2 * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * File name: ir/opt/opt_confirms.h
23 * Purpose: Optimizations regarding Confirm nodes
24 * Author: Michael Beck
28 * Copyright: (c) 1998-2005 Universität Karlsruhe
29 * License: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
31 #ifndef _OPT_CONFIRMS_H_
32 #define _OPT_CONFIRMS_H_
37 * @file opt_confirms.h
39 * Optimizations regarding Confirm nodes.
40 * These optimizations are not means to be run from
41 * frontends, they are called from iropt.
45 * Check, if the value of a node is != 0.
47 * This is a often needed case, so we handle here Confirm
50 * @param n a node representing the value
51 * @param confirm if n is confirmed to be != 0, returns
52 * the the Confirm-node, else NULL
54 int value_not_zero(ir_node *n, ir_node **confirm);
57 * Check, if the value of a node cannot represent a NULL pointer.
59 * - If sel_based_null_check_elim is enabled, all
60 * Sel nodes can be skipped.
61 * - A SymConst(entity) is NEVER a NULL pointer
62 * - A Const != NULL is NEVER a NULL pointer
63 * - Confirms are evaluated
65 * @param n a node representing the value
66 * @param confirm if n is confirmed to be != NULL, returns
67 * the the Confirm-node, else NULL
69 int value_not_null(ir_node *n, ir_node **confirm);
72 * Possible return values of value_classify().
74 typedef enum _value_classify_sign {
75 value_classified_unknown = 0, /**< could not classify */
76 value_classified_positive = 1, /**< value is positive, i.e. >= 0 */
77 value_classified_negative = -1 /**< value is negative, i.e. <= 0 if
78 no signed zero exists or < 0 else */
79 } value_classify_sign;
82 * Check, if the value of a node can be confirmed >= 0 or <= 0,
83 * If the mode of the value did not honor signed zeros, else
84 * check for >= 0 or < 0.
86 * @param n a node representing the value
88 value_classify_sign classify_value_sign(ir_node *n);
91 * Return the value of a Cmp if one or both predecessors
94 * @param cmp the compare node that will be evaluated
95 * @param left the left operand of the Cmp
96 * @param right the right operand of the Cmp
97 * @param pnc the compare relation
99 tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right, pn_Cmp pnc);
101 #endif /* _OPT_CONFIRMS_H_ */