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Alex Bennéecfd88fc2018-01-19 16:36:40 +00001/*
2 * QEMU float support
3 *
4 * The code in this source file is derived from release 2a of the SoftFloat
5 * IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and
6 * some later contributions) are provided under that license, as detailed below.
7 * It has subsequently been modified by contributors to the QEMU Project,
8 * so some portions are provided under:
9 * the SoftFloat-2a license
10 * the BSD license
11 * GPL-v2-or-later
12 *
13 * This header holds definitions for code that might be dealing with
14 * softfloat types but not need access to the actual library functions.
15 */
16/*
17===============================================================================
18This C header file is part of the SoftFloat IEC/IEEE Floating-point
19Arithmetic Package, Release 2a.
20
21Written by John R. Hauser. This work was made possible in part by the
22International Computer Science Institute, located at Suite 600, 1947 Center
23Street, Berkeley, California 94704. Funding was partially provided by the
24National Science Foundation under grant MIP-9311980. The original version
25of this code was written as part of a project to build a fixed-point vector
26processor in collaboration with the University of California at Berkeley,
27overseen by Profs. Nelson Morgan and John Wawrzynek. More information
28is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
29arithmetic/SoftFloat.html'.
30
31THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
32has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
33TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
34PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
35AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
36
37Derivative works are acceptable, even for commercial purposes, so long as
38(1) they include prominent notice that the work is derivative, and (2) they
39include prominent notice akin to these four paragraphs for those parts of
40this code that are retained.
41
42===============================================================================
43*/
44
45/* BSD licensing:
46 * Copyright (c) 2006, Fabrice Bellard
47 * All rights reserved.
48 *
49 * Redistribution and use in source and binary forms, with or without
50 * modification, are permitted provided that the following conditions are met:
51 *
52 * 1. Redistributions of source code must retain the above copyright notice,
53 * this list of conditions and the following disclaimer.
54 *
55 * 2. Redistributions in binary form must reproduce the above copyright notice,
56 * this list of conditions and the following disclaimer in the documentation
57 * and/or other materials provided with the distribution.
58 *
59 * 3. Neither the name of the copyright holder nor the names of its contributors
60 * may be used to endorse or promote products derived from this software without
61 * specific prior written permission.
62 *
63 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
64 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
67 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
68 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
69 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
70 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
71 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
72 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
73 * THE POSSIBILITY OF SUCH DAMAGE.
74 */
75
76/* Portions of this work are licensed under the terms of the GNU GPL,
77 * version 2 or later. See the COPYING file in the top-level directory.
78 */
79
80#ifndef SOFTFLOAT_TYPES_H
81#define SOFTFLOAT_TYPES_H
82
83/*
84 * Software IEC/IEEE floating-point types.
85 */
86
87typedef uint16_t float16;
88typedef uint32_t float32;
89typedef uint64_t float64;
90#define float16_val(x) (x)
91#define float32_val(x) (x)
92#define float64_val(x) (x)
93#define make_float16(x) (x)
94#define make_float32(x) (x)
95#define make_float64(x) (x)
96#define const_float16(x) (x)
97#define const_float32(x) (x)
98#define const_float64(x) (x)
99typedef struct {
100 uint64_t low;
101 uint16_t high;
102} floatx80;
103#define make_floatx80(exp, mant) ((floatx80) { mant, exp })
104#define make_floatx80_init(exp, mant) { .low = mant, .high = exp }
105typedef struct {
Marc-André Lureaue03b5682022-03-23 19:57:17 +0400106#if HOST_BIG_ENDIAN
Alex Bennéecfd88fc2018-01-19 16:36:40 +0000107 uint64_t high, low;
108#else
109 uint64_t low, high;
110#endif
111} float128;
112#define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ })
113#define make_float128_init(high_, low_) { .high = high_, .low = low_ }
114
Alex Bennée24f91e82018-01-19 18:24:22 +0000115/*
LIU Zhiwei82823102020-08-13 15:14:19 +0800116 * Software neural-network floating-point types.
117 */
118typedef uint16_t bfloat16;
119
120/*
Alex Bennée24f91e82018-01-19 18:24:22 +0000121 * Software IEC/IEEE floating-point underflow tininess-detection mode.
122 */
123
Richard Hendersona828b372020-05-04 21:19:39 -0700124#define float_tininess_after_rounding false
125#define float_tininess_before_rounding true
Alex Bennée24f91e82018-01-19 18:24:22 +0000126
127/*
128 *Software IEC/IEEE floating-point rounding mode.
