GCC Code Coverage Report

Directory: ./
File: firmware/util/tinymt32.h
Date: 2025-10-03 00:57:22
Coverage Exec Excl Total
Lines: 100.0% 27 0 27
Functions: 100.0% 3 0 3
Branches: 100.0% 2 0 2
Decisions: 100.0% 2 - 2
Line Branch Decision Exec Source
1 #ifndef TINYMT32_H
2 #define TINYMT32_H
3 /**
4 * @file tinymt32.h
5 *
6 * @brief Tiny Mersenne Twister only 127 bit internal state
7 *
8 * @author Mutsuo Saito (Hiroshima University)
9 * @author Makoto Matsumoto (University of Tokyo)
10 *
11 * Copyright (C) 2011 Mutsuo Saito, Makoto Matsumoto,
12 * Hiroshima University and The University of Tokyo.
13 * All rights reserved.
14 *
15 * The 3-clause BSD License is applied to this software, see
16 * LICENSE.txt
17 */
18
19 #include <stdint.h>
20 #include <inttypes.h>
21
22 #define TINYMT32_MEXP 127
23 #define TINYMT32_SH0 1
24 #define TINYMT32_SH1 10
25 #define TINYMT32_SH8 8
26 #define TINYMT32_MASK UINT32_C(0x7fffffff)
27 #define TINYMT32_MUL (1.0f / 16777216.0f)
28
29 #if defined(__cplusplus)
30 extern "C" {
31 #endif
32
33 /**
34 * tinymt32 internal state vector and parameters
35 */
36 struct TINYMT32_T {
37 uint32_t status[4];
38 uint32_t mat1;
39 uint32_t mat2;
40 uint32_t tmat;
41 };
42
43 typedef struct TINYMT32_T tinymt32_t;
44
45 void tinymt32_init(tinymt32_t * random, uint32_t seed);
46 void tinymt32_init_by_array(tinymt32_t * random, uint32_t init_key[],
47 int key_length);
48
49 #if defined(__GNUC__)
50 /**
51 * This function always returns 127
52 * @param random not used
53 * @return always 127
54 */
55 inline static int tinymt32_get_mexp(
56 tinymt32_t * random __attribute__((unused))) {
57 return TINYMT32_MEXP;
58 }
59 #else
60 inline static int tinymt32_get_mexp(tinymt32_t * random) {
61 return TINYMT32_MEXP;
62 }
63 #endif
64
65 /**
66 * This function changes internal state of tinymt32.
67 * Users should not call this function directly.
68 * @param random tinymt internal status
69 */
70 18985 inline static void tinymt32_next_state(tinymt32_t * random) {
71 uint32_t x;
72 uint32_t y;
73
74 18985 y = random->status[3];
75 18985 x = (random->status[0] & TINYMT32_MASK)
76 18985 ^ random->status[1]
77 18985 ^ random->status[2];
78 18985 x ^= (x << TINYMT32_SH0);
79 18985 y ^= (y >> TINYMT32_SH0) ^ x;
80 18985 random->status[0] = random->status[1];
81 18985 random->status[1] = random->status[2];
82 18985 random->status[2] = x ^ (y << TINYMT32_SH1);
83 18985 random->status[3] = y;
84 18985 int32_t const a = -((int32_t)(y & 1)) & (int32_t)random->mat1;
85 18985 int32_t const b = -((int32_t)(y & 1)) & (int32_t)random->mat2;
86 18985 random->status[1] ^= (uint32_t)a;
87 18985 random->status[2] ^= (uint32_t)b;
88 18985 }
89
90 /**
91 * This function outputs 32-bit unsigned integer from internal state.
92 * Users should not call this function directly.
93 * @param random tinymt internal status
94 * @return 32-bit unsigned pseudorandom number
95 */
96 1001 inline static uint32_t tinymt32_temper(tinymt32_t * random) {
97 uint32_t t0, t1;
98 1001 t0 = random->status[3];
99 #if defined(LINEARITY_CHECK)
100 t1 = random->status[0]
101 ^ (random->status[2] >> TINYMT32_SH8);
102 #else
103 1001 t1 = random->status[0]
104 1001 + (random->status[2] >> TINYMT32_SH8);
105 #endif
106 1001 t0 ^= t1;
107
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 1001 if ((t1 & 1) != 0) {
108 563 t0 ^= random->tmat;
109 }
110 1001 return t0;
111 }
112
113 /**
114 * This function outputs floating point number from internal state.
115 * Users should not call this function directly.
