1 | // SPDX-License-Identifier: MIT |
2 | /* |
3 | * Copyright 2023 Advanced Micro Devices, Inc. |
4 | * |
5 | * Permission is hereby granted, free of charge, to any person obtaining a |
6 | * copy of this software and associated documentation files (the "Software"), |
7 | * to deal in the Software without restriction, including without limitation |
8 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
9 | * and/or sell copies of the Software, and to permit persons to whom the |
10 | * Software is furnished to do so, subject to the following conditions: |
11 | * |
12 | * The above copyright notice and this permission notice shall be included in |
13 | * all copies or substantial portions of the Software. |
14 | * |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
18 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
19 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
20 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
21 | * OTHER DEALINGS IN THE SOFTWARE. |
22 | * |
23 | * Authors: AMD |
24 | * |
25 | */ |
26 | #include "dm_services.h" |
27 | #include "custom_float.h" |
28 | |
29 | static bool build_custom_float(struct fixed31_32 value, |
30 | const struct custom_float_format *format, |
31 | bool *negative, |
32 | uint32_t *mantissa, |
33 | uint32_t *exponenta) |
34 | { |
35 | uint32_t exp_offset = (1 << (format->exponenta_bits - 1)) - 1; |
36 | |
37 | const struct fixed31_32 mantissa_constant_plus_max_fraction = |
38 | dc_fixpt_from_fraction(numerator: (1LL << (format->mantissa_bits + 1)) - 1, |
39 | denominator: 1LL << format->mantissa_bits); |
40 | |
41 | struct fixed31_32 mantiss; |
42 | |
43 | if (dc_fixpt_eq(arg1: value, arg2: dc_fixpt_zero)) { |
44 | *negative = false; |
45 | *mantissa = 0; |
46 | *exponenta = 0; |
47 | return true; |
48 | } |
49 | |
50 | if (dc_fixpt_lt(arg1: value, arg2: dc_fixpt_zero)) { |
51 | *negative = format->sign; |
52 | value = dc_fixpt_neg(arg: value); |
53 | } else { |
54 | *negative = false; |
55 | } |
56 | |
57 | if (dc_fixpt_lt(arg1: value, arg2: dc_fixpt_one)) { |
58 | uint32_t i = 1; |
59 | |
60 | do { |
61 | value = dc_fixpt_shl(arg: value, shift: 1); |
62 | ++i; |
63 | } while (dc_fixpt_lt(arg1: value, arg2: dc_fixpt_one)); |
64 | |
65 | --i; |
66 | |
67 | if (exp_offset <= i) { |
68 | *mantissa = 0; |
69 | *exponenta = 0; |
70 | return true; |
71 | } |
72 | |
73 | *exponenta = exp_offset - i; |
74 | } else if (dc_fixpt_le(arg1: mantissa_constant_plus_max_fraction, arg2: value)) { |
75 | uint32_t i = 1; |
76 | |
77 | do { |
78 | value = dc_fixpt_shr(arg: value, shift: 1); |
79 | ++i; |
80 | } while (dc_fixpt_lt(arg1: mantissa_constant_plus_max_fraction, arg2: value)); |
81 | |
82 | *exponenta = exp_offset + i - 1; |
83 | } else { |
84 | *exponenta = exp_offset; |
85 | } |
86 | |
87 | mantiss = dc_fixpt_sub(arg1: value, arg2: dc_fixpt_one); |
88 | |
89 | if (dc_fixpt_lt(arg1: mantiss, arg2: dc_fixpt_zero) || |
90 | dc_fixpt_lt(arg1: dc_fixpt_one, arg2: mantiss)) |
91 | mantiss = dc_fixpt_zero; |
92 | else |
93 | mantiss = dc_fixpt_shl(arg: mantiss, shift: format->mantissa_bits); |
94 | |
95 | *mantissa = dc_fixpt_floor(arg: mantiss); |
96 | |
97 | return true; |
98 | } |
99 | |
100 | static bool setup_custom_float(const struct custom_float_format *format, |
101 | bool negative, |
102 | uint32_t mantissa, |
103 | uint32_t exponenta, |
104 | uint32_t *result) |
105 | { |
106 | uint32_t i = 0; |
107 | uint32_t j = 0; |
108 | uint32_t value = 0; |
109 | |
110 | /* verification code: |
111 | * once calculation is ok we can remove it |
112 | */ |
113 | |
114 | const uint32_t mantissa_mask = |
115 | (1 << (format->mantissa_bits + 1)) - 1; |
116 | |
117 | const uint32_t exponenta_mask = |
118 | (1 << (format->exponenta_bits + 1)) - 1; |
119 | |
120 | if (mantissa & ~mantissa_mask) { |
121 | BREAK_TO_DEBUGGER(); |
122 | mantissa = mantissa_mask; |
123 | } |
124 | |
125 | if (exponenta & ~exponenta_mask) { |
126 | BREAK_TO_DEBUGGER(); |
127 | exponenta = exponenta_mask; |
128 | } |
129 | |
130 | /* end of verification code */ |
131 | |
132 | while (i < format->mantissa_bits) { |
133 | uint32_t mask = 1 << i; |
134 | |
135 | if (mantissa & mask) |
136 | value |= mask; |
137 | |
138 | ++i; |
139 | } |
140 | |
141 | while (j < format->exponenta_bits) { |
142 | uint32_t mask = 1 << j; |
143 | |
144 | if (exponenta & mask) |
145 | value |= mask << i; |
146 | |
147 | ++j; |
148 | } |
149 | |
150 | if (negative && format->sign) |
151 | value |= 1 << (i + j); |
152 | |
153 | *result = value; |
154 | |
155 | return true; |
156 | } |
157 | |
158 | bool convert_to_custom_float_format(struct fixed31_32 value, |
159 | const struct custom_float_format *format, |
160 | uint32_t *result) |
161 | { |
162 | uint32_t mantissa; |
163 | uint32_t exponenta; |
164 | bool negative; |
165 | |
166 | return build_custom_float(value, format, negative: &negative, mantissa: &mantissa, exponenta: &exponenta) && |
167 | setup_custom_float(format, |
168 | negative, |
169 | mantissa, |
170 | exponenta, |
171 | result); |
172 | } |
173 | |
174 | |