alias;
}
/* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
if (l1 == idx2) {
/* x + c == y */
- if (is_Const(r1)) {
- return classify_Const(r1) == CNST_NULL ? sure_alias : no_alias;
- }
+ if (is_Const(r1))
+ return check_const(r1, size);
}
if (is_Add(idx2)) {
/* both are Adds, check if they are of x + c kind */
ir_node *r2 = get_Add_right(idx2);
if (l1 == l2)
- res = different_index(r1, r2);
+ return different_index(r1, r2, size);
else if (l1 == r2)
- res = different_index(r1, l2);
+ return different_index(r1, l2, size);
else if (r1 == r2)
- res = different_index(l1, l2);
+ return different_index(l1, l2, size);
else if (r1 == l2)
- res = different_index(l1, r2);
- if (res != may_alias)
- return res;
+ return different_index(l1, r2, size);
}
}
if (is_Add(idx2)) {
if (l2 == idx1) {
/* x + c == y */
- if (is_Const(r2)) {
- return classify_Const(r2) == CNST_NULL ? sure_alias : no_alias;
- }
+ if (is_Const(r2))
+ return check_const(r2, size);
}
}
if (l1 == idx2) {
/* x - c == y */
- if (is_Const(r1)) {
- return classify_Const(r1) == CNST_NULL ? sure_alias : no_alias;
- }
+ if (is_Const(r1))
+ return check_const(r1, size);
}
if (is_Sub(idx2)) {
if (l1 == l2) {
ir_node *r2 = get_Sub_right(idx2);
- res = different_index(r1, r2);
+ return different_index(r1, r2, size);
}
}
- if (res != may_alias)
- return res;
}
if (is_Sub(idx2)) {
ir_node *l2 = get_Sub_left(idx2);
if (l2 == idx1) {
/* x - c == y */
- if (is_Const(r2)) {
- return classify_Const(r2) == CNST_NULL ? sure_alias : no_alias;
- }
+ if (is_Const(r2))
+ return check_const(r2, size);
}
}
for (i = 0; i < n; ++i) {
ir_node *idx1 = get_Sel_index(sel1, i);
ir_node *idx2 = get_Sel_index(sel2, i);
- ir_alias_relation res = different_index(idx1, idx2);
+ ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
if (res == may_alias)
return may_alias;
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.
*
if (get_SymConst_entity(adr1) != get_SymConst_entity(adr2))
return no_alias;
else {
- /* equal addresses */
+ /* equal entity addresses */
return sure_alias;
}
}
ir_node *base1 = find_base_adr(adr1, &ent1);
if (base1 == get_irg_frame(irg)) {
- /* the first is a local variable */
+ /* 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)
+ if (base1 == base2) {
+ /* identical bases: check for different offsets */
return different_sel_offsets(adr1, adr2);
- else if (base2 == get_irg_frame(irg)) {
+ } else if (base2 == get_irg_frame(irg)) {
/* both addresses are local variables and we know
they are different (R1 a) */
if (ent1 != ent2)
}
}
}
+ } else {
+ /* 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 (options & aa_opt_type_based) { /* Type based alias analysis */
ir_alias_relation rel;
}
} /* init_taken_flag */
-#if 0
+#ifdef DEBUG_libfirm
/**
* Print the address taken state of all entities of a given type for debugging.
*/
}
}
} /* print_address_taken_state */
-#endif
+#endif /* DEBUG_libfirm */
/**
* Post-walker: check for global entity address
static void analyse_irp_globals_address_taken(void) {
int i;
+ FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
+
init_taken_flag(get_glob_type());
init_taken_flag(get_tls_type());
assure_irg_outs(irg);
irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
}
- //print_address_taken_state(get_glob_type());
- //print_address_taken_state(get_tls_type());
+
+#ifdef DEBUG_libfirm
+ if (firm_dbg_get_mask(dbg) & LEVEL_1) {
+ print_address_taken_state(get_glob_type());
+ print_address_taken_state(get_tls_type());
+ }
+#endif /* DEBUG_libfirm */
/* now computed */
irp->globals_adr_taken_state = ir_address_taken_computed;
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