129 */
130
Richard Henderson3dede402020-05-05 09:01:49 -0700131typedef enum __attribute__((__packed__)) {
Alex Bennée24f91e82018-01-19 18:24:22 +0000132 float_round_nearest_even = 0,
133 float_round_down = 1,
134 float_round_up = 2,
135 float_round_to_zero = 3,
136 float_round_ties_away = 4,
Richard Henderson60c8f722021-05-25 15:58:10 -0700137 /* Not an IEEE rounding mode: round to closest odd, overflow to max */
Alex Bennée24f91e82018-01-19 18:24:22 +0000138 float_round_to_odd = 5,
Richard Henderson60c8f722021-05-25 15:58:10 -0700139 /* Not an IEEE rounding mode: round to closest odd, overflow to inf */
140 float_round_to_odd_inf = 6,
Richard Henderson3dede402020-05-05 09:01:49 -0700141} FloatRoundMode;
Alex Bennée24f91e82018-01-19 18:24:22 +0000142
143/*
144 * Software IEC/IEEE floating-point exception flags.
145 */
146
147enum {
Richard Henderson149a48f2021-12-17 17:57:14 +0100148 float_flag_invalid = 0x0001,
149 float_flag_divbyzero = 0x0002,
150 float_flag_overflow = 0x0004,
151 float_flag_underflow = 0x0008,
152 float_flag_inexact = 0x0010,
153 float_flag_input_denormal = 0x0020,
154 float_flag_output_denormal = 0x0040,
Richard Hendersonba114462021-12-17 17:57:14 +0100155 float_flag_invalid_isi = 0x0080, /* inf - inf */
Richard Hendersonbead3c92021-12-17 17:57:14 +0100156 float_flag_invalid_imz = 0x0100, /* inf * 0 */
Richard Henderson10cc9642021-12-17 17:57:14 +0100157 float_flag_invalid_idi = 0x0200, /* inf / inf */
158 float_flag_invalid_zdz = 0x0400, /* 0 / 0 */
Richard Hendersonf8718aa2021-12-17 17:57:14 +0100159 float_flag_invalid_sqrt = 0x0800, /* sqrt(-x) */
Richard Henderson81254b02021-12-17 17:57:14 +0100160 float_flag_invalid_cvti = 0x1000, /* non-nan to integer */
Richard Hendersone706d442021-12-17 17:57:14 +0100161 float_flag_invalid_snan = 0x2000, /* any operand was snan */
Alex Bennée24f91e82018-01-19 18:24:22 +0000162};
163
Richard Henderson8da5f1d2020-11-21 09:33:36 -0800164/*
165 * Rounding precision for floatx80.
166 */
167typedef enum __attribute__((__packed__)) {
168 floatx80_precision_x,
169 floatx80_precision_d,
170 floatx80_precision_s,
171} FloatX80RoundPrec;
Alex Bennée24f91e82018-01-19 18:24:22 +0000172
173/*
174 * Floating Point Status. Individual architectures may maintain
175 * several versions of float_status for different functions. The
176 * correct status for the operation is then passed by reference to
177 * most of the softfloat functions.
178 */
179
180typedef struct float_status {
Richard Henderson149a48f2021-12-17 17:57:14 +0100181 uint16_t float_exception_flags;
Richard Henderson3dede402020-05-05 09:01:49 -0700182 FloatRoundMode float_rounding_mode;
Richard Henderson8da5f1d2020-11-21 09:33:36 -0800183 FloatX80RoundPrec floatx80_rounding_precision;
Richard Hendersona828b372020-05-04 21:19:39 -0700184 bool tininess_before_rounding;
Alex Bennée24f91e82018-01-19 18:24:22 +0000185 /* should denormalised results go to zero and set the inexact flag? */
Richard Hendersonc1203912020-05-04 19:54:57 -0700186 bool flush_to_zero;
Alex Bennée24f91e82018-01-19 18:24:22 +0000187 /* should denormalised inputs go to zero and set the input_denormal flag? */
Richard Hendersonc1203912020-05-04 19:54:57 -0700188 bool flush_inputs_to_zero;
189 bool default_nan_mode;
Max Filippovcc43c692020-06-30 19:35:49 -0700190 /*
191 * The flags below are not used on all specializations and may
192 * constant fold away (see snan_bit_is_one()/no_signalling_nans() in
193 * softfloat-specialize.inc.c)
194 */
Richard Hendersonc1203912020-05-04 19:54:57 -0700195 bool snan_bit_is_one;
Max Filippov913602e2020-06-30 19:35:57 -0700196 bool use_first_nan;
Max Filippovcc43c692020-06-30 19:35:49 -0700197 bool no_signaling_nans;
Lucas Mateus Castro (alqotel)c40da5c2022-08-05 11:15:21 -0300198 /* should overflowed results subtract re_bias to its exponent? */
199 bool rebias_overflow;
200 /* should underflowed results add re_bias to its exponent? */
201 bool rebias_underflow;
Alex Bennée24f91e82018-01-19 18:24:22 +0000202} float_status;
203
Alex Bennéecfd88fc2018-01-19 16:36:40 +0000204#endif /* SOFTFLOAT_TYPES_H */