116 * @param random tinymt internal status
117 * @return floating point number r (1.0 <= r < 2.0)
118 */
119 inline static float tinymt32_temper_conv(tinymt32_t * random) {
120 uint32_t t0, t1;
121 union {
122 uint32_t u;
123 float f;
124 } conv;
125
126 t0 = random->status[3];
127 #if defined(LINEARITY_CHECK)
128 t1 = random->status[0]
129 ^ (random->status[2] >> TINYMT32_SH8);
130 #else
131 t1 = random->status[0]
132 + (random->status[2] >> TINYMT32_SH8);
133 #endif
134 t0 ^= t1;
135 if ((t1 & 1) != 0) {
136 conv.u = ((t0 ^ random->tmat) >> 9) | UINT32_C(0x3f800000);
137 } else {
138 conv.u = (t0 >> 9) | UINT32_C(0x3f800000);
139 }
140 return conv.f;
141 }
142
143 /**
144 * This function outputs floating point number from internal state.
145 * Users should not call this function directly.
146 * @param random tinymt internal status
147 * @return floating point number r (1.0 < r < 2.0)
148 */
149 inline static float tinymt32_temper_conv_open(tinymt32_t * random) {
150 uint32_t t0, t1;
151 union {
152 uint32_t u;
153 float f;
154 } conv;
155
156 t0 = random->status[3];
157 #if defined(LINEARITY_CHECK)
158 t1 = random->status[0]
159 ^ (random->status[2] >> TINYMT32_SH8);
160 #else
161 t1 = random->status[0]
162 + (random->status[2] >> TINYMT32_SH8);
163 #endif
164 t0 ^= t1;
165 if ((t1 & 1) != 0) {
166 conv.u = ((t0 ^ random->tmat) >> 9) | UINT32_C(0x3f800001);
167 } else {
168 conv.u = (t0 >> 9) | UINT32_C(0x3f800001);
169 }
170 return conv.f;
171 }
172
173 /**
174 * This function outputs 32-bit unsigned integer from internal state.
175 * @param random tinymt internal status
176 * @return 32-bit unsigned integer r (0 <= r < 2^32)
177 */
178 inline static uint32_t tinymt32_generate_uint32(tinymt32_t * random) {
179 tinymt32_next_state(random);
180 return tinymt32_temper(random);
181 }
182
183 /**
184 * This function outputs floating point number from internal state.
185 * This function is implemented using multiplying by (1 / 2^24).
186 * floating point multiplication is faster than using union trick in
187 * my Intel CPU.
188 * @param random tinymt internal status
189 * @return floating point number r (0.0 <= r < 1.0)
190 */
191 1001 inline static float tinymt32_generate_float(tinymt32_t * random) {
192 1001 tinymt32_next_state(random);
193 1001 return (float)(tinymt32_temper(random) >> 8) * TINYMT32_MUL;
194 }
195
196 /**
197 * This function outputs floating point number from internal state.
198 * This function is implemented using union trick.
199 * @param random tinymt internal status
200 * @return floating point number r (1.0 <= r < 2.0)
201 */
202 inline static float tinymt32_generate_float12(tinymt32_t * random) {
203 tinymt32_next_state(random);
204 return tinymt32_temper_conv(random);
205 }
206
207 /**
208 * This function outputs floating point number from internal state.
209 * This function is implemented using union trick.
210 * @param random tinymt internal status
211 * @return floating point number r (0.0 <= r < 1.0)
212 */
213 inline static float tinymt32_generate_float01(tinymt32_t * random) {
214 tinymt32_next_state(random);
215 return tinymt32_temper_conv(random) - 1.0f;
216 }
217
218 /**
219 * This function outputs floating point number from internal state.
220 * This function may return 1.0 and never returns 0.0.
221 * @param random tinymt internal status
222 * @return floating point number r (0.0 < r <= 1.0)
223 */
224 inline static float tinymt32_generate_floatOC(tinymt32_t * random) {
225 tinymt32_next_state(random);
226 return 1.0f - tinymt32_generate_float(random);
227 }
228
229 /**
230 * This function outputs floating point number from internal state.
231 * This function returns neither 0.0 nor 1.0.
232 * @param random tinymt internal status
233 * @return floating point number r (0.0 < r < 1.0)
234 */
235 inline static float tinymt32_generate_floatOO(tinymt32_t * random) {
236 tinymt32_next_state(random);
237 return tinymt32_temper_conv_open(random) - 1.0f;
238 }
239
240 /**
241 * This function outputs double precision floating point number from
242 * internal state. The returned value has 32-bit precision.
243 * In other words, this function makes one double precision floating point
244 * number from one 32-bit unsigned integer.
245 * @param random tinymt internal status
246 * @return floating point number r (0.0 <= r < 1.0)
247 */
248 inline static double tinymt32_generate_32double(tinymt32_t * random) {
249 tinymt32_next_state(random);
250 return tinymt32_temper(random) * (1.0 / 4294967296.0);
251 }
252
253 #if defined(__cplusplus)
254 }
255 #endif
256
257 #endif
258