* Created:
* CVS-ID: $Id$
* Copyright: (c) 1998-2005 Universität Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * License: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*/
#ifndef _OPT_CONFIRMS_H_
#define _OPT_CONFIRMS_H_
#include "irnode.h"
-/**
+/**a
* @file opt_confirms.h
*
* Optimizations regarding Confirm nodes.
- * These optimiztions are not means to be run from
+ * These optimizations are not means to be run from
* frontends, they are called from iropt.
*/
-/**
- * Possible return values of value_classify().
- */
-typedef enum _value_classify {
- VALUE_UNKNOWN = 0, /**< could not classify */
- VALUE_POSITIVE = 1, /**< value is positive, i.e. >= 0 */
- VALUE_NEGATIVE = -1 /**< value is negative, i.e. <= 0 if
- no signed zero exists or < 0 else */
-} value_classify;
-
-
/**
* Check, if the value of a node is != 0.
*
* This is a often needed case, so we handle here Confirm
* nodes too.
*
- * @param n a node representing the value
+ * @param n a node representing the value
+ * @param confirm if n is confirmed to be != 0, returns
+ * the the Confirm-node, else NULL
+ */
+int value_not_zero(ir_node *n, ir_node **confirm);
+
+/**
+ * Check, if the value of a node cannot represent a NULL pointer.
+ *
+ * - If sel_based_null_check_elim is enabled, all
+ * Sel nodes can be skipped.
+ * - A SymConst(entity) is NEVER a NULL pointer
+ * - A Const != NULL is NEVER a NULL pointer
+ * - Confirms are evaluated
+ *
+ * @param n a node representing the value
+ * @param confirm if n is confirmed to be != NULL, returns
+ * the the Confirm-node, else NULL
+ */
+int value_not_null(ir_node *n, ir_node **confirm);
+
+/**
+ * Possible return values of value_classify().
*/
-int value_not_zero(ir_node *n);
+typedef enum _value_classify_sign {
+ value_classified_unknown = 0, /**< could not classify */
+ value_classified_positive = 1, /**< value is positive, i.e. >= 0 */
+ value_classified_negative = -1 /**< value is negative, i.e. <= 0 if
+ no signed zero exists or < 0 else */
+} value_classify_sign;
/**
* Check, if the value of a node can be confirmed >= 0 or <= 0,
*
* @param n a node representing the value
*/
-value_classify classify_value_sign(ir_node *n);
+value_classify_sign classify_value_sign(ir_node *n);
/**
* Return the value of a Cmp if one or both predecessors