} /* 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;
} /* different_types */
/**
- * Check if a offset is constant and bigger than a given size
+ * 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);
if (is_Const(offset) && mode_is_int(mode)) {
tarval *tv = new_tarval_from_long(size, mode);
- if (tarval_cmp(tv, get_Const_tarval(offset)) & (pn_Cmp_Eq|pn_Cmp_Gt))
+ /* size <= offset ? */
+ if (tarval_cmp(tv, get_Const_tarval(offset)) & (pn_Cmp_Eq|pn_Cmp_Lt))
return 1;
}
return 0;
} 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 */