1 /*
2 * Copyright 2015 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: AMD
23 *
24 */
25 #include "dm_services.h"
26 #include "bw_fixed.h"
27
28
29 #define MIN_I64 \
30 (int64_t)(-(1LL << 63))
31
32 #define MAX_I64 \
33 (int64_t)((1ULL << 63) - 1)
34
35 #define FRACTIONAL_PART_MASK \
36 ((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1)
37
38 #define GET_FRACTIONAL_PART(x) \
39 (FRACTIONAL_PART_MASK & (x))
40
abs_i64(int64_t arg)41 static uint64_t abs_i64(int64_t arg)
42 {
43 if (arg >= 0)
44 return (uint64_t)(arg);
45 else
46 return (uint64_t)(-arg);
47 }
48
bw_int_to_fixed_nonconst(int64_t value)49 struct bw_fixed bw_int_to_fixed_nonconst(int64_t value)
50 {
51 struct bw_fixed res;
52 ASSERT(value < BW_FIXED_MAX_I32 && value > BW_FIXED_MIN_I32);
53 res.value = value << BW_FIXED_BITS_PER_FRACTIONAL_PART;
54 return res;
55 }
56
bw_frc_to_fixed(int64_t numerator,int64_t denominator)57 struct bw_fixed bw_frc_to_fixed(int64_t numerator, int64_t denominator)
58 {
59 struct bw_fixed res;
60 bool arg1_negative = numerator < 0;
61 bool arg2_negative = denominator < 0;
62 uint64_t arg1_value;
63 uint64_t arg2_value;
64 uint64_t remainder;
65
66 /* determine integer part */
67 uint64_t res_value;
68
69 ASSERT(denominator != 0);
70
71 arg1_value = abs_i64(numerator);
72 arg2_value = abs_i64(denominator);
73 /* XXX: int64_t* -> u64* conversion! */
74 res_value = div64_u64_rem(arg1_value, arg2_value, (u64 *)&remainder);
75
76 ASSERT(res_value <= BW_FIXED_MAX_I32);
77
78 /* determine fractional part */
79 {
80 uint32_t i = BW_FIXED_BITS_PER_FRACTIONAL_PART;
81
82 do
83 {
84 remainder <<= 1;
85
86 res_value <<= 1;
87
88 if (remainder >= arg2_value)
89 {
90 res_value |= 1;
91 remainder -= arg2_value;
92 }
93 } while (--i != 0);
94 }
95
96 /* round up LSB */
97 {
98 uint64_t summand = (remainder << 1) >= arg2_value;
99
100 ASSERT(res_value <= MAX_I64 - summand);
101
102 res_value += summand;
103 }
104
105 res.value = (int64_t)(res_value);
106
107 if (arg1_negative ^ arg2_negative)
108 res.value = -res.value;
109 return res;
110 }
111
bw_floor2(const struct bw_fixed arg,const struct bw_fixed significance)112 struct bw_fixed bw_floor2(
113 const struct bw_fixed arg,
114 const struct bw_fixed significance)
115 {
116 struct bw_fixed result;
117 int64_t multiplicand;
118
119 multiplicand = div64_s64(arg.value, abs_i64(significance.value));
120 result.value = abs_i64(significance.value) * multiplicand;
121 ASSERT(abs_i64(result.value) <= abs_i64(arg.value));
122 return result;
123 }
124
bw_ceil2(const struct bw_fixed arg,const struct bw_fixed significance)125 struct bw_fixed bw_ceil2(
126 const struct bw_fixed arg,
127 const struct bw_fixed significance)
128 {
129 struct bw_fixed result;
130 int64_t multiplicand;
131
132 multiplicand = div64_s64(arg.value, abs_i64(significance.value));
133 result.value = abs_i64(significance.value) * multiplicand;
134 if (abs_i64(result.value) < abs_i64(arg.value)) {
135 if (arg.value < 0)
136 result.value -= abs_i64(significance.value);
137 else
138 result.value += abs_i64(significance.value);
139 }
140 return result;
141 }
142
bw_mul(const struct bw_fixed arg1,const struct bw_fixed arg2)143 struct bw_fixed bw_mul(const struct bw_fixed arg1, const struct bw_fixed arg2)
144 {
145 struct bw_fixed res;
146
147 bool arg1_negative = arg1.value < 0;
148 bool arg2_negative = arg2.value < 0;
149
150 uint64_t arg1_value = abs_i64(arg1.value);
151 uint64_t arg2_value = abs_i64(arg2.value);
152
153 uint64_t arg1_int = BW_FIXED_GET_INTEGER_PART(arg1_value);
154 uint64_t arg2_int = BW_FIXED_GET_INTEGER_PART(arg2_value);
155
156 uint64_t arg1_fra = GET_FRACTIONAL_PART(arg1_value);
157 uint64_t arg2_fra = GET_FRACTIONAL_PART(arg2_value);
158
159 uint64_t tmp;
160
161 res.value = arg1_int * arg2_int;
162
163 ASSERT(res.value <= BW_FIXED_MAX_I32);
164
165 res.value <<= BW_FIXED_BITS_PER_FRACTIONAL_PART;
166
167 tmp = arg1_int * arg2_fra;
168
169 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));
170
171 res.value += tmp;
172
173 tmp = arg2_int * arg1_fra;
174
175 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));
176
177 res.value += tmp;
178
179 tmp = arg1_fra * arg2_fra;
180
181 tmp = (tmp >> BW_FIXED_BITS_PER_FRACTIONAL_PART) +
182 (tmp >= (uint64_t)(bw_frc_to_fixed(1, 2).value));
183
184 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));
185
186 res.value += tmp;
187
188 if (arg1_negative ^ arg2_negative)
189 res.value = -res.value;
190 return res;
191 }
192
193