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
23 * @author Sebastian Hack
24 * @brief Some machine dependent optimizations.
29 #ifndef _FIRM_IR_IRARCH_H_
30 #define _FIRM_IR_IRARCH_H_
32 #include "firm_types.h"
35 * A parameter structure that drives the machine dependent Firm
39 /* Mul optimization */
40 unsigned also_use_subs : 1; /**< Use also Subs when resolving Muls to shifts */
41 int maximum_shifts; /**< The maximum number of shifts that shall be inserted for a mul. */
42 unsigned highest_shift_amount; /**< The highest shift amount you want to
43 tolerate. Muls which would require a higher
44 shift constant are left. */
46 /* Div/Mod optimization */
47 unsigned allow_mulhs : 1; /**< Use the Mulhs operation for division by constant */
48 unsigned allow_mulhu : 1; /**< Use the Mulhu operation for division by constant */
49 int max_bits_for_mulh; /**< Maximum number of bits the Mulh operation can take.
50 Modes with higher amount of bits will use Mulh */
54 * A factory function, that provides architecture parameters for
55 * machine dependent optimizations.
57 typedef const arch_dep_params_t *(*arch_dep_params_factory_t)(void);
60 * A default parameter factory for testing purposes.
62 const arch_dep_params_t *arch_dep_default_factory(void);
69 arch_dep_mul_to_shift = 1, /**< optimize Mul into Shift/Add/Sub */
70 arch_dep_div_by_const = 2, /**< optimize Div into Shift/Add/Mulh */
71 arch_dep_mod_by_const = 4 /**< optimize Mod into Shift/Add/Mulh */
75 * Initialize the machine dependent optimizations.
76 * @param factory A factory that delivers parameters for these
77 * optimizations. If NULL is passed, or this method
78 * is not called, the machine dependent optimizations
79 * are not enabled at all.
81 void arch_dep_init(arch_dep_params_factory_t factory);
84 * Set the optimizations that shall be applied.
85 * @param opts An optimization bit mask.
87 void arch_dep_set_opts(arch_dep_opts_t opts);
90 * Replace Muls with Shifts and Add/Subs.
91 * This function is driven by the 3 parameters:
94 * - highest_shift_amount
96 * If irn is a Mul with a Const, the constant is inspected if it meets the
97 * requirements of the three variables stated above. If a Shl/Add/Sub
98 * sequence can be generated that meets these requirements, this expression
99 * is returned. In each other case irn is returned unmodified.
101 * @param irn The Firm node to inspect.
102 * @return A replacement expression for irn.
104 ir_node *arch_dep_replace_mul_with_shifts(ir_node *irn);
107 * Replace Divs with Shifts and Add/Subs and Mulh.
108 * This function is driven by the 3 parameters:
111 * - max_bits_for_mulh
113 * If irn is a Div with a Const, the constant is inspected if it meets the
114 * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
115 * sequence can be generated that meets these requirements, this expression
116 * is returned. In each other case irn is returned unmodified.
118 * @param irn The Firm node to inspect.
119 * @return A replacement expression for irn.
121 ir_node *arch_dep_replace_div_by_const(ir_node *irn);
124 * Replace Mods with Shifts and Add/Subs and Mulh.
125 * This function is driven by the 3 parameters:
128 * - max_bits_for_mulh
130 * If irn is a Mod with a Const, the constant is inspected if it meets the
131 * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
132 * sequence can be generated that meets these requirements, this expression
133 * is returned. In each other case irn is returned unmodified.
135 * @param irn The Firm node to inspect.
136 * @return A replacement expression for irn.
138 ir_node *arch_dep_replace_mod_by_const(ir_node *irn);
141 * Replace DivMods with Shifts and Add/Subs and Mulh.
142 * This function is driven by the 3 parameters:
145 * - max_bits_for_mulh
147 * If irn is a DivMod with a Const, the constant is inspected if it meets the
148 * requirements of the variables stated above. If a Shl/Add/Sub/Mulh
149 * sequence can be generated that meets these requirements, this expression
150 * is returned. In each other case irn is returned unmodified.
152 * @param div After call contains the Firm node div result or NULL.
153 * @param mod After call contains the Firm node mod result or NULL.
154 * @param irn The Firm node to inspect.
156 void arch_dep_replace_divmod_by_const(ir_node **div, ir_node **mod, ir_node *irn);
158 #endif /* _FIRM_IR_IRARCH_H_ */