/*
- * 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.
*
* @author Michael Beck
* @version $Id$
*/
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
#undef DEBUG_CONFIRM
* This is a often needed case, so we handle here Confirm
* nodes too.
*/
-int value_not_zero(ir_node *blk, ir_node *n, ir_node **confirm) {
+int value_not_zero(const ir_node *n, ir_node_cnst_ptr *confirm) {
#define RET_ON(x) if (x) { *confirm = n; return 1; }; break
tarval *tv;
ir_mode *mode = get_irn_mode(n);
pn_Cmp pnc;
- if (get_irg_pinned(get_irn_irg(blk)) != op_pin_state_pinned)
- blk = NULL;
-
*confirm = NULL;
/* there might be several Confirms one after other that form an interval */
- for (; is_Confirm(n); n = get_Confirm_value(n)) {
- unsigned long region = get_Confirm_region(n);
-
- /* check if it's legal to use this confirm. */
- if (region != 0) {
- ir_node *curr_blk = get_irn_n(n, -1);
-
- /* this confirm is bound to a region. */
- if (! blk)
- continue;
-
- if (get_Block_exc_region(curr_blk) != region)
- continue;
- /* all went fine, the current Confirm belongs to the same region */
+ 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,
default:
break;
}
+ n = get_Confirm_value(n);
}
tv = value_of(n);
* - A SymConst(entity) is NEVER a NULL pointer
* - Confirms are evaluated
*/
-int value_not_null(ir_node *blk, ir_node *n, ir_node **confirm) {
- ir_op *op;
+int value_not_null(const ir_node *n, ir_node_cnst_ptr *confirm) {
+ tarval *tv;
- if (get_irg_pinned(get_irn_irg(blk)) != op_pin_state_pinned)
- blk = NULL;
*confirm = NULL;
- n = skip_Cast(n);
+ n = skip_Cast_const(n);
+
+ tv = value_of(n);
+ if (tarval_is_constant(tv) && ! tarval_is_null(tv))
+ return 1;
- op = get_irn_op(n);
assert(mode_is_reference(get_irn_mode(n)));
if (get_opt_sel_based_null_check_elim()) {
/* skip all Sel nodes and Cast's */
- while (op == op_Sel) {
+ while (is_Sel(n)) {
n = skip_Cast(get_Sel_ptr(n));
- 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 {
+ /* check for more Confirms */
for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
- unsigned long region = get_Confirm_region(n);
+ if (get_Confirm_cmp(n) == pn_Cmp_Lg) {
+ ir_node *bound = get_Confirm_bound(n);
+ tarval *tv = value_of(bound);
- /* check if it's legal to use this confirm. */
- if (region != 0) {
- ir_node *curr_blk = get_irn_n(n, -1);
-
- /* this confirm is bound to a region. */
- if (! blk)
- continue;
-
- if (get_Block_exc_region(curr_blk) != region)
- continue;
- /* all went fine, the current Confirm belongs to the same region */
- }
-
- if (get_Confirm_cmp(n) == pn_Cmp_Lg &&
- classify_Const(get_Confirm_bound(n)) == CNST_NULL) {
+ if (tarval_is_null(tv)) {
*confirm = n;
return 1;
+ }
}
}
}
tarval *tv, *c;
ir_mode *mode;
pn_Cmp cmp, ncmp;
+ int negate = 1;
- if (get_irn_op(n) != op_Confirm)
+ 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 (!is_Confirm(n))
return value_classified_unknown;
tv = value_of(get_Confirm_bound(n));
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 */
-/**
- * returns a confirm node starting from n that is allowed to be used in the exception
- * region.
- *
- * @param region the exception region
- * @param n the node
- */
-static ir_node *get_allowed_confirm(unsigned long region, ir_node *n) {
- for (; is_Confirm(n); n = get_Confirm_value(n)) {
- unsigned long reg = get_Confirm_region(n);
-
- if (reg == 0 || reg == region) {
- /* found an allowed Confirm */
- return n;
- }
-
- }
- return NULL;
-} /* get_allowed_confirm */
-
/**
* 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, *confirm;
- pn_Cmp l_pnc, res_pnc, neg_pnc;
- interval_t l_iv, r_iv;
- tarval *tv;
- ir_mode *mode;
- unsigned long region;
-
- /* Cmp is pinned, so this always gives the right exception region. */
- region = get_Block_exc_region(get_nodes_block(cmp));
+ ir_node *l_bound;
+ pn_Cmp l_pnc, res_pnc, neg_pnc;
+ interval_t l_iv, r_iv;
+ tarval *tv;
+ ir_mode *mode;
- if ((confirm = get_allowed_confirm(region, right)) != NULL) {
+ if (is_Confirm(right)) {
/* we want the Confirm on the left side */
+ ir_node *t = right;
right = left;
- left = confirm;
+ left = t;
pnc = get_inversed_pnc(pnc);
- } else if ((confirm = get_allowed_confirm(region, left)) != NULL) {
- left = confirm;
- } else {
- /* 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 */
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);
+ const 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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