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 * @brief Some machine dependent optimizations.
24 * @author Sebastian Hack
27 #ifndef FIRM_IR_IRARCH_H
28 #define FIRM_IR_IRARCH_H
30 #include "firm_types.h"
33 * A parameter structure that drives the machine dependent Firm
37 /* Mul optimization */
38 unsigned also_use_subs : 1; /**< Use also Subs when resolving Muls to shifts */
39 int maximum_shifts; /**< The maximum number of shifts that shall be inserted for a mul. */
40 unsigned highest_shift_amount; /**< The highest shift amount you want to
41 tolerate. Muls which would require a higher
42 shift constant are left. */
44 /* Div/Mod optimization */
45 unsigned allow_mulhs : 1; /**< Use the Mulhs operation for division by constant */
46 unsigned allow_mulhu : 1; /**< Use the Mulhu operation for division by constant */
47 int max_bits_for_mulh; /**< Maximum number of bits the Mulh operation can take.
48 Modes with higher amount of bits will use Mulh */
52 * A factory function, that provides architecture parameters for
53 * machine dependent optimizations.
55 typedef const arch_dep_params_t *(*arch_dep_params_factory_t)(void);
58 * A default parameter factory for testing purposes.
60 const arch_dep_params_t *arch_dep_default_factory(void);
67 arch_dep_mul_to_shift = 1, /**< optimize Mul into Shift/Add/Sub */
68 arch_dep_div_by_const = 2, /**< optimize Div into Shift/Add/Mulh */
69 arch_dep_mod_by_const = 4 /**< optimize Mod into Shift/Add/Mulh */
73 * Initialize the machine dependent optimizations.
74 * @param factory A factory that delivers parameters for these
75 * optimizations. If NULL is passed, or this method
76 * is not called, the machine dependent optimizations
77 * are not enabled at all.
79 void arch_dep_init(arch_dep_params_factory_t factory);
82 * Set the optimizations that shall be applied.
83 * @param opts An optimization bit mask.
85 void arch_dep_set_opts(arch_dep_opts_t opts);
88 * Replace Muls with Shifts and Add/Subs.
89 * This function is driven by the 3 parameters:
92 * - highest_shift_amount
94 * If irn is a Mul with a Const, the constant is inspected if it meets the
95 * requirements of the three variables stated above. If a Shl/Add/Sub
96 * sequence can be generated that meets these requirements, this expression
97 * is returned. In each other case irn is returned unmodified.
99 * @param irn The Firm node to inspect.
100 * @return A replacement expression for irn.
102 ir_node *arch_dep_replace_mul_with_shifts(ir_node *irn);
105 * Replace Divs with Shifts and Add/Subs and Mulh.
106 * This function is driven by the 3 parameters:
109 * - max_bits_for_mulh
111 * If irn is a Div with a Const, the constant is inspected if it meets the
112 * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
113 * sequence can be generated that meets these requirements, this expression
114 * is returned. In each other case irn is returned unmodified.
116 * @param irn The Firm node to inspect.
117 * @return A replacement expression for irn.
119 ir_node *arch_dep_replace_div_by_const(ir_node *irn);
122 * Replace Mods with Shifts and Add/Subs and Mulh.
123 * This function is driven by the 3 parameters:
126 * - max_bits_for_mulh
128 * If irn is a Mod with a Const, the constant is inspected if it meets the
129 * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
130 * sequence can be generated that meets these requirements, this expression
131 * is returned. In each other case irn is returned unmodified.
133 * @param irn The Firm node to inspect.
134 * @return A replacement expression for irn.
136 ir_node *arch_dep_replace_mod_by_const(ir_node *irn);
139 * Replace DivMods with Shifts and Add/Subs and Mulh.
140 * This function is driven by the 3 parameters:
143 * - max_bits_for_mulh
145 * If irn is a DivMod with a Const, the constant is inspected if it meets the
146 * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
147 * sequence can be generated that meets these requirements, this expression
148 * is returned. In each other case irn is returned unmodified.
150 * @param div After call contains the Firm node div result or NULL.
151 * @param mod After call contains the Firm node mod result or NULL.
152 * @param irn The Firm node to inspect.
154 void arch_dep_replace_divmod_by_const(ir_node **div, ir_node **mod, ir_node *irn);