/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
pn_Cmp pnc;
*confirm = NULL;
- while (get_irn_op(n) == op_Confirm) {
+
+ /* there might be several Confirms one after other that form an interval */
+ for (;;) {
+ if (is_Minus(n) || is_Abs(n)) {
+ /* we can safely skip Minus and Abs when checking for != 0 */
+ n = get_unop_op(n);
+ continue;
+ }
+ if (! is_Confirm(n))
+ break;
+
/*
* Note: A Confirm is never after a Const. So,
* we simply can check the bound for being a Const
default:
break;
}
-
- /* there might be several Confirms one after other that form an interval */
n = get_Confirm_value(n);
}
tv = value_of(n);
*confirm = NULL;
n = skip_Cast(n);
+
op = get_irn_op(n);
assert(mode_is_reference(get_irn_mode(n)));
if (get_opt_sel_based_null_check_elim()) {
op = get_irn_op(n);
}
}
- if (op == op_SymConst && get_SymConst_kind(n) == symconst_addr_ent)
+ if (is_Global(n)) {
+ /* global references are never NULL */
+ return 1;
+ } else if (n == get_irg_frame(current_ir_graph)) {
+ /* local references are never NULL */
return 1;
- if (op == op_Const) {
- tarval *tv = get_Const_tarval(n);
-
- if (tv != tarval_bad && classify_tarval(tv) != TV_CLASSIFY_NULL)
- return 1;
- } else if (op == op_Confirm) {
- if (get_Confirm_cmp(n) == pn_Cmp_Lg &&
- classify_Const(get_Confirm_bound(n)) == CNST_NULL) {
- *confirm = n;
- return 1;
+ } else if (op == op_Const) {
+ /* explicit non-NULL addresses */
+ return !is_Const_null(n);
+ } else {
+ /* check for more Confirms */
+ for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
+ if (get_Confirm_cmp(n) != pn_Cmp_Lg) {
+ ir_node *bound = get_Confirm_bound(n);
+ if (is_Const(bound) && is_Const_null(bound)) {
+ *confirm = n;
+ return 1;
+ }
+ }
}
}
return 0;
tarval *tv, *c;
ir_mode *mode;
pn_Cmp cmp, ncmp;
+ int negate = 1;
+
+ for (;;) {
+ ir_opcode code = get_irn_opcode(n);
+ switch (code) {
+ case iro_Minus:
+ negate *= -1;
+ n = get_Minus_op(n);
+ continue;
+ case iro_Confirm:
+ break;
+ default:
+ return value_classified_unknown;
+ }
+ break;
+ }
if (get_irn_op(n) != op_Confirm)
return value_classified_unknown;
return value_classified_unknown;
/* yep, negative */
- return value_classified_negative;
+ return value_classified_negative * negate;
case pn_Cmp_Ge:
/*
}
/* yep, positive */
- return value_classified_positive;
+ return value_classified_positive * negate;
default:
return value_classified_unknown;
return (pn_Cmp_False < pnc && pnc < pn_Cmp_Lg);
} /* is_transitive */
-
/**
* Return the value of a Cmp if one or both predecessors
* are Confirm nodes.
* @param pnc the compare relation
*/
tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right, pn_Cmp pnc) {
- ir_node *l_bound;
- pn_Cmp l_pnc, res_pnc, neg_pnc;
- interval_t l_iv, r_iv;
- tarval *tv;
- ir_mode *mode;
-
- if (get_irn_op(right) == op_Confirm) {
- ir_node *t;
+ ir_node *l_bound;
+ pn_Cmp l_pnc, res_pnc, neg_pnc;
+ interval_t l_iv, r_iv;
+ tarval *tv;
+ ir_mode *mode;
+ if (is_Confirm(right)) {
/* we want the Confirm on the left side */
- t = left;
- left = right;
- right = t;
+ ir_node *t = right;
+ right = left;
+ left = t;
pnc = get_inversed_pnc(pnc);
- } else if (get_irn_op(left) != op_Confirm) {
- /* no Confirm on either one side, finish */
- return tarval_bad;
+ } else if (! is_Confirm(left)) {
+ /* nothing more found */
+ tv = tarval_bad;
+ goto check_null_case;
}
/* ok, here at least left is a Confirm, right might be */
l_bound = get_Confirm_bound(left);
l_pnc = get_Confirm_cmp(left);
- if (get_irn_op(right) == op_Confirm) {
+ if (is_Confirm(right)) {
/*
- * both sides are Confirm's. Check some rare cases first.
- */
+ * both sides are Confirm's. Check some rare cases first.
+ */
ir_node *r_bound = get_Confirm_bound(right);
- pn_Cmp r_pnc = get_Confirm_cmp(right);
+ pn_Cmp r_pnc = get_Confirm_cmp(right);
/*
- * some check can be made WITHOUT constant bounds
- */
+ * some check can be made WITHOUT constant bounds
+ */
if (r_bound == l_bound) {
if (is_transitive(l_pnc)) {
pn_Cmp r_inc_pnc = get_inversed_pnc(r_pnc);
get_interval(&l_iv, l_bound, l_pnc),
get_interval_from_tv(&r_iv, tv),
pnc);
+ } else {
+check_null_case:
+ /* check some other cases */
+ if ((pnc == pn_Cmp_Eq || pnc == pn_Cmp_Lg) &&
+ is_Const(right) && is_Const_null(right)) {
+ /* for == 0 or != 0 we have some special tools */
+ ir_mode *mode = get_irn_mode(left);
+ ir_node *dummy;
+ if (mode_is_reference(mode)) {
+ if (value_not_null(left, &dummy)) {
+ tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true;
+ }
+ } else {
+ if (value_not_zero(left, &dummy)) {
+ tv = pnc == pn_Cmp_Eq ? tarval_b_false : tarval_b_true;
+ }
+ }
+ }
}
if (tv != tarval_bad)
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